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;
168 SSH_STATE_BEFORE_SIZE,
172 } ssh_state = SSH_STATE_BEFORE_SIZE;
174 static int size_needed = FALSE;
176 static void s_write (char *buf, int len) {
178 int i = send (s, buf, len, 0);
181 fatalbox("Lost connection while sending");
187 static int s_read (char *buf, int len) {
190 int i = recv (s, buf, len, 0);
193 len -= i, buf += i, ret += i;
200 static void c_write (char *buf, int len) {
201 if (!(flags & FLAG_CONNECTION)) {
203 for (i = 0; i < len; i++)
205 fputc(buf[i], stderr);
221 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
222 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
224 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
225 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
226 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
227 static void ssh_size(void);
229 static int (*s_rdpkt)(unsigned char **data, int *datalen);
232 * Collect incoming data in the incoming packet buffer.
233 * Decipher and verify the packet when it is completely read.
234 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
235 * Update the *data and *datalen variables.
236 * Return the additional nr of bytes needed, or 0 when
237 * a complete packet is available.
239 static int ssh1_rdpkt(unsigned char **data, int *datalen)
241 static long len, pad, biglen, to_read;
242 static unsigned long realcrc, gotcrc;
243 static unsigned char *p;
253 for (i = len = 0; i < 4; i++) {
254 while ((*datalen) == 0)
256 len = (len << 8) + **data;
257 (*data)++, (*datalen)--;
261 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
262 len = 0x300; /* big enough to carry to end */
268 pktin.length = len - 5;
270 if (pktin.maxlen < biglen) {
271 pktin.maxlen = biglen;
272 pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
273 realloc(pktin.data, biglen+APIEXTRA));
275 fatalbox("Out of memory");
280 while (to_read > 0) {
283 while ((*datalen) == 0)
285 if (chunk > (*datalen))
287 memcpy(p, *data, chunk);
295 cipher->decrypt(pktin.data, biglen);
297 pktin.type = pktin.data[pad];
298 pktin.body = pktin.data + pad + 1;
300 realcrc = crc32(pktin.data, biglen-4);
301 gotcrc = GET_32BIT(pktin.data+biglen-4);
302 if (gotcrc != realcrc) {
303 fatalbox("Incorrect CRC received on packet");
306 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
307 pktin.type == SSH1_SMSG_STDERR_DATA ||
308 pktin.type == SSH1_MSG_DEBUG ||
309 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE) {
310 long strlen = GET_32BIT(pktin.body);
311 if (strlen + 4 != pktin.length)
312 fatalbox("Received data packet with bogus string length");
315 if (pktin.type == SSH1_MSG_DEBUG) {
316 /* log debug message */
318 int strlen = GET_32BIT(pktin.body);
319 strcpy(buf, "Remote: ");
320 if (strlen > 70) strlen = 70;
321 memcpy(buf+8, pktin.body+4, strlen);
322 buf[8+strlen] = '\0';
325 } else if (pktin.type == SSH1_MSG_IGNORE) {
333 static int ssh2_rdpkt(unsigned char **data, int *datalen)
335 static long len, pad, payload, packetlen, maclen;
337 static int cipherblk;
338 static unsigned long incoming_sequence = 0;
348 cipherblk = cipher->blksize;
354 if (pktin.maxlen < cipherblk) {
355 pktin.maxlen = cipherblk;
356 pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
357 realloc(pktin.data, cipherblk+APIEXTRA));
359 fatalbox("Out of memory");
363 * Acquire and decrypt the first block of the packet. This will
364 * contain the length and padding details.
366 for (i = len = 0; i < cipherblk; i++) {
367 while ((*datalen) == 0)
368 crReturn(cipherblk-i);
369 pktin.data[i] = *(*data)++;
373 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
378 sccipher->decrypt(pktin.data, cipherblk);
381 * Now get the length and padding figures.
383 len = GET_32BIT(pktin.data);
387 * This enables us to deduce the payload length.
389 payload = len - pad - 1;
391 pktin.length = payload + 5;
394 * So now we can work out the total packet length.
397 maclen = scmac ? scmac->len : 0;
400 * Adjust memory allocation if packet is too big.
402 if (pktin.maxlen < packetlen) {
403 pktin.maxlen = packetlen;
404 pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) :
405 realloc(pktin.data, packetlen+APIEXTRA));
407 fatalbox("Out of memory");
411 * Read and decrypt the remainder of the packet.
413 for (i = cipherblk; i < packetlen + maclen; i++) {
414 while ((*datalen) == 0)
415 crReturn(packetlen + maclen - i);
416 pktin.data[i] = *(*data)++;
419 /* Decrypt everything _except_ the MAC. */
421 sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
424 debug(("Got packet len=%d pad=%d\r\n", len, pad));
425 for (i = 0; i < packetlen; i++)
426 debug((" %02x", (unsigned char)pktin.data[i]));
433 if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence))
434 fatalbox("Incorrect MAC received on packet");
435 incoming_sequence++; /* whether or not we MACed */
438 pktin.type = pktin.data[5];
440 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
441 goto next_packet; /* FIXME: print DEBUG message */
446 static void ssh_gotdata(unsigned char *data, int datalen)
448 while (datalen > 0) {
449 if ( s_rdpkt(&data, &datalen) == 0 ) {
450 ssh_protocol(NULL, 0, 1);
451 if (ssh_state == SSH_STATE_CLOSED) {
459 static void s_wrpkt_start(int type, int len) {
462 len += 5; /* type and CRC */
466 pktout.length = len-5;
467 if (pktout.maxlen < biglen) {
468 pktout.maxlen = biglen;
470 /* Allocate enough buffer space for extra block
471 * for MS CryptEncrypt() */
472 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
473 realloc(pktout.data, biglen+12));
475 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
476 realloc(pktout.data, biglen+4));
479 fatalbox("Out of memory");
483 pktout.body = pktout.data+4+pad+1;
486 static void s_wrpkt(void) {
487 int pad, len, biglen, i;
490 len = pktout.length + 5; /* type and CRC */
494 pktout.body[-1] = pktout.type;
495 for (i=0; i<pad; i++)
496 pktout.data[i+4] = random_byte();
497 crc = crc32(pktout.data+4, biglen-4);
498 PUT_32BIT(pktout.data+biglen, crc);
499 PUT_32BIT(pktout.data, len);
502 cipher->encrypt(pktout.data+4, biglen);
504 s_write(pktout.data, biglen+4);
508 * Construct a packet with the specified contents and
509 * send it to the server.
