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, sk_close(s), \
23 s = NULL, connection_fatal msg )
25 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
26 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
27 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
28 #define SSH1_CMSG_USER 4 /* 0x4 */
29 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
30 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
31 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
32 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
33 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
34 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
35 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
36 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
37 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
38 #define SSH1_SMSG_FAILURE 15 /* 0xf */
39 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
40 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
41 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
42 #define SSH1_CMSG_EOF 19 /* 0x13 */
43 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
44 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
45 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
46 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
47 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
48 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
49 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
50 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
51 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
52 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
53 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
54 #define SSH1_MSG_IGNORE 32 /* 0x20 */
55 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
56 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
57 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
58 #define SSH1_MSG_DEBUG 36 /* 0x24 */
59 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
60 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
61 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
62 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
63 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
64 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
65 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
67 #define SSH1_AUTH_TIS 5 /* 0x5 */
68 #define SSH1_AUTH_CCARD 16 /* 0x10 */
70 #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
71 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
72 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
73 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
74 #define SSH_AGENT_FAILURE 5 /* 0x5 */
75 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
76 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
77 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
79 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
80 #define SSH2_MSG_IGNORE 2 /* 0x2 */
81 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
82 #define SSH2_MSG_DEBUG 4 /* 0x4 */
83 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
84 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
85 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
86 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
87 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
88 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
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 */
129 #define GET_32BIT(cp) \
130 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
131 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
132 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
133 ((unsigned long)(unsigned char)(cp)[3]))
135 #define PUT_32BIT(cp, value) { \
136 (cp)[0] = (unsigned char)((value) >> 24); \
137 (cp)[1] = (unsigned char)((value) >> 16); \
138 (cp)[2] = (unsigned char)((value) >> 8); \
139 (cp)[3] = (unsigned char)(value); }
141 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
143 /* Coroutine mechanics for the sillier bits of the code */
144 #define crBegin1 static int crLine = 0;
145 #define crBegin2 switch(crLine) { case 0:;
146 #define crBegin crBegin1; crBegin2;
147 #define crFinish(z) } crLine = 0; return (z)
148 #define crFinishV } crLine = 0; return
149 #define crReturn(z) \
151 crLine=__LINE__; return (z); case __LINE__:;\
155 crLine=__LINE__; return; case __LINE__:;\
157 #define crStop(z) do{ crLine = 0; return (z); }while(0)
158 #define crStopV do{ crLine = 0; return; }while(0)
159 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
160 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
162 extern const struct ssh_cipher ssh_3des;
163 extern const struct ssh_cipher ssh_3des_ssh2;
164 extern const struct ssh_cipher ssh_des;
165 extern const struct ssh_cipher ssh_blowfish_ssh1;
166 extern const struct ssh_cipher ssh_blowfish_ssh2;
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 ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
181 extern const struct ssh_kex ssh_diffiehellman;
182 const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
184 extern const struct ssh_signkey ssh_dss;
185 const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
187 extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
189 static void nullmac_key(unsigned char *key) { }
190 static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
191 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
192 const static struct ssh_mac ssh_mac_none = {
193 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
195 const static struct ssh_mac *macs[] = {
196 &ssh_sha1, &ssh_md5, &ssh_mac_none };
197 const static struct ssh_mac *buggymacs[] = {
198 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
200 static void ssh_comp_none_init(void) { }
201 static int ssh_comp_none_block(unsigned char *block, int len,
202 unsigned char **outblock, int *outlen) {
205 const static struct ssh_compress ssh_comp_none = {
207 ssh_comp_none_init, ssh_comp_none_block,
208 ssh_comp_none_init, ssh_comp_none_block
210 extern const struct ssh_compress ssh_zlib;
211 const static struct ssh_compress *compressions[] = {
212 &ssh_zlib, &ssh_comp_none };
214 enum { /* channel types */
221 * 2-3-4 tree storing channels.
