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 SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
72 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
73 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
74 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
75 #define SSH_AGENT_FAILURE 5 /* 0x5 */
76 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
77 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
78 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
80 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81 #define SSH2_MSG_IGNORE 2 /* 0x2 */
82 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83 #define SSH2_MSG_DEBUG 4 /* 0x4 */
84 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
87 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
91 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
92 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
93 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
94 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
95 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
96 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
97 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
98 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
99 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
100 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
101 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
102 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
103 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
104 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
105 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
106 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
107 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
108 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
109 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
110 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
111 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
112 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
113 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
127 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
128 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
129 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
130 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
132 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
134 #define GET_32BIT(cp) \
135 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
136 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
137 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
138 ((unsigned long)(unsigned char)(cp)[3]))
140 #define PUT_32BIT(cp, value) { \
141 (cp)[0] = (unsigned char)((value) >> 24); \
142 (cp)[1] = (unsigned char)((value) >> 16); \
143 (cp)[2] = (unsigned char)((value) >> 8); \
144 (cp)[3] = (unsigned char)(value); }
146 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
148 /* Coroutine mechanics for the sillier bits of the code */
149 #define crBegin1 static int crLine = 0;
150 #define crBegin2 switch(crLine) { case 0:;
151 #define crBegin crBegin1; crBegin2;
152 #define crFinish(z) } crLine = 0; return (z)
153 #define crFinishV } crLine = 0; return
154 #define crReturn(z) \
156 crLine=__LINE__; return (z); case __LINE__:;\
160 crLine=__LINE__; return; case __LINE__:;\
162 #define crStop(z) do{ crLine = 0; return (z); }while(0)
163 #define crStopV do{ crLine = 0; return; }while(0)
164 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
165 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
167 extern char *x11_init (Socket *, char *, void *);
168 extern void x11_close (Socket);
169 extern void x11_send (Socket , char *, int);
170 extern void x11_invent_auth(char *, int, char *, int);
173 * Ciphers for SSH2. We miss out single-DES because it isn't
174 * supported; also 3DES and Blowfish are both done differently from
175 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
176 * endianness and different-sized keys.)
178 const static struct ssh2_ciphers *ciphers[] = {
184 const static struct ssh_kex *kex_algs[] = {
185 #ifdef DO_DIFFIE_HELLMAN_GEX
186 &ssh_diffiehellman_gex,
188 &ssh_diffiehellman };
190 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
192 static void nullmac_key(unsigned char *key) { }
193 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
194 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
195 const static struct ssh_mac ssh_mac_none = {
196 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
198 const static struct ssh_mac *macs[] = {
199 &ssh_sha1, &ssh_md5, &ssh_mac_none };
200 const static struct ssh_mac *buggymacs[] = {
201 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
203 static void ssh_comp_none_init(void) { }
204 static int ssh_comp_none_block(unsigned char *block, int len,
205 unsigned char **outblock, int *outlen) {
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
213 extern const struct ssh_compress ssh_zlib;
214 const static struct ssh_compress *compressions[] = {
215 &ssh_zlib, &ssh_comp_none };
217 enum { /* channel types */
224 * 2-3-4 tree storing channels.
227 unsigned remoteid, localid;
230 struct ssh2_data_channel {
231 unsigned char *outbuffer;
232 unsigned outbuflen, outbufsize;
233 unsigned remwindow, remmaxpkt;
236 struct ssh_agent_channel {
237 unsigned char *message;
238 unsigned char msglen[4];
239 int lensofar, totallen;
241 struct ssh_x11_channel {
256 static SHA_State exhash, exhashbase;
258 static Socket s = NULL;
260 static unsigned char session_key[32];
261 static int ssh1_compressing;
262 static int ssh_agentfwd_enabled;
263 static int ssh_X11_fwd_enabled;
264 static const struct ssh_cipher *cipher = NULL;
265 static const struct ssh2_cipher *cscipher = NULL;
266 static const struct ssh2_cipher *sccipher = NULL;
267 static const struct ssh_mac *csmac = NULL;
268 static const struct ssh_mac *scmac = NULL;
269 static const struct ssh_compress *cscomp = NULL;
270 static const struct ssh_compress *sccomp = NULL;
271 static const struct ssh_kex *kex = NULL;
272 static const struct ssh_signkey *hostkey = NULL;
273 static unsigned char ssh2_session_id[20];
274 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
276 static char *savedhost;
277 static int savedport;
278 static int ssh_send_ok;
279 static int ssh_echoing, ssh_editing;
281 static tree234 *ssh_channels; /* indexed by local id */
282 static struct ssh_channel *mainchan; /* primary session channel */
286 SSH_STATE_BEFORE_SIZE,
290 } ssh_state = SSH_STATE_PREPACKET;
292 static int size_needed = FALSE, eof_needed = FALSE;
294 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
295 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
296 static unsigned char *deferred_send_data = NULL;
297 static int deferred_len = 0, deferred_size = 0;
299 static int ssh_version;
300 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
301 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
302 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
303 static void ssh_size(void);
304 static void ssh_special (Telnet_Special);
305 static void ssh2_try_send(struct ssh_channel *c);
306 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
308 static int (*s_rdpkt)(unsigned char **data, int *datalen);
310 static struct rdpkt1_state_tag {
311 long len, pad, biglen, to_read;
312 unsigned long realcrc, gotcrc;
318 static struct rdpkt2_state_tag {
319 long len, pad, payload, packetlen, maclen;
322 unsigned long incoming_sequence;
325 static int ssh_channelcmp(void *av, void *bv) {
326 struct ssh_channel *a = (struct ssh_channel *)av;
327 struct ssh_channel *b = (struct ssh_channel *)bv;
328 if (a->localid < b->localid) return -1;
329 if (a->localid > b->localid) return +1;
332 static int ssh_channelfind(void *av, void *bv) {
333 unsigned *a = (unsigned *)av;
334 struct ssh_channel *b = (struct ssh_channel *)bv;
335 if (*a < b->localid) return -1;
336 if (*a > b->localid) return +1;
340 static void c_write (char *buf, int len) {
341 if ((flags & FLAG_STDERR)) {
343 for (i = 0; i < len; i++)
345 fputc(buf[i], stderr);
348 from_backend(1, buf, len);
351 static void c_write_str (char *buf) {
352 c_write(buf, strlen(buf));
356 * Collect incoming data in the incoming packet buffer.
357 * Decipher and verify the packet when it is completely read.
358 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
359 * Update the *data and *datalen variables.
360 * Return the additional nr of bytes needed, or 0 when
361 * a complete packet is available.
363 static int ssh1_rdpkt(unsigned char **data, int *datalen)
365 struct rdpkt1_state_tag *st = &rdpkt1_state;
374 for (st->i = st->len = 0; st->i < 4; st->i++) {
375 while ((*datalen) == 0)
377 st->len = (st->len << 8) + **data;
378 (*data)++, (*datalen)--;
382 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
383 st->len = 0x300; /* big enough to carry to end */
387 st->pad = 8 - (st->len % 8);
388 st->biglen = st->len + st->pad;
389 pktin.length = st->len - 5;
391 if (pktin.maxlen < st->biglen) {
392 pktin.maxlen = st->biglen;
393 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
394 srealloc(pktin.data, st->biglen+APIEXTRA));
396 fatalbox("Out of memory");
399 st->to_read = st->biglen;
401 while (st->to_read > 0) {
402 st->chunk = st->to_read;
403 while ((*datalen) == 0)
404 crReturn(st->to_read);
405 if (st->chunk > (*datalen))
406 st->chunk = (*datalen);
407 memcpy(st->p, *data, st->chunk);
409 *datalen -= st->chunk;
411 st->to_read -= st->chunk;
415 cipher->decrypt(pktin.data, st->biglen);
417 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
418 for (st->i = 0; st->i < st->biglen; st->i++)
419 debug((" %02x", (unsigned char)pktin.data[st->i]));
423 st->realcrc = crc32(pktin.data, st->biglen-4);
424 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
425 if (st->gotcrc != st->realcrc) {
426 bombout(("Incorrect CRC received on packet"));
430 pktin.body = pktin.data + st->pad + 1;
432 if (ssh1_compressing) {
433 unsigned char *decompblk;
437 debug(("Packet payload pre-decompression:\n"));
438 for (i = -1; i < pktin.length; i++)
439 debug((" %02x", (unsigned char)pktin.body[i]));
442 zlib_decompress_block(pktin.body-1, pktin.length+1,
443 &decompblk, &decomplen);
445 if (pktin.maxlen < st->pad + decomplen) {
446 pktin.maxlen = st->pad + decomplen;
447 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
448 pktin.body = pktin.data + st->pad + 1;
450 fatalbox("Out of memory");
453 memcpy(pktin.body-1, decompblk, decomplen);
455 pktin.length = decomplen-1;
457 debug(("Packet payload post-decompression:\n"));
458 for (i = -1; i < pktin.length; i++)
459 debug((" %02x", (unsigned char)pktin.body[i]));
464 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
465 pktin.type == SSH1_SMSG_STDERR_DATA ||
466 pktin.type == SSH1_MSG_DEBUG ||
467 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
468 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
469 long strlen = GET_32BIT(pktin.body);
470 if (strlen + 4 != pktin.length) {
471 bombout(("Received data packet with bogus string length"));
476 pktin.type = pktin.body[-1];
478 if (pktin.type == SSH1_MSG_DEBUG) {
479 /* log debug message */
481 int strlen = GET_32BIT(pktin.body);
482 strcpy(buf, "Remote: ");
483 if (strlen > 70) strlen = 70;
484 memcpy(buf+8, pktin.body+4, strlen);
485 buf[8+strlen] = '\0';
488 } else if (pktin.type == SSH1_MSG_IGNORE) {
496 static int ssh2_rdpkt(unsigned char **data, int *datalen)
498 struct rdpkt2_state_tag *st = &rdpkt2_state;
506 st->cipherblk = sccipher->blksize;
509 if (st->cipherblk < 8)
512 if (pktin.maxlen < st->cipherblk) {
513 pktin.maxlen = st->cipherblk;
514 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
515 srealloc(pktin.data, st->cipherblk+APIEXTRA));
517 fatalbox("Out of memory");
521 * Acquire and decrypt the first block of the packet. This will
522 * contain the length and padding details.
