18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 fprintf(stderr, "%s\n", s); }
22 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
23 (s ? sk_close(s), s = NULL : 0), \
24 connection_fatal msg )
26 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29 #define SSH1_CMSG_USER 4 /* 0x4 */
30 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
39 #define SSH1_SMSG_FAILURE 15 /* 0xf */
40 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43 #define SSH1_CMSG_EOF 19 /* 0x13 */
44 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
50 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
53 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
55 #define SSH1_MSG_IGNORE 32 /* 0x20 */
56 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
59 #define SSH1_MSG_DEBUG 36 /* 0x24 */
60 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
61 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68 #define SSH1_AUTH_TIS 5 /* 0x5 */
69 #define SSH1_AUTH_CCARD 16 /* 0x10 */
71 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
72 /* Mask for protoflags we will echo back to server if seen */
73 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
75 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76 #define SSH2_MSG_IGNORE 2 /* 0x2 */
77 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78 #define SSH2_MSG_DEBUG 4 /* 0x4 */
79 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
82 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
85 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
89 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
110 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
111 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
112 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
113 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
114 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
115 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
116 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
117 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
118 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
119 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
120 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
122 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
123 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
124 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
125 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
127 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
130 * Various remote-bug flags.
132 #define BUG_CHOKES_ON_SSH1_IGNORE 1
133 #define BUG_SSH2_HMAC 2
135 #define GET_32BIT(cp) \
136 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
137 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
138 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
139 ((unsigned long)(unsigned char)(cp)[3]))
141 #define PUT_32BIT(cp, value) { \
142 (cp)[0] = (unsigned char)((value) >> 24); \
143 (cp)[1] = (unsigned char)((value) >> 16); \
144 (cp)[2] = (unsigned char)((value) >> 8); \
145 (cp)[3] = (unsigned char)(value); }
147 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
149 /* Coroutine mechanics for the sillier bits of the code */
150 #define crBegin1 static int crLine = 0;
151 #define crBegin2 switch(crLine) { case 0:;
152 #define crBegin crBegin1; crBegin2;
153 #define crFinish(z) } crLine = 0; return (z)
154 #define crFinishV } crLine = 0; return
155 #define crReturn(z) \
157 crLine=__LINE__; return (z); case __LINE__:;\
161 crLine=__LINE__; return; case __LINE__:;\
163 #define crStop(z) do{ crLine = 0; return (z); }while(0)
164 #define crStopV do{ crLine = 0; return; }while(0)
165 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
166 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
168 extern char *x11_init (Socket *, char *, void *);
169 extern void x11_close (Socket);
170 extern void x11_send (Socket , char *, int);
171 extern void x11_invent_auth(char *, int, char *, int);
174 * Ciphers for SSH2. We miss out single-DES because it isn't
175 * supported; also 3DES and Blowfish are both done differently from
176 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
177 * endianness and different-sized keys.)
179 const static struct ssh2_ciphers *ciphers[] = {
185 const static struct ssh_kex *kex_algs[] = {
186 &ssh_diffiehellman_gex,
187 &ssh_diffiehellman };
189 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
191 static void nullmac_key(unsigned char *key) { }
192 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
193 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
194 const static struct ssh_mac ssh_mac_none = {
195 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
197 const static struct ssh_mac *macs[] = {
198 &ssh_sha1, &ssh_md5, &ssh_mac_none };
199 const static struct ssh_mac *buggymacs[] = {
200 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
202 static void ssh_comp_none_init(void) { }
203 static int ssh_comp_none_block(unsigned char *block, int len,
204 unsigned char **outblock, int *outlen) {
207 static int ssh_comp_none_disable(void) { return 0; }
208 const static struct ssh_compress ssh_comp_none = {
210 ssh_comp_none_init, ssh_comp_none_block,
211 ssh_comp_none_init, ssh_comp_none_block,
212 ssh_comp_none_disable
214 extern const struct ssh_compress ssh_zlib;
215 const static struct ssh_compress *compressions[] = {
216 &ssh_zlib, &ssh_comp_none };
218 enum { /* channel types */
225 * 2-3-4 tree storing channels.
228 unsigned remoteid, localid;
231 struct ssh2_data_channel {
232 unsigned char *outbuffer;
233 unsigned outbuflen, outbufsize;
234 unsigned remwindow, remmaxpkt;
237 struct ssh_agent_channel {
238 unsigned char *message;
239 unsigned char msglen[4];
240 int lensofar, totallen;
242 struct ssh_x11_channel {
257 static SHA_State exhash, exhashbase;
259 static Socket s = NULL;
261 static unsigned char session_key[32];
262 static int ssh1_compressing;
263 static int ssh1_remote_protoflags;
264 static int ssh1_local_protoflags;
265 static int ssh_agentfwd_enabled;
266 static int ssh_X11_fwd_enabled;
267 static int ssh_remote_bugs;
268 static const struct ssh_cipher *cipher = NULL;
269 static const struct ssh2_cipher *cscipher = NULL;
270 static const struct ssh2_cipher *sccipher = NULL;
271 static const struct ssh_mac *csmac = NULL;
272 static const struct ssh_mac *scmac = NULL;
273 static const struct ssh_compress *cscomp = NULL;
274 static const struct ssh_compress *sccomp = NULL;
275 static const struct ssh_kex *kex = NULL;
276 static const struct ssh_signkey *hostkey = NULL;
277 static unsigned char ssh2_session_id[20];
278 int (*ssh_get_line)(const char *prompt, char *str, int maxlen,
281 static char *savedhost;
282 static int savedport;
283 static int ssh_send_ok;
284 static int ssh_echoing, ssh_editing;
286 static tree234 *ssh_channels; /* indexed by local id */
287 static struct ssh_channel *mainchan; /* primary session channel */
291 SSH_STATE_BEFORE_SIZE,
295 } ssh_state = SSH_STATE_PREPACKET;
297 static int size_needed = FALSE, eof_needed = FALSE;
299 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
300 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
301 static unsigned char *deferred_send_data = NULL;
302 static int deferred_len = 0, deferred_size = 0;
304 static int ssh_version;
305 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
306 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
307 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
308 static void ssh_size(void);
309 static void ssh_special (Telnet_Special);
310 static void ssh2_try_send(struct ssh_channel *c);
311 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
313 static int (*s_rdpkt)(unsigned char **data, int *datalen);
315 static struct rdpkt1_state_tag {
316 long len, pad, biglen, to_read;
317 unsigned long realcrc, gotcrc;
323 static struct rdpkt2_state_tag {
324 long len, pad, payload, packetlen, maclen;
327 unsigned long incoming_sequence;
330 static int ssh_channelcmp(void *av, void *bv) {
331 struct ssh_channel *a = (struct ssh_channel *)av;
332 struct ssh_channel *b = (struct ssh_channel *)bv;
333 if (a->localid < b->localid) return -1;
334 if (a->localid > b->localid) return +1;
337 static int ssh_channelfind(void *av, void *bv) {
338 unsigned *a = (unsigned *)av;
339 struct ssh_channel *b = (struct ssh_channel *)bv;
340 if (*a < b->localid) return -1;
341 if (*a > b->localid) return +1;
345 static void c_write (char *buf, int len) {
346 if ((flags & FLAG_STDERR)) {
348 for (i = 0; i < len; i++)
350 fputc(buf[i], stderr);
353 from_backend(1, buf, len);
356 static void c_write_untrusted(char *buf, int len) {
358 for (i = 0; i < len; i++) {
361 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
366 static void c_write_str (char *buf) {
367 c_write(buf, strlen(buf));
371 * Collect incoming data in the incoming packet buffer.
372 * Decipher and verify the packet when it is completely read.
373 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
374 * Update the *data and *datalen variables.
375 * Return the additional nr of bytes needed, or 0 when
376 * a complete packet is available.
378 static int ssh1_rdpkt(unsigned char **data, int *datalen)
380 struct rdpkt1_state_tag *st = &rdpkt1_state;
389 for (st->i = st->len = 0; st->i < 4; st->i++) {
390 while ((*datalen) == 0)
392 st->len = (st->len << 8) + **data;
393 (*data)++, (*datalen)--;
397 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
398 st->len = 0x300; /* big enough to carry to end */
402 st->pad = 8 - (st->len % 8);
403 st->biglen = st->len + st->pad;
404 pktin.length = st->len - 5;
406 if (pktin.maxlen < st->biglen) {
407 pktin.maxlen = st->biglen;
408 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
409 srealloc(pktin.data, st->biglen+APIEXTRA));
411 fatalbox("Out of memory");
414 st->to_read = st->biglen;
416 while (st->to_read > 0) {
417 st->chunk = st->to_read;
418 while ((*datalen) == 0)
419 crReturn(st->to_read);
420 if (st->chunk > (*datalen))
421 st->chunk = (*datalen);
422 memcpy(st->p, *data, st->chunk);
424 *datalen -= st->chunk;
426 st->to_read -= st->chunk;
430 cipher->decrypt(pktin.data, st->biglen);
432 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
433 for (st->i = 0; st->i < st->biglen; st->i++)
434 debug((" %02x", (unsigned char)pktin.data[st->i]));
438 st->realcrc = crc32(pktin.data, st->biglen-4);
439 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
440 if (st->gotcrc != st->realcrc) {
441 bombout(("Incorrect CRC received on packet"));
445 pktin.body = pktin.data + st->pad + 1;
447 if (ssh1_compressing) {
448 unsigned char *decompblk;
453 debug(("Packet payload pre-decompression:\n"));
454 for (i = -1; i < pktin.length; i++)
455 debug((" %02x", (unsigned char)pktin.body[i]));
459 zlib_decompress_block(pktin.body-1, pktin.length+1,
460 &decompblk, &decomplen);
462 if (pktin.maxlen < st->pad + decomplen) {
463 pktin.maxlen = st->pad + decomplen;
464 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
465 pktin.body = pktin.data + st->pad + 1;
467 fatalbox("Out of memory");
470 memcpy(pktin.body-1, decompblk, decomplen);
472 pktin.length = decomplen-1;
476 debug(("Packet payload post-decompression:\n"));
477 for (i = -1; i < pktin.length; i++)
478 debug((" %02x", (unsigned char)pktin.body[i]));
484 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
485 pktin.type == SSH1_SMSG_STDERR_DATA ||
486 pktin.type == SSH1_MSG_DEBUG ||
487 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
488 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
489 long strlen = GET_32BIT(pktin.body);
490 if (strlen + 4 != pktin.length) {
491 bombout(("Received data packet with bogus string length"));
496 pktin.type = pktin.body[-1];
498 if (pktin.type == SSH1_MSG_DEBUG) {
499 /* log debug message */
501 int strlen = GET_32BIT(pktin.body);
502 strcpy(buf, "Remote: ");
503 if (strlen > 70) strlen = 70;
504 memcpy(buf+8, pktin.body+4, strlen);
505 buf[8+strlen] = '\0';
508 } else if (pktin.type == SSH1_MSG_IGNORE) {
516 static int ssh2_rdpkt(unsigned char **data, int *datalen)
518 struct rdpkt2_state_tag *st = &rdpkt2_state;
526 st->cipherblk = sccipher->blksize;
529 if (st->cipherblk < 8)
532 if (pktin.maxlen < st->cipherblk) {
533 pktin.maxlen = st->cipherblk;
534 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
535 srealloc(pktin.data, st->cipherblk+APIEXTRA));
537 fatalbox("Out of memory");
541 * Acquire and decrypt the first block of the packet. This will
542 * contain the length and padding details.
544 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
545 while ((*datalen) == 0)
546 crReturn(st->cipherblk-st->i);
547 pktin.data[st->i] = *(*data)++;
551 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
556 sccipher->decrypt(pktin.data, st->cipherblk);
559 * Now get the length and padding figures.