224 unsigned remoteid, localid;
227 struct ssh2_data_channel {
228 unsigned char *outbuffer;
229 unsigned outbuflen, outbufsize;
230 unsigned remwindow, remmaxpkt;
233 struct ssh_agent_channel {
234 unsigned char *message;
235 unsigned char msglen[4];
236 int lensofar, totallen;
238 struct ssh_x11_channel {
253 static SHA_State exhash, exhashbase;
255 static Socket s = NULL;
257 static unsigned char session_key[32];
258 static int ssh1_compressing;
259 static int ssh_agentfwd_enabled;
260 static int ssh_X11_fwd_enabled;
261 static const struct ssh_cipher *cipher = NULL;
262 static const struct ssh_cipher *cscipher = NULL;
263 static const struct ssh_cipher *sccipher = NULL;
264 static const struct ssh_mac *csmac = NULL;
265 static const struct ssh_mac *scmac = NULL;
266 static const struct ssh_compress *cscomp = NULL;
267 static const struct ssh_compress *sccomp = NULL;
268 static const struct ssh_kex *kex = NULL;
269 static const struct ssh_signkey *hostkey = NULL;
270 int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
272 static char *savedhost;
273 static int savedport;
274 static int ssh_send_ok;
275 static int ssh_echoing, ssh_editing;
277 static tree234 *ssh_channels; /* indexed by local id */
278 static struct ssh_channel *mainchan; /* primary session channel */
282 SSH_STATE_BEFORE_SIZE,
286 } ssh_state = SSH_STATE_PREPACKET;
288 static int size_needed = FALSE, eof_needed = FALSE;
290 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
291 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
293 static int ssh_version;
294 static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
295 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
296 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
297 static void ssh_size(void);
298 static void ssh_special (Telnet_Special);
299 static void ssh2_try_send(struct ssh_channel *c);
300 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
302 static int (*s_rdpkt)(unsigned char **data, int *datalen);
304 static struct rdpkt1_state_tag {
305 long len, pad, biglen, to_read;
306 unsigned long realcrc, gotcrc;
312 static struct rdpkt2_state_tag {
313 long len, pad, payload, packetlen, maclen;
316 unsigned long incoming_sequence;
319 static int ssh_channelcmp(void *av, void *bv) {
320 struct ssh_channel *a = (struct ssh_channel *)av;
321 struct ssh_channel *b = (struct ssh_channel *)bv;
322 if (a->localid < b->localid) return -1;
323 if (a->localid > b->localid) return +1;
326 static int ssh_channelfind(void *av, void *bv) {
327 unsigned *a = (unsigned *)av;
328 struct ssh_channel *b = (struct ssh_channel *)bv;
329 if (*a < b->localid) return -1;
330 if (*a > b->localid) return +1;
334 static void c_write (char *buf, int len) {
335 if ((flags & FLAG_STDERR)) {
337 for (i = 0; i < len; i++)
339 fputc(buf[i], stderr);
342 from_backend(1, buf, len);
346 * Collect incoming data in the incoming packet buffer.
347 * Decipher and verify the packet when it is completely read.
348 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
349 * Update the *data and *datalen variables.
350 * Return the additional nr of bytes needed, or 0 when
351 * a complete packet is available.
353 static int ssh1_rdpkt(unsigned char **data, int *datalen)
355 struct rdpkt1_state_tag *st = &rdpkt1_state;
364 for (st->i = st->len = 0; st->i < 4; st->i++) {
365 while ((*datalen) == 0)
367 st->len = (st->len << 8) + **data;
368 (*data)++, (*datalen)--;
372 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
373 st->len = 0x300; /* big enough to carry to end */
377 st->pad = 8 - (st->len % 8);
378 st->biglen = st->len + st->pad;
379 pktin.length = st->len - 5;
381 if (pktin.maxlen < st->biglen) {
382 pktin.maxlen = st->biglen;
383 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
384 srealloc(pktin.data, st->biglen+APIEXTRA));
386 fatalbox("Out of memory");
389 st->to_read = st->biglen;
391 while (st->to_read > 0) {
392 st->chunk = st->to_read;
393 while ((*datalen) == 0)
394 crReturn(st->to_read);
395 if (st->chunk > (*datalen))
396 st->chunk = (*datalen);
397 memcpy(st->p, *data, st->chunk);