511 static void send_packet(int pkttype, ...)
514 unsigned char *p, *argp, argchar;
515 unsigned long argint;
516 int pktlen, argtype, arglen;
521 va_start(args, pkttype);
522 while ((argtype = va_arg(args, int)) != PKT_END) {
525 (void) va_arg(args, int);
529 (void) va_arg(args, char);
533 (void) va_arg(args, unsigned char *);
534 arglen = va_arg(args, int);
538 argp = va_arg(args, unsigned char *);
539 arglen = strlen(argp);
540 pktlen += 4 + arglen;
543 bn = va_arg(args, Bignum);
545 while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 )
547 pktlen += 2 + (i+7)/8;
555 s_wrpkt_start(pkttype, pktlen);
558 va_start(args, pkttype);
559 while ((argtype = va_arg(args, int)) != PKT_END) {
562 argint = va_arg(args, int);
563 PUT_32BIT(p, argint);
567 argchar = va_arg(args, unsigned char);
572 argp = va_arg(args, unsigned char *);
573 arglen = va_arg(args, int);
574 memcpy(p, argp, arglen);
578 argp = va_arg(args, unsigned char *);
579 arglen = strlen(argp);
580 PUT_32BIT(p, arglen);
581 memcpy(p + 4, argp, arglen);
585 bn = va_arg(args, Bignum);
587 while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 )
589 *p++ = (i >> 8) & 0xFF;
594 *p++ = bn[i/2+1] >> 8;
596 *p++ = bn[i/2+1] & 0xFF;
608 * Connect to specified host and port.
609 * Returns an error message, or NULL on success.
610 * Also places the canonical host name into `realhost'.
612 static char *connect_to_host(char *host, int port, char **realhost)
622 savedhost = malloc(1+strlen(host));
624 fatalbox("Out of memory");
625 strcpy(savedhost, host);
628 port = 22; /* default ssh port */
640 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
641 if ( (h = gethostbyname(host)) == NULL)
642 switch (WSAGetLastError()) {
643 case WSAENETDOWN: return "Network is down";
644 case WSAHOST_NOT_FOUND: case WSANO_DATA:
645 return "Host does not exist";
646 case WSATRY_AGAIN: return "Host not found";
647 default: return "gethostbyname: unknown error";
649 memcpy (&a, h->h_addr, sizeof(a));
650 *realhost = h->h_name;
661 s = socket(AF_INET, SOCK_STREAM, 0);
662 if (s == INVALID_SOCKET)
663 switch (WSAGetLastError()) {
664 case WSAENETDOWN: return "Network is down";
665 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
666 default: return "socket(): unknown error";
670 * Bind to local address.
672 addr.sin_family = AF_INET;
673 addr.sin_addr.s_addr = htonl(INADDR_ANY);
674 addr.sin_port = htons(0);
675 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
676 switch (WSAGetLastError()) {
677 case WSAENETDOWN: return "Network is down";
678 default: return "bind(): unknown error";
682 * Connect to remote address.
684 addr.sin_addr.s_addr = htonl(a);
685 addr.sin_port = htons((short)port);
686 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
687 switch (WSAGetLastError()) {
688 case WSAENETDOWN: return "Network is down";
689 case WSAECONNREFUSED: return "Connection refused";
690 case WSAENETUNREACH: return "Network is unreachable";
691 case WSAEHOSTUNREACH: return "No route to host";
692 default: return "connect(): unknown error";
696 send(s, "connect ", 8, 0);
697 send(s, FWhost, strlen(FWhost), 0);
700 sprintf(buf, " %d\n", FWport);
701 send (s, buf, strlen(buf), 0);
708 static int ssh_versioncmp(char *a, char *b) {
710 unsigned long av, bv;
712 av = strtoul(a, &ae, 10);
713 bv = strtoul(b, &be, 10);
714 if (av != bv) return (av < bv ? -1 : +1);
715 if (*ae == '.') ae++;
716 if (*be == '.') be++;
717 av = strtoul(ae, &ae, 10);
718 bv = strtoul(be, &be, 10);
719 if (av != bv) return (av < bv ? -1 : +1);
725 * Utility routine for putting an SSH-protocol `string' into a SHA
729 void sha_string(SHA_State *s, void *str, int len) {
730 unsigned char lenblk[4];
732 PUT_32BIT(lenblk, len);
733 if (!fp) fp = fopen("h:\\statham\\windows\\putty\\data","wb");
734 fwrite(lenblk, 4, 1, fp);
735 SHA_Bytes(s, lenblk, 4);
736 fwrite(str, len, 1, fp);
738 SHA_Bytes(s, str, len);
742 * SSH2 packet construction functions.