561 st->len = GET_32BIT(pktin.data);
562 st->pad = pktin.data[4];
565 * This enables us to deduce the payload length.
567 st->payload = st->len - st->pad - 1;
569 pktin.length = st->payload + 5;
572 * So now we can work out the total packet length.
574 st->packetlen = st->len + 4;
575 st->maclen = scmac ? scmac->len : 0;
578 * Adjust memory allocation if packet is too big.
580 if (pktin.maxlen < st->packetlen+st->maclen) {
581 pktin.maxlen = st->packetlen+st->maclen;
582 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
583 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
585 fatalbox("Out of memory");
589 * Read and decrypt the remainder of the packet.
591 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
592 while ((*datalen) == 0)
593 crReturn(st->packetlen + st->maclen - st->i);
594 pktin.data[st->i] = *(*data)++;
597 /* Decrypt everything _except_ the MAC. */
599 sccipher->decrypt(pktin.data + st->cipherblk,
600 st->packetlen - st->cipherblk);
603 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
604 for (st->i = 0; st->i < st->packetlen; st->i++)
605 debug((" %02x", (unsigned char)pktin.data[st->i]));
612 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
613 bombout(("Incorrect MAC received on packet"));
616 st->incoming_sequence++; /* whether or not we MACed */
619 * Decompress packet payload.
622 unsigned char *newpayload;
624 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
625 &newpayload, &newlen)) {
626 if (pktin.maxlen < newlen+5) {
627 pktin.maxlen = newlen+5;
628 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
629 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
631 fatalbox("Out of memory");
633 pktin.length = 5 + newlen;
634 memcpy(pktin.data+5, newpayload, newlen);
636 debug(("Post-decompression payload:\r\n"));
637 for (st->i = 0; st->i < newlen; st->i++)
638 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
647 pktin.type = pktin.data[5];
649 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
650 goto next_packet; /* FIXME: print DEBUG message */
655 static void ssh1_pktout_size(int len) {
658 len += 5; /* type and CRC */
662 pktout.length = len-5;
663 if (pktout.maxlen < biglen) {
664 pktout.maxlen = biglen;
666 /* Allocate enough buffer space for extra block
667 * for MS CryptEncrypt() */
668 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
669 srealloc(pktout.data, biglen+12));
671 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
672 srealloc(pktout.data, biglen+4));
675 fatalbox("Out of memory");
677 pktout.body = pktout.data+4+pad+1;
680 static void s_wrpkt_start(int type, int len) {
681 ssh1_pktout_size(len);
685 static int s_wrpkt_prepare(void) {
686 int pad, len, biglen, i;
689 pktout.body[-1] = pktout.type;
692 debug(("Packet payload pre-compression:\n"));
693 for (i = -1; i < pktout.length; i++)
694 debug((" %02x", (unsigned char)pktout.body[i]));
698 if (ssh1_compressing) {
699 unsigned char *compblk;
701 zlib_compress_block(pktout.body-1, pktout.length+1,
703 ssh1_pktout_size(complen-1);
704 memcpy(pktout.body-1, compblk, complen);
707 debug(("Packet payload post-compression:\n"));
708 for (i = -1; i < pktout.length; i++)
709 debug((" %02x", (unsigned char)pktout.body[i]));
714 len = pktout.length + 5; /* type and CRC */
718 for (i=0; i<pad; i++)
719 pktout.data[i+4] = random_byte();
720 crc = crc32(pktout.data+4, biglen-4);
721 PUT_32BIT(pktout.data+biglen, crc);
722 PUT_32BIT(pktout.data, len);
725 debug(("Sending packet len=%d\r\n", biglen+4));
726 for (i = 0; i < biglen+4; i++)
727 debug((" %02x", (unsigned char)pktout.data[i]));
731 cipher->encrypt(pktout.data+4, biglen);
736 static void s_wrpkt(void) {
738 len = s_wrpkt_prepare();
739 sk_write(s, pktout.data, len);
742 static void s_wrpkt_defer(void) {
744 len = s_wrpkt_prepare();
745 if (deferred_len + len > deferred_size) {
746 deferred_size = deferred_len + len + 128;
747 deferred_send_data = srealloc(deferred_send_data, deferred_size);
749 memcpy(deferred_send_data+deferred_len, pktout.data, len);
754 * Construct a packet with the specified contents.
756 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
758 unsigned char *p, *argp, argchar;
759 unsigned long argint;
760 int pktlen, argtype, arglen;
764 while ((argtype = va_arg(ap1, int)) != PKT_END) {
767 (void) va_arg(ap1, int);
771 (void) va_arg(ap1, char);
775 (void) va_arg(ap1, unsigned char *);
776 arglen = va_arg(ap1, int);
780 argp = va_arg(ap1, unsigned char *);
781 arglen = strlen(argp);
782 pktlen += 4 + arglen;
785 bn = va_arg(ap1, Bignum);
786 pktlen += ssh1_bignum_length(bn);
793 s_wrpkt_start(pkttype, pktlen);
796 while ((argtype = va_arg(ap2, int)) != PKT_END) {
799 argint = va_arg(ap2, int);
800 PUT_32BIT(p, argint);
804 argchar = va_arg(ap2, unsigned char);
809 argp = va_arg(ap2, unsigned char *);
810 arglen = va_arg(ap2, int);
811 memcpy(p, argp, arglen);
815 argp = va_arg(ap2, unsigned char *);
816 arglen = strlen(argp);
817 PUT_32BIT(p, arglen);
818 memcpy(p + 4, argp, arglen);
822 bn = va_arg(ap2, Bignum);
823 p += ssh1_write_bignum(p, bn);
829 static void send_packet(int pkttype, ...) {
831 va_start(ap1, pkttype);
832 va_start(ap2, pkttype);
833 construct_packet(pkttype, ap1, ap2);
837 static void defer_packet(int pkttype, ...) {
839 va_start(ap1, pkttype);
840 va_start(ap2, pkttype);
841 construct_packet(pkttype, ap1, ap2);
845 static int ssh_versioncmp(char *a, char *b) {
847 unsigned long av, bv;
849 av = strtoul(a, &ae, 10);
850 bv = strtoul(b, &be, 10);
851 if (av != bv) return (av < bv ? -1 : +1);
852 if (*ae == '.') ae++;
853 if (*be == '.') be++;
854 av = strtoul(ae, &ae, 10);
855 bv = strtoul(be, &be, 10);
856 if (av != bv) return (av < bv ? -1 : +1);
862 * Utility routines for putting an SSH-protocol `string' and
863 * `uint32' into a SHA state.
866 static void sha_string(SHA_State *s, void *str, int len) {
867 unsigned char lenblk[4];
868 PUT_32BIT(lenblk, len);
869 SHA_Bytes(s, lenblk, 4);
870 SHA_Bytes(s, str, len);
873 static void sha_uint32(SHA_State *s, unsigned i) {
874 unsigned char intblk[4];
875 PUT_32BIT(intblk, i);
876 SHA_Bytes(s, intblk, 4);
880 * SSH2 packet construction functions.
882 static void ssh2_pkt_ensure(int length) {
883 if (pktout.maxlen < length) {
884 pktout.maxlen = length + 256;
885 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
886 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
888 fatalbox("Out of memory");
891 static void ssh2_pkt_adddata(void *data, int len) {
892 pktout.length += len;
893 ssh2_pkt_ensure(pktout.length);
894 memcpy(pktout.data+pktout.length-len, data, len);
896 static void ssh2_pkt_addbyte(unsigned char byte) {
897 ssh2_pkt_adddata(&byte, 1);
899 static void ssh2_pkt_init(int pkt_type) {
901 ssh2_pkt_addbyte((unsigned char)pkt_type);
903 static void ssh2_pkt_addbool(unsigned char value) {
904 ssh2_pkt_adddata(&value, 1);
906 static void ssh2_pkt_adduint32(unsigned long value) {
909 ssh2_pkt_adddata(x, 4);
911 static void ssh2_pkt_addstring_start(void) {
912 ssh2_pkt_adduint32(0);
913 pktout.savedpos = pktout.length;
915 static void ssh2_pkt_addstring_str(char *data) {
916 ssh2_pkt_adddata(data, strlen(data));
917 PUT_32BIT(pktout.data + pktout.savedpos - 4,
918 pktout.length - pktout.savedpos);
920 static void ssh2_pkt_addstring_data(char *data, int len) {
921 ssh2_pkt_adddata(data, len);
922 PUT_32BIT(pktout.data + pktout.savedpos - 4,
923 pktout.length - pktout.savedpos);
925 static void ssh2_pkt_addstring(char *data) {
926 ssh2_pkt_addstring_start();
927 ssh2_pkt_addstring_str(data);
929 static char *ssh2_mpint_fmt(Bignum b, int *len) {
931 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
934 fatalbox("out of memory");
936 for (i = 1; i <= n; i++)
937 p[i] = bignum_byte(b, n-i);
939 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
941 memmove(p, p+i, n+1-i);
945 static void ssh2_pkt_addmp(Bignum b) {
948 p = ssh2_mpint_fmt(b, &len);
949 ssh2_pkt_addstring_start();
950 ssh2_pkt_addstring_data(p, len);
955 * Construct an SSH2 final-form packet: compress it, encrypt it,
956 * put the MAC on it. Final packet, ready to be sent, is stored in
957 * pktout.data. Total length is returned.
959 static int ssh2_pkt_construct(void) {
960 int cipherblk, maclen, padding, i;
961 static unsigned long outgoing_sequence = 0;
964 * Compress packet payload.
967 debug(("Pre-compression payload:\r\n"));
968 for (i = 5; i < pktout.length; i++)
969 debug((" %02x", (unsigned char)pktout.data[i]));
973 unsigned char *newpayload;
975 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
976 &newpayload, &newlen)) {
978 ssh2_pkt_adddata(newpayload, newlen);
984 * Add padding. At least four bytes, and must also bring total
985 * length (minus MAC) up to a multiple of the block size.
987 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
988 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
990 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
991 maclen = csmac ? csmac->len : 0;
992 ssh2_pkt_ensure(pktout.length + padding + maclen);
993 pktout.data[4] = padding;
994 for (i = 0; i < padding; i++)
995 pktout.data[pktout.length + i] = random_byte();
996 PUT_32BIT(pktout.data, pktout.length + padding - 4);
998 csmac->generate(pktout.data, pktout.length + padding,
1000 outgoing_sequence++; /* whether or not we MACed */
1003 debug(("Sending packet len=%d\r\n", pktout.length+padding));
1004 for (i = 0; i < pktout.length+padding; i++)
1005 debug((" %02x", (unsigned char)pktout.data[i]));
1010 cscipher->encrypt(pktout.data, pktout.length + padding);
1012 /* Ready-to-send packet starts at pktout.data. We return length. */
1013 return pktout.length + padding + maclen;
1017 * Construct and send an SSH2 packet immediately.
1019 static void ssh2_pkt_send(void) {
1020 int len = ssh2_pkt_construct();
1021 sk_write(s, pktout.data, len);
1025 * Construct an SSH2 packet and add it to a deferred data block.
1026 * Useful for sending multiple packets in a single sk_write() call,
1027 * to prevent a traffic-analysing listener from being able to work
1028 * out the length of any particular packet (such as the password
1031 * Note that because SSH2 sequence-numbers its packets, this can
1032 * NOT be used as an m4-style `defer' allowing packets to be
1033 * constructed in one order and sent in another.
1035 static void ssh2_pkt_defer(void) {
1036 int len = ssh2_pkt_construct();
1037 if (deferred_len + len > deferred_size) {
1038 deferred_size = deferred_len + len + 128;
1039 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1041 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1042 deferred_len += len;
1046 * Send the whole deferred data block constructed by
1047 * ssh2_pkt_defer() or SSH1's defer_packet().