399 *datalen -= st->chunk;
401 st->to_read -= st->chunk;
405 cipher->decrypt(pktin.data, st->biglen);
407 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
408 for (st->i = 0; st->i < st->biglen; st->i++)
409 debug((" %02x", (unsigned char)pktin.data[st->i]));
413 st->realcrc = crc32(pktin.data, st->biglen-4);
414 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
415 if (st->gotcrc != st->realcrc) {
416 bombout(("Incorrect CRC received on packet"));
420 pktin.body = pktin.data + st->pad + 1;
422 if (ssh1_compressing) {
423 unsigned char *decompblk;
427 debug(("Packet payload pre-decompression:\n"));
428 for (i = -1; i < pktin.length; i++)
429 debug((" %02x", (unsigned char)pktin.body[i]));
432 zlib_decompress_block(pktin.body-1, pktin.length+1,
433 &decompblk, &decomplen);
435 if (pktin.maxlen < st->pad + decomplen) {
436 pktin.maxlen = st->pad + decomplen;
437 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
438 pktin.body = pktin.data + st->pad + 1;
440 fatalbox("Out of memory");
443 memcpy(pktin.body-1, decompblk, decomplen);
445 pktin.length = decomplen-1;
447 debug(("Packet payload post-decompression:\n"));
448 for (i = -1; i < pktin.length; i++)
449 debug((" %02x", (unsigned char)pktin.body[i]));
454 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
455 pktin.type == SSH1_SMSG_STDERR_DATA ||
456 pktin.type == SSH1_MSG_DEBUG ||
457 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
458 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
459 long strlen = GET_32BIT(pktin.body);
460 if (strlen + 4 != pktin.length) {
461 bombout(("Received data packet with bogus string length"));
466 pktin.type = pktin.body[-1];
468 if (pktin.type == SSH1_MSG_DEBUG) {
469 /* log debug message */
471 int strlen = GET_32BIT(pktin.body);
472 strcpy(buf, "Remote: ");
473 if (strlen > 70) strlen = 70;
474 memcpy(buf+8, pktin.body+4, strlen);
475 buf[8+strlen] = '\0';
478 } else if (pktin.type == SSH1_MSG_IGNORE) {
486 static int ssh2_rdpkt(unsigned char **data, int *datalen)
488 struct rdpkt2_state_tag *st = &rdpkt2_state;
496 st->cipherblk = sccipher->blksize;
499 if (st->cipherblk < 8)
502 if (pktin.maxlen < st->cipherblk) {
503 pktin.maxlen = st->cipherblk;
504 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
505 srealloc(pktin.data, st->cipherblk+APIEXTRA));
507 fatalbox("Out of memory");
511 * Acquire and decrypt the first block of the packet. This will
512 * contain the length and padding details.
514 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
515 while ((*datalen) == 0)
516 crReturn(st->cipherblk-st->i);
517 pktin.data[st->i] = *(*data)++;
521 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
526 sccipher->decrypt(pktin.data, st->cipherblk);
529 * Now get the length and padding figures.
531 st->len = GET_32BIT(pktin.data);
532 st->pad = pktin.data[4];
535 * This enables us to deduce the payload length.
537 st->payload = st->len - st->pad - 1;
539 pktin.length = st->payload + 5;
542 * So now we can work out the total packet length.
544 st->packetlen = st->len + 4;
545 st->maclen = scmac ? scmac->len : 0;
548 * Adjust memory allocation if packet is too big.
550 if (pktin.maxlen < st->packetlen+st->maclen) {
551 pktin.maxlen = st->packetlen+st->maclen;
552 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
553 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
555 fatalbox("Out of memory");
559 * Read and decrypt the remainder of the packet.
561 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
562 while ((*datalen) == 0)
563 crReturn(st->packetlen + st->maclen - st->i);
564 pktin.data[st->i] = *(*data)++;
567 /* Decrypt everything _except_ the MAC. */
569 sccipher->decrypt(pktin.data + st->cipherblk,
570 st->packetlen - st->cipherblk);
573 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
574 for (st->i = 0; st->i < st->packetlen; st->i++)
575 debug((" %02x", (unsigned char)pktin.data[st->i]));
582 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
583 bombout(("Incorrect MAC received on packet"));
586 st->incoming_sequence++; /* whether or not we MACed */
589 * Decompress packet payload.
