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
47 #define SSH1_CMSG_AUTH_CCARD 70
48 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71
49 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72
51 #define SSH1_AUTH_TIS 5
52 #define SSH1_AUTH_CCARD 16
54 #define SSH2_MSG_DISCONNECT 1
55 #define SSH2_MSG_IGNORE 2
56 #define SSH2_MSG_UNIMPLEMENTED 3
57 #define SSH2_MSG_DEBUG 4
58 #define SSH2_MSG_SERVICE_REQUEST 5
59 #define SSH2_MSG_SERVICE_ACCEPT 6
60 #define SSH2_MSG_KEXINIT 20
61 #define SSH2_MSG_NEWKEYS 21
62 #define SSH2_MSG_KEXDH_INIT 30
63 #define SSH2_MSG_KEXDH_REPLY 31
64 #define SSH2_MSG_USERAUTH_REQUEST 50
65 #define SSH2_MSG_USERAUTH_FAILURE 51
66 #define SSH2_MSG_USERAUTH_SUCCESS 52
67 #define SSH2_MSG_USERAUTH_BANNER 53
68 #define SSH2_MSG_USERAUTH_PK_OK 60
69 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60
70 #define SSH2_MSG_GLOBAL_REQUEST 80
71 #define SSH2_MSG_REQUEST_SUCCESS 81
72 #define SSH2_MSG_REQUEST_FAILURE 82
73 #define SSH2_MSG_CHANNEL_OPEN 90
74 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91
75 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92
76 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93
77 #define SSH2_MSG_CHANNEL_DATA 94
78 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95
79 #define SSH2_MSG_CHANNEL_EOF 96
80 #define SSH2_MSG_CHANNEL_CLOSE 97
81 #define SSH2_MSG_CHANNEL_REQUEST 98
82 #define SSH2_MSG_CHANNEL_SUCCESS 99
83 #define SSH2_MSG_CHANNEL_FAILURE 100
85 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1
86 #define SSH2_OPEN_CONNECT_FAILED 2
87 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3
88 #define SSH2_OPEN_RESOURCE_SHORTAGE 4
89 #define SSH2_EXTENDED_DATA_STDERR 1
91 #define GET_32BIT(cp) \
92 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
93 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
94 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
95 ((unsigned long)(unsigned char)(cp)[3]))
97 #define PUT_32BIT(cp, value) { \
98 (cp)[0] = (unsigned char)((value) >> 24); \
99 (cp)[1] = (unsigned char)((value) >> 16); \
100 (cp)[2] = (unsigned char)((value) >> 8); \
101 (cp)[3] = (unsigned char)(value); }
103 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
105 /* Coroutine mechanics for the sillier bits of the code */
106 #define crBegin1 static int crLine = 0;
107 #define crBegin2 switch(crLine) { case 0:;
108 #define crBegin crBegin1; crBegin2;
109 #define crFinish(z) } crLine = 0; return (z)
110 #define crFinishV } crLine = 0; return
111 #define crReturn(z) \
113 crLine=__LINE__; return (z); case __LINE__:;\
117 crLine=__LINE__; return; case __LINE__:;\
119 #define crStop(z) do{ crLine = 0; return (z); }while(0)
120 #define crStopV do{ crLine = 0; return; }while(0)
121 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
122 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
124 extern struct ssh_cipher ssh_3des;
125 extern struct ssh_cipher ssh_3des_ssh2;
126 extern struct ssh_cipher ssh_des;
127 extern struct ssh_cipher ssh_blowfish;
129 /* for ssh 2; we miss out single-DES because it isn't supported */
130 struct ssh_cipher *ciphers[] = { &ssh_3des_ssh2, &ssh_blowfish };
132 extern struct ssh_kex ssh_diffiehellman;
133 struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
135 extern struct ssh_hostkey ssh_dss;
136 struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
138 extern struct ssh_mac ssh_sha1;
142 static void nullmac_key(unsigned char *key) { }
143 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
144 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
145 struct ssh_mac ssh_mac_none = {
146 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
148 struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
150 struct ssh_compress ssh_comp_none = {
153 struct ssh_compress *compressions[] = { &ssh_comp_none };
155 static SOCKET s = INVALID_SOCKET;
157 static unsigned char session_key[32];
158 static struct ssh_cipher *cipher = NULL;
159 static struct ssh_cipher *cscipher = NULL;
160 static struct ssh_cipher *sccipher = NULL;
161 static struct ssh_mac *csmac = NULL;
162 static struct ssh_mac *scmac = NULL;
163 static struct ssh_compress *cscomp = NULL;
164 static struct ssh_compress *sccomp = NULL;
165 static struct ssh_kex *kex = NULL;
166 static struct ssh_hostkey *hostkey = NULL;
167 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
169 static char *savedhost;
170 static int ssh_send_ok;
173 SSH_STATE_BEFORE_SIZE,
177 } ssh_state = SSH_STATE_BEFORE_SIZE;
179 static int size_needed = FALSE;
181 static void s_write (char *buf, int len) {
183 int i = send (s, buf, len, 0);
186 fatalbox("Lost connection while sending");
192 static int s_read (char *buf, int len) {
195 int i = recv (s, buf, len, 0);
198 len -= i, buf += i, ret += i;
205 static void c_write (char *buf, int len) {
206 if (!(flags & FLAG_CONNECTION)) {
208 for (i = 0; i < len; i++)
210 fputc(buf[i], stderr);
226 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
227 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
229 static int ssh_version;
230 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
231 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
232 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
233 static void ssh_size(void);
235 static int (*s_rdpkt)(unsigned char **data, int *datalen);
238 * Collect incoming data in the incoming packet buffer.
239 * Decipher and verify the packet when it is completely read.
240 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
241 * Update the *data and *datalen variables.
242 * Return the additional nr of bytes needed, or 0 when
243 * a complete packet is available.