524 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
525 while ((*datalen) == 0)
526 crReturn(st->cipherblk-st->i);
527 pktin.data[st->i] = *(*data)++;
531 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
536 sccipher->decrypt(pktin.data, st->cipherblk);
539 * Now get the length and padding figures.
541 st->len = GET_32BIT(pktin.data);
542 st->pad = pktin.data[4];
545 * This enables us to deduce the payload length.
547 st->payload = st->len - st->pad - 1;
549 pktin.length = st->payload + 5;
552 * So now we can work out the total packet length.
554 st->packetlen = st->len + 4;
555 st->maclen = scmac ? scmac->len : 0;
558 * Adjust memory allocation if packet is too big.
560 if (pktin.maxlen < st->packetlen+st->maclen) {
561 pktin.maxlen = st->packetlen+st->maclen;
562 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
563 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
565 fatalbox("Out of memory");
569 * Read and decrypt the remainder of the packet.
571 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
572 while ((*datalen) == 0)
573 crReturn(st->packetlen + st->maclen - st->i);
574 pktin.data[st->i] = *(*data)++;
577 /* Decrypt everything _except_ the MAC. */
579 sccipher->decrypt(pktin.data + st->cipherblk,
580 st->packetlen - st->cipherblk);
583 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
584 for (st->i = 0; st->i < st->packetlen; st->i++)
585 debug((" %02x", (unsigned char)pktin.data[st->i]));
592 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
593 bombout(("Incorrect MAC received on packet"));
596 st->incoming_sequence++; /* whether or not we MACed */
599 * Decompress packet payload.
602 unsigned char *newpayload;
604 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
605 &newpayload, &newlen)) {
606 if (pktin.maxlen < newlen+5) {
607 pktin.maxlen = newlen+5;
608 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
609 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
611 fatalbox("Out of memory");
613 pktin.length = 5 + newlen;
614 memcpy(pktin.data+5, newpayload, newlen);
616 debug(("Post-decompression payload:\r\n"));
617 for (st->i = 0; st->i < newlen; st->i++)
618 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
627 pktin.type = pktin.data[5];
629 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
630 goto next_packet; /* FIXME: print DEBUG message */
635 static void ssh1_pktout_size(int len) {
638 len += 5; /* type and CRC */
642 pktout.length = len-5;
643 if (pktout.maxlen < biglen) {
644 pktout.maxlen = biglen;
646 /* Allocate enough buffer space for extra block
647 * for MS CryptEncrypt() */
648 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
649 srealloc(pktout.data, biglen+12));
651 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
652 srealloc(pktout.data, biglen+4));
655 fatalbox("Out of memory");
657 pktout.body = pktout.data+4+pad+1;
660 static void s_wrpkt_start(int type, int len) {
661 ssh1_pktout_size(len);
665 static void s_wrpkt(void) {
666 int pad, len, biglen, i;
669 pktout.body[-1] = pktout.type;
671 if (ssh1_compressing) {
672 unsigned char *compblk;
675 debug(("Packet payload pre-compression:\n"));
676 for (i = -1; i < pktout.length; i++)
677 debug((" %02x", (unsigned char)pktout.body[i]));
680 zlib_compress_block(pktout.body-1, pktout.length+1,
682 ssh1_pktout_size(complen-1);
683 memcpy(pktout.body-1, compblk, complen);
686 debug(("Packet payload post-compression:\n"));
687 for (i = -1; i < pktout.length; i++)
688 debug((" %02x", (unsigned char)pktout.body[i]));
693 len = pktout.length + 5; /* type and CRC */
697 for (i=0; i<pad; i++)
698 pktout.data[i+4] = random_byte();
699 crc = crc32(pktout.data+4, biglen-4);
700 PUT_32BIT(pktout.data+biglen, crc);
701 PUT_32BIT(pktout.data, len);
704 debug(("Sending packet len=%d\r\n", biglen+4));
705 for (i = 0; i < biglen+4; i++)
706 debug((" %02x", (unsigned char)pktout.data[i]));
710 cipher->encrypt(pktout.data+4, biglen);
712 sk_write(s, pktout.data, biglen+4);
716 * Construct a packet with the specified contents and
717 * send it to the server.
719 static void send_packet(int pkttype, ...)
722 unsigned char *p, *argp, argchar;
723 unsigned long argint;
724 int pktlen, argtype, arglen;
728 va_start(args, pkttype);
729 while ((argtype = va_arg(args, int)) != PKT_END) {
732 (void) va_arg(args, int);
736 (void) va_arg(args, char);
740 (void) va_arg(args, unsigned char *);
741 arglen = va_arg(args, int);
745 argp = va_arg(args, unsigned char *);
746 arglen = strlen(argp);
747 pktlen += 4 + arglen;
750 bn = va_arg(args, Bignum);
751 pktlen += ssh1_bignum_length(bn);
759 s_wrpkt_start(pkttype, pktlen);
762 va_start(args, pkttype);
763 while ((argtype = va_arg(args, int)) != PKT_END) {
766 argint = va_arg(args, int);
767 PUT_32BIT(p, argint);
771 argchar = va_arg(args, unsigned char);
776 argp = va_arg(args, unsigned char *);
777 arglen = va_arg(args, int);
778 memcpy(p, argp, arglen);
782 argp = va_arg(args, unsigned char *);
783 arglen = strlen(argp);
784 PUT_32BIT(p, arglen);
785 memcpy(p + 4, argp, arglen);
789 bn = va_arg(args, Bignum);
790 p += ssh1_write_bignum(p, bn);
799 static int ssh_versioncmp(char *a, char *b) {
801 unsigned long av, bv;
803 av = strtoul(a, &ae, 10);
804 bv = strtoul(b, &be, 10);
805 if (av != bv) return (av < bv ? -1 : +1);
806 if (*ae == '.') ae++;
807 if (*be == '.') be++;
808 av = strtoul(ae, &ae, 10);
809 bv = strtoul(be, &be, 10);
810 if (av != bv) return (av < bv ? -1 : +1);
816 * Utility routines for putting an SSH-protocol `string' and
817 * `uint32' into a SHA state.
820 static void sha_string(SHA_State *s, void *str, int len) {
821 unsigned char lenblk[4];
822 PUT_32BIT(lenblk, len);
823 SHA_Bytes(s, lenblk, 4);
824 SHA_Bytes(s, str, len);
827 static void sha_uint32(SHA_State *s, unsigned i) {
828 unsigned char intblk[4];
829 PUT_32BIT(intblk, i);
830 SHA_Bytes(s, intblk, 4);
834 * SSH2 packet construction functions.
836 static void ssh2_pkt_ensure(int length) {
837 if (pktout.maxlen < length) {
838 pktout.maxlen = length + 256;
839 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
840 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
842 fatalbox("Out of memory");
845 static void ssh2_pkt_adddata(void *data, int len) {
846 pktout.length += len;
847 ssh2_pkt_ensure(pktout.length);
848 memcpy(pktout.data+pktout.length-len, data, len);
850 static void ssh2_pkt_addbyte(unsigned char byte) {
851 ssh2_pkt_adddata(&byte, 1);
853 static void ssh2_pkt_init(int pkt_type) {
855 ssh2_pkt_addbyte((unsigned char)pkt_type);
857 static void ssh2_pkt_addbool(unsigned char value) {
858 ssh2_pkt_adddata(&value, 1);
860 static void ssh2_pkt_adduint32(unsigned long value) {
863 ssh2_pkt_adddata(x, 4);
865 static void ssh2_pkt_addstring_start(void) {
866 ssh2_pkt_adduint32(0);
867 pktout.savedpos = pktout.length;
869 static void ssh2_pkt_addstring_str(char *data) {
870 ssh2_pkt_adddata(data, strlen(data));
871 PUT_32BIT(pktout.data + pktout.savedpos - 4,
872 pktout.length - pktout.savedpos);
874 static void ssh2_pkt_addstring_data(char *data, int len) {
875 ssh2_pkt_adddata(data, len);
876 PUT_32BIT(pktout.data + pktout.savedpos - 4,
877 pktout.length - pktout.savedpos);
879 static void ssh2_pkt_addstring(char *data) {
880 ssh2_pkt_addstring_start();
881 ssh2_pkt_addstring_str(data);
883 static char *ssh2_mpint_fmt(Bignum b, int *len) {
885 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
888 fatalbox("out of memory");
890 for (i = 1; i <= n; i++)
891 p[i] = bignum_byte(b, n-i);
893 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
895 memmove(p, p+i, n+1-i);
899 static void ssh2_pkt_addmp(Bignum b) {
902 p = ssh2_mpint_fmt(b, &len);
903 ssh2_pkt_addstring_start();
904 ssh2_pkt_addstring_data(p, len);
909 * Construct an SSH2 final-form packet: compress it, encrypt it,
910 * put the MAC on it. Final packet, ready to be sent, is stored in
911 * pktout.data. Total length is returned.
913 static int ssh2_pkt_construct(void) {
914 int cipherblk, maclen, padding, i;
915 static unsigned long outgoing_sequence = 0;
918 * Compress packet payload.
921 debug(("Pre-compression payload:\r\n"));
922 for (i = 5; i < pktout.length; i++)
923 debug((" %02x", (unsigned char)pktout.data[i]));
927 unsigned char *newpayload;
929 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
930 &newpayload, &newlen)) {
932 ssh2_pkt_adddata(newpayload, newlen);
938 * Add padding. At least four bytes, and must also bring total
939 * length (minus MAC) up to a multiple of the block size.
941 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
942 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
944 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
945 maclen = csmac ? csmac->len : 0;
946 ssh2_pkt_ensure(pktout.length + padding + maclen);
947 pktout.data[4] = padding;
948 for (i = 0; i < padding; i++)
949 pktout.data[pktout.length + i] = random_byte();
950 PUT_32BIT(pktout.data, pktout.length + padding - 4);
952 csmac->generate(pktout.data, pktout.length + padding,
954 outgoing_sequence++; /* whether or not we MACed */
957 debug(("Sending packet len=%d\r\n", pktout.length+padding));
958 for (i = 0; i < pktout.length+padding; i++)
959 debug((" %02x", (unsigned char)pktout.data[i]));
964 cscipher->encrypt(pktout.data, pktout.length + padding);
966 /* Ready-to-send packet starts at pktout.data. We return length. */
967 return pktout.length + padding + maclen;
971 * Construct and send an SSH2 packet immediately.