592 unsigned char *newpayload;
594 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
595 &newpayload, &newlen)) {
596 if (pktin.maxlen < newlen+5) {
597 pktin.maxlen = newlen+5;
598 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
599 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
601 fatalbox("Out of memory");
603 pktin.length = 5 + newlen;
604 memcpy(pktin.data+5, newpayload, newlen);
606 debug(("Post-decompression payload:\r\n"));
607 for (st->i = 0; st->i < newlen; st->i++)
608 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
617 pktin.type = pktin.data[5];
619 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
620 goto next_packet; /* FIXME: print DEBUG message */
625 static void ssh1_pktout_size(int len) {
628 len += 5; /* type and CRC */
632 pktout.length = len-5;
633 if (pktout.maxlen < biglen) {
634 pktout.maxlen = biglen;
636 /* Allocate enough buffer space for extra block
637 * for MS CryptEncrypt() */
638 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
639 srealloc(pktout.data, biglen+12));
641 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
642 srealloc(pktout.data, biglen+4));
645 fatalbox("Out of memory");
647 pktout.body = pktout.data+4+pad+1;
650 static void s_wrpkt_start(int type, int len) {
651 ssh1_pktout_size(len);
655 static void s_wrpkt(void) {
656 int pad, len, biglen, i;
659 pktout.body[-1] = pktout.type;
661 if (ssh1_compressing) {
662 unsigned char *compblk;
665 debug(("Packet payload pre-compression:\n"));
666 for (i = -1; i < pktout.length; i++)
667 debug((" %02x", (unsigned char)pktout.body[i]));
670 zlib_compress_block(pktout.body-1, pktout.length+1,
672 ssh1_pktout_size(complen-1);
673 memcpy(pktout.body-1, compblk, complen);
676 debug(("Packet payload post-compression:\n"));
677 for (i = -1; i < pktout.length; i++)
678 debug((" %02x", (unsigned char)pktout.body[i]));
683 len = pktout.length + 5; /* type and CRC */
687 for (i=0; i<pad; i++)
688 pktout.data[i+4] = random_byte();
689 crc = crc32(pktout.data+4, biglen-4);
690 PUT_32BIT(pktout.data+biglen, crc);
691 PUT_32BIT(pktout.data, len);
694 debug(("Sending packet len=%d\r\n", biglen+4));
695 for (i = 0; i < biglen+4; i++)
696 debug((" %02x", (unsigned char)pktout.data[i]));
700 cipher->encrypt(pktout.data+4, biglen);
702 sk_write(s, pktout.data, biglen+4);
706 * Construct a packet with the specified contents and
707 * send it to the server.
709 static void send_packet(int pkttype, ...)
712 unsigned char *p, *argp, argchar;
713 unsigned long argint;
714 int pktlen, argtype, arglen;
718 va_start(args, pkttype);
719 while ((argtype = va_arg(args, int)) != PKT_END) {
722 (void) va_arg(args, int);
726 (void) va_arg(args, char);
730 (void) va_arg(args, unsigned char *);
731 arglen = va_arg(args, int);
735 argp = va_arg(args, unsigned char *);
736 arglen = strlen(argp);
737 pktlen += 4 + arglen;
740 bn = va_arg(args, Bignum);
741 pktlen += ssh1_bignum_length(bn);
749 s_wrpkt_start(pkttype, pktlen);
752 va_start(args, pkttype);
753 while ((argtype = va_arg(args, int)) != PKT_END) {
756 argint = va_arg(args, int);
757 PUT_32BIT(p, argint);
761 argchar = va_arg(args, unsigned char);
766 argp = va_arg(args, unsigned char *);
767 arglen = va_arg(args, int);
768 memcpy(p, argp, arglen);
772 argp = va_arg(args, unsigned char *);
773 arglen = strlen(argp);
774 PUT_32BIT(p, arglen);
775 memcpy(p + 4, argp, arglen);
779 bn = va_arg(args, Bignum);
780 p += ssh1_write_bignum(p, bn);
789 static int ssh_versioncmp(char *a, char *b) {
791 unsigned long av, bv;
793 av = strtoul(a, &ae, 10);
794 bv = strtoul(b, &be, 10);
795 if (av != bv) return (av < bv ? -1 : +1);
796 if (*ae == '.') ae++;
797 if (*be == '.') be++;
798 av = strtoul(ae, &ae, 10);
799 bv = strtoul(be, &be, 10);
800 if (av != bv) return (av < bv ? -1 : +1);
806 * Utility routine for putting an SSH-protocol `string' into a SHA
810 static void sha_string(SHA_State *s, void *str, int len) {
811 unsigned char lenblk[4];
812 PUT_32BIT(lenblk, len);
813 SHA_Bytes(s, lenblk, 4);
814 SHA_Bytes(s, str, len);
818 * SSH2 packet construction functions.