744 void ssh2_pkt_adddata(void *data, int len) {
745 pktout.length += len;
746 if (pktout.maxlen < pktout.length) {
747 pktout.maxlen = pktout.length + 256;
748 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
749 realloc(pktout.data, pktout.maxlen+APIEXTRA));
751 fatalbox("Out of memory");
753 memcpy(pktout.data+pktout.length-len, data, len);
755 void ssh2_pkt_addbyte(unsigned char byte) {
756 ssh2_pkt_adddata(&byte, 1);
758 void ssh2_pkt_init(int pkt_type) {
760 ssh2_pkt_addbyte((unsigned char)pkt_type);
762 void ssh2_pkt_addbool(unsigned char value) {
763 ssh2_pkt_adddata(&value, 1);
765 void ssh2_pkt_adduint32(unsigned long value) {
768 ssh2_pkt_adddata(x, 4);
770 void ssh2_pkt_addstring_start(void) {
771 ssh2_pkt_adduint32(0);
772 pktout.savedpos = pktout.length;
774 void ssh2_pkt_addstring_str(char *data) {
775 ssh2_pkt_adddata(data, strlen(data));
776 PUT_32BIT(pktout.data + pktout.savedpos - 4,
777 pktout.length - pktout.savedpos);
779 void ssh2_pkt_addstring_data(char *data, int len) {
780 ssh2_pkt_adddata(data, len);
781 PUT_32BIT(pktout.data + pktout.savedpos - 4,
782 pktout.length - pktout.savedpos);
784 void ssh2_pkt_addstring(char *data) {
785 ssh2_pkt_addstring_start();
786 ssh2_pkt_addstring_str(data);
788 char *ssh2_mpint_fmt(Bignum b, int *len) {
791 p = malloc(n * 2 + 1);
793 fatalbox("out of memory");
795 for (i = 0; i < n; i++) {
796 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
797 p[i*2+2] = (b[n-i] ) & 0xFF;
800 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
802 memmove(p, p+i, n*2+1-i);
806 void ssh2_pkt_addmp(Bignum b) {
809 p = ssh2_mpint_fmt(b, &len);
810 ssh2_pkt_addstring_start();
811 ssh2_pkt_addstring_data(p, len);
814 void ssh2_pkt_send(void) {
815 int cipherblk, maclen, padding, i;
816 static unsigned long outgoing_sequence = 0;
819 * Add padding. At least four bytes, and must also bring total
820 * length (minus MAC) up to a multiple of the block size.
822 cipherblk = cipher ? cipher->blksize : 8; /* block size */
823 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
825 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
826 pktout.data[4] = padding;
827 for (i = 0; i < padding; i++)
828 pktout.data[pktout.length + i] = random_byte();
829 PUT_32BIT(pktout.data, pktout.length + padding - 4);
831 csmac->generate(pktout.data, pktout.length + padding,
833 outgoing_sequence++; /* whether or not we MACed */
836 debug(("Sending packet len=%d\r\n", pktout.length+padding));
837 for (i = 0; i < pktout.length+padding; i++)
838 debug((" %02x", (unsigned char)pktout.data[i]));
843 cscipher->encrypt(pktout.data, pktout.length + padding);
844 maclen = csmac ? csmac->len : 0;
846 s_write(pktout.data, pktout.length + padding + maclen);
850 void bndebug(char *string, Bignum b) {
853 p = ssh2_mpint_fmt(b, &len);
854 debug(("%s", string));
855 for (i = 0; i < len; i++)
856 debug((" %02x", p[i]));
862 void sha_mpint(SHA_State *s, Bignum b) {
865 p = ssh2_mpint_fmt(b, &len);
866 sha_string(s, p, len);
871 * SSH2 packet decode functions.
873 unsigned long ssh2_pkt_getuint32(void) {
875 if (pktin.length - pktin.savedpos < 4)
876 return 0; /* arrgh, no way to decline (FIXME?) */
877 value = GET_32BIT(pktin.data+pktin.savedpos);
881 void ssh2_pkt_getstring(char **p, int *length) {
883 if (pktin.length - pktin.savedpos < 4)
885 *length = GET_32BIT(pktin.data+pktin.savedpos);
887 if (pktin.length - pktin.savedpos < *length)
889 *p = pktin.data+pktin.savedpos;
890 pktin.savedpos += *length;
892 Bignum ssh2_pkt_getmp(void) {
897 ssh2_pkt_getstring(&p, &length);
901 fatalbox("internal error: Can't handle negative mpints");
902 b = newbn((length+1)/2);
903 for (i = 0; i < length; i++) {
906 b[j/2+1] |= ((unsigned char)p[i]) << 8;
908 b[j/2+1] |= ((unsigned char)p[i]);
913 static int do_ssh_init(void) {
917 char vlog[sizeof(vstring)+20];
922 while (s_read(&c, 1) == 1) {
923 if (c == 'S' && i < 2) i++;
924 else if (c == 'S' && i == 2) i = 2;
925 else if (c == 'H' && i == 2) break;
929 if (s_read(&c,1) != 1 || c != 'S') return 0;
930 if (s_read(&c,1) != 1 || c != 'S') return 0;
931 if (s_read(&c,1) != 1 || c != 'H') return 0;
933 strcpy(vstring, "SSH-");
935 if (s_read(&c,1) != 1 || c != '-') return 0;
938 if (s_read(&c,1) != 1)
940 if (vsp < vstring+sizeof(vstring)-1)
946 } else if (i < sizeof(version)-1)
954 sprintf(vlog, "Server version: %s", vstring);
955 vlog[strcspn(vlog, "\r\n")] = '\0';
958 if (ssh_versioncmp(version, "2.0" /* FIXME: "1.99" */ ) >= 0) {
960 * This is a v2 server. Begin v2 protocol.
962 char *verstring = "SSH-2.0-PuTTY";
965 * Hash our version string and their version string.
967 sha_string(&exhash, verstring, strlen(verstring));
968 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
969 sprintf(vstring, "%s\n", verstring);
970 sprintf(vlog, "We claim version: %s", verstring);
972 logevent("Using SSH protocol version 2");
973 s_write(vstring, strlen(vstring));
974 ssh_protocol = ssh2_protocol;
975 s_rdpkt = ssh2_rdpkt;
978 * This is a v1 server. Begin v1 protocol.
980 sprintf(vstring, "SSH-%s-PuTTY\n",
981 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
982 sprintf(vlog, "We claim version: %s", vstring);
983 vlog[strcspn(vlog, "\r\n")] = '\0';
985 logevent("Using SSH protocol version 1");
986 s_write(vstring, strlen(vstring));
987 ssh_protocol = ssh1_protocol;
988 s_rdpkt = ssh1_rdpkt;
994 * Handle the key exchange and user authentication phases.
