16 #define SSH_MSG_DISCONNECT 1
17 #define SSH_SMSG_PUBLIC_KEY 2
18 #define SSH_CMSG_SESSION_KEY 3
19 #define SSH_CMSG_USER 4
20 #define SSH_CMSG_AUTH_PASSWORD 9
21 #define SSH_CMSG_REQUEST_PTY 10
22 #define SSH_CMSG_EXEC_SHELL 12
23 #define SSH_CMSG_STDIN_DATA 16
24 #define SSH_SMSG_STDOUT_DATA 17
25 #define SSH_SMSG_STDERR_DATA 18
26 #define SSH_SMSG_SUCCESS 14
27 #define SSH_SMSG_FAILURE 15
28 #define SSH_SMSG_EXITSTATUS 20
29 #define SSH_MSG_IGNORE 32
30 #define SSH_CMSG_EXIT_CONFIRMATION 33
31 #define SSH_MSG_DEBUG 36
33 /* Coroutine mechanics for the sillier bits of the code */
34 #define crBegin1 static int crLine = 0;
35 #define crBegin2 switch(crLine) { case 0:;
36 #define crBegin crBegin1; crBegin2;
37 #define crFinish(z) } crLine = 0; return (z)
38 #define crFinishV } crLine = 0; return
41 crLine=__LINE__; return (z); case __LINE__:;\
45 crLine=__LINE__; return; case __LINE__:;\
47 #define crStop(z) do{ crLine = 0; return (z); }while(0)
48 #define crStopV do{ crLine = 0; return; }while(0)
57 static SOCKET s
= INVALID_SOCKET
;
59 static unsigned char session_key
[32];
60 static struct ssh_cipher
*cipher
= NULL
;
62 static char *savedhost
;
65 SSH_STATE_BEFORE_SIZE
,
69 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
71 static int size_needed
= FALSE
;
73 static void s_write (char *buf
, int len
) {
75 int i
= send (s
, buf
, len
, 0);
81 static int s_read (char *buf
, int len
) {
84 int i
= recv (s
, buf
, len
, 0);
86 len
-= i
, buf
+= i
, ret
+= i
;
93 static void c_write (char *buf
, int len
) {
95 int new_head
= (inbuf_head
+ 1) & INBUF_MASK
;
96 if (new_head
!= inbuf_reap
) {
97 inbuf
[inbuf_head
] = *buf
++;
98 inbuf_head
= new_head
;
112 static struct Packet pktin
= { 0, 0, 0, NULL
, 0 };
113 static struct Packet pktout
= { 0, 0, 0, NULL
, 0 };
115 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
);
116 static void ssh_size(void);
118 static void ssh_gotdata(unsigned char *data
, int datalen
) {
119 static long len
, biglen
, to_read
;
120 static unsigned char *p
;
125 for (i
= len
= 0; i
< 4; i
++) {
128 len
= (len
<< 8) + *data
;
133 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
134 len
= 0x300; /* big enough to carry to end */
142 len
-= 5; /* type and CRC */
145 if (pktin
.maxlen
< biglen
) {
146 pktin
.maxlen
= biglen
;
147 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
) :
148 realloc(pktin
.data
, biglen
));
150 fatalbox("Out of memory");
153 p
= pktin
.data
, to_read
= biglen
;
154 while (to_read
> 0) {
161 memcpy(p
, data
, chunk
);
169 cipher
->decrypt(pktin
.data
, biglen
);
171 pktin
.type
= pktin
.data
[pad
];
172 pktin
.body
= pktin
.data
+pad
+1;
174 if (pktin
.type
== SSH_MSG_DEBUG
) {
176 } else if (pktin
.type
== SSH_MSG_IGNORE
) {
179 ssh_protocol(NULL
, 0, 1);
184 static void s_wrpkt_start(int type
, int len
) {
187 len
+= 5; /* type and CRC */
191 pktout
.length
= len
-5;
192 if (pktout
.maxlen
< biglen
) {
193 pktout
.maxlen
= biglen
;
194 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
195 realloc(pktout
.data
, biglen
+4));
197 fatalbox("Out of memory");
201 pktout
.body
= pktout
.data
+4+pad
+1;
204 static void s_wrpkt(void) {
205 int pad
, len
, biglen
, i
;
208 len
= pktout
.length
+ 5; /* type and CRC */
212 pktout
.body
[-1] = pktout
.type
;
213 for (i
=0; i
<pad
; i
++)
214 pktout
.data
[i
+4] = random_byte();
215 crc
= crc32(pktout
.data
+4, biglen
-4);
217 pktout
.data
[biglen
+0] = (unsigned char) ((crc
>> 24) & 0xFF);
218 pktout
.data
[biglen
+1] = (unsigned char) ((crc
>> 16) & 0xFF);
219 pktout
.data
[biglen
+2] = (unsigned char) ((crc
>> 8) & 0xFF);
220 pktout
.data
[biglen
+3] = (unsigned char) (crc
& 0xFF);
222 pktout
.data
[0] = (len
>> 24) & 0xFF;
223 pktout
.data
[1] = (len
>> 16) & 0xFF;
224 pktout
.data
[2] = (len
>> 8) & 0xFF;
225 pktout
.data
[3] = len
& 0xFF;
228 cipher
->encrypt(pktout
.data
+4, biglen
);
230 s_write(pktout
.data
, biglen
+4);
233 static int ssh_versioncmp(char *a
, char *b
) {
235 unsigned long av
, bv
;
237 av
= strtoul(a
, &ae
, 10);
238 bv
= strtoul(b
, &be
, 10);
239 if (av
!= bv
) return (av
< bv ?
