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 SSH_AGENTC_REQUEST_RSA_IDENTITIES 1
55 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2
56 #define SSH_AGENTC_RSA_CHALLENGE 3
57 #define SSH_AGENT_RSA_RESPONSE 4
58 #define SSH_AGENT_FAILURE 5
59 #define SSH_AGENT_SUCCESS 6
60 #define SSH_AGENTC_ADD_RSA_IDENTITY 7
61 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8
63 #define SSH2_MSG_DISCONNECT 1
64 #define SSH2_MSG_IGNORE 2
65 #define SSH2_MSG_UNIMPLEMENTED 3
66 #define SSH2_MSG_DEBUG 4
67 #define SSH2_MSG_SERVICE_REQUEST 5
68 #define SSH2_MSG_SERVICE_ACCEPT 6
69 #define SSH2_MSG_KEXINIT 20
70 #define SSH2_MSG_NEWKEYS 21
71 #define SSH2_MSG_KEXDH_INIT 30
72 #define SSH2_MSG_KEXDH_REPLY 31
73 #define SSH2_MSG_USERAUTH_REQUEST 50
74 #define SSH2_MSG_USERAUTH_FAILURE 51
75 #define SSH2_MSG_USERAUTH_SUCCESS 52
76 #define SSH2_MSG_USERAUTH_BANNER 53
77 #define SSH2_MSG_USERAUTH_PK_OK 60
78 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60
79 #define SSH2_MSG_GLOBAL_REQUEST 80
80 #define SSH2_MSG_REQUEST_SUCCESS 81
81 #define SSH2_MSG_REQUEST_FAILURE 82
82 #define SSH2_MSG_CHANNEL_OPEN 90
83 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91
84 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92
85 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93
86 #define SSH2_MSG_CHANNEL_DATA 94
87 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95
88 #define SSH2_MSG_CHANNEL_EOF 96
89 #define SSH2_MSG_CHANNEL_CLOSE 97
90 #define SSH2_MSG_CHANNEL_REQUEST 98
91 #define SSH2_MSG_CHANNEL_SUCCESS 99
92 #define SSH2_MSG_CHANNEL_FAILURE 100
94 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1
95 #define SSH2_OPEN_CONNECT_FAILED 2
96 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3
97 #define SSH2_OPEN_RESOURCE_SHORTAGE 4
98 #define SSH2_EXTENDED_DATA_STDERR 1
100 #define GET_32BIT(cp) \
101 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
102 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
103 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
104 ((unsigned long)(unsigned char)(cp)[3]))
106 #define PUT_32BIT(cp, value) { \
107 (cp)[0] = (unsigned char)((value) >> 24); \
108 (cp)[1] = (unsigned char)((value) >> 16); \
109 (cp)[2] = (unsigned char)((value) >> 8); \
110 (cp)[3] = (unsigned char)(value); }
112 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
114 /* Coroutine mechanics for the sillier bits of the code */
115 #define crBegin1 static int crLine = 0;
116 #define crBegin2 switch(crLine) { case 0:;
117 #define crBegin crBegin1; crBegin2;
118 #define crFinish(z) } crLine = 0; return (z)
119 #define crFinishV } crLine = 0; return
120 #define crReturn(z) \
122 crLine=__LINE__; return (z); case __LINE__:;\
126 crLine=__LINE__; return; case __LINE__:;\
128 #define crStop(z) do{ crLine = 0; return (z); }while(0)
129 #define crStopV do{ crLine = 0; return; }while(0)
130 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
131 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
133 extern struct ssh_cipher ssh_3des;
134 extern struct ssh_cipher ssh_3des_ssh2;
135 extern struct ssh_cipher ssh_des;
136 extern struct ssh_cipher ssh_blowfish;
138 /* for ssh 2; we miss out single-DES because it isn't supported */
139 struct ssh_cipher *ciphers[] = { &ssh_3des_ssh2, &ssh_blowfish };
141 extern struct ssh_kex ssh_diffiehellman;
142 struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
144 extern struct ssh_hostkey ssh_dss;
145 struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
147 extern struct ssh_mac ssh_sha1;
151 static void nullmac_key(unsigned char *key) { }
152 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
153 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
154 struct ssh_mac ssh_mac_none = {
155 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
157 struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
159 struct ssh_compress ssh_comp_none = {
162 struct ssh_compress *compressions[] = { &ssh_comp_none };
164 static SOCKET s = INVALID_SOCKET;
166 static unsigned char session_key[32];
167 static struct ssh_cipher *cipher = NULL;
168 static struct ssh_cipher *cscipher = NULL;
169 static struct ssh_cipher *sccipher = NULL;
170 static struct ssh_mac *csmac = NULL;
171 static struct ssh_mac *scmac = NULL;
172 static struct ssh_compress *cscomp = NULL;
173 static struct ssh_compress *sccomp = NULL;
174 static struct ssh_kex *kex = NULL;
175 static struct ssh_hostkey *hostkey = NULL;
176 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
178 static char *savedhost;
179 static int ssh_send_ok;
182 SSH_STATE_BEFORE_SIZE,
186 } ssh_state = SSH_STATE_BEFORE_SIZE;
188 static int size_needed = FALSE;
190 static void s_write (char *buf, int len) {
192 int i = send (s, buf, len, 0);
195 fatalbox("Lost connection while sending");
201 static int s_read (char *buf, int len) {
204 int i = recv (s, buf, len, 0);
207 len -= i, buf += i, ret += i;
214 static void c_write (char *buf, int len) {
215 if (!(flags & FLAG_CONNECTION)) {
217 for (i = 0; i < len; i++)
219 fputc(buf[i], stderr);
235 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
236 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
238 static int ssh_version;
239 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
240 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
241 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
242 static void ssh_size(void);
244 static int (*s_rdpkt)(unsigned char **data, int *datalen);
247 * Collect incoming data in the incoming packet buffer.
248 * Decipher and verify the packet when it is completely read.
249 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
250 * Update the *data and *datalen variables.
251 * Return the additional nr of bytes needed, or 0 when
252 * a complete packet is available.