996 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
999 unsigned char *rsabuf, *keystr1, *keystr2;
1000 unsigned char cookie[8];
1001 struct RSAKey servkey, hostkey;
1002 struct MD5Context md5c;
1003 static unsigned long supported_ciphers_mask, supported_auths_mask;
1004 static int tried_publickey;
1005 static unsigned char session_id[16];
1010 if (!ispkt) crWaitUntil(ispkt);
1012 if (pktin.type != SSH1_SMSG_PUBLIC_KEY)
1013 fatalbox("Public key packet not received");
1015 logevent("Received public keys");
1017 memcpy(cookie, pktin.body, 8);
1019 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1020 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1023 * Hash the host key and print the hash in the log box. Just as
1024 * a last resort in case the registry's host key checking is
1025 * compromised, we'll allow the user some ability to verify
1029 MD5Update(&md5c, keystr2, hostkey.bytes);
1030 MD5Final(session_id, &md5c);
1034 logevent("Host key MD5 is:");
1035 strcpy(logmsg, " ");
1036 for (i = 0; i < 16; i++)
1037 sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
1041 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1042 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1045 MD5Update(&md5c, keystr2, hostkey.bytes);
1046 MD5Update(&md5c, keystr1, servkey.bytes);
1047 MD5Update(&md5c, pktin.body, 8);
1048 MD5Final(session_id, &md5c);
1050 for (i=0; i<32; i++)
1051 session_key[i] = random_byte();
1053 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1055 rsabuf = malloc(len);
1057 fatalbox("Out of memory");
1060 * Verify the host key.
1064 * First format the key into a string.
1066 int len = rsastr_len(&hostkey);
1067 char *keystr = malloc(len);
1069 fatalbox("Out of memory");
1070 rsastr_fmt(keystr, &hostkey);
1071 verify_ssh_host_key(savedhost, keystr);
1075 for (i=0; i<32; i++) {
1076 rsabuf[i] = session_key[i];
1078 rsabuf[i] ^= session_id[i];
1081 if (hostkey.bytes > servkey.bytes) {
1082 rsaencrypt(rsabuf, 32, &servkey);
1083 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1085 rsaencrypt(rsabuf, 32, &hostkey);
1086 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1089 logevent("Encrypted session key");
1091 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1092 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1094 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1095 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1096 cipher_type = SSH_CIPHER_3DES;
1098 switch (cipher_type) {
1099 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1100 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1101 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1104 send_packet(SSH1_CMSG_SESSION_KEY,
1105 PKT_CHAR, cipher_type,
1106 PKT_DATA, cookie, 8,
1107 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1108 PKT_DATA, rsabuf, len,
1112 logevent("Trying to enable encryption...");
1116 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
1117 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1119 cipher->sesskey(session_key);
1123 if (pktin.type != SSH1_SMSG_SUCCESS)
1124 fatalbox("Encryption not successfully enabled");
1126 logevent("Successfully started encryption");
1130 static char username[100];
1133 if (!(flags & FLAG_CONNECTION) && !*cfg.username) {
1134 c_write("login as: ", 10);
1136 crWaitUntil(!ispkt);
1137 while (inlen--) switch (c = *in++) {
1144 c_write("\b \b", 3);
1150 c_write("\b \b", 3);
1159 if (((c >= ' ' && c <= '~') ||
1160 ((unsigned char)c >= 160)) && pos < 40) {
1161 username[pos++] = c;
1168 username[strcspn(username, "\n\r")] = '\0';
1171 strncpy(username, cfg.username, 99);
1172 username[99] = '\0';
1173 if (flags & FLAG_VERBOSE) {
1174 sprintf(stuff, "Sent username \"%s\".\r\n", username);
1175 c_write(stuff, strlen(stuff));
1179 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1181 char userlog[20+sizeof(username)];
1182 sprintf(userlog, "Sent username \"%s\"", username);
1189 tried_publickey = 0;
1191 while (pktin.type == SSH1_SMSG_FAILURE) {
1192 static char password[100];
1195 static int pwpkt_type;
1197 * Show password prompt, having first obtained it via a TIS
1198 * exchange if we're doing TIS authentication.
1200 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1201 if (*cfg.keyfile && !tried_publickey)
1202 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1204 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD && !FLAG_WINDOWED) {
1206 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1207 if (!ssh_get_password(prompt, password, sizeof(password))) {
1209 * get_password failed to get a password (for
1210 * example because one was supplied on the command
1211 * line which has already failed to work).
1214 logevent("No more passwords to try");
1215 ssh_state = SSH_STATE_CLOSED;
1220 if (pktin.type == SSH1_SMSG_FAILURE &&
1222 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1223 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1224 logevent("Requested TIS authentication");
1225 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1227 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1228 logevent("TIS authentication declined");
1229 c_write("TIS authentication refused.\r\n", 29);
1231 int challengelen = ((pktin.body[0] << 24) |
1232 (pktin.body[1] << 16) |
1233 (pktin.body[2] << 8) |
1235 logevent("Received TIS challenge");
1236 c_write(pktin.body+4, challengelen);
1239 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD)
1240 c_write("password: ", 10);
1241 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1242 if (flags & FLAG_VERBOSE)
1243 c_write("Trying public key authentication.\r\n", 35);
1244 if (!rsakey_encrypted(cfg.keyfile)) {
1245 if (flags & FLAG_VERBOSE)
1246 c_write("No passphrase required.\r\n", 25);
1249 c_write("passphrase: ", 12);
1254 crWaitUntil(!ispkt);
1255 while (inlen--) switch (c = *in++) {
1272 if (((c >= ' ' && c <= '~') ||
1273 ((unsigned char)c >= 160)) && pos < sizeof(password))
1274 password[pos++] = c;
1283 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1285 * Try public key authentication with the specified
1288 static struct RSAKey pubkey;
1289 static Bignum challenge, response;
1291 static unsigned char buffer[32];
1293 tried_publickey = 1;
1294 i = loadrsakey(cfg.keyfile, &pubkey, password);
1296 c_write("Couldn't load public key from ", 30);
1297 c_write(cfg.keyfile, strlen(cfg.keyfile));
1298 c_write(".\r\n", 3);
1299 continue; /* go and try password */
1302 c_write("Wrong passphrase.\r\n", 19);
1303 tried_publickey = 0;
1304 continue; /* try again */
1308 * Send a public key attempt.
