18 #define logevent(s) { logevent(s); \
19 if (!(flags & FLAG_CONNECTION) && (flags & FLAG_VERBOSE)) \
20 fprintf(stderr, "%s\n", s); }
22 #define SSH1_MSG_DISCONNECT 1
23 #define SSH1_SMSG_PUBLIC_KEY 2
24 #define SSH1_CMSG_SESSION_KEY 3
25 #define SSH1_CMSG_USER 4
26 #define SSH1_CMSG_AUTH_RSA 6
27 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7
28 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8
29 #define SSH1_CMSG_AUTH_PASSWORD 9
30 #define SSH1_CMSG_REQUEST_PTY 10
31 #define SSH1_CMSG_WINDOW_SIZE 11
32 #define SSH1_CMSG_EXEC_SHELL 12
33 #define SSH1_CMSG_EXEC_CMD 13
34 #define SSH1_SMSG_SUCCESS 14
35 #define SSH1_SMSG_FAILURE 15
36 #define SSH1_CMSG_STDIN_DATA 16
37 #define SSH1_SMSG_STDOUT_DATA 17
38 #define SSH1_SMSG_STDERR_DATA 18
39 #define SSH1_CMSG_EOF 19
40 #define SSH1_SMSG_EXIT_STATUS 20
41 #define SSH1_CMSG_EXIT_CONFIRMATION 33
42 #define SSH1_MSG_IGNORE 32
43 #define SSH1_MSG_DEBUG 36
44 #define SSH1_CMSG_AUTH_TIS 39
45 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40
46 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41
48 #define SSH1_AUTH_TIS 5
50 #define SSH2_MSG_DISCONNECT 1
51 #define SSH2_MSG_IGNORE 2
52 #define SSH2_MSG_UNIMPLEMENTED 3
53 #define SSH2_MSG_DEBUG 4
54 #define SSH2_MSG_SERVICE_REQUEST 5
55 #define SSH2_MSG_SERVICE_ACCEPT 6
56 #define SSH2_MSG_KEXINIT 20
57 #define SSH2_MSG_NEWKEYS 21
58 #define SSH2_MSG_KEXDH_INIT 30
59 #define SSH2_MSG_KEXDH_REPLY 31
60 #define SSH2_MSG_USERAUTH_REQUEST 50
61 #define SSH2_MSG_USERAUTH_FAILURE 51
62 #define SSH2_MSG_USERAUTH_SUCCESS 52
63 #define SSH2_MSG_USERAUTH_BANNER 53
64 #define SSH2_MSG_USERAUTH_PK_OK 60
65 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60
66 #define SSH2_MSG_GLOBAL_REQUEST 80
67 #define SSH2_MSG_REQUEST_SUCCESS 81
68 #define SSH2_MSG_REQUEST_FAILURE 82
69 #define SSH2_MSG_CHANNEL_OPEN 90
70 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91
71 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92
72 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93
73 #define SSH2_MSG_CHANNEL_DATA 94
74 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95
75 #define SSH2_MSG_CHANNEL_EOF 96
76 #define SSH2_MSG_CHANNEL_CLOSE 97
77 #define SSH2_MSG_CHANNEL_REQUEST 98
78 #define SSH2_MSG_CHANNEL_SUCCESS 99
79 #define SSH2_MSG_CHANNEL_FAILURE 100
81 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1
82 #define SSH2_OPEN_CONNECT_FAILED 2
83 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3
84 #define SSH2_OPEN_RESOURCE_SHORTAGE 4
85 #define SSH2_EXTENDED_DATA_STDERR 1
87 #define GET_32BIT(cp) \
88 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
89 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
90 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
91 ((unsigned long)(unsigned char)(cp)[3]))
93 #define PUT_32BIT(cp, value) { \
94 (cp)[0] = (unsigned char)((value) >> 24); \
95 (cp)[1] = (unsigned char)((value) >> 16); \
96 (cp)[2] = (unsigned char)((value) >> 8); \
97 (cp)[3] = (unsigned char)(value); }
99 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
101 /* Coroutine mechanics for the sillier bits of the code */
102 #define crBegin1 static int crLine = 0;
103 #define crBegin2 switch(crLine) { case 0:;
104 #define crBegin crBegin1; crBegin2;
105 #define crFinish(z) } crLine = 0; return (z)
106 #define crFinishV } crLine = 0; return
107 #define crReturn(z) \
109 crLine=__LINE__; return (z); case __LINE__:;\
113 crLine=__LINE__; return; case __LINE__:;\
115 #define crStop(z) do{ crLine = 0; return (z); }while(0)
116 #define crStopV do{ crLine = 0; return; }while(0)
117 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
118 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
120 extern struct ssh_cipher ssh_3des;
121 extern struct ssh_cipher ssh_3des_ssh2;
122 extern struct ssh_cipher ssh_des;
123 extern struct ssh_cipher ssh_blowfish;
125 /* for ssh 2; we miss out single-DES because it isn't supported */
126 struct ssh_cipher *ciphers[] = { &ssh_3des_ssh2, &ssh_blowfish };
128 extern struct ssh_kex ssh_diffiehellman;
129 struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
131 extern struct ssh_hostkey ssh_dss;
132 struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
134 extern struct ssh_mac ssh_sha1;
138 static void nullmac_key(unsigned char *key) { }
139 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
140 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
141 struct ssh_mac ssh_mac_none = {
142 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
144 struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
146 struct ssh_compress ssh_comp_none = {
149 struct ssh_compress *compressions[] = { &ssh_comp_none };
151 static SOCKET s = INVALID_SOCKET;
153 static unsigned char session_key[32];
154 static struct ssh_cipher *cipher = NULL;
155 static struct ssh_cipher *cscipher = NULL;
156 static struct ssh_cipher *sccipher = NULL;
157 static struct ssh_mac *csmac = NULL;
158 static struct ssh_mac *scmac = NULL;
159 static struct ssh_compress *cscomp = NULL;
160 static struct ssh_compress *sccomp = NULL;
161 static struct ssh_kex *kex = NULL;
162 static struct ssh_hostkey *hostkey = NULL;
163 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
165 static char *savedhost;
166 static int ssh_send_ok;
169 SSH_STATE_BEFORE_SIZE,
173 } ssh_state = SSH_STATE_BEFORE_SIZE;
175 static int size_needed = FALSE;
177 static void s_write (char *buf, int len) {
179 int i = send (s, buf, len, 0);
182 fatalbox("Lost connection while sending");
188 static int s_read (char *buf, int len) {
191 int i = recv (s, buf, len, 0);
194 len -= i, buf += i, ret += i;
201 static void c_write (char *buf, int len) {
202 if (!(flags & FLAG_CONNECTION)) {
204 for (i = 0; i < len; i++)
206 fputc(buf[i], stderr);
222 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
223 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
225 static int ssh_version;
226 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
227 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
228 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
229 static void ssh_size(void);
231 static int (*s_rdpkt)(unsigned char **data, int *datalen);
234 * Collect incoming data in the incoming packet buffer.