254 static int ssh1_rdpkt(unsigned char **data, int *datalen)
256 static long len, pad, biglen, to_read;
257 static unsigned long realcrc, gotcrc;
258 static unsigned char *p;
268 for (i = len = 0; i < 4; i++) {
269 while ((*datalen) == 0)
271 len = (len << 8) + **data;
272 (*data)++, (*datalen)--;
276 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
277 len = 0x300; /* big enough to carry to end */
283 pktin.length = len - 5;
285 if (pktin.maxlen < biglen) {
286 pktin.maxlen = biglen;
287 pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
288 realloc(pktin.data, biglen+APIEXTRA));
290 fatalbox("Out of memory");
295 while (to_read > 0) {
298 while ((*datalen) == 0)
300 if (chunk > (*datalen))
302 memcpy(p, *data, chunk);
310 cipher->decrypt(pktin.data, biglen);
312 pktin.type = pktin.data[pad];
313 pktin.body = pktin.data + pad + 1;
315 realcrc = crc32(pktin.data, biglen-4);
316 gotcrc = GET_32BIT(pktin.data+biglen-4);
317 if (gotcrc != realcrc) {
318 fatalbox("Incorrect CRC received on packet");
321 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
322 pktin.type == SSH1_SMSG_STDERR_DATA ||
323 pktin.type == SSH1_MSG_DEBUG ||
324 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
325 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
326 long strlen = GET_32BIT(pktin.body);
327 if (strlen + 4 != pktin.length)
328 fatalbox("Received data packet with bogus string length");
331 if (pktin.type == SSH1_MSG_DEBUG) {
332 /* log debug message */
334 int strlen = GET_32BIT(pktin.body);
335 strcpy(buf, "Remote: ");
336 if (strlen > 70) strlen = 70;
337 memcpy(buf+8, pktin.body+4, strlen);
338 buf[8+strlen] = '\0';
341 } else if (pktin.type == SSH1_MSG_IGNORE) {
349 static int ssh2_rdpkt(unsigned char **data, int *datalen)
351 static long len, pad, payload, packetlen, maclen;
353 static int cipherblk;
354 static unsigned long incoming_sequence = 0;
364 cipherblk = cipher->blksize;
370 if (pktin.maxlen < cipherblk) {
371 pktin.maxlen = cipherblk;
372 pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
373 realloc(pktin.data, cipherblk+APIEXTRA));
375 fatalbox("Out of memory");
379 * Acquire and decrypt the first block of the packet. This will
380 * contain the length and padding details.
382 for (i = len = 0; i < cipherblk; i++) {
383 while ((*datalen) == 0)
384 crReturn(cipherblk-i);
385 pktin.data[i] = *(*data)++;
389 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
394 sccipher->decrypt(pktin.data, cipherblk);
397 * Now get the length and padding figures.
399 len = GET_32BIT(pktin.data);
403 * This enables us to deduce the payload length.
405 payload = len - pad - 1;
407 pktin.length = payload + 5;
410 * So now we can work out the total packet length.
413 maclen = scmac ? scmac->len : 0;
416 * Adjust memory allocation if packet is too big.
418 if (pktin.maxlen < packetlen) {
419 pktin.maxlen = packetlen;
420 pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) :
421 realloc(pktin.data, packetlen+APIEXTRA));
423 fatalbox("Out of memory");
427 * Read and decrypt the remainder of the packet.
429 for (i = cipherblk; i < packetlen + maclen; i++) {
430 while ((*datalen) == 0)
431 crReturn(packetlen + maclen - i);
432 pktin.data[i] = *(*data)++;
435 /* Decrypt everything _except_ the MAC. */
437 sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
440 debug(("Got packet len=%d pad=%d\r\n", len, pad));
441 for (i = 0; i < packetlen; i++)
442 debug((" %02x", (unsigned char)pktin.data[i]));
449 if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence))
450 fatalbox("Incorrect MAC received on packet");
451 incoming_sequence++; /* whether or not we MACed */
454 pktin.type = pktin.data[5];
456 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
457 goto next_packet; /* FIXME: print DEBUG message */
462 static void ssh_gotdata(unsigned char *data, int datalen)
464 while (datalen > 0) {
465 if ( s_rdpkt(&data, &datalen) == 0 ) {
466 ssh_protocol(NULL, 0, 1);
467 if (ssh_state == SSH_STATE_CLOSED) {
475 static void s_wrpkt_start(int type, int len) {
478 len += 5; /* type and CRC */
482 pktout.length = len-5;
483 if (pktout.maxlen < biglen) {
484 pktout.maxlen = biglen;
486 /* Allocate enough buffer space for extra block
487 * for MS CryptEncrypt() */
488 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
489 realloc(pktout.data, biglen+12));
491 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
492 realloc(pktout.data, biglen+4));
495 fatalbox("Out of memory");
499 pktout.body = pktout.data+4+pad+1;
502 static void s_wrpkt(void) {
503 int pad, len, biglen, i;
506 len = pktout.length + 5; /* type and CRC */
510 pktout.body[-1] = pktout.type;
511 for (i=0; i<pad; i++)
512 pktout.data[i+4] = random_byte();
513 crc = crc32(pktout.data+4, biglen-4);
514 PUT_32BIT(pktout.data+biglen, crc);
515 PUT_32BIT(pktout.data, len);
518 cipher->encrypt(pktout.data+4, biglen);
520 s_write(pktout.data, biglen+4);
524 * Construct a packet with the specified contents and
525 * send it to the server.
527 static void send_packet(int pkttype, ...)
530 unsigned char *p, *argp, argchar;
531 unsigned long argint;
532 int pktlen, argtype, arglen;
536 va_start(args, pkttype);
537 while ((argtype = va_arg(args, int)) != PKT_END) {
540 (void) va_arg(args, int);
544 (void) va_arg(args, char);
548 (void) va_arg(args, unsigned char *);
549 arglen = va_arg(args, int);
553 argp = va_arg(args, unsigned char *);
554 arglen = strlen(argp);
555 pktlen += 4 + arglen;
558 bn = va_arg(args, Bignum);
559 pktlen += ssh1_bignum_length(bn);
567 s_wrpkt_start(pkttype, pktlen);
570 va_start(args, pkttype);
571 while ((argtype = va_arg(args, int)) != PKT_END) {
574 argint = va_arg(args, int);
575 PUT_32BIT(p, argint);
579 argchar = va_arg(args, unsigned char);
584 argp = va_arg(args, unsigned char *);
585 arglen = va_arg(args, int);
586 memcpy(p, argp, arglen);
590 argp = va_arg(args, unsigned char *);
591 arglen = strlen(argp);
592 PUT_32BIT(p, arglen);
593 memcpy(p + 4, argp, arglen);
597 bn = va_arg(args, Bignum);
598 p += ssh1_write_bignum(p, bn);
609 * Connect to specified host and port.
610 * Returns an error message, or NULL on success.
611 * Also places the canonical host name into `realhost'.
613 static char *connect_to_host(char *host, int port, char **realhost)
623 savedhost = malloc(1+strlen(host));
625 fatalbox("Out of memory");
626 strcpy(savedhost, host);
629 port = 22; /* default ssh port */
641 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
642 if ( (h = gethostbyname(host)) == NULL)
643 switch (WSAGetLastError()) {
644 case WSAENETDOWN: return "Network is down";
645 case WSAHOST_NOT_FOUND: case WSANO_DATA:
646 return "Host does not exist";
647 case WSATRY_AGAIN: return "Host not found";
648 default: return "gethostbyname: unknown error";
650 memcpy (&a, h->h_addr, sizeof(a));
651 *realhost = h->h_name;
662 s = socket(AF_INET, SOCK_STREAM, 0);
663 if (s == INVALID_SOCKET)
664 switch (WSAGetLastError()) {
665 case WSAENETDOWN: return "Network is down";
666 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
667 default: return "socket(): unknown error";
671 * Bind to local address.