973 static void ssh2_pkt_send(void) {
974 int len = ssh2_pkt_construct();
975 sk_write(s, pktout.data, len);
979 * Construct an SSH2 packet and add it to a deferred data block.
980 * Useful for sending multiple packets in a single sk_write() call,
981 * to prevent a traffic-analysing listener from being able to work
982 * out the length of any particular packet (such as the password
985 * Note that because SSH2 sequence-numbers its packets, this can
986 * NOT be used as an m4-style `defer' allowing packets to be
987 * constructed in one order and sent in another.
989 static void ssh2_pkt_defer(void) {
990 int len = ssh2_pkt_construct();
991 if (deferred_len + len > deferred_size) {
992 deferred_size = deferred_len + len + 128;
993 deferred_send_data = srealloc(deferred_send_data, deferred_size);
995 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1000 * Send the whole deferred data block constructed by
1003 static void ssh2_pkt_defersend(void) {
1004 sk_write(s, deferred_send_data, deferred_len);
1005 deferred_len = deferred_size = 0;
1006 sfree(deferred_send_data);
1007 deferred_send_data = NULL;
1011 void bndebug(char *string, Bignum b) {
1014 p = ssh2_mpint_fmt(b, &len);
1015 debug(("%s", string));
1016 for (i = 0; i < len; i++)
1017 debug((" %02x", p[i]));
1023 static void sha_mpint(SHA_State *s, Bignum b) {
1026 p = ssh2_mpint_fmt(b, &len);
1027 sha_string(s, p, len);
1032 * SSH2 packet decode functions.
1034 static unsigned long ssh2_pkt_getuint32(void) {
1035 unsigned long value;
1036 if (pktin.length - pktin.savedpos < 4)
1037 return 0; /* arrgh, no way to decline (FIXME?) */
1038 value = GET_32BIT(pktin.data+pktin.savedpos);
1039 pktin.savedpos += 4;
1042 static int ssh2_pkt_getbool(void) {
1043 unsigned long value;
1044 if (pktin.length - pktin.savedpos < 1)
1045 return 0; /* arrgh, no way to decline (FIXME?) */
1046 value = pktin.data[pktin.savedpos] != 0;
1050 static void ssh2_pkt_getstring(char **p, int *length) {
1052 if (pktin.length - pktin.savedpos < 4)
1054 *length = GET_32BIT(pktin.data+pktin.savedpos);
1055 pktin.savedpos += 4;
1056 if (pktin.length - pktin.savedpos < *length)
1058 *p = pktin.data+pktin.savedpos;
1059 pktin.savedpos += *length;
1061 static Bignum ssh2_pkt_getmp(void) {
1066 ssh2_pkt_getstring(&p, &length);
1070 bombout(("internal error: Can't handle negative mpints"));
1073 b = bignum_from_bytes(p, length);
1077 static int do_ssh_init(unsigned char c) {
1079 static char version[10];
1080 static char vstring[80];
1081 static char vlog[sizeof(vstring)+20];
1086 /* Search for the string "SSH-" in the input. */
1089 static const int transS[] = { 1, 2, 2, 1 };
1090 static const int transH[] = { 0, 0, 3, 0 };
1091 static const int transminus[] = { 0, 0, 0, -1 };
1092 if (c == 'S') i = transS[i];
1093 else if (c == 'H') i = transH[i];
1094 else if (c == '-') i = transminus[i];
1098 crReturn(1); /* get another character */
1101 strcpy(vstring, "SSH-");
1105 crReturn(1); /* get another char */
1106 if (vsp < vstring+sizeof(vstring)-1)
1112 } else if (i < sizeof(version)-1)
1119 ssh_agentfwd_enabled = FALSE;
1120 rdpkt2_state.incoming_sequence = 0;
1123 sprintf(vlog, "Server version: %s", vstring);
1124 vlog[strcspn(vlog, "\r\n")] = '\0';
1128 * Server version "1.99" means we can choose whether we use v1
1129 * or v2 protocol. Choice is based on cfg.sshprot.
1131 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1133 * This is a v2 server. Begin v2 protocol.
1135 char *verstring = "SSH-2.0-PuTTY";
1136 SHA_Init(&exhashbase);
1138 * Hash our version string and their version string.
1140 sha_string(&exhashbase, verstring, strlen(verstring));
1141 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1142 sprintf(vstring, "%s\n", verstring);
1143 sprintf(vlog, "We claim version: %s", verstring);
1145 logevent("Using SSH protocol version 2");
1146 sk_write(s, vstring, strlen(vstring));
1147 ssh_protocol = ssh2_protocol;
1149 s_rdpkt = ssh2_rdpkt;
1152 * This is a v1 server. Begin v1 protocol.
1154 sprintf(vstring, "SSH-%s-PuTTY\n",
1155 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1156 sprintf(vlog, "We claim version: %s", vstring);
1157 vlog[strcspn(vlog, "\r\n")] = '\0';
1159 logevent("Using SSH protocol version 1");
1160 sk_write(s, vstring, strlen(vstring));
1161 ssh_protocol = ssh1_protocol;
1163 s_rdpkt = ssh1_rdpkt;
1165 ssh_state = SSH_STATE_BEFORE_SIZE;
1170 static void ssh_gotdata(unsigned char *data, int datalen)
1175 * To begin with, feed the characters one by one to the
1176 * protocol initialisation / selection function do_ssh_init().
1177 * When that returns 0, we're done with the initial greeting
1178 * exchange and can move on to packet discipline.
1183 crReturnV; /* more data please */
1184 ret = do_ssh_init(*data);
1191 * We emerge from that loop when the initial negotiation is
1192 * over and we have selected an s_rdpkt function. Now pass
1193 * everything to s_rdpkt, and then pass the resulting packets
1194 * to the proper protocol handler.
1199 while (datalen > 0) {
1200 if ( s_rdpkt(&data, &datalen) == 0 ) {
1201 ssh_protocol(NULL, 0, 1);
1202 if (ssh_state == SSH_STATE_CLOSED) {
1212 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1214 /* A socket error has occurred. */
1215 ssh_state = SSH_STATE_CLOSED;
1218 connection_fatal(data);
1221 /* Connection has closed. */
1222 ssh_state = SSH_STATE_CLOSED;
1227 ssh_gotdata (data, len);
1228 if (ssh_state == SSH_STATE_CLOSED) {
1239 * Connect to specified host and port.
1240 * Returns an error message, or NULL on success.
1241 * Also places the canonical host name into `realhost'.
1243 static char *connect_to_host(char *host, int port, char **realhost)
1252 savedhost = smalloc(1+strlen(host));
1254 fatalbox("Out of memory");
1255 strcpy(savedhost, host);
1258 port = 22; /* default ssh port */
1271 addr = sk_namelookup(host, realhost);
1272 if ( (err = sk_addr_error(addr)) )
1282 s = sk_new(addr, port, 0, 1, ssh_receive);
1283 if ( (err = sk_socket_error(s)) )
1287 sk_write(s, "connect ", 8);
1288 sk_write(s, FWhost, strlen(FWhost));
1291 sprintf(buf, " %d\n", FWport);
1292 sk_write(s, buf, strlen(buf));
1300 * Handle the key exchange and user authentication phases.
1302 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1305 unsigned char *rsabuf, *keystr1, *keystr2;
1306 unsigned char cookie[8];
1307 struct RSAKey servkey, hostkey;
1308 struct MD5Context md5c;
1309 static unsigned long supported_ciphers_mask, supported_auths_mask;
1310 static int tried_publickey;
1311 static unsigned char session_id[16];
1313 static char username[100];
1317 if (!ispkt) crWaitUntil(ispkt);
1319 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1320 bombout(("Public key packet not received"));
1324 logevent("Received public keys");
1326 memcpy(cookie, pktin.body, 8);
1328 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1329 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1332 * Log the host key fingerprint.
1336 logevent("Host key fingerprint is:");
1337 strcpy(logmsg, " ");
1338 hostkey.comment = NULL;
1339 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1344 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1345 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1348 MD5Update(&md5c, keystr2, hostkey.bytes);
1349 MD5Update(&md5c, keystr1, servkey.bytes);
1350 MD5Update(&md5c, pktin.body, 8);
1351 MD5Final(session_id, &md5c);
1353 for (i=0; i<32; i++)
1354 session_key[i] = random_byte();
1356 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1358 rsabuf = smalloc(len);
1360 fatalbox("Out of memory");
1363 * Verify the host key.
1367 * First format the key into a string.
1369 int len = rsastr_len(&hostkey);
1370 char fingerprint[100];
1371 char *keystr = smalloc(len);
1373 fatalbox("Out of memory");
1374 rsastr_fmt(keystr, &hostkey);
1375 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1376 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1380 for (i=0; i<32; i++) {
1381 rsabuf[i] = session_key[i];
1383 rsabuf[i] ^= session_id[i];
1386 if (hostkey.bytes > servkey.bytes) {
1387 rsaencrypt(rsabuf, 32, &servkey);
1388 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1390 rsaencrypt(rsabuf, 32, &hostkey);
1391 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1394 logevent("Encrypted session key");
1396 switch (cfg.cipher) {
1397 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1398 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1399 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1401 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1402 cipher_type = SSH_CIPHER_3DES;
1405 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1406 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
1407 cipher_type = SSH_CIPHER_3DES;
1409 switch (cipher_type) {
1410 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1411 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1412 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1415 send_packet(SSH1_CMSG_SESSION_KEY,
1416 PKT_CHAR, cipher_type,
1417 PKT_DATA, cookie, 8,
1418 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1419 PKT_DATA, rsabuf, len,
1423 logevent("Trying to enable encryption...");
1427 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1428 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1430 cipher->sesskey(session_key);
1434 if (pktin.type != SSH1_SMSG_SUCCESS) {
1435 bombout(("Encryption not successfully enabled"));
1439 logevent("Successfully started encryption");
1445 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1446 c_write_str("login as: ");
1449 crWaitUntil(!ispkt);
1450 while (inlen--) switch (c = *in++) {
1457 c_write_str("\b \b");
1463 c_write_str("\b \b");
1472 if (((c >= ' ' && c <= '~') ||
1473 ((unsigned char)c >= 160)) && pos < 40) {
1474 username[pos++] = c;
1480 c_write_str("\r\n");
1481 username[strcspn(username, "\n\r")] = '\0';
1483 strncpy(username, cfg.username, 99);
1484 username[99] = '\0';
1487 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1489 char userlog[22+sizeof(username)];
1490 sprintf(userlog, "Sent username \"%s\"", username);
1492 if (flags & FLAG_INTERACTIVE &&
1493 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1494 strcat(userlog, "\r\n");
1495 c_write_str(userlog);
1502 tried_publickey = 0;
1504 while (pktin.type == SSH1_SMSG_FAILURE) {
1505 static char password[100];
1506 static char prompt[200];
1509 static int pwpkt_type;
1511 * Show password prompt, having first obtained it via a TIS
1512 * or CryptoCard exchange if we're doing TIS or CryptoCard
1515 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1516 if (agent_exists()) {
1518 * Attempt RSA authentication using Pageant.