235 * Decipher and verify the packet when it is completely read.
236 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
237 * Update the *data and *datalen variables.
238 * Return the additional nr of bytes needed, or 0 when
239 * a complete packet is available.
241 static int ssh1_rdpkt(unsigned char **data, int *datalen)
243 static long len, pad, biglen, to_read;
244 static unsigned long realcrc, gotcrc;
245 static unsigned char *p;
255 for (i = len = 0; i < 4; i++) {
256 while ((*datalen) == 0)
258 len = (len << 8) + **data;
259 (*data)++, (*datalen)--;
263 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
264 len = 0x300; /* big enough to carry to end */
270 pktin.length = len - 5;
272 if (pktin.maxlen < biglen) {
273 pktin.maxlen = biglen;
274 pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
275 realloc(pktin.data, biglen+APIEXTRA));
277 fatalbox("Out of memory");
282 while (to_read > 0) {
285 while ((*datalen) == 0)
287 if (chunk > (*datalen))
289 memcpy(p, *data, chunk);
297 cipher->decrypt(pktin.data, biglen);
299 pktin.type = pktin.data[pad];
300 pktin.body = pktin.data + pad + 1;
302 realcrc = crc32(pktin.data, biglen-4);
303 gotcrc = GET_32BIT(pktin.data+biglen-4);
304 if (gotcrc != realcrc) {
305 fatalbox("Incorrect CRC received on packet");
308 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
309 pktin.type == SSH1_SMSG_STDERR_DATA ||
310 pktin.type == SSH1_MSG_DEBUG ||
311 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE) {
312 long strlen = GET_32BIT(pktin.body);
313 if (strlen + 4 != pktin.length)
314 fatalbox("Received data packet with bogus string length");
317 if (pktin.type == SSH1_MSG_DEBUG) {
318 /* log debug message */
320 int strlen = GET_32BIT(pktin.body);
321 strcpy(buf, "Remote: ");
322 if (strlen > 70) strlen = 70;
323 memcpy(buf+8, pktin.body+4, strlen);
324 buf[8+strlen] = '\0';
327 } else if (pktin.type == SSH1_MSG_IGNORE) {
335 static int ssh2_rdpkt(unsigned char **data, int *datalen)
337 static long len, pad, payload, packetlen, maclen;
339 static int cipherblk;
340 static unsigned long incoming_sequence = 0;
350 cipherblk = cipher->blksize;
356 if (pktin.maxlen < cipherblk) {
357 pktin.maxlen = cipherblk;
358 pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
359 realloc(pktin.data, cipherblk+APIEXTRA));
361 fatalbox("Out of memory");
365 * Acquire and decrypt the first block of the packet. This will
366 * contain the length and padding details.
368 for (i = len = 0; i < cipherblk; i++) {
369 while ((*datalen) == 0)
370 crReturn(cipherblk-i);
371 pktin.data[i] = *(*data)++;
375 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
380 sccipher->decrypt(pktin.data, cipherblk);
383 * Now get the length and padding figures.
385 len = GET_32BIT(pktin.data);
389 * This enables us to deduce the payload length.
391 payload = len - pad - 1;
393 pktin.length = payload + 5;
396 * So now we can work out the total packet length.
399 maclen = scmac ? scmac->len : 0;
402 * Adjust memory allocation if packet is too big.
404 if (pktin.maxlen < packetlen) {
405 pktin.maxlen = packetlen;
406 pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) :
407 realloc(pktin.data, packetlen+APIEXTRA));
409 fatalbox("Out of memory");
413 * Read and decrypt the remainder of the packet.
415 for (i = cipherblk; i < packetlen + maclen; i++) {
416 while ((*datalen) == 0)
417 crReturn(packetlen + maclen - i);
418 pktin.data[i] = *(*data)++;
421 /* Decrypt everything _except_ the MAC. */
423 sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
426 debug(("Got packet len=%d pad=%d\r\n", len, pad));
427 for (i = 0; i < packetlen; i++)
428 debug((" %02x", (unsigned char)pktin.data[i]));
435 if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence))
436 fatalbox("Incorrect MAC received on packet");
437 incoming_sequence++; /* whether or not we MACed */
440 pktin.type = pktin.data[5];
442 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
443 goto next_packet; /* FIXME: print DEBUG message */
448 static void ssh_gotdata(unsigned char *data, int datalen)
450 while (datalen > 0) {
451 if ( s_rdpkt(&data, &datalen) == 0 ) {
452 ssh_protocol(NULL, 0, 1);
453 if (ssh_state == SSH_STATE_CLOSED) {
461 static void s_wrpkt_start(int type, int len) {
464 len += 5; /* type and CRC */
468 pktout.length = len-5;
469 if (pktout.maxlen < biglen) {
470 pktout.maxlen = biglen;
472 /* Allocate enough buffer space for extra block
473 * for MS CryptEncrypt() */
474 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
475 realloc(pktout.data, biglen+12));
477 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
478 realloc(pktout.data, biglen+4));
481 fatalbox("Out of memory");
485 pktout.body = pktout.data+4+pad+1;
488 static void s_wrpkt(void) {
489 int pad, len, biglen, i;
492 len = pktout.length + 5; /* type and CRC */
496 pktout.body[-1] = pktout.type;
497 for (i=0; i<pad; i++)
498 pktout.data[i+4] = random_byte();
499 crc = crc32(pktout.data+4, biglen-4);
500 PUT_32BIT(pktout.data+biglen, crc);
501 PUT_32BIT(pktout.data, len);
504 cipher->encrypt(pktout.data+4, biglen);
506 s_write(pktout.data, biglen+4);
510 * Construct a packet with the specified contents and
511 * send it to the server.
513 static void send_packet(int pkttype, ...)
516 unsigned char *p, *argp, argchar;
517 unsigned long argint;
518 int pktlen, argtype, arglen;
523 va_start(args, pkttype);
524 while ((argtype = va_arg(args, int)) != PKT_END) {
527 (void) va_arg(args, int);
531 (void) va_arg(args, char);
535 (void) va_arg(args, unsigned char *);
536 arglen = va_arg(args, int);
540 argp = va_arg(args, unsigned char *);
541 arglen = strlen(argp);
542 pktlen += 4 + arglen;
545 bn = va_arg(args, Bignum);
547 while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 )
549 pktlen += 2 + (i+7)/8;
557 s_wrpkt_start(pkttype, pktlen);
560 va_start(args, pkttype);
561 while ((argtype = va_arg(args, int)) != PKT_END) {
564 argint = va_arg(args, int);
565 PUT_32BIT(p, argint);
569 argchar = va_arg(args, unsigned char);
574 argp = va_arg(args, unsigned char *);
575 arglen = va_arg(args, int);
576 memcpy(p, argp, arglen);
580 argp = va_arg(args, unsigned char *);
581 arglen = strlen(argp);
582 PUT_32BIT(p, arglen);
583 memcpy(p + 4, argp, arglen);
587 bn = va_arg(args, Bignum);
589 while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 )
591 *p++ = (i >> 8) & 0xFF;
596 *p++ = bn[i/2+1] >> 8;
598 *p++ = bn[i/2+1] & 0xFF;
610 * Connect to specified host and port.