820 static void ssh2_pkt_ensure(int length) {
821 if (pktout.maxlen < length) {
822 pktout.maxlen = length + 256;
823 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
824 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
826 fatalbox("Out of memory");
829 static void ssh2_pkt_adddata(void *data, int len) {
830 pktout.length += len;
831 ssh2_pkt_ensure(pktout.length);
832 memcpy(pktout.data+pktout.length-len, data, len);
834 static void ssh2_pkt_addbyte(unsigned char byte) {
835 ssh2_pkt_adddata(&byte, 1);
837 static void ssh2_pkt_init(int pkt_type) {
839 ssh2_pkt_addbyte((unsigned char)pkt_type);
841 static void ssh2_pkt_addbool(unsigned char value) {
842 ssh2_pkt_adddata(&value, 1);
844 static void ssh2_pkt_adduint32(unsigned long value) {
847 ssh2_pkt_adddata(x, 4);
849 static void ssh2_pkt_addstring_start(void) {
850 ssh2_pkt_adduint32(0);
851 pktout.savedpos = pktout.length;
853 static void ssh2_pkt_addstring_str(char *data) {
854 ssh2_pkt_adddata(data, strlen(data));
855 PUT_32BIT(pktout.data + pktout.savedpos - 4,
856 pktout.length - pktout.savedpos);
858 static void ssh2_pkt_addstring_data(char *data, int len) {
859 ssh2_pkt_adddata(data, len);
860 PUT_32BIT(pktout.data + pktout.savedpos - 4,
861 pktout.length - pktout.savedpos);
863 static void ssh2_pkt_addstring(char *data) {
864 ssh2_pkt_addstring_start();
865 ssh2_pkt_addstring_str(data);
867 static char *ssh2_mpint_fmt(Bignum b, int *len) {
870 p = smalloc(n * 2 + 1);
872 fatalbox("out of memory");
874 for (i = 0; i < n; i++) {
875 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
876 p[i*2+2] = (b[n-i] ) & 0xFF;
879 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
881 memmove(p, p+i, n*2+1-i);
885 static void ssh2_pkt_addmp(Bignum b) {
888 p = ssh2_mpint_fmt(b, &len);
889 ssh2_pkt_addstring_start();
890 ssh2_pkt_addstring_data(p, len);
893 static void ssh2_pkt_send(void) {
894 int cipherblk, maclen, padding, i;
895 static unsigned long outgoing_sequence = 0;
898 * Compress packet payload.
901 debug(("Pre-compression payload:\r\n"));
902 for (i = 5; i < pktout.length; i++)
903 debug((" %02x", (unsigned char)pktout.data[i]));
907 unsigned char *newpayload;
909 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
910 &newpayload, &newlen)) {
912 ssh2_pkt_adddata(newpayload, newlen);
918 * Add padding. At least four bytes, and must also bring total
919 * length (minus MAC) up to a multiple of the block size.
921 cipherblk = cipher ? cipher->blksize : 8; /* block size */
922 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
924 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
925 maclen = csmac ? csmac->len : 0;
926 ssh2_pkt_ensure(pktout.length + padding + maclen);
927 pktout.data[4] = padding;
928 for (i = 0; i < padding; i++)
929 pktout.data[pktout.length + i] = random_byte();
930 PUT_32BIT(pktout.data, pktout.length + padding - 4);
932 csmac->generate(pktout.data, pktout.length + padding,
934 outgoing_sequence++; /* whether or not we MACed */
937 debug(("Sending packet len=%d\r\n", pktout.length+padding));
938 for (i = 0; i < pktout.length+padding; i++)
939 debug((" %02x", (unsigned char)pktout.data[i]));
944 cscipher->encrypt(pktout.data, pktout.length + padding);
946 sk_write(s, pktout.data, pktout.length + padding + maclen);
950 void bndebug(char *string, Bignum b) {
953 p = ssh2_mpint_fmt(b, &len);
954 debug(("%s", string));
955 for (i = 0; i < len; i++)
956 debug((" %02x", p[i]));
962 static void sha_mpint(SHA_State *s, Bignum b) {
965 p = ssh2_mpint_fmt(b, &len);
966 sha_string(s, p, len);
971 * SSH2 packet decode functions.