245 static int ssh1_rdpkt(unsigned char **data, int *datalen)
247 static long len, pad, biglen, to_read;
248 static unsigned long realcrc, gotcrc;
249 static unsigned char *p;
259 for (i = len = 0; i < 4; i++) {
260 while ((*datalen) == 0)
262 len = (len << 8) + **data;
263 (*data)++, (*datalen)--;
267 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
268 len = 0x300; /* big enough to carry to end */
274 pktin.length = len - 5;
276 if (pktin.maxlen < biglen) {
277 pktin.maxlen = biglen;
278 pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
279 realloc(pktin.data, biglen+APIEXTRA));
281 fatalbox("Out of memory");
286 while (to_read > 0) {
289 while ((*datalen) == 0)
291 if (chunk > (*datalen))
293 memcpy(p, *data, chunk);
301 cipher->decrypt(pktin.data, biglen);
303 pktin.type = pktin.data[pad];
304 pktin.body = pktin.data + pad + 1;
306 realcrc = crc32(pktin.data, biglen-4);
307 gotcrc = GET_32BIT(pktin.data+biglen-4);
308 if (gotcrc != realcrc) {
309 fatalbox("Incorrect CRC received on packet");
312 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
313 pktin.type == SSH1_SMSG_STDERR_DATA ||
314 pktin.type == SSH1_MSG_DEBUG ||
315 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
316 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
317 long strlen = GET_32BIT(pktin.body);
318 if (strlen + 4 != pktin.length)
319 fatalbox("Received data packet with bogus string length");
322 if (pktin.type == SSH1_MSG_DEBUG) {
323 /* log debug message */
325 int strlen = GET_32BIT(pktin.body);
326 strcpy(buf, "Remote: ");
327 if (strlen > 70) strlen = 70;
328 memcpy(buf+8, pktin.body+4, strlen);
329 buf[8+strlen] = '\0';
332 } else if (pktin.type == SSH1_MSG_IGNORE) {
340 static int ssh2_rdpkt(unsigned char **data, int *datalen)
342 static long len, pad, payload, packetlen, maclen;
344 static int cipherblk;
345 static unsigned long incoming_sequence = 0;
355 cipherblk = cipher->blksize;
361 if (pktin.maxlen < cipherblk) {
362 pktin.maxlen = cipherblk;
363 pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
364 realloc(pktin.data, cipherblk+APIEXTRA));
366 fatalbox("Out of memory");
370 * Acquire and decrypt the first block of the packet. This will
371 * contain the length and padding details.
373 for (i = len = 0; i < cipherblk; i++) {
374 while ((*datalen) == 0)
375 crReturn(cipherblk-i);
376 pktin.data[i] = *(*data)++;
380 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
385 sccipher->decrypt(pktin.data, cipherblk);
388 * Now get the length and padding figures.
390 len = GET_32BIT(pktin.data);
394 * This enables us to deduce the payload length.
396 payload = len - pad - 1;
398 pktin.length = payload + 5;
401 * So now we can work out the total packet length.
404 maclen = scmac ? scmac->len : 0;
407 * Adjust memory allocation if packet is too big.
409 if (pktin.maxlen < packetlen) {
410 pktin.maxlen = packetlen;
411 pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) :
412 realloc(pktin.data, packetlen+APIEXTRA));
414 fatalbox("Out of memory");
418 * Read and decrypt the remainder of the packet.
420 for (i = cipherblk; i < packetlen + maclen; i++) {
421 while ((*datalen) == 0)
422 crReturn(packetlen + maclen - i);
423 pktin.data[i] = *(*data)++;
426 /* Decrypt everything _except_ the MAC. */
428 sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
431 debug(("Got packet len=%d pad=%d\r\n", len, pad));
432 for (i = 0; i < packetlen; i++)
433 debug((" %02x", (unsigned char)pktin.data[i]));
440 if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence))
441 fatalbox("Incorrect MAC received on packet");
442 incoming_sequence++; /* whether or not we MACed */
445 pktin.type = pktin.data[5];
447 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
448 goto next_packet; /* FIXME: print DEBUG message */
453 static void ssh_gotdata(unsigned char *data, int datalen)
455 while (datalen > 0) {
456 if ( s_rdpkt(&data, &datalen) == 0 ) {
457 ssh_protocol(NULL, 0, 1);
458 if (ssh_state == SSH_STATE_CLOSED) {
466 static void s_wrpkt_start(int type, int len) {
469 len += 5; /* type and CRC */
473 pktout.length = len-5;
474 if (pktout.maxlen < biglen) {
475 pktout.maxlen = biglen;
477 /* Allocate enough buffer space for extra block
478 * for MS CryptEncrypt() */
479 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
480 realloc(pktout.data, biglen+12));
482 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
483 realloc(pktout.data, biglen+4));
486 fatalbox("Out of memory");
490 pktout.body = pktout.data+4+pad+1;
493 static void s_wrpkt(void) {
494 int pad, len, biglen, i;
497 len = pktout.length + 5; /* type and CRC */
501 pktout.body[-1] = pktout.type;
502 for (i=0; i<pad; i++)
503 pktout.data[i+4] = random_byte();
504 crc = crc32(pktout.data+4, biglen-4);
505 PUT_32BIT(pktout.data+biglen, crc);
506 PUT_32BIT(pktout.data, len);
509 cipher->encrypt(pktout.data+4, biglen);
511 s_write(pktout.data, biglen+4);
515 * Construct a packet with the specified contents and
516 * send it to the server.
518 static void send_packet(int pkttype, ...)