611 * Returns an error message, or NULL on success.
612 * Also places the canonical host name into `realhost'.
614 static char *connect_to_host(char *host, int port, char **realhost)
624 savedhost = malloc(1+strlen(host));
626 fatalbox("Out of memory");
627 strcpy(savedhost, host);
630 port = 22; /* default ssh port */
642 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
643 if ( (h = gethostbyname(host)) == NULL)
644 switch (WSAGetLastError()) {
645 case WSAENETDOWN: return "Network is down";
646 case WSAHOST_NOT_FOUND: case WSANO_DATA:
647 return "Host does not exist";
648 case WSATRY_AGAIN: return "Host not found";
649 default: return "gethostbyname: unknown error";
651 memcpy (&a, h->h_addr, sizeof(a));
652 *realhost = h->h_name;
663 s = socket(AF_INET, SOCK_STREAM, 0);
664 if (s == INVALID_SOCKET)
665 switch (WSAGetLastError()) {
666 case WSAENETDOWN: return "Network is down";
667 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
668 default: return "socket(): unknown error";
672 * Bind to local address.
674 addr.sin_family = AF_INET;
675 addr.sin_addr.s_addr = htonl(INADDR_ANY);
676 addr.sin_port = htons(0);
677 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
678 switch (WSAGetLastError()) {
679 case WSAENETDOWN: return "Network is down";
680 default: return "bind(): unknown error";
684 * Connect to remote address.
686 addr.sin_addr.s_addr = htonl(a);
687 addr.sin_port = htons((short)port);
688 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
689 switch (WSAGetLastError()) {
690 case WSAENETDOWN: return "Network is down";
691 case WSAECONNREFUSED: return "Connection refused";
692 case WSAENETUNREACH: return "Network is unreachable";
693 case WSAEHOSTUNREACH: return "No route to host";
694 default: return "connect(): unknown error";
698 send(s, "connect ", 8, 0);
699 send(s, FWhost, strlen(FWhost), 0);
702 sprintf(buf, " %d\n", FWport);
703 send (s, buf, strlen(buf), 0);
710 static int ssh_versioncmp(char *a, char *b) {
712 unsigned long av, bv;
714 av = strtoul(a, &ae, 10);
715 bv = strtoul(b, &be, 10);
716 if (av != bv) return (av < bv ? -1 : +1);
717 if (*ae == '.') ae++;
718 if (*be == '.') be++;
719 av = strtoul(ae, &ae, 10);
720 bv = strtoul(be, &be, 10);
721 if (av != bv) return (av < bv ? -1 : +1);
727 * Utility routine for putting an SSH-protocol `string' into a SHA
731 void sha_string(SHA_State *s, void *str, int len) {
732 unsigned char lenblk[4];
734 PUT_32BIT(lenblk, len);
735 if (!fp) fp = fopen("h:\\statham\\windows\\putty\\data","wb");
736 fwrite(lenblk, 4, 1, fp);
737 SHA_Bytes(s, lenblk, 4);
738 fwrite(str, len, 1, fp);
740 SHA_Bytes(s, str, len);
744 * SSH2 packet construction functions.
746 void ssh2_pkt_adddata(void *data, int len) {
747 pktout.length += len;
748 if (pktout.maxlen < pktout.length) {
749 pktout.maxlen = pktout.length + 256;
750 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
751 realloc(pktout.data, pktout.maxlen+APIEXTRA));
753 fatalbox("Out of memory");
755 memcpy(pktout.data+pktout.length-len, data, len);
757 void ssh2_pkt_addbyte(unsigned char byte) {
758 ssh2_pkt_adddata(&byte, 1);
760 void ssh2_pkt_init(int pkt_type) {
762 ssh2_pkt_addbyte((unsigned char)pkt_type);
764 void ssh2_pkt_addbool(unsigned char value) {
765 ssh2_pkt_adddata(&value, 1);
767 void ssh2_pkt_adduint32(unsigned long value) {
770 ssh2_pkt_adddata(x, 4);
772 void ssh2_pkt_addstring_start(void) {
773 ssh2_pkt_adduint32(0);
774 pktout.savedpos = pktout.length;
776 void ssh2_pkt_addstring_str(char *data) {
777 ssh2_pkt_adddata(data, strlen(data));
778 PUT_32BIT(pktout.data + pktout.savedpos - 4,
779 pktout.length - pktout.savedpos);
781 void ssh2_pkt_addstring_data(char *data, int len) {
782 ssh2_pkt_adddata(data, len);
783 PUT_32BIT(pktout.data + pktout.savedpos - 4,
784 pktout.length - pktout.savedpos);
786 void ssh2_pkt_addstring(char *data) {
787 ssh2_pkt_addstring_start();
788 ssh2_pkt_addstring_str(data);
790 char *ssh2_mpint_fmt(Bignum b, int *len) {
793 p = malloc(n * 2 + 1);
795 fatalbox("out of memory");
797 for (i = 0; i < n; i++) {
798 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
799 p[i*2+2] = (b[n-i] ) & 0xFF;
802 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
804 memmove(p, p+i, n*2+1-i);
808 void ssh2_pkt_addmp(Bignum b) {
811 p = ssh2_mpint_fmt(b, &len);
812 ssh2_pkt_addstring_start();
813 ssh2_pkt_addstring_data(p, len);
816 void ssh2_pkt_send(void) {
817 int cipherblk, maclen, padding, i;
818 static unsigned long outgoing_sequence = 0;
821 * Add padding. At least four bytes, and must also bring total
822 * length (minus MAC) up to a multiple of the block size.
824 cipherblk = cipher ? cipher->blksize : 8; /* block size */
825 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
827 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
828 pktout.data[4] = padding;
829 for (i = 0; i < padding; i++)
830 pktout.data[pktout.length + i] = random_byte();
831 PUT_32BIT(pktout.data, pktout.length + padding - 4);
833 csmac->generate(pktout.data, pktout.length + padding,
835 outgoing_sequence++; /* whether or not we MACed */
838 debug(("Sending packet len=%d\r\n", pktout.length+padding));
839 for (i = 0; i < pktout.length+padding; i++)
840 debug((" %02x", (unsigned char)pktout.data[i]));
845 cscipher->encrypt(pktout.data, pktout.length + padding);
846 maclen = csmac ? csmac->len : 0;
848 s_write(pktout.data, pktout.length + padding + maclen);
852 void bndebug(char *string, Bignum b) {
855 p = ssh2_mpint_fmt(b, &len);
856 debug(("%s", string));
857 for (i = 0; i < len; i++)
858 debug((" %02x", p[i]));
864 void sha_mpint(SHA_State *s, Bignum b) {
867 p = ssh2_mpint_fmt(b, &len);
868 sha_string(s, p, len);
873 * SSH2 packet decode functions.