1310 send_packet(SSH1_CMSG_AUTH_RSA,
1311 PKT_BIGNUM, pubkey.modulus, PKT_END);
1314 if (pktin.type == SSH1_SMSG_FAILURE) {
1315 if (flags & FLAG_VERBOSE)
1316 c_write("Server refused our public key.\r\n", 32);
1317 continue; /* go and try password */
1319 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE)
1320 fatalbox("Bizarre response to offer of public key");
1321 ssh1_read_bignum(pktin.body, &challenge);
1322 response = rsadecrypt(challenge, &pubkey);
1323 freebn(pubkey.private_exponent); /* burn the evidence */
1325 for (i = 0; i < 32; i += 2) {
1326 buffer[i] = response[16-i/2] >> 8;
1327 buffer[i+1] = response[16-i/2] & 0xFF;
1331 MD5Update(&md5c, buffer, 32);
1332 MD5Update(&md5c, session_id, 16);
1333 MD5Final(buffer, &md5c);
1335 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1336 PKT_DATA, buffer, 16, PKT_END);
1339 if (pktin.type == SSH1_SMSG_FAILURE) {
1340 if (flags & FLAG_VERBOSE)
1341 c_write("Failed to authenticate with our public key.\r\n",
1343 continue; /* go and try password */
1344 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1345 fatalbox("Bizarre response to RSA authentication response");
1348 break; /* we're through! */
1350 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1352 logevent("Sent password");
1353 memset(password, 0, strlen(password));
1355 if (pktin.type == SSH1_SMSG_FAILURE) {
1356 if (flags & FLAG_VERBOSE)
1357 c_write("Access denied\r\n", 15);
1358 logevent("Authentication refused");
1359 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1360 logevent("Received disconnect request");
1361 ssh_state = SSH_STATE_CLOSED;
1363 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1364 fatalbox("Strange packet received, type %d", pktin.type);
1368 logevent("Authentication successful");
1373 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1378 while (!do_ssh1_login(in, inlen, ispkt)) {
1381 if (ssh_state == SSH_STATE_CLOSED)
1385 send_packet(SSH1_CMSG_REQUEST_PTY,
1386 PKT_STR, cfg.termtype,
1387 PKT_INT, rows, PKT_INT, cols,
1388 PKT_INT, 0, PKT_INT, 0,
1391 ssh_state = SSH_STATE_INTERMED;
1392 do { crReturnV; } while (!ispkt);
1393 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1394 fatalbox("Protocol confusion");
1395 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1396 c_write("Server refused to allocate pty\r\n", 32);
1398 logevent("Allocated pty");
1401 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1402 logevent("Started session");
1404 ssh_state = SSH_STATE_SESSION;
1411 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1412 pktin.type == SSH1_SMSG_STDERR_DATA) {
1413 long len = GET_32BIT(pktin.body);
1414 c_write(pktin.body+4, len);
1415 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1416 ssh_state = SSH_STATE_CLOSED;
1417 logevent("Received disconnect request");
1418 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
1419 /* may be from EXEC_SHELL on some servers */
1420 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1421 /* may be from EXEC_SHELL on some servers
1422 * if no pty is available or in other odd cases. Ignore */
1423 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1424 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
1426 fatalbox("Strange packet received: type %d", pktin.type);
1429 send_packet(SSH1_CMSG_STDIN_DATA,
1430 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
1438 * Utility routine for decoding comma-separated strings in KEXINIT.
1440 int in_commasep_string(char *needle, char *haystack, int haylen) {
1441 int needlen = strlen(needle);
1444 * Is it at the start of the string?
1446 if (haylen >= needlen && /* haystack is long enough */
1447 !memcmp(needle, haystack, needlen) && /* initial match */
1448 (haylen == needlen || haystack[needlen] == ',')
1449 /* either , or EOS follows */
1453 * If not, search for the next comma and resume after that.
1454 * If no comma found, terminate.
1456 while (haylen > 0 && *haystack != ',')
1457 haylen--, haystack++;
1460 haylen--, haystack++; /* skip over comma itself */
1465 * SSH2 key creation method.
1467 void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1469 /* First 20 bytes. */
1472 SHA_Bytes(&s, H, 20);
1473 SHA_Bytes(&s, &chr, 1);
1474 SHA_Bytes(&s, H, 20);
1475 SHA_Final(&s, keyspace);
1476 /* Next 20 bytes. */
1479 SHA_Bytes(&s, H, 20);
1480 SHA_Bytes(&s, keyspace, 20);
1481 SHA_Final(&s, keyspace+20);
1485 * Handle the SSH2 transport layer.
1487 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
1491 static Bignum e, f, K;
1492 static struct ssh_cipher *cscipher_tobe = NULL;
1493 static struct ssh_cipher *sccipher_tobe = NULL;
1494 static struct ssh_mac *csmac_tobe = NULL;
1495 static struct ssh_mac *scmac_tobe = NULL;
1496 static struct ssh_compress *cscomp_tobe = NULL;
1497 static struct ssh_compress *sccomp_tobe = NULL;
1498 static char *hostkeydata, *sigdata, *keystr;
1499 static int hostkeylen, siglen;
1500 static unsigned char exchange_hash[20];
1501 static unsigned char keyspace[40];
1508 * Construct and send our key exchange packet.