521 unsigned char *p, *argp, argchar;
522 unsigned long argint;
523 int pktlen, argtype, arglen;
528 va_start(args, pkttype);
529 while ((argtype = va_arg(args, int)) != PKT_END) {
532 (void) va_arg(args, int);
536 (void) va_arg(args, char);
540 (void) va_arg(args, unsigned char *);
541 arglen = va_arg(args, int);
545 argp = va_arg(args, unsigned char *);
546 arglen = strlen(argp);
547 pktlen += 4 + arglen;
550 bn = va_arg(args, Bignum);
552 while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 )
554 pktlen += 2 + (i+7)/8;
562 s_wrpkt_start(pkttype, pktlen);
565 va_start(args, pkttype);
566 while ((argtype = va_arg(args, int)) != PKT_END) {
569 argint = va_arg(args, int);
570 PUT_32BIT(p, argint);
574 argchar = va_arg(args, unsigned char);
579 argp = va_arg(args, unsigned char *);
580 arglen = va_arg(args, int);
581 memcpy(p, argp, arglen);
585 argp = va_arg(args, unsigned char *);
586 arglen = strlen(argp);
587 PUT_32BIT(p, arglen);
588 memcpy(p + 4, argp, arglen);
592 bn = va_arg(args, Bignum);
594 while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 )
596 *p++ = (i >> 8) & 0xFF;
601 *p++ = bn[i/2+1] >> 8;
603 *p++ = bn[i/2+1] & 0xFF;
615 * Connect to specified host and port.
616 * Returns an error message, or NULL on success.
617 * Also places the canonical host name into `realhost'.
619 static char *connect_to_host(char *host, int port, char **realhost)
629 savedhost = malloc(1+strlen(host));
631 fatalbox("Out of memory");
632 strcpy(savedhost, host);
635 port = 22; /* default ssh port */
647 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
648 if ( (h = gethostbyname(host)) == NULL)
649 switch (WSAGetLastError()) {
650 case WSAENETDOWN: return "Network is down";
651 case WSAHOST_NOT_FOUND: case WSANO_DATA:
652 return "Host does not exist";
653 case WSATRY_AGAIN: return "Host not found";
654 default: return "gethostbyname: unknown error";
656 memcpy (&a, h->h_addr, sizeof(a));
657 *realhost = h->h_name;
668 s = socket(AF_INET, SOCK_STREAM, 0);
669 if (s == INVALID_SOCKET)
670 switch (WSAGetLastError()) {
671 case WSAENETDOWN: return "Network is down";
672 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
673 default: return "socket(): unknown error";
677 * Bind to local address.
679 addr.sin_family = AF_INET;
680 addr.sin_addr.s_addr = htonl(INADDR_ANY);
681 addr.sin_port = htons(0);
682 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
683 switch (WSAGetLastError()) {
684 case WSAENETDOWN: return "Network is down";
685 default: return "bind(): unknown error";
689 * Connect to remote address.
691 addr.sin_addr.s_addr = htonl(a);
692 addr.sin_port = htons((short)port);
693 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
694 switch (WSAGetLastError()) {
695 case WSAENETDOWN: return "Network is down";
696 case WSAECONNREFUSED: return "Connection refused";
697 case WSAENETUNREACH: return "Network is unreachable";
698 case WSAEHOSTUNREACH: return "No route to host";
699 default: return "connect(): unknown error";
703 send(s, "connect ", 8, 0);
704 send(s, FWhost, strlen(FWhost), 0);
707 sprintf(buf, " %d\n", FWport);
708 send (s, buf, strlen(buf), 0);
715 static int ssh_versioncmp(char *a, char *b) {
717 unsigned long av, bv;
719 av = strtoul(a, &ae, 10);
720 bv = strtoul(b, &be, 10);
721 if (av != bv) return (av < bv ? -1 : +1);
722 if (*ae == '.') ae++;
723 if (*be == '.') be++;
724 av = strtoul(ae, &ae, 10);
725 bv = strtoul(be, &be, 10);
726 if (av != bv) return (av < bv ? -1 : +1);
732 * Utility routine for putting an SSH-protocol `string' into a SHA
736 void sha_string(SHA_State *s, void *str, int len) {
737 unsigned char lenblk[4];
738 PUT_32BIT(lenblk, len);
739 SHA_Bytes(s, lenblk, 4);
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';
961 * Server version "1.99" means we can choose whether we use v1
962 * or v2 protocol. Choice is based on cfg.sshprot.
964 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
966 * This is a v2 server. Begin v2 protocol.
968 char *verstring = "SSH-2.0-PuTTY";
971 * Hash our version string and their version string.
973 sha_string(&exhash, verstring, strlen(verstring));
974 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
975 sprintf(vstring, "%s\n", verstring);
976 sprintf(vlog, "We claim version: %s", verstring);
978 logevent("Using SSH protocol version 2");
979 s_write(vstring, strlen(vstring));
980 ssh_protocol = ssh2_protocol;
982 s_rdpkt = ssh2_rdpkt;
985 * This is a v1 server. Begin v1 protocol.
987 sprintf(vstring, "SSH-%s-PuTTY\n",
988 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
989 sprintf(vlog, "We claim version: %s", vstring);
990 vlog[strcspn(vlog, "\r\n")] = '\0';
992 logevent("Using SSH protocol version 1");
993 s_write(vstring, strlen(vstring));
994 ssh_protocol = ssh1_protocol;
996 s_rdpkt = ssh1_rdpkt;
1003 * Handle the key exchange and user authentication phases.
1005 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1008 unsigned char *rsabuf, *keystr1, *keystr2;
1009 unsigned char cookie[8];
1010 struct RSAKey servkey, hostkey;
1011 struct MD5Context md5c;
1012 static unsigned long supported_ciphers_mask, supported_auths_mask;
1013 static int tried_publickey;
1014 static unsigned char session_id[16];
1019 if (!ispkt) crWaitUntil(ispkt);
1021 if (pktin.type != SSH1_SMSG_PUBLIC_KEY)
1022 fatalbox("Public key packet not received");
1024 logevent("Received public keys");
1026 memcpy(cookie, pktin.body, 8);
1028 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1029 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1032 * Hash the host key and print the hash in the log box. Just as
1033 * a last resort in case the registry's host key checking is
1034 * compromised, we'll allow the user some ability to verify
1038 MD5Update(&md5c, keystr2, hostkey.bytes);
1039 MD5Final(session_id, &md5c);
1043 logevent("Host key MD5 is:");
1044 strcpy(logmsg, " ");
1045 for (i = 0; i < 16; i++)
1046 sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
1050 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1051 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1054 MD5Update(&md5c, keystr2, hostkey.bytes);
1055 MD5Update(&md5c, keystr1, servkey.bytes);
1056 MD5Update(&md5c, pktin.body, 8);
1057 MD5Final(session_id, &md5c);
1059 for (i=0; i<32; i++)
1060 session_key[i] = random_byte();
1062 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1064 rsabuf = malloc(len);
1066 fatalbox("Out of memory");
1069 * Verify the host key.