673 addr.sin_family = AF_INET;
674 addr.sin_addr.s_addr = htonl(INADDR_ANY);
675 addr.sin_port = htons(0);
676 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
677 switch (WSAGetLastError()) {
678 case WSAENETDOWN: return "Network is down";
679 default: return "bind(): unknown error";
683 * Connect to remote address.
685 addr.sin_addr.s_addr = htonl(a);
686 addr.sin_port = htons((short)port);
687 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
688 switch (WSAGetLastError()) {
689 case WSAENETDOWN: return "Network is down";
690 case WSAECONNREFUSED: return "Connection refused";
691 case WSAENETUNREACH: return "Network is unreachable";
692 case WSAEHOSTUNREACH: return "No route to host";
693 default: return "connect(): unknown error";
697 send(s, "connect ", 8, 0);
698 send(s, FWhost, strlen(FWhost), 0);
701 sprintf(buf, " %d\n", FWport);
702 send (s, buf, strlen(buf), 0);
709 static int ssh_versioncmp(char *a, char *b) {
711 unsigned long av, bv;
713 av = strtoul(a, &ae, 10);
714 bv = strtoul(b, &be, 10);
715 if (av != bv) return (av < bv ? -1 : +1);
716 if (*ae == '.') ae++;
717 if (*be == '.') be++;
718 av = strtoul(ae, &ae, 10);
719 bv = strtoul(be, &be, 10);
720 if (av != bv) return (av < bv ? -1 : +1);
726 * Utility routine for putting an SSH-protocol `string' into a SHA
730 void sha_string(SHA_State *s, void *str, int len) {
731 unsigned char lenblk[4];
732 PUT_32BIT(lenblk, len);
733 SHA_Bytes(s, lenblk, 4);
734 SHA_Bytes(s, str, len);
738 * SSH2 packet construction functions.
740 void ssh2_pkt_adddata(void *data, int len) {
741 pktout.length += len;
742 if (pktout.maxlen < pktout.length) {
743 pktout.maxlen = pktout.length + 256;
744 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
745 realloc(pktout.data, pktout.maxlen+APIEXTRA));
747 fatalbox("Out of memory");
749 memcpy(pktout.data+pktout.length-len, data, len);
751 void ssh2_pkt_addbyte(unsigned char byte) {
752 ssh2_pkt_adddata(&byte, 1);
754 void ssh2_pkt_init(int pkt_type) {
756 ssh2_pkt_addbyte((unsigned char)pkt_type);
758 void ssh2_pkt_addbool(unsigned char value) {
759 ssh2_pkt_adddata(&value, 1);
761 void ssh2_pkt_adduint32(unsigned long value) {
764 ssh2_pkt_adddata(x, 4);
766 void ssh2_pkt_addstring_start(void) {
767 ssh2_pkt_adduint32(0);
768 pktout.savedpos = pktout.length;
770 void ssh2_pkt_addstring_str(char *data) {
771 ssh2_pkt_adddata(data, strlen(data));
772 PUT_32BIT(pktout.data + pktout.savedpos - 4,
773 pktout.length - pktout.savedpos);
775 void ssh2_pkt_addstring_data(char *data, int len) {
776 ssh2_pkt_adddata(data, len);
777 PUT_32BIT(pktout.data + pktout.savedpos - 4,
778 pktout.length - pktout.savedpos);
780 void ssh2_pkt_addstring(char *data) {
781 ssh2_pkt_addstring_start();
782 ssh2_pkt_addstring_str(data);
784 char *ssh2_mpint_fmt(Bignum b, int *len) {
787 p = malloc(n * 2 + 1);
789 fatalbox("out of memory");
791 for (i = 0; i < n; i++) {
792 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
793 p[i*2+2] = (b[n-i] ) & 0xFF;
796 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
798 memmove(p, p+i, n*2+1-i);
802 void ssh2_pkt_addmp(Bignum b) {
805 p = ssh2_mpint_fmt(b, &len);
806 ssh2_pkt_addstring_start();
807 ssh2_pkt_addstring_data(p, len);
810 void ssh2_pkt_send(void) {
811 int cipherblk, maclen, padding, i;
812 static unsigned long outgoing_sequence = 0;
815 * Add padding. At least four bytes, and must also bring total
816 * length (minus MAC) up to a multiple of the block size.
818 cipherblk = cipher ? cipher->blksize : 8; /* block size */
819 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
821 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
822 pktout.data[4] = padding;
823 for (i = 0; i < padding; i++)
824 pktout.data[pktout.length + i] = random_byte();
825 PUT_32BIT(pktout.data, pktout.length + padding - 4);
827 csmac->generate(pktout.data, pktout.length + padding,
829 outgoing_sequence++; /* whether or not we MACed */
832 debug(("Sending packet len=%d\r\n", pktout.length+padding));
833 for (i = 0; i < pktout.length+padding; i++)
834 debug((" %02x", (unsigned char)pktout.data[i]));
839 cscipher->encrypt(pktout.data, pktout.length + padding);
840 maclen = csmac ? csmac->len : 0;
842 s_write(pktout.data, pktout.length + padding + maclen);
846 void bndebug(char *string, Bignum b) {
849 p = ssh2_mpint_fmt(b, &len);
850 debug(("%s", string));
851 for (i = 0; i < len; i++)
852 debug((" %02x", p[i]));
858 void sha_mpint(SHA_State *s, Bignum b) {
861 p = ssh2_mpint_fmt(b, &len);
862 sha_string(s, p, len);
867 * SSH2 packet decode functions.
869 unsigned long ssh2_pkt_getuint32(void) {
871 if (pktin.length - pktin.savedpos < 4)
872 return 0; /* arrgh, no way to decline (FIXME?) */
873 value = GET_32BIT(pktin.data+pktin.savedpos);
877 void ssh2_pkt_getstring(char **p, int *length) {
879 if (pktin.length - pktin.savedpos < 4)
881 *length = GET_32BIT(pktin.data+pktin.savedpos);
883 if (pktin.length - pktin.savedpos < *length)
885 *p = pktin.data+pktin.savedpos;
886 pktin.savedpos += *length;
888 Bignum ssh2_pkt_getmp(void) {
893 ssh2_pkt_getstring(&p, &length);
897 fatalbox("internal error: Can't handle negative mpints");
898 b = newbn((length+1)/2);
899 for (i = 0; i < length; i++) {
902 b[j/2+1] |= ((unsigned char)p[i]) << 8;
904 b[j/2+1] |= ((unsigned char)p[i]);
909 static int do_ssh_init(void) {
913 char vlog[sizeof(vstring)+20];
918 while (s_read(&c, 1) == 1) {
919 if (c == 'S' && i < 2) i++;
920 else if (c == 'S' && i == 2) i = 2;
921 else if (c == 'H' && i == 2) break;
925 if (s_read(&c,1) != 1 || c != 'S') return 0;
926 if (s_read(&c,1) != 1 || c != 'S') return 0;
927 if (s_read(&c,1) != 1 || c != 'H') return 0;
929 strcpy(vstring, "SSH-");
931 if (s_read(&c,1) != 1 || c != '-') return 0;
934 if (s_read(&c,1) != 1)
936 if (vsp < vstring+sizeof(vstring)-1)
942 } else if (i < sizeof(version)-1)
950 sprintf(vlog, "Server version: %s", vstring);
951 vlog[strcspn(vlog, "\r\n")] = '\0';
955 * Server version "1.99" means we can choose whether we use v1
956 * or v2 protocol. Choice is based on cfg.sshprot.