1049 static void ssh_pkt_defersend(void) {
1050 sk_write(s, deferred_send_data, deferred_len);
1051 deferred_len = deferred_size = 0;
1052 sfree(deferred_send_data);
1053 deferred_send_data = NULL;
1057 void bndebug(char *string, Bignum b) {
1060 p = ssh2_mpint_fmt(b, &len);
1061 debug(("%s", string));
1062 for (i = 0; i < len; i++)
1063 debug((" %02x", p[i]));
1069 static void sha_mpint(SHA_State *s, Bignum b) {
1072 p = ssh2_mpint_fmt(b, &len);
1073 sha_string(s, p, len);
1078 * SSH2 packet decode functions.
1080 static unsigned long ssh2_pkt_getuint32(void) {
1081 unsigned long value;
1082 if (pktin.length - pktin.savedpos < 4)
1083 return 0; /* arrgh, no way to decline (FIXME?) */
1084 value = GET_32BIT(pktin.data+pktin.savedpos);
1085 pktin.savedpos += 4;
1088 static int ssh2_pkt_getbool(void) {
1089 unsigned long value;
1090 if (pktin.length - pktin.savedpos < 1)
1091 return 0; /* arrgh, no way to decline (FIXME?) */
1092 value = pktin.data[pktin.savedpos] != 0;
1096 static void ssh2_pkt_getstring(char **p, int *length) {
1098 if (pktin.length - pktin.savedpos < 4)
1100 *length = GET_32BIT(pktin.data+pktin.savedpos);
1101 pktin.savedpos += 4;
1102 if (pktin.length - pktin.savedpos < *length)
1104 *p = pktin.data+pktin.savedpos;
1105 pktin.savedpos += *length;
1107 static Bignum ssh2_pkt_getmp(void) {
1112 ssh2_pkt_getstring(&p, &length);
1116 bombout(("internal error: Can't handle negative mpints"));
1119 b = bignum_from_bytes(p, length);
1124 * Examine the remote side's version string and compare it against
1125 * a list of known buggy implementations.
1127 static void ssh_detect_bugs(char *vstring) {
1128 char *imp; /* pointer to implementation part */
1130 imp += strcspn(imp, "-");
1131 imp += strcspn(imp, "-");
1133 ssh_remote_bugs = 0;
1135 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1136 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1137 !strcmp(imp, "1.2.22")) {
1139 * These versions don't support SSH1_MSG_IGNORE, so we have
1140 * to use a different defence against password length
1143 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1144 logevent("We believe remote version has SSH1 ignore bug");
1147 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1148 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1149 !strncmp(imp, "2.1 ", 4)) {
1151 * These versions have the HMAC bug.
1153 ssh_remote_bugs |= BUG_SSH2_HMAC;
1154 logevent("We believe remote version has SSH2 HMAC bug");
1158 static int do_ssh_init(unsigned char c) {
1160 static char version[10];
1161 static char vstring[80];
1162 static char vlog[sizeof(vstring)+20];
1167 /* Search for the string "SSH-" in the input. */
1170 static const int transS[] = { 1, 2, 2, 1 };
1171 static const int transH[] = { 0, 0, 3, 0 };
1172 static const int transminus[] = { 0, 0, 0, -1 };
1173 if (c == 'S') i = transS[i];
1174 else if (c == 'H') i = transH[i];
1175 else if (c == '-') i = transminus[i];
1179 crReturn(1); /* get another character */
1182 strcpy(vstring, "SSH-");
1186 crReturn(1); /* get another char */
1187 if (vsp < vstring+sizeof(vstring)-1)
1193 } else if (i < sizeof(version)-1)
1200 ssh_agentfwd_enabled = FALSE;
1201 rdpkt2_state.incoming_sequence = 0;
1204 sprintf(vlog, "Server version: %s", vstring);
1205 ssh_detect_bugs(vstring);
1206 vlog[strcspn(vlog, "\r\n")] = '\0';
1210 * Server version "1.99" means we can choose whether we use v1
1211 * or v2 protocol. Choice is based on cfg.sshprot.
1213 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1215 * This is a v2 server. Begin v2 protocol.
1218 sprintf(verstring, "SSH-2.0-%s", sshver);
1219 SHA_Init(&exhashbase);
1221 * Hash our version string and their version string.
1223 sha_string(&exhashbase, verstring, strlen(verstring));
1224 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1225 sprintf(vstring, "%s\n", verstring);
1226 sprintf(vlog, "We claim version: %s", verstring);
1228 logevent("Using SSH protocol version 2");
1229 sk_write(s, vstring, strlen(vstring));
1230 ssh_protocol = ssh2_protocol;
1232 s_rdpkt = ssh2_rdpkt;
1235 * This is a v1 server. Begin v1 protocol.
1237 sprintf(vstring, "SSH-%s-%s\n",
1238 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1240 sprintf(vlog, "We claim version: %s", vstring);
1241 vlog[strcspn(vlog, "\r\n")] = '\0';
1243 logevent("Using SSH protocol version 1");
1244 sk_write(s, vstring, strlen(vstring));
1245 ssh_protocol = ssh1_protocol;
1247 s_rdpkt = ssh1_rdpkt;
1249 ssh_state = SSH_STATE_BEFORE_SIZE;
1254 static void ssh_gotdata(unsigned char *data, int datalen)
1259 * To begin with, feed the characters one by one to the
1260 * protocol initialisation / selection function do_ssh_init().
1261 * When that returns 0, we're done with the initial greeting
1262 * exchange and can move on to packet discipline.
1267 crReturnV; /* more data please */
1268 ret = do_ssh_init(*data);
1275 * We emerge from that loop when the initial negotiation is
1276 * over and we have selected an s_rdpkt function. Now pass
1277 * everything to s_rdpkt, and then pass the resulting packets
1278 * to the proper protocol handler.
1283 while (datalen > 0) {
1284 if ( s_rdpkt(&data, &datalen) == 0 ) {
1285 ssh_protocol(NULL, 0, 1);
1286 if (ssh_state == SSH_STATE_CLOSED) {
1296 static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) {
1297 ssh_state = SSH_STATE_CLOSED;
1301 /* A socket error has occurred. */
1302 connection_fatal (error_msg);
1304 /* Otherwise, the remote side closed the connection normally. */
1309 static int ssh_receive(Plug plug, int urgent, char *data, int len) {
1310 ssh_gotdata (data, len);
1311 if (ssh_state == SSH_STATE_CLOSED) {
1322 * Connect to specified host and port.
1323 * Returns an error message, or NULL on success.
1324 * Also places the canonical host name into `realhost'.
1326 static char *connect_to_host(char *host, int port, char **realhost)
1328 static struct plug_function_table fn_table = {
1331 }, *fn_table_ptr = &fn_table;
1340 savedhost = smalloc(1+strlen(host));
1342 fatalbox("Out of memory");
1343 strcpy(savedhost, host);
1346 port = 22; /* default ssh port */
1359 addr = sk_namelookup(host, realhost);
1360 if ( (err = sk_addr_error(addr)) )
1370 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1371 if ( (err = sk_socket_error(s)) )
1375 sk_write(s, "connect ", 8);
1376 sk_write(s, FWhost, strlen(FWhost));
1379 sprintf(buf, " %d\n", FWport);
1380 sk_write(s, buf, strlen(buf));
1388 * Handle the key exchange and user authentication phases.
1390 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1393 unsigned char *rsabuf, *keystr1, *keystr2;
1394 unsigned char cookie[8];
1395 struct RSAKey servkey, hostkey;
1396 struct MD5Context md5c;
1397 static unsigned long supported_ciphers_mask, supported_auths_mask;
1398 static int tried_publickey;
1399 static unsigned char session_id[16];
1401 static char username[100];
1405 if (!ispkt) crWaitUntil(ispkt);
1407 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1408 bombout(("Public key packet not received"));
1412 logevent("Received public keys");
1414 memcpy(cookie, pktin.body, 8);
1416 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1417 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1420 * Log the host key fingerprint.
1424 logevent("Host key fingerprint is:");
1425 strcpy(logmsg, " ");
1426 hostkey.comment = NULL;
1427 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1432 ssh1_remote_protoflags = GET_32BIT(pktin.body+8+i+j);
1433 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1434 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1436 ssh1_local_protoflags = ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1437 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1440 MD5Update(&md5c, keystr2, hostkey.bytes);
1441 MD5Update(&md5c, keystr1, servkey.bytes);
1442 MD5Update(&md5c, pktin.body, 8);
1443 MD5Final(session_id, &md5c);
1445 for (i=0; i<32; i++)
1446 session_key[i] = random_byte();
1448 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1450 rsabuf = smalloc(len);
1452 fatalbox("Out of memory");
1455 * Verify the host key.
1459 * First format the key into a string.
1461 int len = rsastr_len(&hostkey);
1462 char fingerprint[100];
1463 char *keystr = smalloc(len);
1465 fatalbox("Out of memory");
1466 rsastr_fmt(keystr, &hostkey);
1467 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1468 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1472 for (i=0; i<32; i++) {
1473 rsabuf[i] = session_key[i];
1475 rsabuf[i] ^= session_id[i];
1478 if (hostkey.bytes > servkey.bytes) {
1479 rsaencrypt(rsabuf, 32, &servkey);
1480 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1482 rsaencrypt(rsabuf, 32, &hostkey);
1483 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1486 logevent("Encrypted session key");
1488 switch (cfg.cipher) {
1489 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1490 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1491 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1493 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1494 cipher_type = SSH_CIPHER_3DES;
1497 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1498 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
1499 cipher_type = SSH_CIPHER_3DES;
1501 switch (cipher_type) {
1502 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1503 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1504 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1507 send_packet(SSH1_CMSG_SESSION_KEY,
1508 PKT_CHAR, cipher_type,
1509 PKT_DATA, cookie, 8,
1510 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1511 PKT_DATA, rsabuf, len,
1512 PKT_INT, ssh1_local_protoflags,
1515 logevent("Trying to enable encryption...");
1519 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1520 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1522 cipher->sesskey(session_key);
1526 if (pktin.type != SSH1_SMSG_SUCCESS) {
1527 bombout(("Encryption not successfully enabled"));
1531 logevent("Successfully started encryption");
1537 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1539 if (!ssh_get_line("login as: ",
1540 username, sizeof(username), FALSE)) {
1542 * get_line failed to get a username.
1545 logevent("No username provided. Abandoning session.");
1546 ssh_state = SSH_STATE_CLOSED;
1550 c_write_str("login as: ");
1553 crWaitUntil(!ispkt);
1554 while (inlen--) switch (c = *in++) {
1561 c_write_str("\b \b");
1567 c_write_str("\b \b");
1576 if (((c >= ' ' && c <= '~') ||
1577 ((unsigned char)c >= 160)) && pos < 40) {
1578 username[pos++] = c;
1584 c_write_str("\r\n");
1585 username[strcspn(username, "\n\r")] = '\0';
1588 strncpy(username, cfg.username, 99);
1589 username[99] = '\0';
1592 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1594 char userlog[22+sizeof(username)];
1595 sprintf(userlog, "Sent username \"%s\"", username);
1597 if (flags & FLAG_INTERACTIVE &&
1598 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1599 strcat(userlog, "\r\n");
1600 c_write_str(userlog);
1607 tried_publickey = 0;
1609 while (pktin.type == SSH1_SMSG_FAILURE) {
1610 static char password[100];
1611 static char prompt[200];
1614 static int pwpkt_type;
1616 * Show password prompt, having first obtained it via a TIS
1617 * or CryptoCard exchange if we're doing TIS or CryptoCard
1620 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1621 if (agent_exists()) {
1623 * Attempt RSA authentication using Pageant.