1073 * First format the key into a string.
1075 int len = rsastr_len(&hostkey);
1076 char *keystr = malloc(len);
1078 fatalbox("Out of memory");
1079 rsastr_fmt(keystr, &hostkey);
1080 verify_ssh_host_key(savedhost, keystr);
1084 for (i=0; i<32; i++) {
1085 rsabuf[i] = session_key[i];
1087 rsabuf[i] ^= session_id[i];
1090 if (hostkey.bytes > servkey.bytes) {
1091 rsaencrypt(rsabuf, 32, &servkey);
1092 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1094 rsaencrypt(rsabuf, 32, &hostkey);
1095 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1098 logevent("Encrypted session key");
1100 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1101 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1103 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1104 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1105 cipher_type = SSH_CIPHER_3DES;
1107 switch (cipher_type) {
1108 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1109 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1110 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1113 send_packet(SSH1_CMSG_SESSION_KEY,
1114 PKT_CHAR, cipher_type,
1115 PKT_DATA, cookie, 8,
1116 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1117 PKT_DATA, rsabuf, len,
1121 logevent("Trying to enable encryption...");
1125 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
1126 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1128 cipher->sesskey(session_key);
1132 if (pktin.type != SSH1_SMSG_SUCCESS)
1133 fatalbox("Encryption not successfully enabled");
1135 logevent("Successfully started encryption");
1139 static char username[100];
1142 if (!(flags & FLAG_CONNECTION) && !*cfg.username) {
1143 c_write("login as: ", 10);
1145 crWaitUntil(!ispkt);
1146 while (inlen--) switch (c = *in++) {
1153 c_write("\b \b", 3);
1159 c_write("\b \b", 3);
1168 if (((c >= ' ' && c <= '~') ||
1169 ((unsigned char)c >= 160)) && pos < 40) {
1170 username[pos++] = c;
1177 username[strcspn(username, "\n\r")] = '\0';
1180 strncpy(username, cfg.username, 99);
1181 username[99] = '\0';
1182 if (flags & FLAG_VERBOSE) {
1183 sprintf(stuff, "Sent username \"%s\".\r\n", username);
1184 c_write(stuff, strlen(stuff));
1188 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1190 char userlog[20+sizeof(username)];
1191 sprintf(userlog, "Sent username \"%s\"", username);
1198 tried_publickey = 0;
1200 while (pktin.type == SSH1_SMSG_FAILURE) {
1201 static char password[100];
1204 static int pwpkt_type;
1206 * Show password prompt, having first obtained it via a TIS
1207 * or CryptoCard exchange if we're doing TIS or CryptoCard
1210 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1211 if (*cfg.keyfile && !tried_publickey)
1212 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1214 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD && !FLAG_WINDOWED) {
1216 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1217 if (!ssh_get_password(prompt, password, sizeof(password))) {
1219 * get_password failed to get a password (for
1220 * example because one was supplied on the command
1221 * line which has already failed to work).
1224 logevent("No more passwords to try");
1225 ssh_state = SSH_STATE_CLOSED;
1230 if (pktin.type == SSH1_SMSG_FAILURE &&
1232 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1233 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1234 logevent("Requested TIS authentication");
1235 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1237 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1238 logevent("TIS authentication declined");
1239 c_write("TIS authentication refused.\r\n", 29);
1241 int challengelen = ((pktin.body[0] << 24) |
1242 (pktin.body[1] << 16) |
1243 (pktin.body[2] << 8) |
1245 logevent("Received TIS challenge");
1246 c_write(pktin.body+4, challengelen);
1249 if (pktin.type == SSH1_SMSG_FAILURE &&
1251 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1252 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1253 logevent("Requested CryptoCard authentication");
1254 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1256 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1257 logevent("CryptoCard authentication declined");
1258 c_write("CryptoCard authentication refused.\r\n", 29);
1260 int challengelen = ((pktin.body[0] << 24) |
1261 (pktin.body[1] << 16) |
1262 (pktin.body[2] << 8) |
1264 logevent("Received CryptoCard challenge");
1265 c_write(pktin.body+4, challengelen);
1266 c_write("\r\nResponse : ", 13);
1269 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD)
1270 c_write("password: ", 10);
1271 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1272 if (flags & FLAG_VERBOSE)
1273 c_write("Trying public key authentication.\r\n", 35);
1274 if (!rsakey_encrypted(cfg.keyfile)) {
1275 if (flags & FLAG_VERBOSE)
1276 c_write("No passphrase required.\r\n", 25);
1279 c_write("passphrase: ", 12);
1284 crWaitUntil(!ispkt);
1285 while (inlen--) switch (c = *in++) {
1302 if (((c >= ' ' && c <= '~') ||
1303 ((unsigned char)c >= 160)) && pos < sizeof(password))
1304 password[pos++] = c;
1313 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1315 * Try public key authentication with the specified
1318 static struct RSAKey pubkey;
1319 static Bignum challenge, response;
1321 static unsigned char buffer[32];
1323 tried_publickey = 1;
1324 i = loadrsakey(cfg.keyfile, &pubkey, password);
1326 c_write("Couldn't load public key from ", 30);
1327 c_write(cfg.keyfile, strlen(cfg.keyfile));
1328 c_write(".\r\n", 3);
1329 continue; /* go and try password */
1332 c_write("Wrong passphrase.\r\n", 19);
1333 tried_publickey = 0;
1334 continue; /* try again */
1338 * Send a public key attempt.