958 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "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;
976 s_rdpkt = ssh2_rdpkt;
979 * This is a v1 server. Begin v1 protocol.
981 sprintf(vstring, "SSH-%s-PuTTY\n",
982 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
983 sprintf(vlog, "We claim version: %s", vstring);
984 vlog[strcspn(vlog, "\r\n")] = '\0';
986 logevent("Using SSH protocol version 1");
987 s_write(vstring, strlen(vstring));
988 ssh_protocol = ssh1_protocol;
990 s_rdpkt = ssh1_rdpkt;
997 * Handle the key exchange and user authentication phases.
999 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1002 unsigned char *rsabuf, *keystr1, *keystr2;
1003 unsigned char cookie[8];
1004 struct RSAKey servkey, hostkey;
1005 struct MD5Context md5c;
1006 static unsigned long supported_ciphers_mask, supported_auths_mask;
1007 static int tried_publickey;
1008 static unsigned char session_id[16];
1013 if (!ispkt) crWaitUntil(ispkt);
1015 if (pktin.type != SSH1_SMSG_PUBLIC_KEY)
1016 fatalbox("Public key packet not received");
1018 logevent("Received public keys");
1020 memcpy(cookie, pktin.body, 8);
1022 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1023 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1026 * Hash the host key and print the hash in the log box. Just as
1027 * a last resort in case the registry's host key checking is
1028 * compromised, we'll allow the user some ability to verify
1032 MD5Update(&md5c, keystr2, hostkey.bytes);
1033 MD5Final(session_id, &md5c);
1037 logevent("Host key MD5 is:");
1038 strcpy(logmsg, " ");
1039 for (i = 0; i < 16; i++)
1040 sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
1044 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1045 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1048 MD5Update(&md5c, keystr2, hostkey.bytes);
1049 MD5Update(&md5c, keystr1, servkey.bytes);
1050 MD5Update(&md5c, pktin.body, 8);
1051 MD5Final(session_id, &md5c);
1053 for (i=0; i<32; i++)
1054 session_key[i] = random_byte();
1056 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1058 rsabuf = malloc(len);
1060 fatalbox("Out of memory");
1063 * Verify the host key.
1067 * First format the key into a string.
1069 int len = rsastr_len(&hostkey);
1070 char *keystr = malloc(len);
1072 fatalbox("Out of memory");
1073 rsastr_fmt(keystr, &hostkey);
1074 verify_ssh_host_key(savedhost, keystr);
1078 for (i=0; i<32; i++) {
1079 rsabuf[i] = session_key[i];
1081 rsabuf[i] ^= session_id[i];
1084 if (hostkey.bytes > servkey.bytes) {
1085 rsaencrypt(rsabuf, 32, &servkey);
1086 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1088 rsaencrypt(rsabuf, 32, &hostkey);
1089 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1092 logevent("Encrypted session key");
1094 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1095 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1097 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1098 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1099 cipher_type = SSH_CIPHER_3DES;
1101 switch (cipher_type) {
1102 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1103 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1104 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1107 send_packet(SSH1_CMSG_SESSION_KEY,
1108 PKT_CHAR, cipher_type,
1109 PKT_DATA, cookie, 8,
1110 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1111 PKT_DATA, rsabuf, len,
1115 logevent("Trying to enable encryption...");
1119 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
1120 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1122 cipher->sesskey(session_key);
1126 if (pktin.type != SSH1_SMSG_SUCCESS)
1127 fatalbox("Encryption not successfully enabled");
1129 logevent("Successfully started encryption");
1133 static char username[100];
1136 if ((flags & FLAG_CONNECTION) && !*cfg.username) {
1137 c_write("login as: ", 10);
1139 crWaitUntil(!ispkt);
1140 while (inlen--) switch (c = *in++) {
1147 c_write("\b \b", 3);
1153 c_write("\b \b", 3);
1162 if (((c >= ' ' && c <= '~') ||
1163 ((unsigned char)c >= 160)) && pos < 40) {
1164 username[pos++] = c;
1171 username[strcspn(username, "\n\r")] = '\0';
1174 strncpy(username, cfg.username, 99);
1175 username[99] = '\0';
1176 if (flags & FLAG_VERBOSE) {
1177 sprintf(stuff, "Sent username \"%s\".\r\n", username);
1178 c_write(stuff, strlen(stuff));
1182 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1184 char userlog[20+sizeof(username)];
1185 sprintf(userlog, "Sent username \"%s\"", username);
1192 tried_publickey = 0;
1194 while (pktin.type == SSH1_SMSG_FAILURE) {
1195 static char password[100];
1198 static int pwpkt_type;
1200 * Show password prompt, having first obtained it via a TIS
1201 * or CryptoCard exchange if we're doing TIS or CryptoCard
1204 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1205 if (agent_exists()) {
1207 * Attempt RSA authentication using Pageant.
1209 static unsigned char request[5], *response, *p;
1210 static int responselen;
1211 static int i, nkeys;
1212 static int authed = FALSE;
1215 logevent("Pageant is running. Requesting keys.");
1217 /* Request the keys held by the agent. */
1218 PUT_32BIT(request, 1);
1219 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1220 agent_query(request, 5, &r, &responselen);
1221 response = (unsigned char *)r;
1224 nkeys = GET_32BIT(p); p += 4;
1225 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1227 for (i = 0; i < nkeys; i++) {
1228 static struct RSAKey key;
1229 static Bignum challenge;
1231 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1234 p += ssh1_read_bignum(p, &key.exponent);
1235 p += ssh1_read_bignum(p, &key.modulus);
1236 send_packet(SSH1_CMSG_AUTH_RSA,
1237 PKT_BIGNUM, key.modulus, PKT_END);
1239 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1240 logevent("Key refused");
1243 logevent("Received RSA challenge");
1244 ssh1_read_bignum(pktin.body, &challenge);
1246 char *agentreq, *q, *ret;
1248 len = 1 + 4; /* message type, bit count */
1249 len += ssh1_bignum_length(key.exponent);
1250 len += ssh1_bignum_length(key.modulus);
1251 len += ssh1_bignum_length(challenge);
1252 len += 16; /* session id */
1253 len += 4; /* response format */
1254 agentreq = malloc(4 + len);
1255 PUT_32BIT(agentreq, len);
1257 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1258 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1260 q += ssh1_write_bignum(q, key.exponent);
1261 q += ssh1_write_bignum(q, key.modulus);
1262 q += ssh1_write_bignum(q, challenge);
1263 memcpy(q, session_id, 16); q += 16;
1264 PUT_32BIT(q, 1); /* response format */
1265 agent_query(agentreq, len+4, &ret, &retlen);
1268 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1269 logevent("Sending Pageant's response");
1270 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1271 PKT_DATA, ret+5, 16, PKT_END);
1274 if (pktin.type == SSH1_SMSG_SUCCESS) {
1275 logevent("Pageant's response accepted");
1278 logevent("Pageant's response not accepted");
1280 logevent("Pageant failed to answer challenge");
1284 logevent("No reply received from Pageant");
1287 freebn(key.exponent);
1288 freebn(key.modulus);
1297 if (*cfg.keyfile && !tried_publickey)
1298 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1300 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD && !FLAG_WINDOWED) {
1302 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1303 if (!ssh_get_password(prompt, password, sizeof(password))) {
1305 * get_password failed to get a password (for
1306 * example because one was supplied on the command
1307 * line which has already failed to work).