1625 static unsigned char request[5], *response, *p;
1626 static int responselen;
1627 static int i, nkeys;
1628 static int authed = FALSE;
1631 logevent("Pageant is running. Requesting keys.");
1633 /* Request the keys held by the agent. */
1634 PUT_32BIT(request, 1);
1635 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1636 agent_query(request, 5, &r, &responselen);
1637 response = (unsigned char *)r;
1638 if (response && responselen >= 5 &&
1639 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1641 nkeys = GET_32BIT(p); p += 4;
1642 { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1644 for (i = 0; i < nkeys; i++) {
1645 static struct RSAKey key;
1646 static Bignum challenge;
1647 static char *commentp;
1648 static int commentlen;
1650 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1653 p += ssh1_read_bignum(p, &key.exponent);
1654 p += ssh1_read_bignum(p, &key.modulus);
1655 commentlen = GET_32BIT(p); p += 4;
1656 commentp = p; p += commentlen;
1657 send_packet(SSH1_CMSG_AUTH_RSA,
1658 PKT_BIGNUM, key.modulus, PKT_END);
1660 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1661 logevent("Key refused");
1664 logevent("Received RSA challenge");
1665 ssh1_read_bignum(pktin.body, &challenge);
1667 char *agentreq, *q, *ret;
1669 len = 1 + 4; /* message type, bit count */
1670 len += ssh1_bignum_length(key.exponent);
1671 len += ssh1_bignum_length(key.modulus);
1672 len += ssh1_bignum_length(challenge);
1673 len += 16; /* session id */
1674 len += 4; /* response format */
1675 agentreq = smalloc(4 + len);
1676 PUT_32BIT(agentreq, len);
1678 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1679 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1681 q += ssh1_write_bignum(q, key.exponent);
1682 q += ssh1_write_bignum(q, key.modulus);
1683 q += ssh1_write_bignum(q, challenge);
1684 memcpy(q, session_id, 16); q += 16;
1685 PUT_32BIT(q, 1); /* response format */
1686 agent_query(agentreq, len+4, &ret, &retlen);
1689 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1690 logevent("Sending Pageant's response");
1691 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1692 PKT_DATA, ret+5, 16, PKT_END);
1695 if (pktin.type == SSH1_SMSG_SUCCESS) {
1696 logevent("Pageant's response accepted");
1697 if (flags & FLAG_VERBOSE) {
1698 c_write_str("Authenticated using RSA key \"");
1699 c_write(commentp, commentlen);
1700 c_write_str("\" from agent\r\n");
1704 logevent("Pageant's response not accepted");
1706 logevent("Pageant failed to answer challenge");
1710 logevent("No reply received from Pageant");
1713 freebn(key.exponent);
1714 freebn(key.modulus);
1723 if (*cfg.keyfile && !tried_publickey)
1724 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1726 if (pktin.type == SSH1_SMSG_FAILURE &&
1728 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1729 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1730 logevent("Requested TIS authentication");
1731 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1733 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1734 logevent("TIS authentication declined");
1735 if (flags & FLAG_INTERACTIVE)
1736 c_write_str("TIS authentication refused.\r\n");
1738 int challengelen = ((pktin.body[0] << 24) |
1739 (pktin.body[1] << 16) |
1740 (pktin.body[2] << 8) |
1742 logevent("Received TIS challenge");
1743 if (challengelen > sizeof(prompt)-1)
1744 challengelen = sizeof(prompt)-1; /* prevent overrun */
1745 memcpy(prompt, pktin.body+4, challengelen);
1746 prompt[challengelen] = '\0';
1749 if (pktin.type == SSH1_SMSG_FAILURE &&
1751 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1752 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1753 logevent("Requested CryptoCard authentication");
1754 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1756 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1757 logevent("CryptoCard authentication declined");
1758 c_write_str("CryptoCard authentication refused.\r\n");
1760 int challengelen = ((pktin.body[0] << 24) |
1761 (pktin.body[1] << 16) |
1762 (pktin.body[2] << 8) |
1764 logevent("Received CryptoCard challenge");
1765 if (challengelen > sizeof(prompt)-1)
1766 challengelen = sizeof(prompt)-1; /* prevent overrun */
1767 memcpy(prompt, pktin.body+4, challengelen);
1768 strncpy(prompt + challengelen, "\r\nResponse : ",
1769 sizeof(prompt)-challengelen);
1770 prompt[sizeof(prompt)-1] = '\0';
1773 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1774 sprintf(prompt, "%.90s@%.90s's password: ",
1775 username, savedhost);
1777 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1778 char *comment = NULL;
1779 if (flags & FLAG_VERBOSE)
1780 c_write_str("Trying public key authentication.\r\n");
1781 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1782 if (flags & FLAG_VERBOSE)
1783 c_write_str("No passphrase required.\r\n");
1786 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1791 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
1793 * get_line failed to get a password (for example
1794 * because one was supplied on the command line
1795 * which has already failed to work). Terminate.
1797 logevent("No more passwords to try");
1798 ssh_state = SSH_STATE_CLOSED;
1802 c_write_str(prompt);
1806 crWaitUntil(!ispkt);
1807 while (inlen--) switch (c = *in++) {
1824 if (((c >= ' ' && c <= '~') ||
1825 ((unsigned char)c >= 160)) && pos < sizeof(password))
1826 password[pos++] = c;
1830 c_write_str("\r\n");
1834 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1836 * Try public key authentication with the specified
1839 static struct RSAKey pubkey;
1840 static Bignum challenge, response;
1842 static unsigned char buffer[32];
1844 tried_publickey = 1;
1845 i = loadrsakey(cfg.keyfile, &pubkey, password);
1847 c_write_str("Couldn't load public key from ");
1848 c_write_str(cfg.keyfile);
1849 c_write_str(".\r\n");
1850 continue; /* go and try password */
1853 c_write_str("Wrong passphrase.\r\n");
1854 tried_publickey = 0;
1855 continue; /* try again */
1859 * Send a public key attempt.
1861 send_packet(SSH1_CMSG_AUTH_RSA,
1862 PKT_BIGNUM, pubkey.modulus, PKT_END);
1865 if (pktin.type == SSH1_SMSG_FAILURE) {
1866 c_write_str("Server refused our public key.\r\n");
1867 continue; /* go and try password */
1869 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1870 bombout(("Bizarre response to offer of public key"));
1873 ssh1_read_bignum(pktin.body, &challenge);
1874 response = rsadecrypt(challenge, &pubkey);
1875 freebn(pubkey.private_exponent); /* burn the evidence */
1877 for (i = 0; i < 32; i++) {
1878 buffer[i] = bignum_byte(response, 31-i);
1882 MD5Update(&md5c, buffer, 32);
1883 MD5Update(&md5c, session_id, 16);
1884 MD5Final(buffer, &md5c);
1886 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1887 PKT_DATA, buffer, 16, PKT_END);
1890 if (pktin.type == SSH1_SMSG_FAILURE) {
1891 if (flags & FLAG_VERBOSE)
1892 c_write_str("Failed to authenticate with our public key.\r\n");
1893 continue; /* go and try password */
1894 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1895 bombout(("Bizarre response to RSA authentication response"));
1899 break; /* we're through! */
1901 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1903 * Defence against traffic analysis: we send a
1904 * whole bunch of packets containing strings of
1905 * different lengths. One of these strings is the
1906 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
1907 * The others are all random data in
1908 * SSH1_MSG_IGNORE packets. This way a passive
1909 * listener can't tell which is the password, and
1910 * hence can't deduce the password length.
1912 * Anybody with a password length greater than 16
1913 * bytes is going to have enough entropy in their
1914 * password that a listener won't find it _that_
1915 * much help to know how long it is. So what we'll
1918 * - if password length < 16, we send 15 packets
1919 * containing string lengths 1 through 15
1921 * - otherwise, we let N be the nearest multiple
1922 * of 8 below the password length, and send 8
1923 * packets containing string lengths N through
1924 * N+7. This won't obscure the order of
1925 * magnitude of the password length, but it will
1926 * introduce a bit of extra uncertainty.
1928 * A few servers (the old 1.2.18 through 1.2.22)
1929 * can't deal with SSH1_MSG_IGNORE. For these
1930 * servers, we need an alternative defence. We make
1931 * use of the fact that the password is interpreted
1932 * as a C string: so we can append a NUL, then some
1935 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
1940 len = strlen(password);
1941 if (len < sizeof(string)) {
1943 strcpy(string, password);
1944 len++; /* cover the zero byte */
1945 while (len < sizeof(string)) {
1946 string[len++] = (char)random_byte();
1951 send_packet(pwpkt_type, PKT_INT, len,
1952 PKT_DATA, s, len, PKT_END);
1954 int bottom, top, pwlen, i;
1957 pwlen = strlen(password);
1959 bottom = 0; /* zero length passwords are OK! :-) */
1962 bottom = pwlen &~ 7;
1966 assert(pwlen >= bottom && pwlen <= top);
1968 randomstr = smalloc(top+1);
1970 for (i = bottom; i <= top; i++) {
1972 defer_packet(pwpkt_type, PKT_STR, password, PKT_END);
1974 for (j = 0; j < i; j++) {
1976 randomstr[j] = random_byte();
1977 } while (randomstr[j] == '\0');
1979 randomstr[i] = '\0';
1980 defer_packet(SSH1_MSG_IGNORE,
1981 PKT_STR, randomstr, PKT_END);
1984 ssh_pkt_defersend();
1987 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1990 logevent("Sent password");
1991 memset(password, 0, strlen(password));
1993 if (pktin.type == SSH1_SMSG_FAILURE) {
1994 if (flags & FLAG_VERBOSE)
1995 c_write_str("Access denied\r\n");
1996 logevent("Authentication refused");
1997 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1998 logevent("Received disconnect request");
1999 ssh_state = SSH_STATE_CLOSED;
2001 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2002 bombout(("Strange packet received, type %d", pktin.type));
2007 logevent("Authentication successful");
2012 void sshfwd_close(struct ssh_channel *c) {
2013 if (c && !c->closes) {
2014 if (ssh_version == 1) {
2015 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
2017 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2018 ssh2_pkt_adduint32(c->remoteid);
2022 if (c->type == CHAN_X11) {
2024 logevent("X11 connection terminated");
2029 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
2030 if (ssh_version == 1) {
2031 send_packet(SSH1_MSG_CHANNEL_DATA,
2032 PKT_INT, c->remoteid,
2037 ssh2_add_channel_data(c, buf, len);
2042 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
2047 while (!do_ssh1_login(in, inlen, ispkt)) {
2050 if (ssh_state == SSH_STATE_CLOSED)
2053 if (cfg.agentfwd && agent_exists()) {
2054 logevent("Requesting agent forwarding");
2055 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2056 do { crReturnV; } while (!ispkt);
2057 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2058 bombout(("Protocol confusion"));
2060 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2061 logevent("Agent forwarding refused");
2063 logevent("Agent forwarding enabled");
2064 ssh_agentfwd_enabled = TRUE;
2068 if (cfg.x11_forward) {
2069 char proto[20], data[64];
2070 logevent("Requesting X11 forwarding");
2071 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2072 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2073 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2074 PKT_STR, proto, PKT_STR, data,
2078 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2079 PKT_STR, proto, PKT_STR, data,
2082 do { crReturnV; } while (!ispkt);
2083 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2084 bombout(("Protocol confusion"));
2086 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2087 logevent("X11 forwarding refused");
2089 logevent("X11 forwarding enabled");
2090 ssh_X11_fwd_enabled = TRUE;
2095 send_packet(SSH1_CMSG_REQUEST_PTY,
2096 PKT_STR, cfg.termtype,
2097 PKT_INT, rows, PKT_INT, cols,
2098 PKT_INT, 0, PKT_INT, 0,
2101 ssh_state = SSH_STATE_INTERMED;
2102 do { crReturnV; } while (!ispkt);
2103 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2104 bombout(("Protocol confusion"));
2106 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2107 c_write_str("Server refused to allocate pty\r\n");
2108 ssh_editing = ssh_echoing = 1;
2110 logevent("Allocated pty");
2112 ssh_editing = ssh_echoing = 1;
2115 if (cfg.compression) {
2116 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2117 do { crReturnV; } while (!ispkt);
2118 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2119 bombout(("Protocol confusion"));
2121 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2122 c_write_str("Server refused to compress\r\n");
2124 logevent("Started compression");
2125 ssh1_compressing = TRUE;
2126 zlib_compress_init();
2127 zlib_decompress_init();
2130 if (*cfg.remote_cmd)
2131 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
2133 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2134 logevent("Started session");
2136 ssh_state = SSH_STATE_SESSION;
2140 ssh_special(TS_EOF);
2142 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2144 ssh_channels = newtree234(ssh_channelcmp);