1340 send_packet(SSH1_CMSG_AUTH_RSA,
1341 PKT_BIGNUM, pubkey.modulus, PKT_END);
1344 if (pktin.type == SSH1_SMSG_FAILURE) {
1345 if (flags & FLAG_VERBOSE)
1346 c_write("Server refused our public key.\r\n", 32);
1347 continue; /* go and try password */
1349 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE)
1350 fatalbox("Bizarre response to offer of public key");
1351 ssh1_read_bignum(pktin.body, &challenge);
1352 response = rsadecrypt(challenge, &pubkey);
1353 freebn(pubkey.private_exponent); /* burn the evidence */
1355 for (i = 0; i < 32; i += 2) {
1356 buffer[i] = response[16-i/2] >> 8;
1357 buffer[i+1] = response[16-i/2] & 0xFF;
1361 MD5Update(&md5c, buffer, 32);
1362 MD5Update(&md5c, session_id, 16);
1363 MD5Final(buffer, &md5c);
1365 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1366 PKT_DATA, buffer, 16, PKT_END);
1369 if (pktin.type == SSH1_SMSG_FAILURE) {
1370 if (flags & FLAG_VERBOSE)
1371 c_write("Failed to authenticate with our public key.\r\n",
1373 continue; /* go and try password */
1374 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1375 fatalbox("Bizarre response to RSA authentication response");
1378 break; /* we're through! */
1380 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1382 logevent("Sent password");
1383 memset(password, 0, strlen(password));
1385 if (pktin.type == SSH1_SMSG_FAILURE) {
1386 if (flags & FLAG_VERBOSE)
1387 c_write("Access denied\r\n", 15);
1388 logevent("Authentication refused");
1389 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1390 logevent("Received disconnect request");
1391 ssh_state = SSH_STATE_CLOSED;
1393 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1394 fatalbox("Strange packet received, type %d", pktin.type);
1398 logevent("Authentication successful");
1403 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1408 while (!do_ssh1_login(in, inlen, ispkt)) {
1411 if (ssh_state == SSH_STATE_CLOSED)
1415 send_packet(SSH1_CMSG_REQUEST_PTY,
1416 PKT_STR, cfg.termtype,
1417 PKT_INT, rows, PKT_INT, cols,
1418 PKT_INT, 0, PKT_INT, 0,
1421 ssh_state = SSH_STATE_INTERMED;
1422 do { crReturnV; } while (!ispkt);
1423 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1424 fatalbox("Protocol confusion");
1425 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1426 c_write("Server refused to allocate pty\r\n", 32);
1428 logevent("Allocated pty");
1431 if (*cfg.remote_cmd)
1432 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1434 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1435 logevent("Started session");
1437 ssh_state = SSH_STATE_SESSION;
1445 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1446 pktin.type == SSH1_SMSG_STDERR_DATA) {
1447 long len = GET_32BIT(pktin.body);
1448 c_write(pktin.body+4, len);
1449 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1450 ssh_state = SSH_STATE_CLOSED;
1451 logevent("Received disconnect request");
1452 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
1453 /* may be from EXEC_SHELL on some servers */
1454 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1455 /* may be from EXEC_SHELL on some servers
1456 * if no pty is available or in other odd cases. Ignore */
1457 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1458 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
1460 fatalbox("Strange packet received: type %d", pktin.type);
1463 send_packet(SSH1_CMSG_STDIN_DATA,
1464 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
1472 * Utility routine for decoding comma-separated strings in KEXINIT.
1474 int in_commasep_string(char *needle, char *haystack, int haylen) {
1475 int needlen = strlen(needle);
1478 * Is it at the start of the string?
1480 if (haylen >= needlen && /* haystack is long enough */
1481 !memcmp(needle, haystack, needlen) && /* initial match */
1482 (haylen == needlen || haystack[needlen] == ',')
1483 /* either , or EOS follows */
1487 * If not, search for the next comma and resume after that.
1488 * If no comma found, terminate.
1490 while (haylen > 0 && *haystack != ',')
1491 haylen--, haystack++;
1494 haylen--, haystack++; /* skip over comma itself */
1499 * SSH2 key creation method.
1501 void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1503 /* First 20 bytes. */
1506 SHA_Bytes(&s, H, 20);
1507 SHA_Bytes(&s, &chr, 1);
1508 SHA_Bytes(&s, H, 20);
1509 SHA_Final(&s, keyspace);
1510 /* Next 20 bytes. */
1513 SHA_Bytes(&s, H, 20);
1514 SHA_Bytes(&s, keyspace, 20);
1515 SHA_Final(&s, keyspace+20);
1519 * Handle the SSH2 transport layer.
1521 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
1525 static Bignum e, f, K;
1526 static struct ssh_cipher *cscipher_tobe = NULL;
1527 static struct ssh_cipher *sccipher_tobe = NULL;
1528 static struct ssh_mac *csmac_tobe = NULL;
1529 static struct ssh_mac *scmac_tobe = NULL;
1530 static struct ssh_compress *cscomp_tobe = NULL;
1531 static struct ssh_compress *sccomp_tobe = NULL;
1532 static char *hostkeydata, *sigdata, *keystr;
1533 static int hostkeylen, siglen;
1534 static unsigned char exchange_hash[20];
1535 static unsigned char keyspace[40];
1542 * Construct and send our key exchange packet.