1520 static unsigned char request[5], *response, *p;
1521 static int responselen;
1522 static int i, nkeys;
1523 static int authed = FALSE;
1526 logevent("Pageant is running. Requesting keys.");
1528 /* Request the keys held by the agent. */
1529 PUT_32BIT(request, 1);
1530 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1531 agent_query(request, 5, &r, &responselen);
1532 response = (unsigned char *)r;
1535 nkeys = GET_32BIT(p); p += 4;
1536 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1538 for (i = 0; i < nkeys; i++) {
1539 static struct RSAKey key;
1540 static Bignum challenge;
1541 static char *commentp;
1542 static int commentlen;
1544 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1547 p += ssh1_read_bignum(p, &key.exponent);
1548 p += ssh1_read_bignum(p, &key.modulus);
1549 commentlen = GET_32BIT(p); p += 4;
1550 commentp = p; p += commentlen;
1551 send_packet(SSH1_CMSG_AUTH_RSA,
1552 PKT_BIGNUM, key.modulus, PKT_END);
1554 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1555 logevent("Key refused");
1558 logevent("Received RSA challenge");
1559 ssh1_read_bignum(pktin.body, &challenge);
1561 char *agentreq, *q, *ret;
1563 len = 1 + 4; /* message type, bit count */
1564 len += ssh1_bignum_length(key.exponent);
1565 len += ssh1_bignum_length(key.modulus);
1566 len += ssh1_bignum_length(challenge);
1567 len += 16; /* session id */
1568 len += 4; /* response format */
1569 agentreq = smalloc(4 + len);
1570 PUT_32BIT(agentreq, len);
1572 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1573 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1575 q += ssh1_write_bignum(q, key.exponent);
1576 q += ssh1_write_bignum(q, key.modulus);
1577 q += ssh1_write_bignum(q, challenge);
1578 memcpy(q, session_id, 16); q += 16;
1579 PUT_32BIT(q, 1); /* response format */
1580 agent_query(agentreq, len+4, &ret, &retlen);
1583 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1584 logevent("Sending Pageant's response");
1585 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1586 PKT_DATA, ret+5, 16, PKT_END);
1589 if (pktin.type == SSH1_SMSG_SUCCESS) {
1590 logevent("Pageant's response accepted");
1591 if (flags & FLAG_VERBOSE) {
1592 c_write_str("Authenticated using RSA key \"");
1593 c_write(commentp, commentlen);
1594 c_write_str("\" from agent\r\n");
1598 logevent("Pageant's response not accepted");
1600 logevent("Pageant failed to answer challenge");
1604 logevent("No reply received from Pageant");
1607 freebn(key.exponent);
1608 freebn(key.modulus);
1617 if (*cfg.keyfile && !tried_publickey)
1618 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1620 if (pktin.type == SSH1_SMSG_FAILURE &&
1622 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1623 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1624 logevent("Requested TIS authentication");
1625 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1627 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1628 logevent("TIS authentication declined");
1629 if (flags & FLAG_INTERACTIVE)
1630 c_write_str("TIS authentication refused.\r\n");
1632 int challengelen = ((pktin.body[0] << 24) |
1633 (pktin.body[1] << 16) |
1634 (pktin.body[2] << 8) |
1636 logevent("Received TIS challenge");
1637 if (challengelen > sizeof(prompt)-1)
1638 challengelen = sizeof(prompt)-1; /* prevent overrun */
1639 memcpy(prompt, pktin.body+4, challengelen);
1640 prompt[challengelen] = '\0';
1643 if (pktin.type == SSH1_SMSG_FAILURE &&
1645 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1646 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1647 logevent("Requested CryptoCard authentication");
1648 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1650 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1651 logevent("CryptoCard authentication declined");
1652 c_write_str("CryptoCard authentication refused.\r\n");
1654 int challengelen = ((pktin.body[0] << 24) |
1655 (pktin.body[1] << 16) |
1656 (pktin.body[2] << 8) |
1658 logevent("Received CryptoCard challenge");
1659 if (challengelen > sizeof(prompt)-1)
1660 challengelen = sizeof(prompt)-1; /* prevent overrun */
1661 memcpy(prompt, pktin.body+4, challengelen);
1662 strncpy(prompt + challengelen, "\r\nResponse : ",
1663 sizeof(prompt)-challengelen);
1664 prompt[sizeof(prompt)-1] = '\0';
1667 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1668 sprintf(prompt, "%.90s@%.90s's password: ",
1669 username, savedhost);
1671 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1672 char *comment = NULL;
1673 if (flags & FLAG_VERBOSE)
1674 c_write_str("Trying public key authentication.\r\n");
1675 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1676 if (flags & FLAG_VERBOSE)
1677 c_write_str("No passphrase required.\r\n");
1680 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1684 if (ssh_get_password) {
1685 if (!ssh_get_password(prompt, password, sizeof(password))) {
1687 * get_password failed to get a password (for
1688 * example because one was supplied on the command
1689 * line which has already failed to work).
1692 logevent("No more passwords to try");
1693 ssh_state = SSH_STATE_CLOSED;
1697 c_write_str(prompt);
1701 crWaitUntil(!ispkt);
1702 while (inlen--) switch (c = *in++) {
1719 if (((c >= ' ' && c <= '~') ||
1720 ((unsigned char)c >= 160)) && pos < sizeof(password))
1721 password[pos++] = c;
1725 c_write_str("\r\n");
1729 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1731 * Try public key authentication with the specified
1734 static struct RSAKey pubkey;
1735 static Bignum challenge, response;
1737 static unsigned char buffer[32];
1739 tried_publickey = 1;
1740 i = loadrsakey(cfg.keyfile, &pubkey, password);
1742 c_write_str("Couldn't load public key from ");
1743 c_write_str(cfg.keyfile);
1744 c_write_str(".\r\n");
1745 continue; /* go and try password */
1748 c_write_str("Wrong passphrase.\r\n");
1749 tried_publickey = 0;
1750 continue; /* try again */
1754 * Send a public key attempt.