2148 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2149 pktin.type == SSH1_SMSG_STDERR_DATA) {
2150 long len = GET_32BIT(pktin.body);
2151 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2153 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2154 ssh_state = SSH_STATE_CLOSED;
2155 logevent("Received disconnect request");
2157 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2158 /* Remote side is trying to open a channel to talk to our
2159 * X-Server. Give them back a local channel number. */
2161 struct ssh_channel *c, *d;
2164 logevent("Received X11 connect request");
2165 /* Refuse if X11 forwarding is disabled. */
2166 if (!ssh_X11_fwd_enabled) {
2167 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2168 PKT_INT, GET_32BIT(pktin.body),
2170 logevent("Rejected X11 connect request");
2172 c = smalloc(sizeof(struct ssh_channel));
2174 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
2175 logevent("opening X11 forward connection failed");
2177 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2178 PKT_INT, GET_32BIT(pktin.body),
2181 logevent("opening X11 forward connection succeeded");
2182 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
2184 break; /* found a free number */
2187 c->remoteid = GET_32BIT(pktin.body);
2190 c->type = CHAN_X11; /* identify channel type */
2191 add234(ssh_channels, c);
2192 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2193 PKT_INT, c->remoteid, PKT_INT, c->localid,
2195 logevent("Opened X11 forward channel");
2198 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2199 /* Remote side is trying to open a channel to talk to our
2200 * agent. Give them back a local channel number. */
2202 struct ssh_channel *c;
2205 /* Refuse if agent forwarding is disabled. */
2206 if (!ssh_agentfwd_enabled) {
2207 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2208 PKT_INT, GET_32BIT(pktin.body),
2212 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2214 break; /* found a free number */
2217 c = smalloc(sizeof(struct ssh_channel));
2218 c->remoteid = GET_32BIT(pktin.body);
2221 c->type = CHAN_AGENT; /* identify channel type */
2222 c->u.a.lensofar = 0;
2223 add234(ssh_channels, c);
2224 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2225 PKT_INT, c->remoteid, PKT_INT, c->localid,
2228 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2229 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2230 /* Remote side closes a channel. */
2231 unsigned i = GET_32BIT(pktin.body);
2232 struct ssh_channel *c;
2233 c = find234(ssh_channels, &i, ssh_channelfind);
2236 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2237 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
2238 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2239 logevent("X11 connection closed");
2240 assert(c->u.x11.s != NULL);
2241 x11_close(c->u.x11.s);
2244 c->closes |= closetype;
2245 if (c->closes == 3) {
2246 del234(ssh_channels, c);
2250 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2251 /* Data sent down one of our channels. */
2252 int i = GET_32BIT(pktin.body);
2253 int len = GET_32BIT(pktin.body+4);
2254 unsigned char *p = pktin.body+8;
2255 struct ssh_channel *c;
2256 c = find234(ssh_channels, &i, ssh_channelfind);
2260 x11_send(c->u.x11.s, p, len);
2263 /* Data for an agent message. Buffer it. */
2265 if (c->u.a.lensofar < 4) {
2266 int l = min(4 - c->u.a.lensofar, len);
2267 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2268 p += l; len -= l; c->u.a.lensofar += l;
2270 if (c->u.a.lensofar == 4) {
2271 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2272 c->u.a.message = smalloc(c->u.a.totallen);
2273 memcpy(c->u.a.message, c->u.a.msglen, 4);
2275 if (c->u.a.lensofar >= 4 && len > 0) {
2276 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2277 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2278 p += l; len -= l; c->u.a.lensofar += l;
2280 if (c->u.a.lensofar == c->u.a.totallen) {
2281 void *reply, *sentreply;
2283 agent_query(c->u.a.message, c->u.a.totallen,
2288 /* Fake SSH_AGENT_FAILURE. */
2289 sentreply = "\0\0\0\1\5";
2292 send_packet(SSH1_MSG_CHANNEL_DATA,
2293 PKT_INT, c->remoteid,
2295 PKT_DATA, sentreply, replylen,
2299 sfree(c->u.a.message);
2300 c->u.a.lensofar = 0;
2306 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2307 /* may be from EXEC_SHELL on some servers */
2308 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2309 /* may be from EXEC_SHELL on some servers
2310 * if no pty is available or in other odd cases. Ignore */
2311 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2312 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2314 bombout(("Strange packet received: type %d", pktin.type));
2319 int len = min(inlen, 512);
2320 send_packet(SSH1_CMSG_STDIN_DATA,
2321 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2332 * Utility routine for decoding comma-separated strings in KEXINIT.
2334 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2335 int needlen = strlen(needle);
2338 * Is it at the start of the string?
2340 if (haylen >= needlen && /* haystack is long enough */
2341 !memcmp(needle, haystack, needlen) && /* initial match */
2342 (haylen == needlen || haystack[needlen] == ',')
2343 /* either , or EOS follows */
2347 * If not, search for the next comma and resume after that.
2348 * If no comma found, terminate.
2350 while (haylen > 0 && *haystack != ',')
2351 haylen--, haystack++;
2354 haylen--, haystack++; /* skip over comma itself */
2359 * SSH2 key creation method.
2361 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2363 /* First 20 bytes. */
2366 SHA_Bytes(&s, H, 20);
2367 SHA_Bytes(&s, &chr, 1);
2368 SHA_Bytes(&s, sessid, 20);
2369 SHA_Final(&s, keyspace);
2370 /* Next 20 bytes. */
2373 SHA_Bytes(&s, H, 20);
2374 SHA_Bytes(&s, keyspace, 20);
2375 SHA_Final(&s, keyspace+20);
2379 * Handle the SSH2 transport layer.
2381 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2383 static int i, j, len, nbits, pbits;
2385 static Bignum p, g, e, f, K;
2386 static int kex_init_value, kex_reply_value;
2387 static const struct ssh_mac **maclist;
2389 static const struct ssh2_cipher *cscipher_tobe = NULL;
2390 static const struct ssh2_cipher *sccipher_tobe = NULL;
2391 static const struct ssh_mac *csmac_tobe = NULL;
2392 static const struct ssh_mac *scmac_tobe = NULL;
2393 static const struct ssh_compress *cscomp_tobe = NULL;
2394 static const struct ssh_compress *sccomp_tobe = NULL;
2395 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2396 static int hostkeylen, siglen;
2397 static void *hkey; /* actual host key */
2398 static unsigned char exchange_hash[20];
2399 static unsigned char keyspace[40];
2400 static const struct ssh2_ciphers *preferred_cipher;
2401 static const struct ssh_compress *preferred_comp;
2402 static int first_kex;
2409 * Set up the preferred cipher and compression.
2411 if (cfg.cipher == CIPHER_BLOWFISH) {
2412 preferred_cipher = &ssh2_blowfish;
2413 } else if (cfg.cipher == CIPHER_DES) {
2414 logevent("Single DES not supported in SSH2; using 3DES");
2415 preferred_cipher = &ssh2_3des;
2416 } else if (cfg.cipher == CIPHER_3DES) {
2417 preferred_cipher = &ssh2_3des;
2418 } else if (cfg.cipher == CIPHER_AES) {
2419 preferred_cipher = &ssh2_aes;
2421 /* Shouldn't happen, but we do want to initialise to _something_. */
2422 preferred_cipher = &ssh2_3des;
2424 if (cfg.compression)
2425 preferred_comp = &ssh_zlib;
2427 preferred_comp = &ssh_comp_none;
2430 * Be prepared to work around the buggy MAC problem.
2432 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2433 maclist = buggymacs, nmacs = lenof(buggymacs);
2435 maclist = macs, nmacs = lenof(macs);
2439 * Construct and send our key exchange packet.
2441 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2442 for (i = 0; i < 16; i++)
2443 ssh2_pkt_addbyte((unsigned char)random_byte());
2444 /* List key exchange algorithms. */
2445 ssh2_pkt_addstring_start();
2446 for (i = 0; i < lenof(kex_algs); i++) {
2447 ssh2_pkt_addstring_str(kex_algs[i]->name);
2448 if (i < lenof(kex_algs)-1)
2449 ssh2_pkt_addstring_str(",");
2451 /* List server host key algorithms. */
2452 ssh2_pkt_addstring_start();
2453 for (i = 0; i < lenof(hostkey_algs); i++) {
2454 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2455 if (i < lenof(hostkey_algs)-1)
2456 ssh2_pkt_addstring_str(",");
2458 /* List client->server encryption algorithms. */
2459 ssh2_pkt_addstring_start();
2460 for (i = 0; i < lenof(ciphers)+1; i++) {
2461 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2462 for (j = 0; j < c->nciphers; j++) {
2463 ssh2_pkt_addstring_str(c->list[j]->name);
2464 if (i < lenof(ciphers) || j < c->nciphers-1)
2465 ssh2_pkt_addstring_str(",");
2468 /* List server->client encryption algorithms. */
2469 ssh2_pkt_addstring_start();
2470 for (i = 0; i < lenof(ciphers)+1; i++) {
2471 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2472 for (j = 0; j < c->nciphers; j++) {
2473 ssh2_pkt_addstring_str(c->list[j]->name);
2474 if (i < lenof(ciphers) || j < c->nciphers-1)
2475 ssh2_pkt_addstring_str(",");
2478 /* List client->server MAC algorithms. */
2479 ssh2_pkt_addstring_start();
2480 for (i = 0; i < nmacs; i++) {
2481 ssh2_pkt_addstring_str(maclist[i]->name);
2483 ssh2_pkt_addstring_str(",");
2485 /* List server->client MAC algorithms. */
2486 ssh2_pkt_addstring_start();
2487 for (i = 0; i < nmacs; i++) {
2488 ssh2_pkt_addstring_str(maclist[i]->name);
2490 ssh2_pkt_addstring_str(",");
2492 /* List client->server compression algorithms. */
2493 ssh2_pkt_addstring_start();
2494 for (i = 0; i < lenof(compressions)+1; i++) {
2495 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2496 ssh2_pkt_addstring_str(c->name);
2497 if (i < lenof(compressions))
2498 ssh2_pkt_addstring_str(",");
2500 /* List server->client compression algorithms. */
2501 ssh2_pkt_addstring_start();
2502 for (i = 0; i < lenof(compressions)+1; i++) {
2503 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2504 ssh2_pkt_addstring_str(c->name);
2505 if (i < lenof(compressions))
2506 ssh2_pkt_addstring_str(",");
2508 /* List client->server languages. Empty list. */
2509 ssh2_pkt_addstring_start();
2510 /* List server->client languages. Empty list. */
2511 ssh2_pkt_addstring_start();
2512 /* First KEX packet does _not_ follow, because we're not that brave. */
2513 ssh2_pkt_addbool(FALSE);
2515 ssh2_pkt_adduint32(0);
2517 exhash = exhashbase;
2518 sha_string(&exhash, pktout.data+5, pktout.length-5);
2522 if (!ispkt) crWaitUntil(ispkt);
2523 sha_string(&exhash, pktin.data+5, pktin.length-5);
2526 * Now examine the other side's KEXINIT to see what we're up
2529 if (pktin.type != SSH2_MSG_KEXINIT) {
2530 bombout(("expected key exchange packet from server"));
2533 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2534 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2535 pktin.savedpos += 16; /* skip garbage cookie */
2536 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2537 for (i = 0; i < lenof(kex_algs); i++) {
2538 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2543 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2544 for (i = 0; i < lenof(hostkey_algs); i++) {
2545 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2546 hostkey = hostkey_algs[i];
2550 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2551 for (i = 0; i < lenof(ciphers)+1; i++) {
2552 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2553 for (j = 0; j < c->nciphers; j++) {
2554 if (in_commasep_string(c->list[j]->name, str, len)) {
2555 cscipher_tobe = c->list[j];
2562 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2563 for (i = 0; i < lenof(ciphers)+1; i++) {
2564 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2565 for (j = 0; j < c->nciphers; j++) {
2566 if (in_commasep_string(c->list[j]->name, str, len)) {
2567 sccipher_tobe = c->list[j];
2574 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2575 for (i = 0; i < nmacs; i++) {
2576 if (in_commasep_string(maclist[i]->name, str, len)) {
2577 csmac_tobe = maclist[i];
2581 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2582 for (i = 0; i < nmacs; i++) {
2583 if (in_commasep_string(maclist[i]->name, str, len)) {
2584 scmac_tobe = maclist[i];
2588 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2589 for (i = 0; i < lenof(compressions)+1; i++) {
2590 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2591 if (in_commasep_string(c->name, str, len)) {
2596 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2597 for (i = 0; i < lenof(compressions)+1; i++) {
2598 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2599 if (in_commasep_string(c->name, str, len)) {
2606 * Work out the number of bits of key we will need from the key
2607 * exchange. We start with the maximum key length of either
2613 csbits = cscipher_tobe->keylen;
2614 scbits = sccipher_tobe->keylen;
2615 nbits = (csbits > scbits ? csbits : scbits);
2617 /* The keys only have 160-bit entropy, since they're based on
2618 * a SHA-1 hash. So cap the key size at 160 bits. */
2619 if (nbits > 160) nbits = 160;
2622 * If we're doing Diffie-Hellman group exchange, start by
2623 * requesting a group.