875 unsigned long ssh2_pkt_getuint32(void) {
877 if (pktin.length - pktin.savedpos < 4)
878 return 0; /* arrgh, no way to decline (FIXME?) */
879 value = GET_32BIT(pktin.data+pktin.savedpos);
883 void ssh2_pkt_getstring(char **p, int *length) {
885 if (pktin.length - pktin.savedpos < 4)
887 *length = GET_32BIT(pktin.data+pktin.savedpos);
889 if (pktin.length - pktin.savedpos < *length)
891 *p = pktin.data+pktin.savedpos;
892 pktin.savedpos += *length;
894 Bignum ssh2_pkt_getmp(void) {
899 ssh2_pkt_getstring(&p, &length);
903 fatalbox("internal error: Can't handle negative mpints");
904 b = newbn((length+1)/2);
905 for (i = 0; i < length; i++) {
908 b[j/2+1] |= ((unsigned char)p[i]) << 8;
910 b[j/2+1] |= ((unsigned char)p[i]);
915 static int do_ssh_init(void) {
919 char vlog[sizeof(vstring)+20];
924 while (s_read(&c, 1) == 1) {
925 if (c == 'S' && i < 2) i++;
926 else if (c == 'S' && i == 2) i = 2;
927 else if (c == 'H' && i == 2) break;
931 if (s_read(&c,1) != 1 || c != 'S') return 0;
932 if (s_read(&c,1) != 1 || c != 'S') return 0;
933 if (s_read(&c,1) != 1 || c != 'H') return 0;
935 strcpy(vstring, "SSH-");
937 if (s_read(&c,1) != 1 || c != '-') return 0;
940 if (s_read(&c,1) != 1)
942 if (vsp < vstring+sizeof(vstring)-1)
948 } else if (i < sizeof(version)-1)
956 sprintf(vlog, "Server version: %s", vstring);
957 vlog[strcspn(vlog, "\r\n")] = '\0';
960 if (ssh_versioncmp(version, "2.0" /* FIXME: "1.99" */ ) >= 0) {
962 * This is a v2 server. Begin v2 protocol.
964 char *verstring = "SSH-2.0-PuTTY";
967 * Hash our version string and their version string.
969 sha_string(&exhash, verstring, strlen(verstring));
970 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
971 sprintf(vstring, "%s\n", verstring);
972 sprintf(vlog, "We claim version: %s", verstring);
974 logevent("Using SSH protocol version 2");
975 s_write(vstring, strlen(vstring));
976 ssh_protocol = ssh2_protocol;
978 s_rdpkt = ssh2_rdpkt;
981 * This is a v1 server. Begin v1 protocol.
983 sprintf(vstring, "SSH-%s-PuTTY\n",
984 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
985 sprintf(vlog, "We claim version: %s", vstring);
986 vlog[strcspn(vlog, "\r\n")] = '\0';
988 logevent("Using SSH protocol version 1");
989 s_write(vstring, strlen(vstring));
990 ssh_protocol = ssh1_protocol;
992 s_rdpkt = ssh1_rdpkt;
999 * Handle the key exchange and user authentication phases.
1001 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1004 unsigned char *rsabuf, *keystr1, *keystr2;
1005 unsigned char cookie[8];
1006 struct RSAKey servkey, hostkey;
1007 struct MD5Context md5c;
1008 static unsigned long supported_ciphers_mask, supported_auths_mask;
1009 static int tried_publickey;
1010 static unsigned char session_id[16];
1015 if (!ispkt) crWaitUntil(ispkt);
1017 if (pktin.type != SSH1_SMSG_PUBLIC_KEY)
1018 fatalbox("Public key packet not received");
1020 logevent("Received public keys");
1022 memcpy(cookie, pktin.body, 8);
1024 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1025 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1028 * Hash the host key and print the hash in the log box. Just as
1029 * a last resort in case the registry's host key checking is
1030 * compromised, we'll allow the user some ability to verify
1034 MD5Update(&md5c, keystr2, hostkey.bytes);
1035 MD5Final(session_id, &md5c);
1039 logevent("Host key MD5 is:");
1040 strcpy(logmsg, " ");
1041 for (i = 0; i < 16; i++)
1042 sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
1046 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1047 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1050 MD5Update(&md5c, keystr2, hostkey.bytes);
1051 MD5Update(&md5c, keystr1, servkey.bytes);
1052 MD5Update(&md5c, pktin.body, 8);
1053 MD5Final(session_id, &md5c);
1055 for (i=0; i<32; i++)
1056 session_key[i] = random_byte();
1058 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1060 rsabuf = malloc(len);
1062 fatalbox("Out of memory");
1065 * Verify the host key.
1069 * First format the key into a string.
1071 int len = rsastr_len(&hostkey);
1072 char *keystr = malloc(len);
1074 fatalbox("Out of memory");
1075 rsastr_fmt(keystr, &hostkey);
1076 verify_ssh_host_key(savedhost, keystr);
1080 for (i=0; i<32; i++) {
1081 rsabuf[i] = session_key[i];
1083 rsabuf[i] ^= session_id[i];
1086 if (hostkey.bytes > servkey.bytes) {
1087 rsaencrypt(rsabuf, 32, &servkey);
1088 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1090 rsaencrypt(rsabuf, 32, &hostkey);
1091 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1094 logevent("Encrypted session key");
1096 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1097 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1099 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1100 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1101 cipher_type = SSH_CIPHER_3DES;
1103 switch (cipher_type) {
1104 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1105 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1106 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1109 send_packet(SSH1_CMSG_SESSION_KEY,
1110 PKT_CHAR, cipher_type,
1111 PKT_DATA, cookie, 8,
1112 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1113 PKT_DATA, rsabuf, len,
1117 logevent("Trying to enable encryption...");
1121 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
1122 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1124 cipher->sesskey(session_key);
1128 if (pktin.type != SSH1_SMSG_SUCCESS)
1129 fatalbox("Encryption not successfully enabled");
1131 logevent("Successfully started encryption");
1135 static char username[100];
1138 if (!(flags & FLAG_CONNECTION) && !*cfg.username) {
1139 c_write("login as: ", 10);
1141 crWaitUntil(!ispkt);
1142 while (inlen--) switch (c = *in++) {
1149 c_write("\b \b", 3);
1155 c_write("\b \b", 3);
1164 if (((c >= ' ' && c <= '~') ||
1165 ((unsigned char)c >= 160)) && pos < 40) {
1166 username[pos++] = c;
1173 username[strcspn(username, "\n\r")] = '\0';
1176 strncpy(username, cfg.username, 99);
1177 username[99] = '\0';
1178 if (flags & FLAG_VERBOSE) {
1179 sprintf(stuff, "Sent username \"%s\".\r\n", username);
1180 c_write(stuff, strlen(stuff));
1184 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1186 char userlog[20+sizeof(username)];
1187 sprintf(userlog, "Sent username \"%s\"", username);
1194 tried_publickey = 0;
1196 while (pktin.type == SSH1_SMSG_FAILURE) {
1197 static char password[100];
1200 static int pwpkt_type;
1202 * Show password prompt, having first obtained it via a TIS
1203 * exchange if we're doing TIS authentication.