1756 send_packet(SSH1_CMSG_AUTH_RSA,
1757 PKT_BIGNUM, pubkey.modulus, PKT_END);
1760 if (pktin.type == SSH1_SMSG_FAILURE) {
1761 c_write_str("Server refused our public key.\r\n");
1762 continue; /* go and try password */
1764 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1765 bombout(("Bizarre response to offer of public key"));
1768 ssh1_read_bignum(pktin.body, &challenge);
1769 response = rsadecrypt(challenge, &pubkey);
1770 freebn(pubkey.private_exponent); /* burn the evidence */
1772 for (i = 0; i < 32; i++) {
1773 buffer[i] = bignum_byte(response, 31-i);
1777 MD5Update(&md5c, buffer, 32);
1778 MD5Update(&md5c, session_id, 16);
1779 MD5Final(buffer, &md5c);
1781 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1782 PKT_DATA, buffer, 16, PKT_END);
1785 if (pktin.type == SSH1_SMSG_FAILURE) {
1786 if (flags & FLAG_VERBOSE)
1787 c_write_str("Failed to authenticate with our public key.\r\n");
1788 continue; /* go and try password */
1789 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1790 bombout(("Bizarre response to RSA authentication response"));
1794 break; /* we're through! */
1796 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1798 logevent("Sent password");
1799 memset(password, 0, strlen(password));
1801 if (pktin.type == SSH1_SMSG_FAILURE) {
1802 if (flags & FLAG_VERBOSE)
1803 c_write_str("Access denied\r\n");
1804 logevent("Authentication refused");
1805 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1806 logevent("Received disconnect request");
1807 ssh_state = SSH_STATE_CLOSED;
1809 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1810 bombout(("Strange packet received, type %d", pktin.type));
1815 logevent("Authentication successful");
1820 void sshfwd_close(struct ssh_channel *c) {
1822 if (ssh_version == 1) {
1823 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1825 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1826 ssh2_pkt_adduint32(c->remoteid);
1830 if (c->type == CHAN_X11) {
1832 logevent("X11 connection terminated");
1837 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
1838 if (ssh_version == 1) {
1839 send_packet(SSH1_MSG_CHANNEL_DATA,
1840 PKT_INT, c->remoteid,
1845 ssh2_add_channel_data(c, buf, len);
1850 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1855 while (!do_ssh1_login(in, inlen, ispkt)) {
1858 if (ssh_state == SSH_STATE_CLOSED)
1861 if (cfg.agentfwd && agent_exists()) {
1862 logevent("Requesting agent forwarding");
1863 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1864 do { crReturnV; } while (!ispkt);
1865 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1866 bombout(("Protocol confusion"));
1868 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1869 logevent("Agent forwarding refused");
1871 logevent("Agent forwarding enabled");
1872 ssh_agentfwd_enabled = TRUE;
1876 if (cfg.x11_forward) {
1877 char proto[20], data[64];
1878 logevent("Requesting X11 forwarding");
1879 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1880 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1881 PKT_STR, proto, PKT_STR, data,
1884 do { crReturnV; } while (!ispkt);
1885 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1886 bombout(("Protocol confusion"));
1888 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1889 logevent("X11 forwarding refused");
1891 logevent("X11 forwarding enabled");
1892 ssh_X11_fwd_enabled = TRUE;
1897 send_packet(SSH1_CMSG_REQUEST_PTY,
1898 PKT_STR, cfg.termtype,
1899 PKT_INT, rows, PKT_INT, cols,
1900 PKT_INT, 0, PKT_INT, 0,
1903 ssh_state = SSH_STATE_INTERMED;
1904 do { crReturnV; } while (!ispkt);
1905 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1906 bombout(("Protocol confusion"));
1908 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1909 c_write_str("Server refused to allocate pty\r\n");
1910 ssh_editing = ssh_echoing = 1;
1912 logevent("Allocated pty");
1914 ssh_editing = ssh_echoing = 1;
1917 if (cfg.compression) {
1918 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1919 do { crReturnV; } while (!ispkt);
1920 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1921 bombout(("Protocol confusion"));
1923 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1924 c_write_str("Server refused to compress\r\n");
1926 logevent("Started compression");
1927 ssh1_compressing = TRUE;
1928 zlib_compress_init();
1929 zlib_decompress_init();
1932 if (*cfg.remote_cmd)
1933 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1935 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1936 logevent("Started session");
1938 ssh_state = SSH_STATE_SESSION;
1942 ssh_special(TS_EOF);
1944 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
1946 ssh_channels = newtree234(ssh_channelcmp);
1950 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1951 pktin.type == SSH1_SMSG_STDERR_DATA) {
1952 long len = GET_32BIT(pktin.body);
1953 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1955 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1956 ssh_state = SSH_STATE_CLOSED;
1957 logevent("Received disconnect request");
1959 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1960 /* Remote side is trying to open a channel to talk to our
1961 * X-Server. Give them back a local channel number. */
1963 struct ssh_channel *c, *d;
1966 logevent("Received X11 connect request");
1967 /* Refuse if X11 forwarding is disabled. */
1968 if (!ssh_X11_fwd_enabled) {
1969 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1970 PKT_INT, GET_32BIT(pktin.body),
1972 logevent("Rejected X11 connect request");
1974 c = smalloc(sizeof(struct ssh_channel));
1976 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
1977 logevent("opening X11 forward connection failed");
1979 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1980 PKT_INT, GET_32BIT(pktin.body),
1983 logevent("opening X11 forward connection succeeded");
1984 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
1986 break; /* found a free number */
1989 c->remoteid = GET_32BIT(pktin.body);
1992 c->type = CHAN_X11; /* identify channel type */
1993 add234(ssh_channels, c);
1994 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1995 PKT_INT, c->remoteid, PKT_INT, c->localid,
1997 logevent("Opened X11 forward channel");
2000 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2001 /* Remote side is trying to open a channel to talk to our
2002 * agent. Give them back a local channel number. */
2004 struct ssh_channel *c;
2007 /* Refuse if agent forwarding is disabled. */
2008 if (!ssh_agentfwd_enabled) {
2009 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2010 PKT_INT, GET_32BIT(pktin.body),
2014 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2016 break; /* found a free number */
2019 c = smalloc(sizeof(struct ssh_channel));
2020 c->remoteid = GET_32BIT(pktin.body);
2023 c->type = CHAN_AGENT; /* identify channel type */
2024 c->u.a.lensofar = 0;
2025 add234(ssh_channels, c);
2026 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2027 PKT_INT, c->remoteid, PKT_INT, c->localid,
2030 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2031 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2032 /* Remote side closes a channel. */
2033 unsigned i = GET_32BIT(pktin.body);
2034 struct ssh_channel *c;
2035 c = find234(ssh_channels, &i, ssh_channelfind);
2038 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2039 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
2040 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2041 logevent("X11 connection closed");
2042 assert(c->u.x11.s != NULL);
2043 x11_close(c->u.x11.s);
2046 c->closes |= closetype;
2047 if (c->closes == 3) {
2048 del234(ssh_channels, c);
2052 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2053 /* Data sent down one of our channels. */
2054 int i = GET_32BIT(pktin.body);
2055 int len = GET_32BIT(pktin.body+4);
2056 unsigned char *p = pktin.body+8;
2057 struct ssh_channel *c;
2058 c = find234(ssh_channels, &i, ssh_channelfind);
2062 x11_send(c->u.x11.s, p, len);
2065 /* Data for an agent message. Buffer it. */
2067 if (c->u.a.lensofar < 4) {
2068 int l = min(4 - c->u.a.lensofar, len);
2069 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2070 p += l; len -= l; c->u.a.lensofar += l;
2072 if (c->u.a.lensofar == 4) {
2073 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2074 c->u.a.message = smalloc(c->u.a.totallen);
2075 memcpy(c->u.a.message, c->u.a.msglen, 4);
2077 if (c->u.a.lensofar >= 4 && len > 0) {
2078 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2079 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2080 p += l; len -= l; c->u.a.lensofar += l;
2082 if (c->u.a.lensofar == c->u.a.totallen) {
2083 void *reply, *sentreply;
2085 agent_query(c->u.a.message, c->u.a.totallen,
2090 /* Fake SSH_AGENT_FAILURE. */
2091 sentreply = "\0\0\0\1\5";
2094 send_packet(SSH1_MSG_CHANNEL_DATA,
2095 PKT_INT, c->remoteid,
2097 PKT_DATA, sentreply, replylen,
2101 sfree(c->u.a.message);
2102 c->u.a.lensofar = 0;
2108 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2109 /* may be from EXEC_SHELL on some servers */
2110 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2111 /* may be from EXEC_SHELL on some servers
2112 * if no pty is available or in other odd cases. Ignore */
2113 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2114 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2116 bombout(("Strange packet received: type %d", pktin.type));
2121 int len = min(inlen, 512);
2122 send_packet(SSH1_CMSG_STDIN_DATA,
2123 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2134 * Utility routine for decoding comma-separated strings in KEXINIT.
2136 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2137 int needlen = strlen(needle);
2140 * Is it at the start of the string?
2142 if (haylen >= needlen && /* haystack is long enough */
2143 !memcmp(needle, haystack, needlen) && /* initial match */
2144 (haylen == needlen || haystack[needlen] == ',')
2145 /* either , or EOS follows */
2149 * If not, search for the next comma and resume after that.
2150 * If no comma found, terminate.
2152 while (haylen > 0 && *haystack != ',')
2153 haylen--, haystack++;
2156 haylen--, haystack++; /* skip over comma itself */
2161 * SSH2 key creation method.
2163 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
2165 /* First 20 bytes. */
2168 SHA_Bytes(&s, H, 20);
2169 SHA_Bytes(&s, &chr, 1);
2170 SHA_Bytes(&s, sessid, 20);
2171 SHA_Final(&s, keyspace);
2172 /* Next 20 bytes. */
2175 SHA_Bytes(&s, H, 20);
2176 SHA_Bytes(&s, keyspace, 20);
2177 SHA_Final(&s, keyspace+20);
2181 * Handle the SSH2 transport layer.
2183 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2185 static int i, j, len, nbits;
2187 static Bignum p, g, e, f, K;
2188 static int kex_init_value, kex_reply_value;
2189 static const struct ssh_mac **maclist;
2191 static const struct ssh2_cipher *cscipher_tobe = NULL;
2192 static const struct ssh2_cipher *sccipher_tobe = NULL;
2193 static const struct ssh_mac *csmac_tobe = NULL;
2194 static const struct ssh_mac *scmac_tobe = NULL;
2195 static const struct ssh_compress *cscomp_tobe = NULL;
2196 static const struct ssh_compress *sccomp_tobe = NULL;
2197 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2198 static int hostkeylen, siglen;
2199 static void *hkey; /* actual host key */
2200 static unsigned char exchange_hash[20];
2201 static unsigned char keyspace[40];
2202 static const struct ssh2_ciphers *preferred_cipher;
2203 static const struct ssh_compress *preferred_comp;
2204 static int first_kex;
2211 * Set up the preferred cipher and compression.
2213 if (cfg.cipher == CIPHER_BLOWFISH) {
2214 preferred_cipher = &ssh2_blowfish;
2215 } else if (cfg.cipher == CIPHER_DES) {
2216 logevent("Single DES not supported in SSH2; using 3DES");
2217 preferred_cipher = &ssh2_3des;
2218 } else if (cfg.cipher == CIPHER_3DES) {
2219 preferred_cipher = &ssh2_3des;
2220 } else if (cfg.cipher == CIPHER_AES) {
2221 preferred_cipher = &ssh2_aes;
2223 /* Shouldn't happen, but we do want to initialise to _something_. */
2224 preferred_cipher = &ssh2_3des;
2226 if (cfg.compression)
2227 preferred_comp = &ssh_zlib;
2229 preferred_comp = &ssh_comp_none;
2232 * Be prepared to work around the buggy MAC problem.
2235 maclist = buggymacs, nmacs = lenof(buggymacs);
2237 maclist = macs, nmacs = lenof(macs);
2241 * Construct and send our key exchange packet.