2625 if (kex == &ssh_diffiehellman_gex) {
2626 logevent("Doing Diffie-Hellman group exchange");
2628 * Work out how big a DH group we will need to allow that
2631 pbits = 512 << ((nbits-1) / 64);
2632 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2633 ssh2_pkt_adduint32(pbits);
2637 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2638 bombout(("expected key exchange group packet from server"));
2641 p = ssh2_pkt_getmp();
2642 g = ssh2_pkt_getmp();
2643 dh_setup_group(p, g);
2644 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2645 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2648 kex_init_value = SSH2_MSG_KEXDH_INIT;
2649 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2652 logevent("Doing Diffie-Hellman key exchange");
2654 * Now generate and send e for Diffie-Hellman.
2656 e = dh_create_e(nbits*2);
2657 ssh2_pkt_init(kex_init_value);
2662 if (pktin.type != kex_reply_value) {
2663 bombout(("expected key exchange reply packet from server"));
2666 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2667 f = ssh2_pkt_getmp();
2668 ssh2_pkt_getstring(&sigdata, &siglen);
2672 sha_string(&exhash, hostkeydata, hostkeylen);
2673 if (kex == &ssh_diffiehellman_gex) {
2674 sha_uint32(&exhash, pbits);
2675 sha_mpint(&exhash, p);
2676 sha_mpint(&exhash, g);
2678 sha_mpint(&exhash, e);
2679 sha_mpint(&exhash, f);
2680 sha_mpint(&exhash, K);
2681 SHA_Final(&exhash, exchange_hash);
2686 debug(("Exchange hash is:\r\n"));
2687 for (i = 0; i < 20; i++)
2688 debug((" %02x", exchange_hash[i]));
2692 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2693 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2694 bombout(("Server failed host key check"));
2699 * Expect SSH2_MSG_NEWKEYS from server.
2702 if (pktin.type != SSH2_MSG_NEWKEYS) {
2703 bombout(("expected new-keys packet from server"));
2708 * Authenticate remote host: verify host key. (We've already
2709 * checked the signature of the exchange hash.)
2711 keystr = hostkey->fmtkey(hkey);
2712 fingerprint = hostkey->fingerprint(hkey);
2713 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2714 keystr, fingerprint);
2715 if (first_kex) { /* don't bother logging this in rekeys */
2716 logevent("Host key fingerprint is:");
2717 logevent(fingerprint);
2721 hostkey->freekey(hkey);
2724 * Send SSH2_MSG_NEWKEYS.
2726 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2730 * Create and initialise session keys.
2732 cscipher = cscipher_tobe;
2733 sccipher = sccipher_tobe;
2736 cscomp = cscomp_tobe;
2737 sccomp = sccomp_tobe;
2738 cscomp->compress_init();
2739 sccomp->decompress_init();
2741 * Set IVs after keys. Here we use the exchange hash from the
2742 * _first_ key exchange.
2745 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2746 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
2747 cscipher->setcskey(keyspace);
2748 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
2749 sccipher->setsckey(keyspace);
2750 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
2751 cscipher->setcsiv(keyspace);
2752 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
2753 sccipher->setsciv(keyspace);
2754 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
2755 csmac->setcskey(keyspace);
2756 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
2757 scmac->setsckey(keyspace);
2760 * If this is the first key exchange phase, we must pass the
2761 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2762 * wants to see it but because it will need time to initialise
2763 * itself before it sees an actual packet. In subsequent key
2764 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2765 * it would only confuse the layer above.
2773 * Now we're encrypting. Begin returning 1 to the protocol main
2774 * function so that other things can run on top of the
2775 * transport. If we ever see a KEXINIT, we must go back to the
2778 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
2781 logevent("Server initiated key re-exchange");
2782 goto begin_key_exchange;
2788 * Add data to an SSH2 channel output buffer.
2790 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2791 if (c->v2.outbufsize <
2792 c->v2.outbuflen + len) {
2794 c->v2.outbuflen + len + 1024;
2795 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2798 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2800 c->v2.outbuflen += len;
2804 * Attempt to send data on an SSH2 channel.
2806 static void ssh2_try_send(struct ssh_channel *c) {
2807 while (c->v2.remwindow > 0 &&
2808 c->v2.outbuflen > 0) {
2809 unsigned len = c->v2.remwindow;
2810 if (len > c->v2.outbuflen)
2811 len = c->v2.outbuflen;
2812 if (len > c->v2.remmaxpkt)
2813 len = c->v2.remmaxpkt;
2814 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2815 ssh2_pkt_adduint32(c->remoteid);
2816 ssh2_pkt_addstring_start();
2817 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2819 c->v2.outbuflen -= len;
2820 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2822 c->v2.remwindow -= len;
2827 * Handle the SSH2 userauth and connection layers.
2829 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2831 static unsigned long remote_winsize;
2832 static unsigned long remote_maxpkt;
2834 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2838 AUTH_TYPE_PUBLICKEY,
2839 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2840 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2843 static int gotit, need_pw, can_pubkey, can_passwd;
2844 static int tried_pubkey_config, tried_agent;
2845 static int we_are_in;
2846 static char username[100];
2847 static char pwprompt[200];
2848 static char password[100];
2853 * Request userauth protocol, and await a response to it.
2855 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2856 ssh2_pkt_addstring("ssh-userauth");
2858 crWaitUntilV(ispkt);
2859 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2860 bombout(("Server refused user authentication protocol"));
2865 * We repeat this whole loop, including the username prompt,
2866 * until we manage a successful authentication. If the user
2867 * types the wrong _password_, they are sent back to the
2868 * beginning to try another username. (If they specify a
2869 * username in the config, they are never asked, even if they
2870 * do give a wrong password.)
2872 * I think this best serves the needs of
2874 * - the people who have no configuration, no keys, and just
2875 * want to try repeated (username,password) pairs until they
2876 * type both correctly
2878 * - people who have keys and configuration but occasionally
2879 * need to fall back to passwords
2881 * - people with a key held in Pageant, who might not have
2882 * logged in to a particular machine before; so they want to
2883 * type a username, and then _either_ their key will be
2884 * accepted, _or_ they will type a password. If they mistype
2885 * the username they will want to be able to get back and
2896 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2898 if (!ssh_get_line("login as: ",
2899 username, sizeof(username), FALSE)) {
2901 * get_line failed to get a username.
2904 logevent("No username provided. Abandoning session.");
2905 ssh_state = SSH_STATE_CLOSED;
2909 c_write_str("login as: ");
2912 crWaitUntilV(!ispkt);
2913 while (inlen--) switch (c = *in++) {
2920 c_write_str("\b \b");
2926 c_write_str("\b \b");
2935 if (((c >= ' ' && c <= '~') ||
2936 ((unsigned char)c >= 160)) && pos < 40) {
2937 username[pos++] = c;
2944 c_write_str("\r\n");
2945 username[strcspn(username, "\n\r")] = '\0';
2948 strncpy(username, cfg.username, 99);
2949 username[99] = '\0';
2950 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2951 sprintf(stuff, "Using username \"%s\".\r\n", username);
2957 * Send an authentication request using method "none": (a)
2958 * just in case it succeeds, and (b) so that we know what
2959 * authentication methods we can usefully try next.
2961 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2962 ssh2_pkt_addstring(username);
2963 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2964 ssh2_pkt_addstring("none"); /* method */
2966 type = AUTH_TYPE_NONE;
2970 tried_pubkey_config = FALSE;
2971 tried_agent = FALSE;
2975 * Wait for the result of the last authentication request.
2978 crWaitUntilV(ispkt);
2979 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
2982 ssh2_pkt_getstring(&banner, &size);
2984 c_write_untrusted(banner, size);
2985 crWaitUntilV(ispkt);
2987 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
2988 logevent("Access granted");
2993 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
2994 bombout(("Strange packet received during authentication: type %d",
3001 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3002 * we can look at the string in it and know what we can
3003 * helpfully try next.
3008 ssh2_pkt_getstring(&methods, &methlen);
3009 if (!ssh2_pkt_getbool()) {
3011 * We have received an unequivocal Access
3012 * Denied. This can translate to a variety of
3015 * - if we'd just tried "none" authentication,
3016 * it's not worth printing anything at all
3018 * - if we'd just tried a public key _offer_,
3019 * the message should be "Server refused our
3020 * key" (or no message at all if the key
3021 * came from Pageant)
3023 * - if we'd just tried anything else, the
3024 * message really should be "Access denied".
3026 * Additionally, if we'd just tried password
3027 * authentication, we should break out of this
3028 * whole loop so as to go back to the username
3031 if (type == AUTH_TYPE_NONE) {
3033 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3034 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3035 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3036 c_write_str("Server refused our key\r\n");
3037 logevent("Server refused public key");
3039 c_write_str("Access denied\r\n");
3040 logevent("Access denied");
3041 if (type == AUTH_TYPE_PASSWORD) {
3047 c_write_str("Further authentication required\r\n");
3048 logevent("Further authentication required");
3051 can_pubkey = in_commasep_string("publickey", methods, methlen);
3052 can_passwd = in_commasep_string("password", methods, methlen);
3057 if (!method && can_pubkey && agent_exists && !tried_agent) {
3059 * Attempt public-key authentication using Pageant.