1205 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1206 if (*cfg.keyfile && !tried_publickey)
1207 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1209 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD && !FLAG_WINDOWED) {
1211 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1212 if (!ssh_get_password(prompt, password, sizeof(password))) {
1214 * get_password failed to get a password (for
1215 * example because one was supplied on the command
1216 * line which has already failed to work).
1219 logevent("No more passwords to try");
1220 ssh_state = SSH_STATE_CLOSED;
1225 if (pktin.type == SSH1_SMSG_FAILURE &&
1227 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1228 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1229 logevent("Requested TIS authentication");
1230 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1232 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1233 logevent("TIS authentication declined");
1234 c_write("TIS authentication refused.\r\n", 29);
1236 int challengelen = ((pktin.body[0] << 24) |
1237 (pktin.body[1] << 16) |
1238 (pktin.body[2] << 8) |
1240 logevent("Received TIS challenge");
1241 c_write(pktin.body+4, challengelen);
1244 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD)
1245 c_write("password: ", 10);
1246 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1247 if (flags & FLAG_VERBOSE)
1248 c_write("Trying public key authentication.\r\n", 35);
1249 if (!rsakey_encrypted(cfg.keyfile)) {
1250 if (flags & FLAG_VERBOSE)
1251 c_write("No passphrase required.\r\n", 25);
1254 c_write("passphrase: ", 12);
1259 crWaitUntil(!ispkt);
1260 while (inlen--) switch (c = *in++) {
1277 if (((c >= ' ' && c <= '~') ||
1278 ((unsigned char)c >= 160)) && pos < sizeof(password))
1279 password[pos++] = c;
1288 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1290 * Try public key authentication with the specified
1293 static struct RSAKey pubkey;
1294 static Bignum challenge, response;
1296 static unsigned char buffer[32];
1298 tried_publickey = 1;
1299 i = loadrsakey(cfg.keyfile, &pubkey, password);
1301 c_write("Couldn't load public key from ", 30);
1302 c_write(cfg.keyfile, strlen(cfg.keyfile));
1303 c_write(".\r\n", 3);
1304 continue; /* go and try password */
1307 c_write("Wrong passphrase.\r\n", 19);
1308 tried_publickey = 0;
1309 continue; /* try again */
1313 * Send a public key attempt.
1315 send_packet(SSH1_CMSG_AUTH_RSA,
1316 PKT_BIGNUM, pubkey.modulus, PKT_END);
1319 if (pktin.type == SSH1_SMSG_FAILURE) {
1320 if (flags & FLAG_VERBOSE)
1321 c_write("Server refused our public key.\r\n", 32);
1322 continue; /* go and try password */
1324 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE)
1325 fatalbox("Bizarre response to offer of public key");
1326 ssh1_read_bignum(pktin.body, &challenge);
1327 response = rsadecrypt(challenge, &pubkey);
1328 freebn(pubkey.private_exponent); /* burn the evidence */
1330 for (i = 0; i < 32; i += 2) {
1331 buffer[i] = response[16-i/2] >> 8;
1332 buffer[i+1] = response[16-i/2] & 0xFF;
1336 MD5Update(&md5c, buffer, 32);
1337 MD5Update(&md5c, session_id, 16);
1338 MD5Final(buffer, &md5c);
1340 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1341 PKT_DATA, buffer, 16, PKT_END);
1344 if (pktin.type == SSH1_SMSG_FAILURE) {
1345 if (flags & FLAG_VERBOSE)
1346 c_write("Failed to authenticate with our public key.\r\n",
1348 continue; /* go and try password */
1349 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1350 fatalbox("Bizarre response to RSA authentication response");
1353 break; /* we're through! */
1355 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1357 logevent("Sent password");
1358 memset(password, 0, strlen(password));
1360 if (pktin.type == SSH1_SMSG_FAILURE) {
1361 if (flags & FLAG_VERBOSE)
1362 c_write("Access denied\r\n", 15);
1363 logevent("Authentication refused");
1364 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1365 logevent("Received disconnect request");
1366 ssh_state = SSH_STATE_CLOSED;
1368 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1369 fatalbox("Strange packet received, type %d", pktin.type);
1373 logevent("Authentication successful");
1378 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1383 while (!do_ssh1_login(in, inlen, ispkt)) {
1386 if (ssh_state == SSH_STATE_CLOSED)
1390 send_packet(SSH1_CMSG_REQUEST_PTY,
1391 PKT_STR, cfg.termtype,
1392 PKT_INT, rows, PKT_INT, cols,
1393 PKT_INT, 0, PKT_INT, 0,
1396 ssh_state = SSH_STATE_INTERMED;
1397 do { crReturnV; } while (!ispkt);
1398 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1399 fatalbox("Protocol confusion");
1400 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1401 c_write("Server refused to allocate pty\r\n", 32);
1403 logevent("Allocated pty");
1406 if (*cfg.remote_cmd)
1407 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1409 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1410 logevent("Started session");
1412 ssh_state = SSH_STATE_SESSION;
1420 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1421 pktin.type == SSH1_SMSG_STDERR_DATA) {
1422 long len = GET_32BIT(pktin.body);
1423 c_write(pktin.body+4, len);
1424 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1425 ssh_state = SSH_STATE_CLOSED;
1426 logevent("Received disconnect request");
1427 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
1428 /* may be from EXEC_SHELL on some servers */
1429 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1430 /* may be from EXEC_SHELL on some servers
1431 * if no pty is available or in other odd cases. Ignore */
1432 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1433 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
1435 fatalbox("Strange packet received: type %d", pktin.type);
1438 send_packet(SSH1_CMSG_STDIN_DATA,
1439 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
1447 * Utility routine for decoding comma-separated strings in KEXINIT.
1449 int in_commasep_string(char *needle, char *haystack, int haylen) {
1450 int needlen = strlen(needle);
1453 * Is it at the start of the string?