2243 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2244 for (i = 0; i < 16; i++)
2245 ssh2_pkt_addbyte((unsigned char)random_byte());
2246 /* List key exchange algorithms. */
2247 ssh2_pkt_addstring_start();
2248 for (i = 0; i < lenof(kex_algs); i++) {
2249 ssh2_pkt_addstring_str(kex_algs[i]->name);
2250 if (i < lenof(kex_algs)-1)
2251 ssh2_pkt_addstring_str(",");
2253 /* List server host key algorithms. */
2254 ssh2_pkt_addstring_start();
2255 for (i = 0; i < lenof(hostkey_algs); i++) {
2256 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2257 if (i < lenof(hostkey_algs)-1)
2258 ssh2_pkt_addstring_str(",");
2260 /* List client->server encryption algorithms. */
2261 ssh2_pkt_addstring_start();
2262 for (i = 0; i < lenof(ciphers)+1; i++) {
2263 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2264 for (j = 0; j < c->nciphers; j++) {
2265 ssh2_pkt_addstring_str(c->list[j]->name);
2266 if (i < lenof(ciphers) || j < c->nciphers-1)
2267 ssh2_pkt_addstring_str(",");
2270 /* List server->client encryption algorithms. */
2271 ssh2_pkt_addstring_start();
2272 for (i = 0; i < lenof(ciphers)+1; i++) {
2273 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2274 for (j = 0; j < c->nciphers; j++) {
2275 ssh2_pkt_addstring_str(c->list[j]->name);
2276 if (i < lenof(ciphers) || j < c->nciphers-1)
2277 ssh2_pkt_addstring_str(",");
2280 /* List client->server MAC algorithms. */
2281 ssh2_pkt_addstring_start();
2282 for (i = 0; i < nmacs; i++) {
2283 ssh2_pkt_addstring_str(maclist[i]->name);
2285 ssh2_pkt_addstring_str(",");
2287 /* List server->client MAC algorithms. */
2288 ssh2_pkt_addstring_start();
2289 for (i = 0; i < nmacs; i++) {
2290 ssh2_pkt_addstring_str(maclist[i]->name);
2292 ssh2_pkt_addstring_str(",");
2294 /* List client->server compression algorithms. */
2295 ssh2_pkt_addstring_start();
2296 for (i = 0; i < lenof(compressions)+1; i++) {
2297 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2298 ssh2_pkt_addstring_str(c->name);
2299 if (i < lenof(compressions))
2300 ssh2_pkt_addstring_str(",");
2302 /* List server->client compression algorithms. */
2303 ssh2_pkt_addstring_start();
2304 for (i = 0; i < lenof(compressions)+1; i++) {
2305 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2306 ssh2_pkt_addstring_str(c->name);
2307 if (i < lenof(compressions))
2308 ssh2_pkt_addstring_str(",");
2310 /* List client->server languages. Empty list. */
2311 ssh2_pkt_addstring_start();
2312 /* List server->client languages. Empty list. */
2313 ssh2_pkt_addstring_start();
2314 /* First KEX packet does _not_ follow, because we're not that brave. */
2315 ssh2_pkt_addbool(FALSE);
2317 ssh2_pkt_adduint32(0);
2319 exhash = exhashbase;
2320 sha_string(&exhash, pktout.data+5, pktout.length-5);
2324 if (!ispkt) crWaitUntil(ispkt);
2325 sha_string(&exhash, pktin.data+5, pktin.length-5);
2328 * Now examine the other side's KEXINIT to see what we're up
2331 if (pktin.type != SSH2_MSG_KEXINIT) {
2332 bombout(("expected key exchange packet from server"));
2335 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2336 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2337 pktin.savedpos += 16; /* skip garbage cookie */
2338 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2339 for (i = 0; i < lenof(kex_algs); i++) {
2340 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2345 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2346 for (i = 0; i < lenof(hostkey_algs); i++) {
2347 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2348 hostkey = hostkey_algs[i];
2352 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2353 for (i = 0; i < lenof(ciphers)+1; i++) {
2354 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2355 for (j = 0; j < c->nciphers; j++) {
2356 if (in_commasep_string(c->list[j]->name, str, len)) {
2357 cscipher_tobe = c->list[j];
2364 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2365 for (i = 0; i < lenof(ciphers)+1; i++) {
2366 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2367 for (j = 0; j < c->nciphers; j++) {
2368 if (in_commasep_string(c->list[j]->name, str, len)) {
2369 sccipher_tobe = c->list[j];
2376 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2377 for (i = 0; i < nmacs; i++) {
2378 if (in_commasep_string(maclist[i]->name, str, len)) {
2379 csmac_tobe = maclist[i];
2383 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2384 for (i = 0; i < nmacs; i++) {
2385 if (in_commasep_string(maclist[i]->name, str, len)) {
2386 scmac_tobe = maclist[i];
2390 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2391 for (i = 0; i < lenof(compressions)+1; i++) {
2392 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2393 if (in_commasep_string(c->name, str, len)) {
2398 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2399 for (i = 0; i < lenof(compressions)+1; i++) {
2400 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2401 if (in_commasep_string(c->name, str, len)) {
2408 * If we're doing Diffie-Hellman group exchange, start by
2409 * requesting a group.
2411 if (kex == &ssh_diffiehellman_gex) {
2414 logevent("Doing Diffie-Hellman group exchange");
2416 * Work out number of bits. We start with the maximum key
2417 * length of either cipher...
2419 csbits = cscipher_tobe->keylen;
2420 scbits = sccipher_tobe->keylen;
2421 nbits = (csbits > scbits ? csbits : scbits);
2422 /* The keys only have 160-bit entropy, since they're based on
2423 * a SHA-1 hash. So cap the key size at 160 bits. */
2424 if (nbits > 160) nbits = 160;
2426 * ... and then work out how big a DH group we will need to
2427 * allow that much data.
2429 nbits = 512 << ((nbits-1) / 64);
2430 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2431 ssh2_pkt_adduint32(nbits);
2435 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2436 bombout(("expected key exchange group packet from server"));
2439 p = ssh2_pkt_getmp();
2440 g = ssh2_pkt_getmp();
2441 dh_setup_group(p, g);
2442 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2443 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2446 kex_init_value = SSH2_MSG_KEXDH_INIT;
2447 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
2450 logevent("Doing Diffie-Hellman key exchange");
2452 * Now generate and send e for Diffie-Hellman.
2455 ssh2_pkt_init(kex_init_value);
2460 if (pktin.type != kex_reply_value) {
2461 bombout(("expected key exchange reply packet from server"));
2464 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2465 f = ssh2_pkt_getmp();
2466 ssh2_pkt_getstring(&sigdata, &siglen);
2470 sha_string(&exhash, hostkeydata, hostkeylen);
2471 if (kex == &ssh_diffiehellman_gex) {
2472 sha_uint32(&exhash, nbits);
2473 sha_mpint(&exhash, p);
2474 sha_mpint(&exhash, g);
2476 sha_mpint(&exhash, e);
2477 sha_mpint(&exhash, f);
2478 sha_mpint(&exhash, K);
2479 SHA_Final(&exhash, exchange_hash);
2484 debug(("Exchange hash is:\r\n"));
2485 for (i = 0; i < 20; i++)
2486 debug((" %02x", exchange_hash[i]));
2490 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2491 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2492 bombout(("Server failed host key check"));
2497 * Expect SSH2_MSG_NEWKEYS from server.
2500 if (pktin.type != SSH2_MSG_NEWKEYS) {
2501 bombout(("expected new-keys packet from server"));
2506 * Authenticate remote host: verify host key. (We've already
2507 * checked the signature of the exchange hash.)
2509 keystr = hostkey->fmtkey(hkey);
2510 fingerprint = hostkey->fingerprint(hkey);
2511 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2512 keystr, fingerprint);
2513 if (first_kex) { /* don't bother logging this in rekeys */
2514 logevent("Host key fingerprint is:");
2515 logevent(fingerprint);
2519 hostkey->freekey(hkey);
2522 * Send SSH2_MSG_NEWKEYS.
2524 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2528 * Create and initialise session keys.
2530 cscipher = cscipher_tobe;
2531 sccipher = sccipher_tobe;
2534 cscomp = cscomp_tobe;
2535 sccomp = sccomp_tobe;
2536 cscomp->compress_init();
2537 sccomp->decompress_init();
2539 * Set IVs after keys. Here we use the exchange hash from the
2540 * _first_ key exchange.
2543 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2544 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
2545 cscipher->setcskey(keyspace);
2546 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
2547 sccipher->setsckey(keyspace);
2548 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
2549 cscipher->setcsiv(keyspace);
2550 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
2551 sccipher->setsciv(keyspace);
2552 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
2553 csmac->setcskey(keyspace);
2554 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
2555 scmac->setsckey(keyspace);
2558 * If this is the first key exchange phase, we must pass the
2559 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2560 * wants to see it but because it will need time to initialise
2561 * itself before it sees an actual packet. In subsequent key
2562 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2563 * it would only confuse the layer above.
2571 * Now we're encrypting. Begin returning 1 to the protocol main
2572 * function so that other things can run on top of the
2573 * transport. If we ever see a KEXINIT, we must go back to the
2576 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
2579 logevent("Server initiated key re-exchange");
2580 goto begin_key_exchange;
2586 * Add data to an SSH2 channel output buffer.
2588 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2589 if (c->v2.outbufsize <
2590 c->v2.outbuflen + len) {
2592 c->v2.outbuflen + len + 1024;
2593 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2596 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2598 c->v2.outbuflen += len;
2602 * Attempt to send data on an SSH2 channel.
2604 static void ssh2_try_send(struct ssh_channel *c) {
2605 while (c->v2.remwindow > 0 &&
2606 c->v2.outbuflen > 0) {
2607 unsigned len = c->v2.remwindow;
2608 if (len > c->v2.outbuflen)
2609 len = c->v2.outbuflen;
2610 if (len > c->v2.remmaxpkt)
2611 len = c->v2.remmaxpkt;
2612 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2613 ssh2_pkt_adduint32(c->remoteid);
2614 ssh2_pkt_addstring_start();
2615 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2617 c->v2.outbuflen -= len;
2618 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2620 c->v2.remwindow -= len;
2625 * Handle the SSH2 userauth and connection layers.
2627 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2629 static unsigned long remote_winsize;
2630 static unsigned long remote_maxpkt;
2632 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2636 AUTH_TYPE_PUBLICKEY,
2637 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2638 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2641 static int gotit, need_pw, can_pubkey, can_passwd, tried_pubkey_config;
2642 static int we_are_in;
2643 static char username[100];
2644 static char pwprompt[200];
2645 static char password[100];
2650 * Request userauth protocol, and await a response to it.
2652 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2653 ssh2_pkt_addstring("ssh-userauth");
2655 crWaitUntilV(ispkt);
2656 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2657 bombout(("Server refused user authentication protocol"));
2662 * We repeat this whole loop, including the username prompt,
2663 * until we manage a successful authentication. If the user
2664 * types the wrong _password_, they are sent back to the
2665 * beginning to try another username. (If they specify a
2666 * username in the config, they are never asked, even if they
2667 * do give a wrong password.)