1310 logevent("No more passwords to try");
1311 ssh_state = SSH_STATE_CLOSED;
1316 if (pktin.type == SSH1_SMSG_FAILURE &&
1318 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1319 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1320 logevent("Requested TIS authentication");
1321 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1323 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1324 logevent("TIS authentication declined");
1325 c_write("TIS authentication refused.\r\n", 29);
1327 int challengelen = ((pktin.body[0] << 24) |
1328 (pktin.body[1] << 16) |
1329 (pktin.body[2] << 8) |
1331 logevent("Received TIS challenge");
1332 c_write(pktin.body+4, challengelen);
1335 if (pktin.type == SSH1_SMSG_FAILURE &&
1337 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1338 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1339 logevent("Requested CryptoCard authentication");
1340 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1342 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1343 logevent("CryptoCard authentication declined");
1344 c_write("CryptoCard authentication refused.\r\n", 29);
1346 int challengelen = ((pktin.body[0] << 24) |
1347 (pktin.body[1] << 16) |
1348 (pktin.body[2] << 8) |
1350 logevent("Received CryptoCard challenge");
1351 c_write(pktin.body+4, challengelen);
1352 c_write("\r\nResponse : ", 13);
1355 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD)
1356 c_write("password: ", 10);
1357 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1358 if (flags & FLAG_VERBOSE)
1359 c_write("Trying public key authentication.\r\n", 35);
1360 if (!rsakey_encrypted(cfg.keyfile)) {
1361 if (flags & FLAG_VERBOSE)
1362 c_write("No passphrase required.\r\n", 25);
1365 c_write("passphrase: ", 12);
1370 crWaitUntil(!ispkt);
1371 while (inlen--) switch (c = *in++) {
1388 if (((c >= ' ' && c <= '~') ||
1389 ((unsigned char)c >= 160)) && pos < sizeof(password))
1390 password[pos++] = c;
1399 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1401 * Try public key authentication with the specified
1404 static struct RSAKey pubkey;
1405 static Bignum challenge, response;
1407 static unsigned char buffer[32];
1409 tried_publickey = 1;
1410 i = loadrsakey(cfg.keyfile, &pubkey, password);
1412 c_write("Couldn't load public key from ", 30);
1413 c_write(cfg.keyfile, strlen(cfg.keyfile));
1414 c_write(".\r\n", 3);
1415 continue; /* go and try password */
1418 c_write("Wrong passphrase.\r\n", 19);
1419 tried_publickey = 0;
1420 continue; /* try again */
1424 * Send a public key attempt.
1426 send_packet(SSH1_CMSG_AUTH_RSA,
1427 PKT_BIGNUM, pubkey.modulus, PKT_END);
1430 if (pktin.type == SSH1_SMSG_FAILURE) {
1431 if (flags & FLAG_VERBOSE)
1432 c_write("Server refused our public key.\r\n", 32);
1433 continue; /* go and try password */
1435 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE)
1436 fatalbox("Bizarre response to offer of public key");
1437 ssh1_read_bignum(pktin.body, &challenge);
1438 response = rsadecrypt(challenge, &pubkey);
1439 freebn(pubkey.private_exponent); /* burn the evidence */
1441 for (i = 0; i < 32; i += 2) {
1442 buffer[i] = response[16-i/2] >> 8;
1443 buffer[i+1] = response[16-i/2] & 0xFF;
1447 MD5Update(&md5c, buffer, 32);
1448 MD5Update(&md5c, session_id, 16);
1449 MD5Final(buffer, &md5c);
1451 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1452 PKT_DATA, buffer, 16, PKT_END);
1455 if (pktin.type == SSH1_SMSG_FAILURE) {
1456 if (flags & FLAG_VERBOSE)
1457 c_write("Failed to authenticate with our public key.\r\n",
1459 continue; /* go and try password */
1460 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1461 fatalbox("Bizarre response to RSA authentication response");
1464 break; /* we're through! */
1466 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1468 logevent("Sent password");
1469 memset(password, 0, strlen(password));
1471 if (pktin.type == SSH1_SMSG_FAILURE) {
1472 if (flags & FLAG_VERBOSE)
1473 c_write("Access denied\r\n", 15);
1474 logevent("Authentication refused");
1475 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1476 logevent("Received disconnect request");
1477 ssh_state = SSH_STATE_CLOSED;
1479 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1480 fatalbox("Strange packet received, type %d", pktin.type);
1484 logevent("Authentication successful");
1489 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1494 while (!do_ssh1_login(in, inlen, ispkt)) {
1497 if (ssh_state == SSH_STATE_CLOSED)
1501 send_packet(SSH1_CMSG_REQUEST_PTY,
1502 PKT_STR, cfg.termtype,
1503 PKT_INT, rows, PKT_INT, cols,
1504 PKT_INT, 0, PKT_INT, 0,
1507 ssh_state = SSH_STATE_INTERMED;
1508 do { crReturnV; } while (!ispkt);
1509 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1510 fatalbox("Protocol confusion");
1511 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1512 c_write("Server refused to allocate pty\r\n", 32);
1514 logevent("Allocated pty");
1517 if (*cfg.remote_cmd)
1518 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1520 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1521 logevent("Started session");
1523 ssh_state = SSH_STATE_SESSION;
1531 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1532 pktin.type == SSH1_SMSG_STDERR_DATA) {
1533 long len = GET_32BIT(pktin.body);
1534 c_write(pktin.body+4, len);
1535 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1536 ssh_state = SSH_STATE_CLOSED;
1537 logevent("Received disconnect request");
1538 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
1539 /* may be from EXEC_SHELL on some servers */
1540 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1541 /* may be from EXEC_SHELL on some servers
1542 * if no pty is available or in other odd cases. Ignore */
1543 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1544 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
1546 fatalbox("Strange packet received: type %d", pktin.type);
1549 send_packet(SSH1_CMSG_STDIN_DATA,
1550 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
1558 * Utility routine for decoding comma-separated strings in KEXINIT.