1544 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1545 for (i = 0; i < 16; i++)
1546 ssh2_pkt_addbyte((unsigned char)random_byte());
1547 /* List key exchange algorithms. */
1548 ssh2_pkt_addstring_start();
1549 for (i = 0; i < lenof(kex_algs); i++) {
1550 ssh2_pkt_addstring_str(kex_algs[i]->name);
1551 if (i < lenof(kex_algs)-1)
1552 ssh2_pkt_addstring_str(",");
1554 /* List server host key algorithms. */
1555 ssh2_pkt_addstring_start();
1556 for (i = 0; i < lenof(hostkey_algs); i++) {
1557 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1558 if (i < lenof(hostkey_algs)-1)
1559 ssh2_pkt_addstring_str(",");
1561 /* List client->server encryption algorithms. */
1562 ssh2_pkt_addstring_start();
1563 for (i = 0; i < lenof(ciphers); i++) {
1564 ssh2_pkt_addstring_str(ciphers[i]->name);
1565 if (i < lenof(ciphers)-1)
1566 ssh2_pkt_addstring_str(",");
1568 /* List server->client encryption algorithms. */
1569 ssh2_pkt_addstring_start();
1570 for (i = 0; i < lenof(ciphers); i++) {
1571 ssh2_pkt_addstring_str(ciphers[i]->name);
1572 if (i < lenof(ciphers)-1)
1573 ssh2_pkt_addstring_str(",");
1575 /* List client->server MAC algorithms. */
1576 ssh2_pkt_addstring_start();
1577 for (i = 0; i < lenof(macs); i++) {
1578 ssh2_pkt_addstring_str(macs[i]->name);
1579 if (i < lenof(macs)-1)
1580 ssh2_pkt_addstring_str(",");
1582 /* List server->client MAC algorithms. */
1583 ssh2_pkt_addstring_start();
1584 for (i = 0; i < lenof(macs); i++) {
1585 ssh2_pkt_addstring_str(macs[i]->name);
1586 if (i < lenof(macs)-1)
1587 ssh2_pkt_addstring_str(",");
1589 /* List client->server compression algorithms. */
1590 ssh2_pkt_addstring_start();
1591 for (i = 0; i < lenof(compressions); i++) {
1592 ssh2_pkt_addstring_str(compressions[i]->name);
1593 if (i < lenof(compressions)-1)
1594 ssh2_pkt_addstring_str(",");
1596 /* List server->client compression algorithms. */
1597 ssh2_pkt_addstring_start();
1598 for (i = 0; i < lenof(compressions); i++) {
1599 ssh2_pkt_addstring_str(compressions[i]->name);
1600 if (i < lenof(compressions)-1)
1601 ssh2_pkt_addstring_str(",");
1603 /* List client->server languages. Empty list. */
1604 ssh2_pkt_addstring_start();
1605 /* List server->client languages. Empty list. */
1606 ssh2_pkt_addstring_start();
1607 /* First KEX packet does _not_ follow, because we're not that brave. */
1608 ssh2_pkt_addbool(FALSE);
1610 ssh2_pkt_adduint32(0);
1611 sha_string(&exhash, pktout.data+5, pktout.length-5);
1614 if (!ispkt) crWaitUntil(ispkt);
1615 sha_string(&exhash, pktin.data+5, pktin.length-5);
1618 * Now examine the other side's KEXINIT to see what we're up
1621 if (pktin.type != SSH2_MSG_KEXINIT) {
1622 fatalbox("expected key exchange packet from server");
1624 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1625 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1626 pktin.savedpos += 16; /* skip garbage cookie */
1627 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1628 for (i = 0; i < lenof(kex_algs); i++) {
1629 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1634 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1635 for (i = 0; i < lenof(hostkey_algs); i++) {
1636 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1637 hostkey = hostkey_algs[i];
1641 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1642 for (i = 0; i < lenof(ciphers); i++) {
1643 if (in_commasep_string(ciphers[i]->name, str, len)) {
1644 cscipher_tobe = ciphers[i];
1648 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1649 for (i = 0; i < lenof(ciphers); i++) {
1650 if (in_commasep_string(ciphers[i]->name, str, len)) {
1651 sccipher_tobe = ciphers[i];
1655 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1656 for (i = 0; i < lenof(macs); i++) {
1657 if (in_commasep_string(macs[i]->name, str, len)) {
1658 csmac_tobe = macs[i];
1662 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1663 for (i = 0; i < lenof(macs); i++) {
1664 if (in_commasep_string(macs[i]->name, str, len)) {
1665 scmac_tobe = macs[i];
1669 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1670 for (i = 0; i < lenof(compressions); i++) {
1671 if (in_commasep_string(compressions[i]->name, str, len)) {
1672 cscomp_tobe = compressions[i];
1676 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1677 for (i = 0; i < lenof(compressions); i++) {
1678 if (in_commasep_string(compressions[i]->name, str, len)) {
1679 sccomp_tobe = compressions[i];
1685 * Currently we only support Diffie-Hellman and DSS, so let's
1686 * bomb out if those aren't selected.
1688 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss)
1689 fatalbox("internal fault: chaos in SSH 2 transport layer");
1692 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1695 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
1700 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
1701 fatalbox("expected key exchange packet from server");
1703 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
1704 f = ssh2_pkt_getmp();
1705 ssh2_pkt_getstring(&sigdata, &siglen);
1709 sha_string(&exhash, hostkeydata, hostkeylen);
1710 sha_mpint(&exhash, e);
1711 sha_mpint(&exhash, f);
1712 sha_mpint(&exhash, K);
1713 SHA_Final(&exhash, exchange_hash);
1716 debug(("Exchange hash is:\r\n"));
1717 for (i = 0; i < 20; i++)
1718 debug((" %02x", exchange_hash[i]));
1722 hostkey->setkey(hostkeydata, hostkeylen);
1723 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20))
1724 fatalbox("Server failed host key check");
1727 * Expect SSH2_MSG_NEWKEYS from server.
1730 if (pktin.type != SSH2_MSG_NEWKEYS)
1731 fatalbox("expected new-keys packet from server");
1734 * Authenticate remote host: verify host key. (We've already
1735 * checked the signature of the exchange hash.)
1737 keystr = hostkey->fmtkey();
1738 verify_ssh_host_key(savedhost, keystr);
1742 * Send SSH2_MSG_NEWKEYS.
1744 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
1748 * Create and initialise session keys.
1750 cscipher = cscipher_tobe;
1751 sccipher = sccipher_tobe;
1754 cscomp = cscomp_tobe;
1755 sccomp = sccomp_tobe;
1757 * Set IVs after keys.
1759 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
1760 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
1761 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
1762 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
1763 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
1764 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
1767 * Now we're encrypting. Begin returning 1 to the protocol main
1768 * function so that other things can run on top of the
1769 * transport. If we ever see a KEXINIT, we must go back to the
1774 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
1775 goto begin_key_exchange;
1781 * SSH2: remote identifier for the main session channel.