-1 : +1);
240 if (*ae
== '.') ae
++;
241 if (*be
== '.') be
++;
242 av
= strtoul(ae
, &ae
, 10);
243 bv
= strtoul(be
, &be
, 10);
244 if (av
!= bv
) return (av
< bv ?
-1 : +1);
248 static int do_ssh_init(void) {
256 while (s_read(&c
, 1) == 1) {
257 if (c
== 'S' && i
< 2) i
++;
258 else if (c
== 'S' && i
== 2) i
= 2;
259 else if (c
== 'H' && i
== 2) break;
263 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
264 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
265 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
267 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
270 if (s_read(&c
,1) != 1)
276 } else if (i
< sizeof(version
)-1)
283 sprintf(vstring
, "SSH-%s-PuTTY\n",
284 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
285 s_write(vstring
, strlen(vstring
));
289 static void ssh_protocol(unsigned char *in
, int inlen
, int ispkt
) {
291 unsigned char session_id
[16];
292 unsigned char *rsabuf
, *keystr1
, *keystr2
;
293 unsigned char cookie
[8];
294 struct RSAKey servkey
, hostkey
;
295 struct MD5Context md5c
;
296 unsigned long supported_ciphers_mask
;
299 extern struct ssh_cipher ssh_3des
;
300 extern struct ssh_cipher ssh_des
;
301 extern struct ssh_cipher ssh_blowfish
;
310 if (pktin
.type
!= SSH_SMSG_PUBLIC_KEY
)
311 fatalbox("Public key packet not received");
313 memcpy(cookie
, pktin
.body
, 8);
317 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
);
319 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
);
321 supported_ciphers_mask
= (pktin
.body
[12+i
+j
] << 24) |
322 (pktin
.body
[13+i
+j
] << 16) |
323 (pktin
.body
[14+i
+j
] << 8) |
324 (pktin
.body
[15+i
+j
]);
326 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
327 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
328 MD5Update(&md5c
, pktin
.body
, 8);
330 MD5Final(session_id
, &md5c
);
333 session_key
[i
] = random_byte();
335 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
337 rsabuf
= malloc(len
);
339 fatalbox("Out of memory");
341 verify_ssh_host_key(savedhost
, &hostkey
);
343 for (i
=0; i
<32; i
++) {
344 rsabuf
[i
] = session_key
[i
];
346 rsabuf
[i
] ^= session_id
[i
];
349 if (hostkey
.bytes
> servkey
.bytes
) {
350 rsaencrypt(rsabuf
, 32, &servkey
);
351 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
353 rsaencrypt(rsabuf
, 32, &hostkey
);
354 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
357 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
358 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
360 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
361 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
362 cipher_type
= SSH_CIPHER_3DES
;
365 s_wrpkt_start(SSH_CMSG_SESSION_KEY
, len
+15);
366 pktout
.body
[0] = cipher_type
;
367 memcpy(pktout
.body
+1, cookie
, 8);
368 pktout
.body
[9] = (len
*8) >> 8;
369 pktout
.body
[10] = (len
*8) & 0xFF;
370 memcpy(pktout
.body
+11, rsabuf
, len
);
371 pktout
.body
[len
+11] = pktout
.body
[len
+12] = 0; /* protocol flags */
372 pktout
.body
[len
+13] = pktout
.body
[len
+14] = 0;
377 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish
:
378 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
380 cipher
->sesskey(session_key
);
382 do { crReturnV
; } while (!ispkt
);
384 if (pktin
.type
!= SSH_SMSG_SUCCESS
)
385 fatalbox("Encryption not successfully enabled");
389 static char username
[100];
392 if (!*cfg
.username
) {
393 c_write("login as: ", 10);
395 do { crReturnV
; } while (ispkt
);
396 while (inlen
--) switch (c