2669 * I think this best serves the needs of
2671 * - the people who have no configuration, no keys, and just
2672 * want to try repeated (username,password) pairs until they
2673 * type both correctly
2675 * - people who have keys and configuration but occasionally
2676 * need to fall back to passwords
2678 * - people with a key held in Pageant, who might not have
2679 * logged in to a particular machine before; so they want to
2680 * type a username, and then _either_ their key will be
2681 * accepted, _or_ they will type a password. If they mistype
2682 * the username they will want to be able to get back and
2693 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2694 c_write_str("login as: ");
2697 crWaitUntilV(!ispkt);
2698 while (inlen--) switch (c = *in++) {
2705 c_write_str("\b \b");
2711 c_write_str("\b \b");
2720 if (((c >= ' ' && c <= '~') ||
2721 ((unsigned char)c >= 160)) && pos < 40) {
2722 username[pos++] = c;
2728 c_write_str("\r\n");
2729 username[strcspn(username, "\n\r")] = '\0';
2732 strncpy(username, cfg.username, 99);
2733 username[99] = '\0';
2734 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2735 sprintf(stuff, "Using username \"%s\".\r\n", username);
2741 * Send an authentication request using method "none": (a)
2742 * just in case it succeeds, and (b) so that we know what
2743 * authentication methods we can usefully try next.
2745 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2746 ssh2_pkt_addstring(username);
2747 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2748 ssh2_pkt_addstring("none"); /* method */
2750 type = AUTH_TYPE_NONE;
2754 tried_pubkey_config = FALSE;
2758 * Wait for the result of the last authentication request.
2761 crWaitUntilV(ispkt);
2762 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
2763 /* FIXME: should support this */
2764 crWaitUntilV(ispkt);
2766 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
2767 logevent("Access granted");
2772 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
2773 bombout(("Strange packet received during authentication: type %d",
2780 * OK, we're now sitting on a USERAUTH_FAILURE message, so
2781 * we can look at the string in it and know what we can
2782 * helpfully try next.
2787 ssh2_pkt_getstring(&methods, &methlen);
2788 if (!ssh2_pkt_getbool()) {
2790 * We have received an unequivocal Access
2791 * Denied. This can translate to a variety of
2794 * - if we'd just tried "none" authentication,
2795 * it's not worth printing anything at all
2797 * - if we'd just tried a public key _offer_,
2798 * the message should be "Server refused our
2799 * key" (or no message at all if the key
2800 * came from Pageant)
2802 * - if we'd just tried anything else, the
2803 * message really should be "Access denied".
2805 * Additionally, if we'd just tried password
2806 * authentication, we should break out of this
2807 * whole loop so as to go back to the username
2810 if (type == AUTH_TYPE_NONE) {
2812 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
2813 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
2814 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
2815 c_write_str("Server refused our key\r\n");
2816 logevent("Server refused public key");
2818 c_write_str("Access denied\r\n");
2819 logevent("Access denied");
2820 if (type == AUTH_TYPE_PASSWORD) {
2826 c_write_str("Further authentication required\r\n");
2827 logevent("Further authentication required");
2830 can_pubkey = in_commasep_string("publickey", methods, methlen);
2831 can_passwd = in_commasep_string("password", methods, methlen);
2836 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
2837 unsigned char *pub_blob;
2838 char *algorithm, *comment;
2841 tried_pubkey_config = TRUE;
2844 * Try the public key supplied in the configuration.
2846 * First, offer the public blob to see if the server is
2847 * willing to accept it.
2849 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
2852 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2853 ssh2_pkt_addstring(username);
2854 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2855 ssh2_pkt_addstring("publickey");/* method */
2856 ssh2_pkt_addbool(FALSE); /* no signature included */
2857 ssh2_pkt_addstring(algorithm);
2858 ssh2_pkt_addstring_start();
2859 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
2861 logevent("Offered public key"); /* FIXME */
2863 crWaitUntilV(ispkt);
2864 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
2866 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
2867 continue; /* key refused; give up on it */
2870 logevent("Offer of public key accepted");
2872 * Actually attempt a serious authentication using
2875 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
2876 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
2881 c_write_str("Authenticating with public key \"");
2882 c_write_str(comment);
2883 c_write_str("\"\r\n");
2884 method = AUTH_PUBLICKEY_FILE;
2888 if (!method && can_passwd) {
2889 method = AUTH_PASSWORD;
2890 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
2895 if (ssh_get_password) {
2896 if (!ssh_get_password(pwprompt, password, sizeof(password))) {
2898 * get_password failed to get a password (for
2899 * example because one was supplied on the command
2900 * line which has already failed to work).
2903 logevent("No more passwords to try");
2904 ssh_state = SSH_STATE_CLOSED;
2911 c_write_str(pwprompt);
2916 crWaitUntilV(!ispkt);
2917 while (inlen--) switch (c = *in++) {
2934 if (((c >= ' ' && c <= '~') ||
2935 ((unsigned char)c >= 160)) && pos < 40)
2936 password[pos++] = c;
2940 c_write_str("\r\n");
2944 if (method == AUTH_PUBLICKEY_FILE) {
2946 * We have our passphrase. Now try the actual authentication.
2948 struct ssh2_userkey *key;
2950 key = ssh2_load_userkey(cfg.keyfile, password);
2951 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
2952 if (key == SSH2_WRONG_PASSPHRASE) {
2953 c_write_str("Wrong passphrase\r\n");
2954 tried_pubkey_config = FALSE;
2956 c_write_str("Unable to load private key\r\n");
2957 tried_pubkey_config = TRUE;
2959 /* Send a spurious AUTH_NONE to return to the top. */
2960 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2961 ssh2_pkt_addstring(username);
2962 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2963 ssh2_pkt_addstring("none"); /* method */
2965 type = AUTH_TYPE_NONE;
2967 unsigned char *blob, *sigdata;
2968 int blob_len, sigdata_len;
2971 * We have loaded the private key and the server
2972 * has announced that it's willing to accept it.
2973 * Hallelujah. Generate a signature and send it.
2975 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2976 ssh2_pkt_addstring(username);
2977 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2978 ssh2_pkt_addstring("publickey"); /* method */
2979 ssh2_pkt_addbool(TRUE);
2980 ssh2_pkt_addstring(key->alg->name);
2981 blob = key->alg->public_blob(key->data, &blob_len);
2982 ssh2_pkt_addstring_start();
2983 ssh2_pkt_addstring_data(blob, blob_len);
2987 * The data to be signed is:
2991 * followed by everything so far placed in the
2994 sigdata_len = pktout.length - 5 + 4 + 20;
2995 sigdata = smalloc(sigdata_len);
2996 PUT_32BIT(sigdata, 20);
2997 memcpy(sigdata+4, ssh2_session_id, 20);
2998 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
2999 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3000 ssh2_pkt_addstring_start();
3001 ssh2_pkt_addstring_data(blob, blob_len);
3006 type = AUTH_TYPE_PUBLICKEY;
3008 } else if (method == AUTH_PASSWORD) {
3010 * We send the password packet lumped tightly together with
3011 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3012 * string long enough to make the total length of the two
3013 * packets constant. This should ensure that a passive
3014 * listener doing traffic analyis can't work out the length
3017 * For this to work, we need an assumption about the
3018 * maximum length of the password packet. I think 256 is
3019 * pretty conservative. Anyone using a password longer than
3020 * that probably doesn't have much to worry about from
3021 * people who find out how long their password is!
3023 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3024 ssh2_pkt_addstring(username);
3025 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3026 ssh2_pkt_addstring("password");
3027 ssh2_pkt_addbool(FALSE);
3028 ssh2_pkt_addstring(password);
3031 * We'll include a string that's an exact multiple of the
3032 * cipher block size. If the cipher is NULL for some
3033 * reason, we don't do this trick at all because we gain
3038 ssh2_pkt_init(SSH2_MSG_IGNORE);
3039 ssh2_pkt_addstring_start();
3040 for (i = deferred_len; i <= 256; i += cscipher->blksize) {
3041 for (j = 0; j < cscipher->blksize; j++) {
3042 char c = (char)random_byte();
3043 ssh2_pkt_addstring_data(&c, 1);
3048 ssh2_pkt_defersend();
3049 type = AUTH_TYPE_PASSWORD;
3051 c_write_str("No supported authentication methods left to try!\r\n");
3052 logevent("No supported authentications offered. Disconnecting");
3053 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3054 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3055 ssh2_pkt_addstring("No supported authentication methods available");
3056 ssh2_pkt_addstring("en"); /* language tag */
3058 ssh_state = SSH_STATE_CLOSED;
3062 } while (!we_are_in);
3065 * Now we're authenticated for the connection protocol. The
3066 * connection protocol will automatically have started at this
3067 * point; there's no need to send SERVICE_REQUEST.
3071 * So now create a channel with a session in it.
3073 mainchan = smalloc(sizeof(struct ssh_channel));
3074 mainchan->localid = 100; /* as good as any */
3075 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3076 ssh2_pkt_addstring("session");
3077 ssh2_pkt_adduint32(mainchan->localid);
3078 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3079 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3081 crWaitUntilV(ispkt);
3082 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
3083 bombout(("Server refused to open a session"));
3085 /* FIXME: error data comes back in FAILURE packet */
3087 if (ssh2_pkt_getuint32() != mainchan->localid) {
3088 bombout(("Server's channel confirmation cited wrong channel"));
3091 mainchan->remoteid = ssh2_pkt_getuint32();
3092 mainchan->type = CHAN_MAINSESSION;
3093 mainchan->closes = 0;
3094 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3095 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3096 mainchan->v2.outbuffer = NULL;
3097 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3098 ssh_channels = newtree234(ssh_channelcmp);
3099 add234(ssh_channels, mainchan);
3100 logevent("Opened channel for session");
3103 * Potentially enable X11 forwarding.