1783 static unsigned long ssh_remote_channel;
1786 * Handle the SSH2 userauth and connection layers.
1788 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
1790 static unsigned long remote_winsize;
1791 static unsigned long remote_maxpkt;
1796 * Request userauth protocol, and await a response to it.
1798 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
1799 ssh2_pkt_addstring("ssh-userauth");
1801 crWaitUntilV(ispkt);
1802 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT)
1803 fatalbox("Server refused user authentication protocol");
1806 * FIXME: currently we support only password authentication.
1807 * (This places us technically in violation of the SSH2 spec.
1808 * We must fix this.)
1812 * Get a username and a password.
1814 static char username[100];
1815 static char password[100];
1819 if ((flags & FLAG_CONNECTION) && !*cfg.username) {
1820 c_write("login as: ", 10);
1822 crWaitUntilV(!ispkt);
1823 while (inlen--) switch (c = *in++) {
1830 c_write("\b \b", 3);
1836 c_write("\b \b", 3);
1845 if (((c >= ' ' && c <= '~') ||
1846 ((unsigned char)c >= 160)) && pos < 40) {
1847 username[pos++] = c;
1854 username[strcspn(username, "\n\r")] = '\0';
1857 strncpy(username, cfg.username, 99);
1858 username[99] = '\0';
1859 if (flags & FLAG_VERBOSE) {
1860 sprintf(stuff, "Using username \"%s\".\r\n", username);
1861 c_write(stuff, strlen(stuff));
1865 if (!(flags & FLAG_WINDOWED)) {
1867 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1868 if (!ssh_get_password(prompt, password, sizeof(password))) {
1870 * get_password failed to get a password (for
1871 * example because one was supplied on the command
1872 * line which has already failed to work).
1875 logevent("No more passwords to try");
1876 ssh_state = SSH_STATE_CLOSED;
1880 c_write("password: ", 10);
1884 crWaitUntilV(!ispkt);
1885 while (inlen--) switch (c = *in++) {
1902 if (((c >= ' ' && c <= '~') ||
1903 ((unsigned char)c >= 160)) && pos < 40)
1904 password[pos++] = c;
1911 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
1912 ssh2_pkt_addstring(username);
1913 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1914 ssh2_pkt_addstring("password");
1915 ssh2_pkt_addbool(FALSE);
1916 ssh2_pkt_addstring(password);
1919 crWaitUntilV(ispkt);
1920 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
1921 c_write("Access denied\r\n", 15);
1922 logevent("Authentication refused");
1928 * Now we're authenticated for the connection protocol. The
1929 * connection protocol will automatically have started at this
1930 * point; there's no need to send SERVICE_REQUEST.
1934 * So now create a channel with a session in it.
1936 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
1937 ssh2_pkt_addstring("session");
1938 ssh2_pkt_adduint32(100); /* as good as any */
1939 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big window which we ignore */
1940 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big max pkt size */
1942 crWaitUntilV(ispkt);
1943 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
1944 fatalbox("Server refused to open a session");
1945 /* FIXME: error data comes back in FAILURE packet */
1947 if (ssh2_pkt_getuint32() != 100) {
1948 fatalbox("Server's channel confirmation cited wrong channel");
1950 ssh_remote_channel = ssh2_pkt_getuint32();
1951 remote_winsize = ssh2_pkt_getuint32();
1952 remote_maxpkt = ssh2_pkt_getuint32();
1953 logevent("Opened channel for session");
1956 * Now allocate a pty for the session.
1958 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
1959 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
1960 ssh2_pkt_addstring("pty-req");
1961 ssh2_pkt_addbool(1); /* want reply */
1962 ssh2_pkt_addstring(cfg.termtype);
1963 ssh2_pkt_adduint32(cols);
1964 ssh2_pkt_adduint32(rows);
1965 ssh2_pkt_adduint32(0); /* pixel width */
1966 ssh2_pkt_adduint32(0); /* pixel height */
1967 ssh2_pkt_addstring_start();
1968 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1971 do { /* FIXME: pay attention to these */
1972 crWaitUntilV(ispkt);
1973 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1975 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
1976 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
1977 fatalbox("Server got confused by pty request");
1979 c_write("Server refused to allocate pty\r\n", 32);
1981 logevent("Allocated pty");
1987 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
1988 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
1989 ssh2_pkt_addstring("shell");
1990 ssh2_pkt_addbool(1); /* want reply */
1992 do { /* FIXME: pay attention to these */
1993 crWaitUntilV(ispkt);
1994 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1995 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
1996 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
1997 fatalbox("Server got confused by shell request");
1999 fatalbox("Server refused to start a shell");
2001 logevent("Started a shell");
2011 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2012 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2015 if (ssh2_pkt_getuint32() != 100)
2016 continue; /* wrong channel */
2017 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2018 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2019 continue; /* extended but not stderr */
2020 ssh2_pkt_getstring(&data, &length);
2022 c_write(data, length);
2023 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2024 ssh_state = SSH_STATE_CLOSED;
2025 logevent("Received disconnect request");
2026 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2027 continue; /* exit status et al; ignore (FIXME?) */
2028 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2029 continue; /* ignore for now (FIXME!) */
2031 fatalbox("Strange packet received: type %d", pktin.type);
2034 /* FIXME: for now, ignore window size */
2035 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2036 ssh2_pkt_adduint32(ssh_remote_channel);
2037 ssh2_pkt_addstring_start();
2038 ssh2_pkt_addstring_data(in, inlen);
2047 * Handle the top-level SSH2 protocol.
2049 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2051 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2053 do_ssh2_authconn(in, inlen, ispkt);
2057 * Called to set up the connection. Will arrange for WM_NETEVENT
2058 * messages to be passed to the specified window, whose window
2059 * procedure should then call telnet_msg().
2061 * Returns an error message, or NULL on success.