973 static unsigned long ssh2_pkt_getuint32(void) {
975 if (pktin.length - pktin.savedpos < 4)
976 return 0; /* arrgh, no way to decline (FIXME?) */
977 value = GET_32BIT(pktin.data+pktin.savedpos);
981 static void ssh2_pkt_getstring(char **p, int *length) {
983 if (pktin.length - pktin.savedpos < 4)
985 *length = GET_32BIT(pktin.data+pktin.savedpos);
987 if (pktin.length - pktin.savedpos < *length)
989 *p = pktin.data+pktin.savedpos;
990 pktin.savedpos += *length;
992 static Bignum ssh2_pkt_getmp(void) {
997 ssh2_pkt_getstring(&p, &length);
1001 bombout(("internal error: Can't handle negative mpints"));
1004 b = newbn((length+1)/2);
1005 for (i = 0; i < length; i++) {
1008 b[j/2+1] |= ((unsigned char)p[i]) << 8;
1010 b[j/2+1] |= ((unsigned char)p[i]);
1012 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
1016 static int do_ssh_init(unsigned char c) {
1018 static char version[10];
1019 static char vstring[80];
1020 static char vlog[sizeof(vstring)+20];
1025 /* Search for the string "SSH-" in the input. */
1028 static const int transS[] = { 1, 2, 2, 1 };
1029 static const int transH[] = { 0, 0, 3, 0 };
1030 static const int transminus[] = { 0, 0, 0, -1 };
1031 if (c == 'S') i = transS[i];
1032 else if (c == 'H') i = transH[i];
1033 else if (c == '-') i = transminus[i];
1037 crReturn(1); /* get another character */
1040 strcpy(vstring, "SSH-");
1044 crReturn(1); /* get another char */
1045 if (vsp < vstring+sizeof(vstring)-1)
1051 } else if (i < sizeof(version)-1)
1058 ssh_agentfwd_enabled = FALSE;
1059 rdpkt2_state.incoming_sequence = 0;
1062 sprintf(vlog, "Server version: %s", vstring);
1063 vlog[strcspn(vlog, "\r\n")] = '\0';
1067 * Server version "1.99" means we can choose whether we use v1
1068 * or v2 protocol. Choice is based on cfg.sshprot.
1070 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1072 * This is a v2 server. Begin v2 protocol.
1074 char *verstring = "SSH-2.0-PuTTY";
1075 SHA_Init(&exhashbase);
1077 * Hash our version string and their version string.
1079 sha_string(&exhashbase, verstring, strlen(verstring));
1080 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1081 sprintf(vstring, "%s\n", verstring);
1082 sprintf(vlog, "We claim version: %s", verstring);
1084 logevent("Using SSH protocol version 2");
1085 sk_write(s, vstring, strlen(vstring));
1086 ssh_protocol = ssh2_protocol;
1088 s_rdpkt = ssh2_rdpkt;
1091 * This is a v1 server. Begin v1 protocol.
1093 sprintf(vstring, "SSH-%s-PuTTY\n",
1094 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1095 sprintf(vlog, "We claim version: %s", vstring);
1096 vlog[strcspn(vlog, "\r\n")] = '\0';
1098 logevent("Using SSH protocol version 1");
1099 sk_write(s, vstring, strlen(vstring));
1100 ssh_protocol = ssh1_protocol;
1102 s_rdpkt = ssh1_rdpkt;
1104 ssh_state = SSH_STATE_BEFORE_SIZE;
1109 static void ssh_gotdata(unsigned char *data, int datalen)
1114 * To begin with, feed the characters one by one to the
1115 * protocol initialisation / selection function do_ssh_init().
1116 * When that returns 0, we're done with the initial greeting
1117 * exchange and can move on to packet discipline.
1122 crReturnV; /* more data please */
1123 ret = do_ssh_init(*data);
1130 * We emerge from that loop when the initial negotiation is
1131 * over and we have selected an s_rdpkt function. Now pass
1132 * everything to s_rdpkt, and then pass the resulting packets
1133 * to the proper protocol handler.
1138 while (datalen > 0) {
1139 if ( s_rdpkt(&data, &datalen) == 0 ) {
1140 ssh_protocol(NULL, 0, 1);
1141 if (ssh_state == SSH_STATE_CLOSED) {
1151 static int ssh_receive(Socket skt, int urgent, char *data, int len) {
1153 /* A socket error has occurred. */
1154 connection_fatal(data);
1158 /* Connection has closed. */
1159 ssh_state = SSH_STATE_CLOSED;
1164 ssh_gotdata (data, len);
1165 if (ssh_state == SSH_STATE_CLOSED) {
1176 * Connect to specified host and port.