3061 static unsigned char request[5], *response, *p;
3062 static int responselen;
3063 static int i, nkeys;
3064 static int authed = FALSE;
3069 logevent("Pageant is running. Requesting keys.");
3071 /* Request the keys held by the agent. */
3072 PUT_32BIT(request, 1);
3073 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3074 agent_query(request, 5, &r, &responselen);
3075 response = (unsigned char *)r;
3076 if (response && responselen >= 5 &&
3077 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3079 nkeys = GET_32BIT(p); p += 4;
3080 { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3082 for (i = 0; i < nkeys; i++) {
3083 static char *pkblob, *alg, *commentp;
3084 static int pklen, alglen, commentlen;
3085 static int siglen, retlen, len;
3086 static char *q, *agentreq, *ret;
3088 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
3090 pklen = GET_32BIT(p); p += 4;
3091 pkblob = p; p += pklen;
3092 alglen = GET_32BIT(pkblob);
3094 commentlen = GET_32BIT(p); p += 4;
3095 commentp = p; p += commentlen;
3096 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3097 ssh2_pkt_addstring(username);
3098 ssh2_pkt_addstring("ssh-connection");/* service requested */
3099 ssh2_pkt_addstring("publickey");/* method */
3100 ssh2_pkt_addbool(FALSE); /* no signature included */
3101 ssh2_pkt_addstring_start();
3102 ssh2_pkt_addstring_data(alg, alglen);
3103 ssh2_pkt_addstring_start();
3104 ssh2_pkt_addstring_data(pkblob, pklen);
3107 crWaitUntilV(ispkt);
3108 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3109 logevent("Key refused");
3113 c_write_str("Authenticating with public key \"");
3114 c_write(commentp, commentlen);
3115 c_write_str("\" from agent\r\n");
3118 * Server is willing to accept the key.
3119 * Construct a SIGN_REQUEST.
3121 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3122 ssh2_pkt_addstring(username);
3123 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3124 ssh2_pkt_addstring("publickey"); /* method */
3125 ssh2_pkt_addbool(TRUE);
3126 ssh2_pkt_addstring_start();
3127 ssh2_pkt_addstring_data(alg, alglen);
3128 ssh2_pkt_addstring_start();
3129 ssh2_pkt_addstring_data(pkblob, pklen);
3131 siglen = pktout.length - 5 + 4 + 20;
3132 len = 1; /* message type */
3133 len += 4 + pklen; /* key blob */
3134 len += 4 + siglen; /* data to sign */
3135 len += 4; /* flags */
3136 agentreq = smalloc(4 + len);
3137 PUT_32BIT(agentreq, len);
3139 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3140 PUT_32BIT(q, pklen); q += 4;
3141 memcpy(q, pkblob, pklen); q += pklen;
3142 PUT_32BIT(q, siglen); q += 4;
3143 /* Now the data to be signed... */
3144 PUT_32BIT(q, 20); q += 4;
3145 memcpy(q, ssh2_session_id, 20); q += 20;
3146 memcpy(q, pktout.data+5, pktout.length-5);
3147 q += pktout.length-5;
3148 /* And finally the (zero) flags word. */
3150 agent_query(agentreq, len+4, &ret, &retlen);
3153 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3154 logevent("Sending Pageant's response");
3155 ssh2_pkt_addstring_start();
3156 ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5));
3161 logevent("Pageant failed to answer challenge");
3171 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
3172 unsigned char *pub_blob;
3173 char *algorithm, *comment;
3176 tried_pubkey_config = TRUE;
3179 * Try the public key supplied in the configuration.
3181 * First, offer the public blob to see if the server is
3182 * willing to accept it.
3184 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3187 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3188 ssh2_pkt_addstring(username);
3189 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3190 ssh2_pkt_addstring("publickey");/* method */
3191 ssh2_pkt_addbool(FALSE); /* no signature included */
3192 ssh2_pkt_addstring(algorithm);
3193 ssh2_pkt_addstring_start();
3194 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3196 logevent("Offered public key"); /* FIXME */
3198 crWaitUntilV(ispkt);
3199 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3201 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3202 continue; /* key refused; give up on it */
3205 logevent("Offer of public key accepted");
3207 * Actually attempt a serious authentication using
3210 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3211 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
3216 c_write_str("Authenticating with public key \"");
3217 c_write_str(comment);
3218 c_write_str("\"\r\n");
3219 method = AUTH_PUBLICKEY_FILE;
3223 if (!method && can_passwd) {
3224 method = AUTH_PASSWORD;
3225 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
3231 if (!ssh_get_line(pwprompt, password,
3232 sizeof(password), TRUE)) {
3234 * get_line failed to get a password (for
3235 * example because one was supplied on the
3236 * command line which has already failed to
3239 logevent("No more passwords to try");
3240 ssh_state = SSH_STATE_CLOSED;
3247 c_write_str(pwprompt);
3252 crWaitUntilV(!ispkt);
3253 while (inlen--) switch (c = *in++) {
3270 if (((c >= ' ' && c <= '~') ||
3271 ((unsigned char)c >= 160)) && pos < 40)
3272 password[pos++] = c;
3276 c_write_str("\r\n");
3280 if (method == AUTH_PUBLICKEY_FILE) {
3282 * We have our passphrase. Now try the actual authentication.
3284 struct ssh2_userkey *key;
3286 key = ssh2_load_userkey(cfg.keyfile, password);
3287 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3288 if (key == SSH2_WRONG_PASSPHRASE) {
3289 c_write_str("Wrong passphrase\r\n");
3290 tried_pubkey_config = FALSE;
3292 c_write_str("Unable to load private key\r\n");
3293 tried_pubkey_config = TRUE;
3295 /* Send a spurious AUTH_NONE to return to the top. */
3296 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3297 ssh2_pkt_addstring(username);
3298 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3299 ssh2_pkt_addstring("none"); /* method */
3301 type = AUTH_TYPE_NONE;
3303 unsigned char *blob, *sigdata;
3304 int blob_len, sigdata_len;
3307 * We have loaded the private key and the server
3308 * has announced that it's willing to accept it.
3309 * Hallelujah. Generate a signature and send it.
3311 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3312 ssh2_pkt_addstring(username);
3313 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3314 ssh2_pkt_addstring("publickey"); /* method */
3315 ssh2_pkt_addbool(TRUE);
3316 ssh2_pkt_addstring(key->alg->name);
3317 blob = key->alg->public_blob(key->data, &blob_len);
3318 ssh2_pkt_addstring_start();
3319 ssh2_pkt_addstring_data(blob, blob_len);
3323 * The data to be signed is:
3327 * followed by everything so far placed in the
3330 sigdata_len = pktout.length - 5 + 4 + 20;
3331 sigdata = smalloc(sigdata_len);
3332 PUT_32BIT(sigdata, 20);
3333 memcpy(sigdata+4, ssh2_session_id, 20);
3334 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
3335 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3336 ssh2_pkt_addstring_start();
3337 ssh2_pkt_addstring_data(blob, blob_len);
3342 type = AUTH_TYPE_PUBLICKEY;
3344 } else if (method == AUTH_PASSWORD) {
3346 * We send the password packet lumped tightly together with
3347 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3348 * string long enough to make the total length of the two
3349 * packets constant. This should ensure that a passive
3350 * listener doing traffic analyis can't work out the length
3353 * For this to work, we need an assumption about the
3354 * maximum length of the password packet. I think 256 is
3355 * pretty conservative. Anyone using a password longer than
3356 * that probably doesn't have much to worry about from
3357 * people who find out how long their password is!
3359 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3360 ssh2_pkt_addstring(username);
3361 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3362 ssh2_pkt_addstring("password");
3363 ssh2_pkt_addbool(FALSE);
3364 ssh2_pkt_addstring(password);
3367 * We'll include a string that's an exact multiple of the
3368 * cipher block size. If the cipher is NULL for some
3369 * reason, we don't do this trick at all because we gain
3375 stringlen = (256 - deferred_len);
3376 stringlen += cscipher->blksize - 1;
3377 stringlen -= (stringlen % cscipher->blksize);
3380 * Temporarily disable actual compression,
3381 * so we can guarantee to get this string
3382 * exactly the length we want it. The
3383 * compression-disabling routine should
3384 * return an integer indicating how many
3385 * bytes we should adjust our string length
3388 stringlen -= cscomp->disable_compression();
3390 ssh2_pkt_init(SSH2_MSG_IGNORE);
3391 ssh2_pkt_addstring_start();
3392 for (i = 0; i < stringlen; i++) {
3393 char c = (char)random_byte();
3394 ssh2_pkt_addstring_data(&c, 1);
3398 ssh_pkt_defersend();
3399 logevent("Sent password");
3400 type = AUTH_TYPE_PASSWORD;
3402 c_write_str("No supported authentication methods left to try!\r\n");
3403 logevent("No supported authentications offered. Disconnecting");
3404 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3405 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3406 ssh2_pkt_addstring("No supported authentication methods available");
3407 ssh2_pkt_addstring("en"); /* language tag */
3409 ssh_state = SSH_STATE_CLOSED;
3413 } while (!we_are_in);
3416 * Now we're authenticated for the connection protocol. The
3417 * connection protocol will automatically have started at this
3418 * point; there's no need to send SERVICE_REQUEST.
3422 * So now create a channel with a session in it.
3424 mainchan = smalloc(sizeof(struct ssh_channel));
3425 mainchan->localid = 100; /* as good as any */
3426 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3427 ssh2_pkt_addstring("session");
3428 ssh2_pkt_adduint32(mainchan->localid);
3429 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3430 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3432 crWaitUntilV(ispkt);
3433 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3434 bombout(("Server refused to open a session"));
3436 /* FIXME: error data comes back in FAILURE packet */
3438 if (ssh2_pkt_getuint32() != mainchan->localid) {
3439 bombout(("Server's channel confirmation cited wrong channel"));
3442 mainchan->remoteid = ssh2_pkt_getuint32();
3443 mainchan->type = CHAN_MAINSESSION;
3444 mainchan->closes = 0;
3445 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3446 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3447 mainchan->v2.outbuffer = NULL;
3448 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3449 ssh_channels = newtree234(ssh_channelcmp);
3450 add234(ssh_channels, mainchan);
3451 logevent("Opened channel for session");
3454 * Potentially enable X11 forwarding.
3456 if (cfg.x11_forward) {
3457 char proto[20], data[64];
3458 logevent("Requesting X11 forwarding");
3459 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3460 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3461 ssh2_pkt_adduint32(mainchan->remoteid);
3462 ssh2_pkt_addstring("x11-req");
3463 ssh2_pkt_addbool(1); /* want reply */
3464 ssh2_pkt_addbool(0); /* many connections */
3465 ssh2_pkt_addstring(proto);
3466 ssh2_pkt_addstring(data);
3467 ssh2_pkt_adduint32(0); /* screen number */
3471 crWaitUntilV(ispkt);
3472 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3473 unsigned i = ssh2_pkt_getuint32();
3474 struct ssh_channel *c;
3475 c = find234(ssh_channels, &i, ssh_channelfind);
3477 continue; /* nonexistent channel */
3478 c->v2.remwindow += ssh2_pkt_getuint32();
3480 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3482 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3483 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3484 bombout(("Server got confused by X11 forwarding request"));
3487 logevent("X11 forwarding refused");
3489 logevent("X11 forwarding enabled");
3490 ssh_X11_fwd_enabled = TRUE;
3495 * Potentially enable agent forwarding.