1455 if (haylen >= needlen && /* haystack is long enough */
1456 !memcmp(needle, haystack, needlen) && /* initial match */
1457 (haylen == needlen || haystack[needlen] == ',')
1458 /* either , or EOS follows */
1462 * If not, search for the next comma and resume after that.
1463 * If no comma found, terminate.
1465 while (haylen > 0 && *haystack != ',')
1466 haylen--, haystack++;
1469 haylen--, haystack++; /* skip over comma itself */
1474 * SSH2 key creation method.
1476 void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1478 /* First 20 bytes. */
1481 SHA_Bytes(&s, H, 20);
1482 SHA_Bytes(&s, &chr, 1);
1483 SHA_Bytes(&s, H, 20);
1484 SHA_Final(&s, keyspace);
1485 /* Next 20 bytes. */
1488 SHA_Bytes(&s, H, 20);
1489 SHA_Bytes(&s, keyspace, 20);
1490 SHA_Final(&s, keyspace+20);
1494 * Handle the SSH2 transport layer.
1496 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
1500 static Bignum e, f, K;
1501 static struct ssh_cipher *cscipher_tobe = NULL;
1502 static struct ssh_cipher *sccipher_tobe = NULL;
1503 static struct ssh_mac *csmac_tobe = NULL;
1504 static struct ssh_mac *scmac_tobe = NULL;
1505 static struct ssh_compress *cscomp_tobe = NULL;
1506 static struct ssh_compress *sccomp_tobe = NULL;
1507 static char *hostkeydata, *sigdata, *keystr;
1508 static int hostkeylen, siglen;
1509 static unsigned char exchange_hash[20];
1510 static unsigned char keyspace[40];
1517 * Construct and send our key exchange packet.
1519 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1520 for (i = 0; i < 16; i++)
1521 ssh2_pkt_addbyte((unsigned char)random_byte());
1522 /* List key exchange algorithms. */
1523 ssh2_pkt_addstring_start();
1524 for (i = 0; i < lenof(kex_algs); i++) {
1525 ssh2_pkt_addstring_str(kex_algs[i]->name);
1526 if (i < lenof(kex_algs)-1)
1527 ssh2_pkt_addstring_str(",");
1529 /* List server host key algorithms. */
1530 ssh2_pkt_addstring_start();
1531 for (i = 0; i < lenof(hostkey_algs); i++) {
1532 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1533 if (i < lenof(hostkey_algs)-1)
1534 ssh2_pkt_addstring_str(",");
1536 /* List client->server encryption algorithms. */
1537 ssh2_pkt_addstring_start();
1538 for (i = 0; i < lenof(ciphers); i++) {
1539 ssh2_pkt_addstring_str(ciphers[i]->name);
1540 if (i < lenof(ciphers)-1)
1541 ssh2_pkt_addstring_str(",");
1543 /* List server->client encryption algorithms. */
1544 ssh2_pkt_addstring_start();
1545 for (i = 0; i < lenof(ciphers); i++) {
1546 ssh2_pkt_addstring_str(ciphers[i]->name);
1547 if (i < lenof(ciphers)-1)
1548 ssh2_pkt_addstring_str(",");
1550 /* List client->server MAC algorithms. */
1551 ssh2_pkt_addstring_start();
1552 for (i = 0; i < lenof(macs); i++) {
1553 ssh2_pkt_addstring_str(macs[i]->name);
1554 if (i < lenof(macs)-1)
1555 ssh2_pkt_addstring_str(",");
1557 /* List server->client MAC algorithms. */
1558 ssh2_pkt_addstring_start();
1559 for (i = 0; i < lenof(macs); i++) {
1560 ssh2_pkt_addstring_str(macs[i]->name);
1561 if (i < lenof(macs)-1)
1562 ssh2_pkt_addstring_str(",");
1564 /* List client->server compression algorithms. */
1565 ssh2_pkt_addstring_start();
1566 for (i = 0; i < lenof(compressions); i++) {
1567 ssh2_pkt_addstring_str(compressions[i]->name);
1568 if (i < lenof(compressions)-1)
1569 ssh2_pkt_addstring_str(",");
1571 /* List server->client compression algorithms. */
1572 ssh2_pkt_addstring_start();
1573 for (i = 0; i < lenof(compressions); i++) {
1574 ssh2_pkt_addstring_str(compressions[i]->name);
1575 if (i < lenof(compressions)-1)
1576 ssh2_pkt_addstring_str(",");
1578 /* List client->server languages. Empty list. */
1579 ssh2_pkt_addstring_start();
1580 /* List server->client languages. Empty list. */
1581 ssh2_pkt_addstring_start();
1582 /* First KEX packet does _not_ follow, because we're not that brave. */
1583 ssh2_pkt_addbool(FALSE);
1585 ssh2_pkt_adduint32(0);
1586 sha_string(&exhash, pktout.data+5, pktout.length-5);
1589 if (!ispkt) crWaitUntil(ispkt);
1590 sha_string(&exhash, pktin.data+5, pktin.length-5);
1593 * Now examine the other side's KEXINIT to see what we're up
1596 if (pktin.type != SSH2_MSG_KEXINIT) {
1597 fatalbox("expected key exchange packet from server");
1599 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1600 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1601 pktin.savedpos += 16; /* skip garbage cookie */
1602 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1603 for (i = 0; i < lenof(kex_algs); i++) {
1604 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1609 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1610 for (i = 0; i < lenof(hostkey_algs); i++) {
1611 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1612 hostkey = hostkey_algs[i];
1616 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1617 for (i = 0; i < lenof(ciphers); i++) {
1618 if (in_commasep_string(ciphers[i]->name, str, len)) {
1619 cscipher_tobe = ciphers[i];
1623 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1624 for (i = 0; i < lenof(ciphers); i++) {
1625 if (in_commasep_string(ciphers[i]->name, str, len)) {
1626 sccipher_tobe = ciphers[i];
1630 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1631 for (i = 0; i < lenof(macs); i++) {
1632 if (in_commasep_string(macs[i]->name, str, len)) {
1633 csmac_tobe = macs[i];
1637 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1638 for (i = 0; i < lenof(macs); i++) {
1639 if (in_commasep_string(macs[i]->name, str, len)) {
1640 scmac_tobe = macs[i];
1644 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1645 for (i = 0; i < lenof(compressions); i++) {
1646 if (in_commasep_string(compressions[i]->name, str, len)) {
1647 cscomp_tobe = compressions[i];
1651 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1652 for (i = 0; i < lenof(compressions); i++) {
1653 if (in_commasep_string(compressions[i]->name, str, len)) {
1654 sccomp_tobe = compressions[i];
1660 * Currently we only support Diffie-Hellman and DSS, so let's
1661 * bomb out if those aren't selected.