1510 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1511 for (i = 0; i < 16; i++)
1512 ssh2_pkt_addbyte((unsigned char)random_byte());
1513 /* List key exchange algorithms. */
1514 ssh2_pkt_addstring_start();
1515 for (i = 0; i < lenof(kex_algs); i++) {
1516 ssh2_pkt_addstring_str(kex_algs[i]->name);
1517 if (i < lenof(kex_algs)-1)
1518 ssh2_pkt_addstring_str(",");
1520 /* List server host key algorithms. */
1521 ssh2_pkt_addstring_start();
1522 for (i = 0; i < lenof(hostkey_algs); i++) {
1523 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1524 if (i < lenof(hostkey_algs)-1)
1525 ssh2_pkt_addstring_str(",");
1527 /* List client->server encryption algorithms. */
1528 ssh2_pkt_addstring_start();
1529 for (i = 0; i < lenof(ciphers); i++) {
1530 ssh2_pkt_addstring_str(ciphers[i]->name);
1531 if (i < lenof(ciphers)-1)
1532 ssh2_pkt_addstring_str(",");
1534 /* List server->client encryption algorithms. */
1535 ssh2_pkt_addstring_start();
1536 for (i = 0; i < lenof(ciphers); i++) {
1537 ssh2_pkt_addstring_str(ciphers[i]->name);
1538 if (i < lenof(ciphers)-1)
1539 ssh2_pkt_addstring_str(",");
1541 /* List client->server MAC algorithms. */
1542 ssh2_pkt_addstring_start();
1543 for (i = 0; i < lenof(macs); i++) {
1544 ssh2_pkt_addstring_str(macs[i]->name);
1545 if (i < lenof(macs)-1)
1546 ssh2_pkt_addstring_str(",");
1548 /* List server->client MAC algorithms. */
1549 ssh2_pkt_addstring_start();
1550 for (i = 0; i < lenof(macs); i++) {
1551 ssh2_pkt_addstring_str(macs[i]->name);
1552 if (i < lenof(macs)-1)
1553 ssh2_pkt_addstring_str(",");
1555 /* List client->server compression algorithms. */
1556 ssh2_pkt_addstring_start();
1557 for (i = 0; i < lenof(compressions); i++) {
1558 ssh2_pkt_addstring_str(compressions[i]->name);
1559 if (i < lenof(compressions)-1)
1560 ssh2_pkt_addstring_str(",");
1562 /* List server->client compression algorithms. */
1563 ssh2_pkt_addstring_start();
1564 for (i = 0; i < lenof(compressions); i++) {
1565 ssh2_pkt_addstring_str(compressions[i]->name);
1566 if (i < lenof(compressions)-1)
1567 ssh2_pkt_addstring_str(",");
1569 /* List client->server languages. Empty list. */
1570 ssh2_pkt_addstring_start();
1571 /* List server->client languages. Empty list. */
1572 ssh2_pkt_addstring_start();
1573 /* First KEX packet does _not_ follow, because we're not that brave. */
1574 ssh2_pkt_addbool(FALSE);
1576 ssh2_pkt_adduint32(0);
1577 sha_string(&exhash, pktout.data+5, pktout.length-5);
1580 if (!ispkt) crWaitUntil(ispkt);
1581 sha_string(&exhash, pktin.data+5, pktin.length-5);
1584 * Now examine the other side's KEXINIT to see what we're up
1587 if (pktin.type != SSH2_MSG_KEXINIT) {
1588 fatalbox("expected key exchange packet from server");
1590 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1591 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1592 pktin.savedpos += 16; /* skip garbage cookie */
1593 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1594 for (i = 0; i < lenof(kex_algs); i++) {
1595 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1600 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1601 for (i = 0; i < lenof(hostkey_algs); i++) {
1602 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1603 hostkey = hostkey_algs[i];
1607 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1608 for (i = 0; i < lenof(ciphers); i++) {
1609 if (in_commasep_string(ciphers[i]->name, str, len)) {
1610 cscipher_tobe = ciphers[i];
1614 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1615 for (i = 0; i < lenof(ciphers); i++) {
1616 if (in_commasep_string(ciphers[i]->name, str, len)) {
1617 sccipher_tobe = ciphers[i];
1621 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1622 for (i = 0; i < lenof(macs); i++) {
1623 if (in_commasep_string(macs[i]->name, str, len)) {
1624 csmac_tobe = macs[i];
1628 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1629 for (i = 0; i < lenof(macs); i++) {
1630 if (in_commasep_string(macs[i]->name, str, len)) {
1631 scmac_tobe = macs[i];
1635 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1636 for (i = 0; i < lenof(compressions); i++) {
1637 if (in_commasep_string(compressions[i]->name, str, len)) {
1638 cscomp_tobe = compressions[i];
1642 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1643 for (i = 0; i < lenof(compressions); i++) {
1644 if (in_commasep_string(compressions[i]->name, str, len)) {
1645 sccomp_tobe = compressions[i];
1651 * Currently we only support Diffie-Hellman and DSS, so let's
1652 * bomb out if those aren't selected.
1654 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss)
1655 fatalbox("internal fault: chaos in SSH 2 transport layer");
1658 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1661 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
1666 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
1667 fatalbox("expected key exchange packet from server");
1669 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
1670 f = ssh2_pkt_getmp();
1671 ssh2_pkt_getstring(&sigdata, &siglen);
1675 sha_string(&exhash, hostkeydata, hostkeylen);
1676 sha_mpint(&exhash, e);
1677 sha_mpint(&exhash, f);
1678 sha_mpint(&exhash, K);
1679 SHA_Final(&exhash, exchange_hash);
1682 debug(("Exchange hash is:\r\n"));
1683 for (i = 0; i < 20; i++)
1684 debug((" %02x", exchange_hash[i]));
1688 hostkey->setkey(hostkeydata, hostkeylen);
1689 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20))
1690 fatalbox("Server failed host key check");
1693 * Expect SSH2_MSG_NEWKEYS from server.
1696 if (pktin.type != SSH2_MSG_NEWKEYS)
1697 fatalbox("expected new-keys packet from server");
1700 * Authenticate remote host: verify host key. (We've already
1701 * checked the signature of the exchange hash.)
1703 keystr = hostkey->fmtkey();
1704 verify_ssh_host_key(savedhost, keystr);
1708 * Send SSH2_MSG_NEWKEYS.
1710 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
1714 * Create and initialise session keys.
1716 cscipher = cscipher_tobe;
1717 sccipher = sccipher_tobe;
1720 cscomp = cscomp_tobe;
1721 sccomp = sccomp_tobe;
1723 * Set IVs after keys.