= *in
++) {
418 if (c
>= ' ' && c
<= '~' && pos
< 40) {
426 username
[strcspn(username
, "\n\r")] = '\0';
429 strncpy(username
, cfg
.username
, 99);
431 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
432 c_write(stuff
, strlen(stuff
));
434 s_wrpkt_start(SSH_CMSG_USER
, 4+strlen(username
));
435 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
436 pktout
.body
[3] = strlen(username
);
437 memcpy(pktout
.body
+4, username
, strlen(username
));
441 do { crReturnV
; } while (!ispkt
);
443 while (pktin
.type
== SSH_SMSG_FAILURE
) {
444 static char password
[100];
447 c_write("password: ", 10);
450 do { crReturnV
; } while (ispkt
);
451 while (inlen
--) switch (c
= *in
++) {
468 if (c
>= ' ' && c
<= '~' && pos
< 40)
474 s_wrpkt_start(SSH_CMSG_AUTH_PASSWORD
, 4+strlen(password
));
475 pktout
.body
[0] = pktout
.body
[1] = pktout
.body
[2] = 0;
476 pktout
.body
[3] = strlen(password
);
477 memcpy(pktout
.body
+4, password
, strlen(password
));
479 memset(password
, 0, strlen(password
));
480 do { crReturnV
; } while (!ispkt
);
481 if (pktin
.type
== 15) {
482 c_write("Access denied\r\n", 15);
483 } else if (pktin
.type
!= 14) {
484 fatalbox("Strange packet received, type %d", pktin
.type
);
489 i
= strlen(cfg
.termtype
);
490 s_wrpkt_start(SSH_CMSG_REQUEST_PTY
, i
+5*4+1);
491 pktout
.body
[0] = (i
>> 24) & 0xFF;
492 pktout
.body
[1] = (i
>> 16) & 0xFF;
493 pktout
.body
[2] = (i
>> 8) & 0xFF;
494 pktout
.body
[3] = i
& 0xFF;
495 memcpy(pktout
.body
+4, cfg
.termtype
, i
);
497 pktout
.body
[i
++] = (rows
>> 24) & 0xFF;
498 pktout
.body
[i
++] = (rows
>> 16) & 0xFF;
499 pktout
.body
[i
++] = (rows
>> 8) & 0xFF;
500 pktout
.body
[i
++] = rows
& 0xFF;
501 pktout
.body
[i
++] = (cols
>> 24) & 0xFF;
502 pktout
.body
[i
++] = (cols
>> 16) & 0xFF;
503 pktout
.body
[i
++] = (cols
>> 8) & 0xFF;
504 pktout
.body
[i
++] = cols
& 0xFF;
505 memset(pktout
.body
+i
, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
507 ssh_state
= SSH_STATE_INTERMED
;
508 do { crReturnV
; } while (!ispkt
);
509 if (pktin
.type
!= SSH_MSG_SUCCESS
&& pktin
.type
!= SSH_MSG_FAILURE
) {
510 fatalbox("Protocol confusion");
511 } else if (pktin
.type
== SSH_MSG_FAILURE
) {
512 c_write("Server refused to allocate pty\r\n", 32);
516 s_wrpkt_start(SSH_CMSG_EXEC_SHELL
, 0);
519 ssh_state
= SSH_STATE_SESSION
;
526 if (pktin
.type
== SSH_SMSG_STDOUT_DATA
||
527 pktin
.type
== SSH_SMSG_STDERR_DATA
) {
529 for (i
= 0; i
< 4; i
++)
530 len
= (len
<< 8) + pktin
.body
[i
];
531 c_write(pktin
.body
+4, len
);
532 } else if (pktin
.type
== SSH_MSG_DISCONNECT
) {
533 ssh_state
= SSH_STATE_CLOSED
;
534 } else if (pktin
.type
== SSH_MSG_SUCCESS
) {
535 /* may be from EXEC_SHELL on some servers */
536 } else if (pktin
.type
== SSH_MSG_FAILURE
) {
537 /* may be from EXEC_SHELL on some servers
538 * if no pty is available or in other odd cases. Ignore */
539 } else if (pktin
.type
== SSH_SMSG_EXITSTATUS
) {
540 s_wrpkt_start(SSH_CMSG_EXIT_CONFIRMATION
, 0);
543 fatalbox("Strange packet received: type %d", pktin
.type
);
546 s_wrpkt_start(SSH_CMSG_STDIN_DATA
, 4+inlen
);
547 pktout
.body
[0] = (inlen
>> 24) & 0xFF;
548 pktout
.body
[1] = (inlen
>> 16) & 0xFF;
549 pktout
.body
[2] = (inlen
>> 8) & 0xFF;
550 pktout
.body
[3] = inlen
& 0xFF;
551 memcpy(pktout
.body
+4, in
, inlen
);
560 * Called to set up the connection. Will arrange for WM_NETEVENT
561 * messages to be passed to the specified window, whose window
562 * procedure should then call telnet_msg().