1177 * Returns an error message, or NULL on success.
1178 * Also places the canonical host name into `realhost'.
1180 static char *connect_to_host(char *host, int port, char **realhost)
1189 savedhost = smalloc(1+strlen(host));
1191 fatalbox("Out of memory");
1192 strcpy(savedhost, host);
1195 port = 22; /* default ssh port */
1208 addr = sk_namelookup(host, realhost);
1209 if ( (err = sk_addr_error(addr)) )
1219 s = sk_new(addr, port, 0, ssh_receive);
1220 if ( (err = sk_socket_error(s)) )
1224 sk_write(s, "connect ", 8);
1225 sk_write(s, FWhost, strlen(FWhost));
1228 sprintf(buf, " %d\n", FWport);
1229 sk_write(s, buf, strlen(buf));
1237 * Handle the key exchange and user authentication phases.
1239 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1242 unsigned char *rsabuf, *keystr1, *keystr2;
1243 unsigned char cookie[8];
1244 struct RSAKey servkey, hostkey;
1245 struct MD5Context md5c;
1246 static unsigned long supported_ciphers_mask, supported_auths_mask;
1247 static int tried_publickey;
1248 static unsigned char session_id[16];
1250 static char username[100];
1254 if (!ispkt) crWaitUntil(ispkt);
1256 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1257 bombout(("Public key packet not received"));
1261 logevent("Received public keys");
1263 memcpy(cookie, pktin.body, 8);
1265 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1266 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
1269 * Log the host key fingerprint.
1273 logevent("Host key fingerprint is:");
1274 strcpy(logmsg, " ");
1275 hostkey.comment = NULL;
1276 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1281 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1282 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
1285 MD5Update(&md5c, keystr2, hostkey.bytes);
1286 MD5Update(&md5c, keystr1, servkey.bytes);
1287 MD5Update(&md5c, pktin.body, 8);
1288 MD5Final(session_id, &md5c);
1290 for (i=0; i<32; i++)
1291 session_key[i] = random_byte();
1293 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1295 rsabuf = smalloc(len);
1297 fatalbox("Out of memory");
1300 * Verify the host key.
1304 * First format the key into a string.
1306 int len = rsastr_len(&hostkey);
1307 char fingerprint[100];
1308 char *keystr = smalloc(len);
1310 fatalbox("Out of memory");
1311 rsastr_fmt(keystr, &hostkey);
1312 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1313 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
1317 for (i=0; i<32; i++) {
1318 rsabuf[i] = session_key[i];
1320 rsabuf[i] ^= session_id[i];
1323 if (hostkey.bytes > servkey.bytes) {
1324 rsaencrypt(rsabuf, 32, &servkey);
1325 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1327 rsaencrypt(rsabuf, 32, &hostkey);
1328 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1331 logevent("Encrypted session key");
1333 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
1334 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
1336 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1337 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1338 cipher_type = SSH_CIPHER_3DES;
1340 switch (cipher_type) {
1341 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1342 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1343 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1346 send_packet(SSH1_CMSG_SESSION_KEY,
1347 PKT_CHAR, cipher_type,
1348 PKT_DATA, cookie, 8,
1349 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1350 PKT_DATA, rsabuf, len,
1354 logevent("Trying to enable encryption...");
1358 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1359 cipher_type == SSH_CIPHER_DES ? &ssh_des :
1361 cipher->sesskey(session_key);
1365 if (pktin.type != SSH1_SMSG_SUCCESS) {
1366 bombout(("Encryption not successfully enabled"));
1370 logevent("Successfully started encryption");
1376 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1377 c_write("login as: ", 10);
1380 crWaitUntil(!ispkt);
1381 while (inlen--) switch (c = *in++) {
1388 c_write("\b \b", 3);
1394 c_write("\b \b", 3);
1403 if (((c >= ' ' && c <= '~') ||
1404 ((unsigned char)c >= 160)) && pos < 40) {
1405 username[pos++] = c;
1412 username[strcspn(username, "\n\r")] = '\0';
1414 strncpy(username, cfg.username, 99);
1415 username[99] = '\0';
1418 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1420 char userlog[22+sizeof(username)];
1421 sprintf(userlog, "Sent username \"%s\"", username);
1423 if (flags & FLAG_INTERACTIVE &&
1424 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1425 strcat(userlog, "\r\n");
1426 c_write(userlog, strlen(userlog));
1433 tried_publickey = 0;
1435 while (pktin.type == SSH1_SMSG_FAILURE) {
1436 static char password[100];
1437 static char prompt[200];
1440 static int pwpkt_type;
1442 * Show password prompt, having first obtained it via a TIS
1443 * or CryptoCard exchange if we're doing TIS or CryptoCard
1446 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1447 if (agent_exists()) {
1449 * Attempt RSA authentication using Pageant.