1560 int in_commasep_string(char *needle, char *haystack, int haylen) {
1561 int needlen = strlen(needle);
1564 * Is it at the start of the string?
1566 if (haylen >= needlen && /* haystack is long enough */
1567 !memcmp(needle, haystack, needlen) && /* initial match */
1568 (haylen == needlen || haystack[needlen] == ',')
1569 /* either , or EOS follows */
1573 * If not, search for the next comma and resume after that.
1574 * If no comma found, terminate.
1576 while (haylen > 0 && *haystack != ',')
1577 haylen--, haystack++;
1580 haylen--, haystack++; /* skip over comma itself */
1585 * SSH2 key creation method.
1587 void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1589 /* First 20 bytes. */
1592 SHA_Bytes(&s, H, 20);
1593 SHA_Bytes(&s, &chr, 1);
1594 SHA_Bytes(&s, H, 20);
1595 SHA_Final(&s, keyspace);
1596 /* Next 20 bytes. */
1599 SHA_Bytes(&s, H, 20);
1600 SHA_Bytes(&s, keyspace, 20);
1601 SHA_Final(&s, keyspace+20);
1605 * Handle the SSH2 transport layer.
1607 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
1611 static Bignum e, f, K;
1612 static struct ssh_cipher *cscipher_tobe = NULL;
1613 static struct ssh_cipher *sccipher_tobe = NULL;
1614 static struct ssh_mac *csmac_tobe = NULL;
1615 static struct ssh_mac *scmac_tobe = NULL;
1616 static struct ssh_compress *cscomp_tobe = NULL;
1617 static struct ssh_compress *sccomp_tobe = NULL;
1618 static char *hostkeydata, *sigdata, *keystr;
1619 static int hostkeylen, siglen;
1620 static unsigned char exchange_hash[20];
1621 static unsigned char keyspace[40];
1628 * Construct and send our key exchange packet.
1630 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1631 for (i = 0; i < 16; i++)
1632 ssh2_pkt_addbyte((unsigned char)random_byte());
1633 /* List key exchange algorithms. */
1634 ssh2_pkt_addstring_start();
1635 for (i = 0; i < lenof(kex_algs); i++) {
1636 ssh2_pkt_addstring_str(kex_algs[i]->name);
1637 if (i < lenof(kex_algs)-1)
1638 ssh2_pkt_addstring_str(",");
1640 /* List server host key algorithms. */
1641 ssh2_pkt_addstring_start();
1642 for (i = 0; i < lenof(hostkey_algs); i++) {
1643 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1644 if (i < lenof(hostkey_algs)-1)
1645 ssh2_pkt_addstring_str(",");
1647 /* List client->server encryption algorithms. */
1648 ssh2_pkt_addstring_start();
1649 for (i = 0; i < lenof(ciphers); i++) {
1650 ssh2_pkt_addstring_str(ciphers[i]->name);
1651 if (i < lenof(ciphers)-1)
1652 ssh2_pkt_addstring_str(",");
1654 /* List server->client encryption algorithms. */
1655 ssh2_pkt_addstring_start();
1656 for (i = 0; i < lenof(ciphers); i++) {
1657 ssh2_pkt_addstring_str(ciphers[i]->name);
1658 if (i < lenof(ciphers)-1)
1659 ssh2_pkt_addstring_str(",");
1661 /* List client->server MAC algorithms. */
1662 ssh2_pkt_addstring_start();
1663 for (i = 0; i < lenof(macs); i++) {
1664 ssh2_pkt_addstring_str(macs[i]->name);
1665 if (i < lenof(macs)-1)
1666 ssh2_pkt_addstring_str(",");
1668 /* List server->client MAC algorithms. */
1669 ssh2_pkt_addstring_start();
1670 for (i = 0; i < lenof(macs); i++) {
1671 ssh2_pkt_addstring_str(macs[i]->name);
1672 if (i < lenof(macs)-1)
1673 ssh2_pkt_addstring_str(",");
1675 /* List client->server compression algorithms. */
1676 ssh2_pkt_addstring_start();
1677 for (i = 0; i < lenof(compressions); i++) {
1678 ssh2_pkt_addstring_str(compressions[i]->name);
1679 if (i < lenof(compressions)-1)
1680 ssh2_pkt_addstring_str(",");
1682 /* List server->client compression algorithms. */
1683 ssh2_pkt_addstring_start();
1684 for (i = 0; i < lenof(compressions); i++) {
1685 ssh2_pkt_addstring_str(compressions[i]->name);
1686 if (i < lenof(compressions)-1)
1687 ssh2_pkt_addstring_str(",");
1689 /* List client->server languages. Empty list. */
1690 ssh2_pkt_addstring_start();
1691 /* List server->client languages. Empty list. */
1692 ssh2_pkt_addstring_start();
1693 /* First KEX packet does _not_ follow, because we're not that brave. */
1694 ssh2_pkt_addbool(FALSE);
1696 ssh2_pkt_adduint32(0);
1697 sha_string(&exhash, pktout.data+5, pktout.length-5);
1700 if (!ispkt) crWaitUntil(ispkt);
1701 sha_string(&exhash, pktin.data+5, pktin.length-5);
1704 * Now examine the other side's KEXINIT to see what we're up
1707 if (pktin.type != SSH2_MSG_KEXINIT) {
1708 fatalbox("expected key exchange packet from server");
1710 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1711 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1712 pktin.savedpos += 16; /* skip garbage cookie */
1713 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1714 for (i = 0; i < lenof(kex_algs); i++) {
1715 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1720 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1721 for (i = 0; i < lenof(hostkey_algs); i++) {
1722 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1723 hostkey = hostkey_algs[i];
1727 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1728 for (i = 0; i < lenof(ciphers); i++) {
1729 if (in_commasep_string(ciphers[i]->name, str, len)) {
1730 cscipher_tobe = ciphers[i];
1734 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1735 for (i = 0; i < lenof(ciphers); i++) {
1736 if (in_commasep_string(ciphers[i]->name, str, len)) {
1737 sccipher_tobe = ciphers[i];
1741 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1742 for (i = 0; i < lenof(macs); i++) {
1743 if (in_commasep_string(macs[i]->name, str, len)) {
1744 csmac_tobe = macs[i];
1748 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1749 for (i = 0; i < lenof(macs); i++) {
1750 if (in_commasep_string(macs[i]->name, str, len)) {
1751 scmac_tobe = macs[i];
1755 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1756 for (i = 0; i < lenof(compressions); i++) {
1757 if (in_commasep_string(compressions[i]->name, str, len)) {
1758 cscomp_tobe = compressions[i];
1762 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1763 for (i = 0; i < lenof(compressions); i++) {
1764 if (in_commasep_string(compressions[i]->name, str, len)) {
1765 sccomp_tobe = compressions[i];
1771 * Currently we only support Diffie-Hellman and DSS, so let's
1772 * bomb out if those aren't selected.