1725 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
1726 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
1727 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
1728 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
1729 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
1730 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
1733 * Now we're encrypting. Begin returning 1 to the protocol main
1734 * function so that other things can run on top of the
1735 * transport. If we ever see a KEXINIT, we must go back to the
1740 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
1741 goto begin_key_exchange;
1747 * Handle the SSH2 userauth and connection layers.
1749 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
1751 static unsigned long their_channel;
1752 static unsigned long remote_winsize;
1753 static unsigned long remote_maxpkt;
1758 * Request userauth protocol, and await a response to it.
1760 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
1761 ssh2_pkt_addstring("ssh-userauth");
1763 crWaitUntilV(ispkt);
1764 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT)
1765 fatalbox("Server refused user authentication protocol");
1768 * FIXME: currently we support only password authentication.
1769 * (This places us technically in violation of the SSH2 spec.
1770 * We must fix this.)
1774 * Get a username and a password.
1776 static char username[100];
1777 static char password[100];
1781 if ((flags & FLAG_CONNECTION) && !*cfg.username) {
1782 c_write("login as: ", 10);
1784 crWaitUntilV(!ispkt);
1785 while (inlen--) switch (c = *in++) {
1792 c_write("\b \b", 3);
1798 c_write("\b \b", 3);
1807 if (((c >= ' ' && c <= '~') ||
1808 ((unsigned char)c >= 160)) && pos < 40) {
1809 username[pos++] = c;
1816 username[strcspn(username, "\n\r")] = '\0';
1819 strncpy(username, cfg.username, 99);
1820 username[99] = '\0';
1821 if (flags & FLAG_VERBOSE) {
1822 sprintf(stuff, "Using username \"%s\".\r\n", username);
1823 c_write(stuff, strlen(stuff));
1827 if (!(flags & FLAG_WINDOWED)) {
1829 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1830 if (!ssh_get_password(prompt, password, sizeof(password))) {
1832 * get_password failed to get a password (for
1833 * example because one was supplied on the command
1834 * line which has already failed to work).
1837 logevent("No more passwords to try");
1838 ssh_state = SSH_STATE_CLOSED;
1842 c_write("password: ", 10);
1846 crWaitUntilV(!ispkt);
1847 while (inlen--) switch (c = *in++) {
1864 if (((c >= ' ' && c <= '~') ||
1865 ((unsigned char)c >= 160)) && pos < 40)
1866 password[pos++] = c;
1873 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
1874 ssh2_pkt_addstring(username);
1875 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1876 ssh2_pkt_addstring("password");
1877 ssh2_pkt_addbool(FALSE);
1878 ssh2_pkt_addstring(password);
1881 crWaitUntilV(ispkt);
1882 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
1883 c_write("Access denied\r\n", 15);
1884 logevent("Authentication refused");
1890 * Now we're authenticated for the connection protocol. The
1891 * connection protocol will automatically have started at this
1892 * point; there's no need to send SERVICE_REQUEST.
1896 * So now create a channel with a session in it.
1898 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
1899 ssh2_pkt_addstring("session");
1900 ssh2_pkt_adduint32(100); /* as good as any */
1901 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big window which we ignore */
1902 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big max pkt size */
1904 crWaitUntilV(ispkt);
1905 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
1906 fatalbox("Server refused to open a session");
1907 /* FIXME: error data comes back in FAILURE packet */
1909 if (ssh2_pkt_getuint32() != 100) {
1910 fatalbox("Server's channel confirmation cited wrong channel");
1912 their_channel = ssh2_pkt_getuint32();
1913 remote_winsize = ssh2_pkt_getuint32();
1914 remote_maxpkt = ssh2_pkt_getuint32();
1915 logevent("Opened channel for session");
1918 * Now allocate a pty for the session.
1920 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
1921 ssh2_pkt_adduint32(their_channel); /* recipient channel */
1922 ssh2_pkt_addstring("pty-req");
1923 ssh2_pkt_addbool(1); /* want reply */
1924 ssh2_pkt_addstring(cfg.termtype);
1925 ssh2_pkt_adduint32(cols);
1926 ssh2_pkt_adduint32(rows);
1927 ssh2_pkt_adduint32(0); /* pixel width */
1928 ssh2_pkt_adduint32(0); /* pixel height */
1929 ssh2_pkt_addstring_start();
1930 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1933 do { /* FIXME: pay attention to these */
1934 crWaitUntilV(ispkt);
1935 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1937 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
1938 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
1939 fatalbox("Server got confused by pty request");
1941 c_write("Server refused to allocate pty\r\n", 32);
1943 logevent("Allocated pty");
1949 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
1950 ssh2_pkt_adduint32(their_channel); /* recipient channel */
1951 ssh2_pkt_addstring("shell");
1952 ssh2_pkt_addbool(1); /* want reply */
1954 do { /* FIXME: pay attention to these */
1955 crWaitUntilV(ispkt);
1956 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1957 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
1958 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
1959 fatalbox("Server got confused by shell request");
1961 fatalbox("Server refused to start a shell");
1963 logevent("Started a shell");
1972 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
1973 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1976 if (ssh2_pkt_getuint32() != 100)
1977 continue; /* wrong channel */
1978 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
1979 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
1980 continue; /* extended but not stderr */
1981 ssh2_pkt_getstring(&data, &length);
1983 c_write(data, length);
1984 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
1985 ssh_state = SSH_STATE_CLOSED;
1986 logevent("Received disconnect request");
1987 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
1988 continue; /* exit status et al; ignore (FIXME?) */
1989 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
1990 continue; /* ignore for now (FIXME!) */
1992 fatalbox("Strange packet received: type %d", pktin.type);
1995 /* FIXME: for now, ignore window size */
1996 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
1997 ssh2_pkt_adduint32(their_channel);
1998 ssh2_pkt_addstring_start();
1999 ssh2_pkt_addstring_data(in, inlen);
2008 * Handle the top-level SSH2 protocol.