1663 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss)
1664 fatalbox("internal fault: chaos in SSH 2 transport layer");
1667 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1670 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
1675 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
1676 fatalbox("expected key exchange packet from server");
1678 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
1679 f = ssh2_pkt_getmp();
1680 ssh2_pkt_getstring(&sigdata, &siglen);
1684 sha_string(&exhash, hostkeydata, hostkeylen);
1685 sha_mpint(&exhash, e);
1686 sha_mpint(&exhash, f);
1687 sha_mpint(&exhash, K);
1688 SHA_Final(&exhash, exchange_hash);
1691 debug(("Exchange hash is:\r\n"));
1692 for (i = 0; i < 20; i++)
1693 debug((" %02x", exchange_hash[i]));
1697 hostkey->setkey(hostkeydata, hostkeylen);
1698 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20))
1699 fatalbox("Server failed host key check");
1702 * Expect SSH2_MSG_NEWKEYS from server.
1705 if (pktin.type != SSH2_MSG_NEWKEYS)
1706 fatalbox("expected new-keys packet from server");
1709 * Authenticate remote host: verify host key. (We've already
1710 * checked the signature of the exchange hash.)
1712 keystr = hostkey->fmtkey();
1713 verify_ssh_host_key(savedhost, keystr);
1717 * Send SSH2_MSG_NEWKEYS.
1719 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
1723 * Create and initialise session keys.
1725 cscipher = cscipher_tobe;
1726 sccipher = sccipher_tobe;
1729 cscomp = cscomp_tobe;
1730 sccomp = sccomp_tobe;
1732 * Set IVs after keys.
1734 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
1735 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
1736 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
1737 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
1738 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
1739 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
1742 * Now we're encrypting. Begin returning 1 to the protocol main
1743 * function so that other things can run on top of the
1744 * transport. If we ever see a KEXINIT, we must go back to the
1749 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
1750 goto begin_key_exchange;
1756 * SSH2: remote identifier for the main session channel.
1758 static unsigned long ssh_remote_channel;
1761 * Handle the SSH2 userauth and connection layers.
1763 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
1765 static unsigned long remote_winsize;
1766 static unsigned long remote_maxpkt;
1771 * Request userauth protocol, and await a response to it.
1773 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
1774 ssh2_pkt_addstring("ssh-userauth");
1776 crWaitUntilV(ispkt);
1777 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT)
1778 fatalbox("Server refused user authentication protocol");
1781 * FIXME: currently we support only password authentication.
1782 * (This places us technically in violation of the SSH2 spec.
1783 * We must fix this.)
1787 * Get a username and a password.
1789 static char username[100];
1790 static char password[100];
1794 if ((flags & FLAG_CONNECTION) && !*cfg.username) {
1795 c_write("login as: ", 10);
1797 crWaitUntilV(!ispkt);
1798 while (inlen--) switch (c = *in++) {
1805 c_write("\b \b", 3);
1811 c_write("\b \b", 3);
1820 if (((c >= ' ' && c <= '~') ||
1821 ((unsigned char)c >= 160)) && pos < 40) {
1822 username[pos++] = c;
1829 username[strcspn(username, "\n\r")] = '\0';
1832 strncpy(username, cfg.username, 99);
1833 username[99] = '\0';
1834 if (flags & FLAG_VERBOSE) {
1835 sprintf(stuff, "Using username \"%s\".\r\n", username);
1836 c_write(stuff, strlen(stuff));
1840 if (!(flags & FLAG_WINDOWED)) {
1842 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1843 if (!ssh_get_password(prompt, password, sizeof(password))) {
1845 * get_password failed to get a password (for
1846 * example because one was supplied on the command
1847 * line which has already failed to work).
1850 logevent("No more passwords to try");
1851 ssh_state = SSH_STATE_CLOSED;
1855 c_write("password: ", 10);
1859 crWaitUntilV(!ispkt);
1860 while (inlen--) switch (c = *in++) {
1877 if (((c >= ' ' && c <= '~') ||
1878 ((unsigned char)c >= 160)) && pos < 40)
1879 password[pos++] = c;
1886 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
1887 ssh2_pkt_addstring(username);
1888 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1889 ssh2_pkt_addstring("password");
1890 ssh2_pkt_addbool(FALSE);
1891 ssh2_pkt_addstring(password);
1894 crWaitUntilV(ispkt);
1895 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
1896 c_write("Access denied\r\n", 15);
1897 logevent("Authentication refused");
1903 * Now we're authenticated for the connection protocol. The
1904 * connection protocol will automatically have started at this
1905 * point; there's no need to send SERVICE_REQUEST.
1909 * So now create a channel with a session in it.
1911 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
1912 ssh2_pkt_addstring("session");
1913 ssh2_pkt_adduint32(100); /* as good as any */
1914 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big window which we ignore */
1915 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big max pkt size */
1917 crWaitUntilV(ispkt);
1918 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
1919 fatalbox("Server refused to open a session");
1920 /* FIXME: error data comes back in FAILURE packet */
1922 if (ssh2_pkt_getuint32() != 100) {
1923 fatalbox("Server's channel confirmation cited wrong channel");
1925 ssh_remote_channel = ssh2_pkt_getuint32();
1926 remote_winsize = ssh2_pkt_getuint32();
1927 remote_maxpkt = ssh2_pkt_getuint32();
1928 logevent("Opened channel for session");
1931 * Now allocate a pty for the session.
1933 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
1934 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
1935 ssh2_pkt_addstring("pty-req");
1936 ssh2_pkt_addbool(1); /* want reply */
1937 ssh2_pkt_addstring(cfg.termtype);
1938 ssh2_pkt_adduint32(cols);
1939 ssh2_pkt_adduint32(rows);
1940 ssh2_pkt_adduint32(0); /* pixel width */
1941 ssh2_pkt_adduint32(0); /* pixel height */
1942 ssh2_pkt_addstring_start();
1943 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1946 do { /* FIXME: pay attention to these */
1947 crWaitUntilV(ispkt);
1948 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1950 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
1951 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
1952 fatalbox("Server got confused by pty request");
1954 c_write("Server refused to allocate pty\r\n", 32);
1956 logevent("Allocated pty");
1962 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
1963 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
1964 ssh2_pkt_addstring("shell");
1965 ssh2_pkt_addbool(1); /* want reply */
1967 do { /* FIXME: pay attention to these */
1968 crWaitUntilV(ispkt);
1969 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1970 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
1971 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
1972 fatalbox("Server got confused by shell request");
1974 fatalbox("Server refused to start a shell");
1976 logevent("Started a shell");
1986 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
1987 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1990 if (ssh2_pkt_getuint32() != 100)
1991 continue; /* wrong channel */
1992 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
1993 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
1994 continue; /* extended but not stderr */
1995 ssh2_pkt_getstring(&data, &length);
1997 c_write(data, length);
1998 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
1999 ssh_state = SSH_STATE_CLOSED;
2000 logevent("Received disconnect request");
2001 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2002 continue; /* exit status et al; ignore (FIXME?) */
2003 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2004 continue; /* ignore for now (FIXME!) */
2006 fatalbox("Strange packet received: type %d", pktin.type);
2009 /* FIXME: for now, ignore window size */
2010 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2011 ssh2_pkt_adduint32(ssh_remote_channel);
2012 ssh2_pkt_addstring_start();
2013 ssh2_pkt_addstring_data(in, inlen);
2022 * Handle the top-level SSH2 protocol.