1774 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss)
1775 fatalbox("internal fault: chaos in SSH 2 transport layer");
1778 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1781 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
1786 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
1787 fatalbox("expected key exchange packet from server");
1789 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
1790 f = ssh2_pkt_getmp();
1791 ssh2_pkt_getstring(&sigdata, &siglen);
1795 sha_string(&exhash, hostkeydata, hostkeylen);
1796 sha_mpint(&exhash, e);
1797 sha_mpint(&exhash, f);
1798 sha_mpint(&exhash, K);
1799 SHA_Final(&exhash, exchange_hash);
1802 debug(("Exchange hash is:\r\n"));
1803 for (i = 0; i < 20; i++)
1804 debug((" %02x", exchange_hash[i]));
1808 hostkey->setkey(hostkeydata, hostkeylen);
1809 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20))
1810 fatalbox("Server failed host key check");
1813 * Expect SSH2_MSG_NEWKEYS from server.
1816 if (pktin.type != SSH2_MSG_NEWKEYS)
1817 fatalbox("expected new-keys packet from server");
1820 * Authenticate remote host: verify host key. (We've already
1821 * checked the signature of the exchange hash.)
1823 keystr = hostkey->fmtkey();
1824 verify_ssh_host_key(savedhost, keystr);
1828 * Send SSH2_MSG_NEWKEYS.
1830 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
1834 * Create and initialise session keys.
1836 cscipher = cscipher_tobe;
1837 sccipher = sccipher_tobe;
1840 cscomp = cscomp_tobe;
1841 sccomp = sccomp_tobe;
1843 * Set IVs after keys.
1845 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
1846 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
1847 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
1848 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
1849 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
1850 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
1853 * Now we're encrypting. Begin returning 1 to the protocol main
1854 * function so that other things can run on top of the
1855 * transport. If we ever see a KEXINIT, we must go back to the
1860 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
1861 goto begin_key_exchange;
1867 * SSH2: remote identifier for the main session channel.
1869 static unsigned long ssh_remote_channel;
1872 * Handle the SSH2 userauth and connection layers.
1874 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
1876 static unsigned long remote_winsize;
1877 static unsigned long remote_maxpkt;
1882 * Request userauth protocol, and await a response to it.
1884 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
1885 ssh2_pkt_addstring("ssh-userauth");
1887 crWaitUntilV(ispkt);
1888 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT)
1889 fatalbox("Server refused user authentication protocol");
1892 * FIXME: currently we support only password authentication.
1893 * (This places us technically in violation of the SSH2 spec.
1894 * We must fix this.)
1898 * Get a username and a password.
1900 static char username[100];
1901 static char password[100];
1905 if ((flags & FLAG_CONNECTION) && !*cfg.username) {
1906 c_write("login as: ", 10);
1908 crWaitUntilV(!ispkt);
1909 while (inlen--) switch (c = *in++) {
1916 c_write("\b \b", 3);
1922 c_write("\b \b", 3);
1931 if (((c >= ' ' && c <= '~') ||
1932 ((unsigned char)c >= 160)) && pos < 40) {
1933 username[pos++] = c;
1940 username[strcspn(username, "\n\r")] = '\0';
1943 strncpy(username, cfg.username, 99);
1944 username[99] = '\0';
1945 if (flags & FLAG_VERBOSE) {
1946 sprintf(stuff, "Using username \"%s\".\r\n", username);
1947 c_write(stuff, strlen(stuff));
1951 if (!(flags & FLAG_WINDOWED)) {
1953 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1954 if (!ssh_get_password(prompt, password, sizeof(password))) {
1956 * get_password failed to get a password (for
1957 * example because one was supplied on the command
1958 * line which has already failed to work).
1961 logevent("No more passwords to try");
1962 ssh_state = SSH_STATE_CLOSED;
1966 c_write("password: ", 10);
1970 crWaitUntilV(!ispkt);
1971 while (inlen--) switch (c = *in++) {
1988 if (((c >= ' ' && c <= '~') ||
1989 ((unsigned char)c >= 160)) && pos < 40)
1990 password[pos++] = c;
1997 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
1998 ssh2_pkt_addstring(username);
1999 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2000 ssh2_pkt_addstring("password");
2001 ssh2_pkt_addbool(FALSE);
2002 ssh2_pkt_addstring(password);
2005 crWaitUntilV(ispkt);
2006 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2007 c_write("Access denied\r\n", 15);
2008 logevent("Authentication refused");
2014 * Now we're authenticated for the connection protocol. The
2015 * connection protocol will automatically have started at this
2016 * point; there's no need to send SERVICE_REQUEST.
2020 * So now create a channel with a session in it.
2022 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2023 ssh2_pkt_addstring("session");
2024 ssh2_pkt_adduint32(100); /* as good as any */
2025 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big window which we ignore */
2026 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big max pkt size */
2028 crWaitUntilV(ispkt);
2029 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2030 fatalbox("Server refused to open a session");
2031 /* FIXME: error data comes back in FAILURE packet */
2033 if (ssh2_pkt_getuint32() != 100) {
2034 fatalbox("Server's channel confirmation cited wrong channel");
2036 ssh_remote_channel = ssh2_pkt_getuint32();
2037 remote_winsize = ssh2_pkt_getuint32();
2038 remote_maxpkt = ssh2_pkt_getuint32();
2039 logevent("Opened channel for session");
2042 * Now allocate a pty for the session.
2044 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2045 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
2046 ssh2_pkt_addstring("pty-req");
2047 ssh2_pkt_addbool(1); /* want reply */
2048 ssh2_pkt_addstring(cfg.termtype);
2049 ssh2_pkt_adduint32(cols);
2050 ssh2_pkt_adduint32(rows);
2051 ssh2_pkt_adduint32(0); /* pixel width */
2052 ssh2_pkt_adduint32(0); /* pixel height */
2053 ssh2_pkt_addstring_start();
2054 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
2057 do { /* FIXME: pay attention to these */
2058 crWaitUntilV(ispkt);
2059 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2061 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2062 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2063 fatalbox("Server got confused by pty request");
2065 c_write("Server refused to allocate pty\r\n", 32);
2067 logevent("Allocated pty");
2073 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2074 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
2075 ssh2_pkt_addstring("shell");
2076 ssh2_pkt_addbool(1); /* want reply */
2078 do { /* FIXME: pay attention to these */
2079 crWaitUntilV(ispkt);
2080 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2081 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2082 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2083 fatalbox("Server got confused by shell request");
2085 fatalbox("Server refused to start a shell");
2087 logevent("Started a shell");
2097 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2098 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2101 if (ssh2_pkt_getuint32() != 100)
2102 continue; /* wrong channel */
2103 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2104 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2105 continue; /* extended but not stderr */
2106 ssh2_pkt_getstring(&data, &length);
2108 c_write(data, length);
2109 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2110 ssh_state = SSH_STATE_CLOSED;
2111 logevent("Received disconnect request");
2112 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2113 continue; /* exit status et al; ignore (FIXME?) */
2114 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2115 continue; /* ignore for now (FIXME!) */
2117 fatalbox("Strange packet received: type %d", pktin.type);
2120 /* FIXME: for now, ignore window size */
2121 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2122 ssh2_pkt_adduint32(ssh_remote_channel);
2123 ssh2_pkt_addstring_start();
2124 ssh2_pkt_addstring_data(in, inlen);
2133 * Handle the top-level SSH2 protocol.