3105 if (cfg.x11_forward) {
3106 char proto[20], data[64];
3107 logevent("Requesting X11 forwarding");
3108 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3109 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3110 ssh2_pkt_adduint32(mainchan->remoteid);
3111 ssh2_pkt_addstring("x11-req");
3112 ssh2_pkt_addbool(1); /* want reply */
3113 ssh2_pkt_addbool(0); /* many connections */
3114 ssh2_pkt_addstring(proto);
3115 ssh2_pkt_addstring(data);
3116 ssh2_pkt_adduint32(0); /* screen number */
3120 crWaitUntilV(ispkt);
3121 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3122 unsigned i = ssh2_pkt_getuint32();
3123 struct ssh_channel *c;
3124 c = find234(ssh_channels, &i, ssh_channelfind);
3126 continue; /* nonexistent channel */
3127 c->v2.remwindow += ssh2_pkt_getuint32();
3129 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3131 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3132 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3133 bombout(("Server got confused by X11 forwarding request"));
3136 logevent("X11 forwarding refused");
3138 logevent("X11 forwarding enabled");
3139 ssh_X11_fwd_enabled = TRUE;
3144 * Now allocate a pty for the session.
3147 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3148 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3149 ssh2_pkt_addstring("pty-req");
3150 ssh2_pkt_addbool(1); /* want reply */
3151 ssh2_pkt_addstring(cfg.termtype);
3152 ssh2_pkt_adduint32(cols);
3153 ssh2_pkt_adduint32(rows);
3154 ssh2_pkt_adduint32(0); /* pixel width */
3155 ssh2_pkt_adduint32(0); /* pixel height */
3156 ssh2_pkt_addstring_start();
3157 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3159 ssh_state = SSH_STATE_INTERMED;
3162 crWaitUntilV(ispkt);
3163 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3164 unsigned i = ssh2_pkt_getuint32();
3165 struct ssh_channel *c;
3166 c = find234(ssh_channels, &i, ssh_channelfind);
3168 continue; /* nonexistent channel */
3169 c->v2.remwindow += ssh2_pkt_getuint32();
3171 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3173 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3174 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3175 bombout(("Server got confused by pty request"));
3178 c_write_str("Server refused to allocate pty\r\n");
3179 ssh_editing = ssh_echoing = 1;
3181 logevent("Allocated pty");
3184 ssh_editing = ssh_echoing = 1;
3188 * Start a shell or a remote command.
3190 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3191 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3192 if (cfg.ssh_subsys) {
3193 ssh2_pkt_addstring("subsystem");
3194 ssh2_pkt_addbool(1); /* want reply */
3195 ssh2_pkt_addstring(cfg.remote_cmd);
3196 } else if (*cfg.remote_cmd) {
3197 ssh2_pkt_addstring("exec");
3198 ssh2_pkt_addbool(1); /* want reply */
3199 ssh2_pkt_addstring(cfg.remote_cmd);
3201 ssh2_pkt_addstring("shell");
3202 ssh2_pkt_addbool(1); /* want reply */
3206 crWaitUntilV(ispkt);
3207 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3208 unsigned i = ssh2_pkt_getuint32();
3209 struct ssh_channel *c;
3210 c = find234(ssh_channels, &i, ssh_channelfind);
3212 continue; /* nonexistent channel */
3213 c->v2.remwindow += ssh2_pkt_getuint32();
3215 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3216 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3217 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3218 bombout(("Server got confused by shell/command request"));
3221 bombout(("Server refused to start a shell/command"));
3224 logevent("Started a shell/command");
3227 ssh_state = SSH_STATE_SESSION;
3231 ssh_special(TS_EOF);
3236 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
3239 static int try_send;
3243 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3244 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3247 unsigned i = ssh2_pkt_getuint32();
3248 struct ssh_channel *c;
3249 c = find234(ssh_channels, &i, ssh_channelfind);
3251 continue; /* nonexistent channel */
3252 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3253 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3254 continue; /* extended but not stderr */
3255 ssh2_pkt_getstring(&data, &length);
3258 case CHAN_MAINSESSION:
3259 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3263 x11_send(c->u.x11.s, data, length);
3267 * Enlarge the window again at the remote
3268 * side, just in case it ever runs down and
3269 * they fail to send us any more data.
3271 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3272 ssh2_pkt_adduint32(c->remoteid);
3273 ssh2_pkt_adduint32(length);
3276 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3277 ssh_state = SSH_STATE_CLOSED;
3278 logevent("Received disconnect message");
3280 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3281 continue; /* exit status et al; ignore (FIXME?) */
3282 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
3283 unsigned i = ssh2_pkt_getuint32();
3284 struct ssh_channel *c;
3286 c = find234(ssh_channels, &i, ssh_channelfind);
3288 continue; /* nonexistent channel */
3290 if (c->type == CHAN_X11) {
3292 * Remote EOF on an X11 channel means we should
3293 * wrap up and close the channel ourselves.
3295 x11_close(c->u.x11.s);
3298 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
3299 unsigned i = ssh2_pkt_getuint32();
3300 struct ssh_channel *c;
3303 c = find234(ssh_channels, &i, ssh_channelfind);
3305 continue; /* nonexistent channel */
3306 if (c->closes == 0) {
3307 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3308 ssh2_pkt_adduint32(c->remoteid);
3311 /* Do pre-close processing on the channel. */
3313 case CHAN_MAINSESSION:
3314 break; /* nothing to see here, move along */
3318 del234(ssh_channels, c);
3319 sfree(c->v2.outbuffer);
3323 * See if that was the last channel left open.
3325 c = first234(ssh_channels, &e);
3327 logevent("All channels closed. Disconnecting");
3328 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3329 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3330 ssh2_pkt_addstring("All open channels closed");
3331 ssh2_pkt_addstring("en"); /* language tag */
3333 ssh_state = SSH_STATE_CLOSED;
3336 continue; /* remote sends close; ignore (FIXME) */
3337 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3338 unsigned i = ssh2_pkt_getuint32();
3339 struct ssh_channel *c;
3340 c = find234(ssh_channels, &i, ssh_channelfind);
3342 continue; /* nonexistent channel */
3343 mainchan->v2.remwindow += ssh2_pkt_getuint32();
3345 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3349 struct ssh_channel *c;
3350 ssh2_pkt_getstring(&type, &typelen);
3351 c = smalloc(sizeof(struct ssh_channel));
3353 if (typelen == 3 && !memcmp(type, "x11", 3)) {
3354 if (!ssh_X11_fwd_enabled)
3355 error = "X11 forwarding is not enabled";
3356 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
3357 error = "Unable to open an X11 connection";
3362 error = "Unsupported channel type requested";
3365 c->remoteid = ssh2_pkt_getuint32();
3367 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3368 ssh2_pkt_adduint32(c->remoteid);
3369 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3370 ssh2_pkt_addstring(error);
3371 ssh2_pkt_addstring("en"); /* language tag */
3375 struct ssh_channel *d;
3379 for (i=1, d = first234(ssh_channels, &e); d;
3382 break; /* found a free number */
3387 c->v2.remwindow = ssh2_pkt_getuint32();
3388 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3389 c->v2.outbuffer = NULL;
3390 c->v2.outbuflen = c->v2.outbufsize = 0;
3391 add234(ssh_channels, c);
3392 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3393 ssh2_pkt_adduint32(c->remoteid);
3394 ssh2_pkt_adduint32(c->localid);
3395 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3396 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3400 bombout(("Strange packet received: type %d", pktin.type));
3405 * We have spare data. Add it to the channel buffer.
3407 ssh2_add_channel_data(mainchan, in, inlen);
3412 struct ssh_channel *c;
3414 * Try to send data on all channels if we can.
3416 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3425 * Handle the top-level SSH2 protocol.
3427 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3429 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3431 do_ssh2_authconn(in, inlen, ispkt);
3435 * Called to set up the connection.
3437 * Returns an error message, or NULL on success.
3439 static char *ssh_init (char *host, int port, char **realhost) {
3443 if(crypto_startup() == 0)
3444 return "Microsoft high encryption pack not installed!";
3451 p = connect_to_host(host, port, realhost);
3459 * Called to send data down the Telnet connection.
3461 static void ssh_send (char *buf, int len) {
3462 if (s == NULL || ssh_protocol == NULL)
3465 ssh_protocol(buf, len, 0);
3469 * Called to set the size of the window from SSH's POV.
3471 static void ssh_size(void) {
3472 switch (ssh_state) {
3473 case SSH_STATE_BEFORE_SIZE:
3474 case SSH_STATE_PREPACKET:
3475 case SSH_STATE_CLOSED:
3476 break; /* do nothing */
3477 case SSH_STATE_INTERMED:
3478 size_needed = TRUE; /* buffer for later */
3480 case SSH_STATE_SESSION:
3482 if (ssh_version == 1) {
3483 send_packet(SSH1_CMSG_WINDOW_SIZE,
3484 PKT_INT, rows, PKT_INT, cols,
3485 PKT_INT, 0, PKT_INT, 0, PKT_END);
3487 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3488 ssh2_pkt_adduint32(mainchan->remoteid);
3489 ssh2_pkt_addstring("window-change");
3490 ssh2_pkt_addbool(0);
3491 ssh2_pkt_adduint32(cols);
3492 ssh2_pkt_adduint32(rows);
3493 ssh2_pkt_adduint32(0);
3494 ssh2_pkt_adduint32(0);
3503 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3504 * can send an EOF and collect resulting output (e.g. `plink
3507 static void ssh_special (Telnet_Special code) {
3508 if (code == TS_EOF) {
3509 if (ssh_state != SSH_STATE_SESSION) {
3511 * Buffer the EOF in case we are pre-SESSION, so we can
3512 * send it as soon as we reach SESSION.
3518 if (ssh_version == 1) {
3519 send_packet(SSH1_CMSG_EOF, PKT_END);
3521 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3522 ssh2_pkt_adduint32(mainchan->remoteid);
3525 logevent("Sent EOF message");
3526 } else if (code == TS_PING) {
3527 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3529 if (ssh_version == 1) {
3530 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3532 ssh2_pkt_init(SSH2_MSG_IGNORE);
3533 ssh2_pkt_addstring_start();
3541 static Socket ssh_socket(void) { return s; }
3543 static int ssh_sendok(void) { return ssh_send_ok; }
3545 static int ssh_ldisc(int option) {
3546 if (option == LD_ECHO) return ssh_echoing;
3547 if (option == LD_EDIT) return ssh_editing;
3551 Backend ssh_backend = {