2063 static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
2067 if(crypto_startup() == 0)
2068 return "Microsoft high encryption pack not installed!";
2071 p = connect_to_host(host, port, realhost);
2076 return "Protocol initialisation error";
2078 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
2079 switch (WSAGetLastError()) {
2080 case WSAENETDOWN: return "Network is down";
2081 default: return "WSAAsyncSelect(): unknown error";
2088 * Process a WM_NETEVENT message. Will return 0 if the connection
2089 * has closed, or <0 for a socket error.
2091 static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2096 * Because reading less than the whole of the available pending
2097 * data can generate an FD_READ event, we need to allow for the
2098 * possibility that FD_READ may arrive with FD_CLOSE already in
2099 * the queue; so it's possible that we can get here even with s
2100 * invalid. If so, we return 1 and don't worry about it.
2102 if (s == INVALID_SOCKET)
2105 if (WSAGETSELECTERROR(lParam) != 0)
2106 return -WSAGETSELECTERROR(lParam);
2108 switch (WSAGETSELECTEVENT(lParam)) {
2111 ret = recv(s, buf, sizeof(buf), 0);
2112 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2114 if (ret < 0) /* any _other_ error */
2115 return -10000-WSAGetLastError();
2120 ssh_gotdata (buf, ret);
2121 if (ssh_state == SSH_STATE_CLOSED) {
2128 return 1; /* shouldn't happen, but WTF */
2132 * Called to send data down the Telnet connection.
2134 static void ssh_send (char *buf, int len) {
2135 if (s == INVALID_SOCKET)
2138 ssh_protocol(buf, len, 0);
2142 * Called to set the size of the window from Telnet's POV.
2144 static void ssh_size(void) {
2145 switch (ssh_state) {
2146 case SSH_STATE_BEFORE_SIZE:
2147 case SSH_STATE_CLOSED:
2148 break; /* do nothing */
2149 case SSH_STATE_INTERMED:
2150 size_needed = TRUE; /* buffer for later */
2152 case SSH_STATE_SESSION:
2154 send_packet(SSH1_CMSG_WINDOW_SIZE,
2155 PKT_INT, rows, PKT_INT, cols,
2156 PKT_INT, 0, PKT_INT, 0, PKT_END);
2162 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2163 * can send an EOF and collect resulting output (e.g. `plink
2166 static void ssh_special (Telnet_Special code) {
2167 if (code == TS_EOF) {
2168 if (ssh_version = 1) {
2169 send_packet(SSH1_CMSG_EOF, PKT_END);
2171 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
2172 ssh2_pkt_adduint32(ssh_remote_channel);
2182 * Read and decrypt one incoming SSH packet.
2183 * (only used by pSCP)
2185 static void get_packet(void)
2187 unsigned char buf[4096], *p;
2194 while ((to_read = s_rdpkt(&p, &len)) > 0) {
2195 if (to_read > sizeof(buf)) to_read = sizeof(buf);
2196 len = s_read(buf, to_read);
2197 if (len != to_read) {
2209 * Receive a block of data over the SSH link. Block until
2210 * all data is available. Return nr of bytes read (0 if lost connection).
2211 * (only used by pSCP)
2213 int ssh_scp_recv(unsigned char *buf, int len)
2215 static int pending_input_len = 0;
2216 static unsigned char *pending_input_ptr;
2219 if (pending_input_len >= to_read) {
2220 memcpy(buf, pending_input_ptr, to_read);
2221 pending_input_ptr += to_read;
2222 pending_input_len -= to_read;
2226 if (pending_input_len > 0) {
2227 memcpy(buf, pending_input_ptr, pending_input_len);
2228 buf += pending_input_len;
2229 to_read -= pending_input_len;
2230 pending_input_len = 0;
2233 if (s == INVALID_SOCKET)
2235 while (to_read > 0) {
2237 if (s == INVALID_SOCKET)
2239 if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
2240 int plen = GET_32BIT(pktin.body);
2241 if (plen <= to_read) {
2242 memcpy(buf, pktin.body + 4, plen);
2246 memcpy(buf, pktin.body + 4, to_read);
2247 pending_input_len = plen - to_read;
2248 pending_input_ptr = pktin.body + 4 + to_read;
2251 } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
2252 int plen = GET_32BIT(pktin.body);
2253 fwrite(pktin.body + 4, plen, 1, stderr);
2254 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2255 logevent("Received disconnect request");
2256 } else if (pktin.type == SSH1_SMSG_SUCCESS ||
2257 pktin.type == SSH1_SMSG_FAILURE) {
2259 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2261 sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
2263 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2264 logevent("Closing connection");
2268 fatalbox("Strange packet received: type %d", pktin.type);
2276 * Send a block of data over the SSH link.
2277 * Block until all data is sent.
2278 * (only used by pSCP)
2280 void ssh_scp_send(unsigned char *buf, int len)
2282 if (s == INVALID_SOCKET)
2284 send_packet(SSH1_CMSG_STDIN_DATA,
2285 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2289 * Send an EOF notification to the server.
2290 * (only used by pSCP)
2292 void ssh_scp_send_eof(void)
2294 if (s == INVALID_SOCKET)
2296 send_packet(SSH1_CMSG_EOF, PKT_END);
2300 * Set up the connection, login on the remote host and
2301 * start execution of a command.
2302 * Returns an error message, or NULL on success.
2303 * (only used by pSCP)
2305 char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
2310 if (crypto_startup() == 0)
2311 return "Microsoft high encryption pack not installed!";
2314 p = connect_to_host(host, port, realhost);
2321 return "Protocol initialisation error";
2323 /* Exchange keys and login */
2326 if (s == INVALID_SOCKET)
2327 return "Connection closed by remote host";
2328 } while (!do_ssh1_login(NULL, 0, 1));
2330 if (ssh_state == SSH_STATE_CLOSED) {
2333 return "Session initialisation error";
2336 /* Execute command */
2337 sprintf(buf, "Sending command: %.100s", cmd);
2339 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2344 static SOCKET ssh_socket(void) { return s; }
2346 static int ssh_sendok(void) { return ssh_send_ok; }
2348 Backend ssh_backend = {