2010 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2012 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2014 do_ssh2_authconn(in, inlen, ispkt);
2018 * Called to set up the connection. Will arrange for WM_NETEVENT
2019 * messages to be passed to the specified window, whose window
2020 * procedure should then call telnet_msg().
2022 * Returns an error message, or NULL on success.
2024 static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
2028 if(crypto_startup() == 0)
2029 return "Microsoft high encryption pack not installed!";
2032 p = connect_to_host(host, port, realhost);
2037 return "Protocol initialisation error";
2039 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
2040 switch (WSAGetLastError()) {
2041 case WSAENETDOWN: return "Network is down";
2042 default: return "WSAAsyncSelect(): unknown error";
2049 * Process a WM_NETEVENT message. Will return 0 if the connection
2050 * has closed, or <0 for a socket error.
2052 static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2057 * Because reading less than the whole of the available pending
2058 * data can generate an FD_READ event, we need to allow for the
2059 * possibility that FD_READ may arrive with FD_CLOSE already in
2060 * the queue; so it's possible that we can get here even with s
2061 * invalid. If so, we return 1 and don't worry about it.
2063 if (s == INVALID_SOCKET)
2066 if (WSAGETSELECTERROR(lParam) != 0)
2067 return -WSAGETSELECTERROR(lParam);
2069 switch (WSAGETSELECTEVENT(lParam)) {
2072 ret = recv(s, buf, sizeof(buf), 0);
2073 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2075 if (ret < 0) /* any _other_ error */
2076 return -10000-WSAGetLastError();
2081 ssh_gotdata (buf, ret);
2082 if (ssh_state == SSH_STATE_CLOSED) {
2089 return 1; /* shouldn't happen, but WTF */
2093 * Called to send data down the Telnet connection.
2095 static void ssh_send (char *buf, int len) {
2096 if (s == INVALID_SOCKET)
2099 ssh_protocol(buf, len, 0);
2103 * Called to set the size of the window from Telnet's POV.
2105 static void ssh_size(void) {
2106 switch (ssh_state) {
2107 case SSH_STATE_BEFORE_SIZE:
2108 case SSH_STATE_CLOSED:
2109 break; /* do nothing */
2110 case SSH_STATE_INTERMED:
2111 size_needed = TRUE; /* buffer for later */
2113 case SSH_STATE_SESSION:
2115 send_packet(SSH1_CMSG_WINDOW_SIZE,
2116 PKT_INT, rows, PKT_INT, cols,
2117 PKT_INT, 0, PKT_INT, 0, PKT_END);
2123 * (Send Telnet special codes)
2125 static void ssh_special (Telnet_Special code) {
2131 * Read and decrypt one incoming SSH packet.
2132 * (only used by pSCP)
2134 static void get_packet(void)
2136 unsigned char buf[4096], *p;
2143 while ((to_read = s_rdpkt(&p, &len)) > 0) {
2144 if (to_read > sizeof(buf)) to_read = sizeof(buf);
2145 len = s_read(buf, to_read);
2146 if (len != to_read) {
2158 * Receive a block of data over the SSH link. Block until
2159 * all data is available. Return nr of bytes read (0 if lost connection).
2160 * (only used by pSCP)
2162 int ssh_scp_recv(unsigned char *buf, int len)
2164 static int pending_input_len = 0;
2165 static unsigned char *pending_input_ptr;
2168 if (pending_input_len >= to_read) {
2169 memcpy(buf, pending_input_ptr, to_read);
2170 pending_input_ptr += to_read;
2171 pending_input_len -= to_read;
2175 if (pending_input_len > 0) {
2176 memcpy(buf, pending_input_ptr, pending_input_len);
2177 buf += pending_input_len;
2178 to_read -= pending_input_len;
2179 pending_input_len = 0;
2182 if (s == INVALID_SOCKET)
2184 while (to_read > 0) {
2186 if (s == INVALID_SOCKET)
2188 if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
2189 int plen = GET_32BIT(pktin.body);
2190 if (plen <= to_read) {
2191 memcpy(buf, pktin.body + 4, plen);
2195 memcpy(buf, pktin.body + 4, to_read);
2196 pending_input_len = plen - to_read;
2197 pending_input_ptr = pktin.body + 4 + to_read;
2200 } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
2201 int plen = GET_32BIT(pktin.body);
2202 fwrite(pktin.body + 4, plen, 1, stderr);
2203 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2204 logevent("Received disconnect request");
2205 } else if (pktin.type == SSH1_SMSG_SUCCESS ||
2206 pktin.type == SSH1_SMSG_FAILURE) {
2208 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2210 sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
2212 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2213 logevent("Closing connection");
2217 fatalbox("Strange packet received: type %d", pktin.type);
2225 * Send a block of data over the SSH link.
2226 * Block until all data is sent.
2227 * (only used by pSCP)
2229 void ssh_scp_send(unsigned char *buf, int len)
2231 if (s == INVALID_SOCKET)
2233 send_packet(SSH1_CMSG_STDIN_DATA,
2234 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2238 * Send an EOF notification to the server.
2239 * (only used by pSCP)
2241 void ssh_scp_send_eof(void)
2243 if (s == INVALID_SOCKET)
2245 send_packet(SSH1_CMSG_EOF, PKT_END);
2249 * Set up the connection, login on the remote host and
2250 * start execution of a command.
2251 * Returns an error message, or NULL on success.
2252 * (only used by pSCP)
2254 char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
2259 if (crypto_startup() == 0)
2260 return "Microsoft high encryption pack not installed!";
2263 p = connect_to_host(host, port, realhost);
2270 return "Protocol initialisation error";
2272 /* Exchange keys and login */
2275 if (s == INVALID_SOCKET)
2276 return "Connection closed by remote host";
2277 } while (!do_ssh1_login(NULL, 0, 1));
2279 if (ssh_state == SSH_STATE_CLOSED) {
2282 return "Session initialisation error";
2285 /* Execute command */
2286 sprintf(buf, "Sending command: %.100s", cmd);
2288 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2293 SOCKET ssh_socket(void) { return s; }
2295 Backend ssh_backend = {