2135 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2137 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2139 do_ssh2_authconn(in, inlen, ispkt);
2143 * Called to set up the connection. Will arrange for WM_NETEVENT
2144 * messages to be passed to the specified window, whose window
2145 * procedure should then call telnet_msg().
2147 * Returns an error message, or NULL on success.
2149 static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
2153 if(crypto_startup() == 0)
2154 return "Microsoft high encryption pack not installed!";
2157 p = connect_to_host(host, port, realhost);
2162 return "Protocol initialisation error";
2164 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
2165 switch (WSAGetLastError()) {
2166 case WSAENETDOWN: return "Network is down";
2167 default: return "WSAAsyncSelect(): unknown error";
2174 * Process a WM_NETEVENT message. Will return 0 if the connection
2175 * has closed, or <0 for a socket error.
2177 static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2182 * Because reading less than the whole of the available pending
2183 * data can generate an FD_READ event, we need to allow for the
2184 * possibility that FD_READ may arrive with FD_CLOSE already in
2185 * the queue; so it's possible that we can get here even with s
2186 * invalid. If so, we return 1 and don't worry about it.
2188 if (s == INVALID_SOCKET)
2191 if (WSAGETSELECTERROR(lParam) != 0)
2192 return -WSAGETSELECTERROR(lParam);
2194 switch (WSAGETSELECTEVENT(lParam)) {
2197 ret = recv(s, buf, sizeof(buf), 0);
2198 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2200 if (ret < 0) /* any _other_ error */
2201 return -10000-WSAGetLastError();
2206 ssh_gotdata (buf, ret);
2207 if (ssh_state == SSH_STATE_CLOSED) {
2214 return 1; /* shouldn't happen, but WTF */
2218 * Called to send data down the Telnet connection.
2220 static void ssh_send (char *buf, int len) {
2221 if (s == INVALID_SOCKET)
2224 ssh_protocol(buf, len, 0);
2228 * Called to set the size of the window from Telnet's POV.
2230 static void ssh_size(void) {
2231 switch (ssh_state) {
2232 case SSH_STATE_BEFORE_SIZE:
2233 case SSH_STATE_CLOSED:
2234 break; /* do nothing */
2235 case SSH_STATE_INTERMED:
2236 size_needed = TRUE; /* buffer for later */
2238 case SSH_STATE_SESSION:
2240 send_packet(SSH1_CMSG_WINDOW_SIZE,
2241 PKT_INT, rows, PKT_INT, cols,
2242 PKT_INT, 0, PKT_INT, 0, PKT_END);
2248 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2249 * can send an EOF and collect resulting output (e.g. `plink
2252 static void ssh_special (Telnet_Special code) {
2253 if (code == TS_EOF) {
2254 if (ssh_version = 1) {
2255 send_packet(SSH1_CMSG_EOF, PKT_END);
2257 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
2258 ssh2_pkt_adduint32(ssh_remote_channel);
2268 * Read and decrypt one incoming SSH packet.
2269 * (only used by pSCP)
2271 static void get_packet(void)
2273 unsigned char buf[4096], *p;
2280 while ((to_read = s_rdpkt(&p, &len)) > 0) {
2281 if (to_read > sizeof(buf)) to_read = sizeof(buf);
2282 len = s_read(buf, to_read);
2283 if (len != to_read) {
2295 * Receive a block of data over the SSH link. Block until
2296 * all data is available. Return nr of bytes read (0 if lost connection).
2297 * (only used by pSCP)
2299 int ssh_scp_recv(unsigned char *buf, int len)
2301 static int pending_input_len = 0;
2302 static unsigned char *pending_input_ptr;
2305 if (pending_input_len >= to_read) {
2306 memcpy(buf, pending_input_ptr, to_read);
2307 pending_input_ptr += to_read;
2308 pending_input_len -= to_read;
2312 if (pending_input_len > 0) {
2313 memcpy(buf, pending_input_ptr, pending_input_len);
2314 buf += pending_input_len;
2315 to_read -= pending_input_len;
2316 pending_input_len = 0;
2319 if (s == INVALID_SOCKET)
2321 while (to_read > 0) {
2323 if (s == INVALID_SOCKET)
2325 if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
2326 int plen = GET_32BIT(pktin.body);
2327 if (plen <= to_read) {
2328 memcpy(buf, pktin.body + 4, plen);
2332 memcpy(buf, pktin.body + 4, to_read);
2333 pending_input_len = plen - to_read;
2334 pending_input_ptr = pktin.body + 4 + to_read;
2337 } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
2338 int plen = GET_32BIT(pktin.body);
2339 fwrite(pktin.body + 4, plen, 1, stderr);
2340 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2341 logevent("Received disconnect request");
2342 } else if (pktin.type == SSH1_SMSG_SUCCESS ||
2343 pktin.type == SSH1_SMSG_FAILURE) {
2345 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2347 sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
2349 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2350 logevent("Closing connection");
2354 fatalbox("Strange packet received: type %d", pktin.type);
2362 * Send a block of data over the SSH link.
2363 * Block until all data is sent.
2364 * (only used by pSCP)
2366 void ssh_scp_send(unsigned char *buf, int len)
2368 if (s == INVALID_SOCKET)
2370 send_packet(SSH1_CMSG_STDIN_DATA,
2371 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2375 * Send an EOF notification to the server.
2376 * (only used by pSCP)
2378 void ssh_scp_send_eof(void)
2380 if (s == INVALID_SOCKET)
2382 send_packet(SSH1_CMSG_EOF, PKT_END);
2386 * Set up the connection, login on the remote host and
2387 * start execution of a command.
2388 * Returns an error message, or NULL on success.
2389 * (only used by pSCP)
2391 char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
2396 if (crypto_startup() == 0)
2397 return "Microsoft high encryption pack not installed!";
2400 p = connect_to_host(host, port, realhost);
2407 return "Protocol initialisation error";
2409 /* Exchange keys and login */
2412 if (s == INVALID_SOCKET)
2413 return "Connection closed by remote host";
2414 } while (!do_ssh1_login(NULL, 0, 1));
2416 if (ssh_state == SSH_STATE_CLOSED) {
2419 return "Session initialisation error";
2422 /* Execute command */
2423 sprintf(buf, "Sending command: %.100s", cmd);
2425 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2430 static SOCKET ssh_socket(void) { return s; }
2432 static int ssh_sendok(void) { return ssh_send_ok; }
2434 Backend ssh_backend = {