3497 if (cfg.agentfwd && agent_exists()) {
3498 logevent("Requesting OpenSSH-style agent forwarding");
3499 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3500 ssh2_pkt_adduint32(mainchan->remoteid);
3501 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3502 ssh2_pkt_addbool(1); /* want reply */
3506 crWaitUntilV(ispkt);
3507 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3508 unsigned i = ssh2_pkt_getuint32();
3509 struct ssh_channel *c;
3510 c = find234(ssh_channels, &i, ssh_channelfind);
3512 continue; /* nonexistent channel */
3513 c->v2.remwindow += ssh2_pkt_getuint32();
3515 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3517 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3518 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3519 bombout(("Server got confused by agent forwarding request"));
3522 logevent("Agent forwarding refused");
3524 logevent("Agent forwarding enabled");
3525 ssh_agentfwd_enabled = TRUE;
3530 * Now allocate a pty for the session.
3533 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3534 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3535 ssh2_pkt_addstring("pty-req");
3536 ssh2_pkt_addbool(1); /* want reply */
3537 ssh2_pkt_addstring(cfg.termtype);
3538 ssh2_pkt_adduint32(cols);
3539 ssh2_pkt_adduint32(rows);
3540 ssh2_pkt_adduint32(0); /* pixel width */
3541 ssh2_pkt_adduint32(0); /* pixel height */
3542 ssh2_pkt_addstring_start();
3543 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3545 ssh_state = SSH_STATE_INTERMED;
3548 crWaitUntilV(ispkt);
3549 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3550 unsigned i = ssh2_pkt_getuint32();
3551 struct ssh_channel *c;
3552 c = find234(ssh_channels, &i, ssh_channelfind);
3554 continue; /* nonexistent channel */
3555 c->v2.remwindow += ssh2_pkt_getuint32();
3557 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3559 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3560 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3561 bombout(("Server got confused by pty request"));
3564 c_write_str("Server refused to allocate pty\r\n");
3565 ssh_editing = ssh_echoing = 1;
3567 logevent("Allocated pty");
3570 ssh_editing = ssh_echoing = 1;
3574 * Start a shell or a remote command.
3576 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3577 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3578 if (cfg.ssh_subsys) {
3579 ssh2_pkt_addstring("subsystem");
3580 ssh2_pkt_addbool(1); /* want reply */
3581 ssh2_pkt_addstring(cfg.remote_cmd);
3582 } else if (*cfg.remote_cmd) {
3583 ssh2_pkt_addstring("exec");
3584 ssh2_pkt_addbool(1); /* want reply */
3585 ssh2_pkt_addstring(cfg.remote_cmd);
3587 ssh2_pkt_addstring("shell");
3588 ssh2_pkt_addbool(1); /* want reply */
3592 crWaitUntilV(ispkt);
3593 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3594 unsigned i = ssh2_pkt_getuint32();
3595 struct ssh_channel *c;
3596 c = find234(ssh_channels, &i, ssh_channelfind);
3598 continue; /* nonexistent channel */
3599 c->v2.remwindow += ssh2_pkt_getuint32();
3601 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3602 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3603 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3604 bombout(("Server got confused by shell/command request"));
3607 bombout(("Server refused to start a shell/command"));
3610 logevent("Started a shell/command");
3613 ssh_state = SSH_STATE_SESSION;
3617 ssh_special(TS_EOF);
3622 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
3625 static int try_send;
3629 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3630 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3633 unsigned i = ssh2_pkt_getuint32();
3634 struct ssh_channel *c;
3635 c = find234(ssh_channels, &i, ssh_channelfind);
3637 continue; /* nonexistent channel */
3638 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3639 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3640 continue; /* extended but not stderr */
3641 ssh2_pkt_getstring(&data, &length);
3644 case CHAN_MAINSESSION:
3645 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3649 x11_send(c->u.x11.s, data, length);
3652 while (length > 0) {
3653 if (c->u.a.lensofar < 4) {
3654 int l = min(4 - c->u.a.lensofar, length);
3655 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
3656 data += l; length -= l; c->u.a.lensofar += l;
3658 if (c->u.a.lensofar == 4) {
3659 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
3660 c->u.a.message = smalloc(c->u.a.totallen);
3661 memcpy(c->u.a.message, c->u.a.msglen, 4);
3663 if (c->u.a.lensofar >= 4 && length > 0) {
3664 int l = min(c->u.a.totallen - c->u.a.lensofar,
3666 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
3667 data += l; length -= l; c->u.a.lensofar += l;
3669 if (c->u.a.lensofar == c->u.a.totallen) {
3670 void *reply, *sentreply;
3672 agent_query(c->u.a.message, c->u.a.totallen,
3677 /* Fake SSH_AGENT_FAILURE. */
3678 sentreply = "\0\0\0\1\5";
3681 ssh2_add_channel_data(c, sentreply, replylen);
3685 sfree(c->u.a.message);
3686 c->u.a.lensofar = 0;
3692 * Enlarge the window again at the remote
3693 * side, just in case it ever runs down and
3694 * they fail to send us any more data.
3696 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3697 ssh2_pkt_adduint32(c->remoteid);
3698 ssh2_pkt_adduint32(length);
3701 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3702 ssh_state = SSH_STATE_CLOSED;
3703 logevent("Received disconnect message");
3705 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3706 continue; /* exit status et al; ignore (FIXME?) */
3707 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
3708 unsigned i = ssh2_pkt_getuint32();
3709 struct ssh_channel *c;
3711 c = find234(ssh_channels, &i, ssh_channelfind);
3713 continue; /* nonexistent channel */
3715 if (c->type == CHAN_X11) {
3717 * Remote EOF on an X11 channel means we should
3718 * wrap up and close the channel ourselves.
3720 x11_close(c->u.x11.s);
3722 } else if (c->type == CHAN_AGENT) {
3725 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
3726 unsigned i = ssh2_pkt_getuint32();
3727 struct ssh_channel *c;
3730 c = find234(ssh_channels, &i, ssh_channelfind);
3732 continue; /* nonexistent channel */
3733 if (c->closes == 0) {
3734 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3735 ssh2_pkt_adduint32(c->remoteid);
3738 /* Do pre-close processing on the channel. */
3740 case CHAN_MAINSESSION:
3741 break; /* nothing to see here, move along */
3747 del234(ssh_channels, c);
3748 sfree(c->v2.outbuffer);
3752 * See if that was the last channel left open.
3754 c = first234(ssh_channels, &e);
3756 logevent("All channels closed. Disconnecting");
3757 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3758 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3759 ssh2_pkt_addstring("All open channels closed");
3760 ssh2_pkt_addstring("en"); /* language tag */
3762 ssh_state = SSH_STATE_CLOSED;
3765 continue; /* remote sends close; ignore (FIXME) */
3766 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3767 unsigned i = ssh2_pkt_getuint32();
3768 struct ssh_channel *c;
3769 c = find234(ssh_channels, &i, ssh_channelfind);
3771 continue; /* nonexistent channel */
3772 mainchan->v2.remwindow += ssh2_pkt_getuint32();
3774 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3778 struct ssh_channel *c;
3779 ssh2_pkt_getstring(&type, &typelen);
3780 c = smalloc(sizeof(struct ssh_channel));
3782 if (typelen == 3 && !memcmp(type, "x11", 3)) {
3783 if (!ssh_X11_fwd_enabled)
3784 error = "X11 forwarding is not enabled";
3785 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
3786 error = "Unable to open an X11 connection";
3790 } else if (typelen == 22 &&
3791 !memcmp(type, "auth-agent@openssh.com", 3)) {
3792 if (!ssh_agentfwd_enabled)
3793 error = "Agent forwarding is not enabled";
3795 c->type = CHAN_AGENT; /* identify channel type */
3796 c->u.a.lensofar = 0;
3799 error = "Unsupported channel type requested";
3802 c->remoteid = ssh2_pkt_getuint32();
3804 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3805 ssh2_pkt_adduint32(c->remoteid);
3806 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3807 ssh2_pkt_addstring(error);
3808 ssh2_pkt_addstring("en"); /* language tag */
3812 struct ssh_channel *d;
3816 for (i=1, d = first234(ssh_channels, &e); d;
3819 break; /* found a free number */
3824 c->v2.remwindow = ssh2_pkt_getuint32();
3825 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3826 c->v2.outbuffer = NULL;
3827 c->v2.outbuflen = c->v2.outbufsize = 0;
3828 add234(ssh_channels, c);
3829 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3830 ssh2_pkt_adduint32(c->remoteid);
3831 ssh2_pkt_adduint32(c->localid);
3832 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3833 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3837 bombout(("Strange packet received: type %d", pktin.type));
3842 * We have spare data. Add it to the channel buffer.
3844 ssh2_add_channel_data(mainchan, in, inlen);
3849 struct ssh_channel *c;
3851 * Try to send data on all channels if we can.
3853 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3862 * Handle the top-level SSH2 protocol.
3864 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3866 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3868 do_ssh2_authconn(in, inlen, ispkt);
3872 * Called to set up the connection.
3874 * Returns an error message, or NULL on success.
3876 static char *ssh_init (char *host, int port, char **realhost) {
3880 if(crypto_startup() == 0)
3881 return "Microsoft high encryption pack not installed!";
3888 p = connect_to_host(host, port, realhost);
3896 * Called to send data down the Telnet connection.
3898 static void ssh_send (char *buf, int len) {
3899 if (s == NULL || ssh_protocol == NULL)
3902 ssh_protocol(buf, len, 0);
3906 * Called to set the size of the window from SSH's POV.
3908 static void ssh_size(void) {
3909 switch (ssh_state) {
3910 case SSH_STATE_BEFORE_SIZE:
3911 case SSH_STATE_PREPACKET:
3912 case SSH_STATE_CLOSED:
3913 break; /* do nothing */
3914 case SSH_STATE_INTERMED:
3915 size_needed = TRUE; /* buffer for later */
3917 case SSH_STATE_SESSION:
3919 if (ssh_version == 1) {
3920 send_packet(SSH1_CMSG_WINDOW_SIZE,
3921 PKT_INT, rows, PKT_INT, cols,
3922 PKT_INT, 0, PKT_INT, 0, PKT_END);
3924 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3925 ssh2_pkt_adduint32(mainchan->remoteid);
3926 ssh2_pkt_addstring("window-change");
3927 ssh2_pkt_addbool(0);
3928 ssh2_pkt_adduint32(cols);
3929 ssh2_pkt_adduint32(rows);
3930 ssh2_pkt_adduint32(0);
3931 ssh2_pkt_adduint32(0);
3940 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3941 * can send an EOF and collect resulting output (e.g. `plink
3944 static void ssh_special (Telnet_Special code) {
3945 if (code == TS_EOF) {
3946 if (ssh_state != SSH_STATE_SESSION) {
3948 * Buffer the EOF in case we are pre-SESSION, so we can
3949 * send it as soon as we reach SESSION.
3955 if (ssh_version == 1) {
3956 send_packet(SSH1_CMSG_EOF, PKT_END);
3958 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3959 ssh2_pkt_adduint32(mainchan->remoteid);
3962 logevent("Sent EOF message");
3963 } else if (code == TS_PING) {
3964 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3966 if (ssh_version == 1) {
3967 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3969 ssh2_pkt_init(SSH2_MSG_IGNORE);
3970 ssh2_pkt_addstring_start();
3978 static Socket ssh_socket(void) { return s; }
3980 static int ssh_sendok(void) { return ssh_send_ok; }
3982 static int ssh_ldisc(int option) {
3983 if (option == LD_ECHO) return ssh_echoing;
3984 if (option == LD_EDIT) return ssh_editing;
3988 Backend ssh_backend = {