2024 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2026 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2028 do_ssh2_authconn(in, inlen, ispkt);
2032 * Called to set up the connection. Will arrange for WM_NETEVENT
2033 * messages to be passed to the specified window, whose window
2034 * procedure should then call telnet_msg().
2036 * Returns an error message, or NULL on success.
2038 static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
2042 if(crypto_startup() == 0)
2043 return "Microsoft high encryption pack not installed!";
2046 p = connect_to_host(host, port, realhost);
2051 return "Protocol initialisation error";
2053 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
2054 switch (WSAGetLastError()) {
2055 case WSAENETDOWN: return "Network is down";
2056 default: return "WSAAsyncSelect(): unknown error";
2063 * Process a WM_NETEVENT message. Will return 0 if the connection
2064 * has closed, or <0 for a socket error.
2066 static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2071 * Because reading less than the whole of the available pending
2072 * data can generate an FD_READ event, we need to allow for the
2073 * possibility that FD_READ may arrive with FD_CLOSE already in
2074 * the queue; so it's possible that we can get here even with s
2075 * invalid. If so, we return 1 and don't worry about it.
2077 if (s == INVALID_SOCKET)
2080 if (WSAGETSELECTERROR(lParam) != 0)
2081 return -WSAGETSELECTERROR(lParam);
2083 switch (WSAGETSELECTEVENT(lParam)) {
2086 ret = recv(s, buf, sizeof(buf), 0);
2087 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2089 if (ret < 0) /* any _other_ error */
2090 return -10000-WSAGetLastError();
2095 ssh_gotdata (buf, ret);
2096 if (ssh_state == SSH_STATE_CLOSED) {
2103 return 1; /* shouldn't happen, but WTF */
2107 * Called to send data down the Telnet connection.
2109 static void ssh_send (char *buf, int len) {
2110 if (s == INVALID_SOCKET)
2113 ssh_protocol(buf, len, 0);
2117 * Called to set the size of the window from Telnet's POV.
2119 static void ssh_size(void) {
2120 switch (ssh_state) {
2121 case SSH_STATE_BEFORE_SIZE:
2122 case SSH_STATE_CLOSED:
2123 break; /* do nothing */
2124 case SSH_STATE_INTERMED:
2125 size_needed = TRUE; /* buffer for later */
2127 case SSH_STATE_SESSION:
2129 send_packet(SSH1_CMSG_WINDOW_SIZE,
2130 PKT_INT, rows, PKT_INT, cols,
2131 PKT_INT, 0, PKT_INT, 0, PKT_END);
2137 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2138 * can send an EOF and collect resulting output (e.g. `plink
2141 static void ssh_special (Telnet_Special code) {
2142 if (code == TS_EOF) {
2143 if (ssh_version = 1) {
2144 send_packet(SSH1_CMSG_EOF, PKT_END);
2146 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
2147 ssh2_pkt_adduint32(ssh_remote_channel);
2157 * Read and decrypt one incoming SSH packet.
2158 * (only used by pSCP)
2160 static void get_packet(void)
2162 unsigned char buf[4096], *p;
2169 while ((to_read = s_rdpkt(&p, &len)) > 0) {
2170 if (to_read > sizeof(buf)) to_read = sizeof(buf);
2171 len = s_read(buf, to_read);
2172 if (len != to_read) {
2184 * Receive a block of data over the SSH link. Block until
2185 * all data is available. Return nr of bytes read (0 if lost connection).
2186 * (only used by pSCP)
2188 int ssh_scp_recv(unsigned char *buf, int len)
2190 static int pending_input_len = 0;
2191 static unsigned char *pending_input_ptr;
2194 if (pending_input_len >= to_read) {
2195 memcpy(buf, pending_input_ptr, to_read);
2196 pending_input_ptr += to_read;
2197 pending_input_len -= to_read;
2201 if (pending_input_len > 0) {
2202 memcpy(buf, pending_input_ptr, pending_input_len);
2203 buf += pending_input_len;
2204 to_read -= pending_input_len;
2205 pending_input_len = 0;
2208 if (s == INVALID_SOCKET)
2210 while (to_read > 0) {
2212 if (s == INVALID_SOCKET)
2214 if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
2215 int plen = GET_32BIT(pktin.body);
2216 if (plen <= to_read) {
2217 memcpy(buf, pktin.body + 4, plen);
2221 memcpy(buf, pktin.body + 4, to_read);
2222 pending_input_len = plen - to_read;
2223 pending_input_ptr = pktin.body + 4 + to_read;
2226 } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
2227 int plen = GET_32BIT(pktin.body);
2228 fwrite(pktin.body + 4, plen, 1, stderr);
2229 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2230 logevent("Received disconnect request");
2231 } else if (pktin.type == SSH1_SMSG_SUCCESS ||
2232 pktin.type == SSH1_SMSG_FAILURE) {
2234 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2236 sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
2238 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2239 logevent("Closing connection");
2243 fatalbox("Strange packet received: type %d", pktin.type);
2251 * Send a block of data over the SSH link.
2252 * Block until all data is sent.
2253 * (only used by pSCP)
2255 void ssh_scp_send(unsigned char *buf, int len)
2257 if (s == INVALID_SOCKET)
2259 send_packet(SSH1_CMSG_STDIN_DATA,
2260 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2264 * Send an EOF notification to the server.
2265 * (only used by pSCP)
2267 void ssh_scp_send_eof(void)
2269 if (s == INVALID_SOCKET)
2271 send_packet(SSH1_CMSG_EOF, PKT_END);
2275 * Set up the connection, login on the remote host and
2276 * start execution of a command.
2277 * Returns an error message, or NULL on success.
2278 * (only used by pSCP)
2280 char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
2285 if (crypto_startup() == 0)
2286 return "Microsoft high encryption pack not installed!";
2289 p = connect_to_host(host, port, realhost);
2296 return "Protocol initialisation error";
2298 /* Exchange keys and login */
2301 if (s == INVALID_SOCKET)
2302 return "Connection closed by remote host";
2303 } while (!do_ssh1_login(NULL, 0, 1));
2305 if (ssh_state == SSH_STATE_CLOSED) {
2308 return "Session initialisation error";
2311 /* Execute command */
2312 sprintf(buf, "Sending command: %.100s", cmd);
2314 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2319 static SOCKET ssh_socket(void) { return s; }
2321 static int ssh_sendok(void) { return ssh_send_ok; }
2323 Backend ssh_backend = {