564 * Returns an error message, or NULL on success.
566 * Also places the canonical host name into `realhost'.
568 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
577 savedhost
= malloc(1+strlen(host
));
579 fatalbox("Out of memory");
580 strcpy(savedhost
, host
);
592 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
593 if ( (h
= gethostbyname(host
)) == NULL
)
594 switch (WSAGetLastError()) {
595 case WSAENETDOWN
: return "Network is down";
596 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
597 return "Host does not exist";
598 case WSATRY_AGAIN
: return "Host not found";
599 default: return "gethostbyname: unknown error";
601 memcpy (&a
, h
->h_addr
, sizeof(a
));
602 *realhost
= h
->h_name
;
611 port
= 22; /* default ssh port */
616 s
= socket(AF_INET
, SOCK_STREAM
, 0);
617 if (s
== INVALID_SOCKET
)
618 switch (WSAGetLastError()) {
619 case WSAENETDOWN
: return "Network is down";
620 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
621 default: return "socket(): unknown error";
625 * Bind to local address.
627 addr
.sin_family
= AF_INET
;
628 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
629 addr
.sin_port
= htons(0);
630 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
631 switch (WSAGetLastError()) {
632 case WSAENETDOWN
: return "Network is down";
633 default: return "bind(): unknown error";
637 * Connect to remote address.
639 addr
.sin_addr
.s_addr
= htonl(a
);
640 addr
.sin_port
= htons((short)port
);
641 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
642 switch (WSAGetLastError()) {
643 case WSAENETDOWN
: return "Network is down";
644 case WSAECONNREFUSED
: return "Connection refused";
645 case WSAENETUNREACH
: return "Network is unreachable";
646 case WSAEHOSTUNREACH
: return "No route to host";
647 default: return "connect(): unknown error";
651 send(s
, "connect ", 8, 0);
652 send(s
, FWhost
, strlen(FWhost
), 0);
655 sprintf(buf
, " %d\n", FWport
);
656 send (s
, buf
, strlen(buf
), 0);
661 return "Protocol initialisation error";
663 if (WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
664 switch (WSAGetLastError()) {
665 case WSAENETDOWN
: return "Network is down";
666 default: return "WSAAsyncSelect(): unknown error";
673 * Process a WM_NETEVENT message. Will return 0 if the connection
674 * has closed, or <0 for a socket error.
676 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
680 if (s
== INVALID_SOCKET
) /* how the hell did we get here?! */
683 if (WSAGETSELECTERROR(lParam
) != 0)
684 return -WSAGETSELECTERROR(lParam
);
686 switch (WSAGETSELECTEVENT(lParam
)) {
688 ret
= recv(s
, buf
, sizeof(buf
), 0);
689 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
691 if (ret
< 0) /* any _other_ error */
692 return -10000-WSAGetLastError();
695 return 0; /* can't happen, in theory */
697 ssh_gotdata (buf
, ret
);
701 ssh_state
= SSH_STATE_CLOSED
;
704 return 1; /* shouldn't happen, but WTF */
708 * Called to send data down the Telnet connection.
710 static void ssh_send (char *buf
, int len
) {
711 if (s
== INVALID_SOCKET
)
714 ssh_protocol(buf
, len
, 0);
718 * Called to set the size of the window from Telnet's POV.
720 static void ssh_size(void) {
722 case SSH_STATE_BEFORE_SIZE
:
723 case SSH_STATE_CLOSED
:
724 break; /* do nothing */
725 case SSH_STATE_INTERMED
:
726 size_needed
= TRUE
; /* buffer for later */
728 case SSH_STATE_SESSION
:
730 s_wrpkt_start(11, 16);
731 pktout
.body
[0] = (rows
>> 24) & 0xFF;
732 pktout
.body
[1] = (rows
>> 16) & 0xFF;
733 pktout
.body
[2] = (rows
>> 8) & 0xFF;
734 pktout
.body
[3] = rows
& 0xFF;
735 pktout
.body
[4] = (cols
>> 24) & 0xFF;
736 pktout
.body
[5] = (cols
>> 16) & 0xFF;
737 pktout
.body
[6] = (cols
>> 8) & 0xFF;
738 pktout
.body
[7] = cols
& 0xFF;
739 memset(pktout
.body
+8, 0, 8);
746 * (Send Telnet special codes)
748 static void ssh_special (Telnet_Special code
) {
752 Backend ssh_backend
= {