1451 static unsigned char request[5], *response, *p;
1452 static int responselen;
1453 static int i, nkeys;
1454 static int authed = FALSE;
1457 logevent("Pageant is running. Requesting keys.");
1459 /* Request the keys held by the agent. */
1460 PUT_32BIT(request, 1);
1461 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1462 agent_query(request, 5, &r, &responselen);
1463 response = (unsigned char *)r;
1466 nkeys = GET_32BIT(p); p += 4;
1467 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1469 for (i = 0; i < nkeys; i++) {
1470 static struct RSAKey key;
1471 static Bignum challenge;
1472 static char *commentp;
1473 static int commentlen;
1475 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1478 p += ssh1_read_bignum(p, &key.exponent);
1479 p += ssh1_read_bignum(p, &key.modulus);
1480 commentlen = GET_32BIT(p); p += 4;
1481 commentp = p; p += commentlen;
1482 send_packet(SSH1_CMSG_AUTH_RSA,
1483 PKT_BIGNUM, key.modulus, PKT_END);
1485 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1486 logevent("Key refused");
1489 logevent("Received RSA challenge");
1490 ssh1_read_bignum(pktin.body, &challenge);
1492 char *agentreq, *q, *ret;
1494 len = 1 + 4; /* message type, bit count */
1495 len += ssh1_bignum_length(key.exponent);
1496 len += ssh1_bignum_length(key.modulus);
1497 len += ssh1_bignum_length(challenge);
1498 len += 16; /* session id */
1499 len += 4; /* response format */
1500 agentreq = smalloc(4 + len);
1501 PUT_32BIT(agentreq, len);
1503 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1504 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1506 q += ssh1_write_bignum(q, key.exponent);
1507 q += ssh1_write_bignum(q, key.modulus);
1508 q += ssh1_write_bignum(q, challenge);
1509 memcpy(q, session_id, 16); q += 16;
1510 PUT_32BIT(q, 1); /* response format */
1511 agent_query(agentreq, len+4, &ret, &retlen);
1514 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1515 logevent("Sending Pageant's response");
1516 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1517 PKT_DATA, ret+5, 16, PKT_END);
1520 if (pktin.type == SSH1_SMSG_SUCCESS) {
1521 logevent("Pageant's response accepted");
1522 if (flags & FLAG_VERBOSE) {
1523 c_write("Authenticated using RSA key \"",
1525 c_write(commentp, commentlen);
1526 c_write("\" from agent\r\n", 14);
1530 logevent("Pageant's response not accepted");
1532 logevent("Pageant failed to answer challenge");
1536 logevent("No reply received from Pageant");
1539 freebn(key.exponent);
1540 freebn(key.modulus);
1549 if (*cfg.keyfile && !tried_publickey)
1550 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1552 if (pktin.type == SSH1_SMSG_FAILURE &&
1554 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1555 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1556 logevent("Requested TIS authentication");
1557 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1559 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1560 logevent("TIS authentication declined");
1561 if (flags & FLAG_INTERACTIVE)
1562 c_write("TIS authentication refused.\r\n", 29);
1564 int challengelen = ((pktin.body[0] << 24) |
1565 (pktin.body[1] << 16) |
1566 (pktin.body[2] << 8) |
1568 logevent("Received TIS challenge");
1569 if (challengelen > sizeof(prompt)-1)
1570 challengelen = sizeof(prompt)-1; /* prevent overrun */
1571 memcpy(prompt, pktin.body+4, challengelen);
1572 prompt[challengelen] = '\0';
1575 if (pktin.type == SSH1_SMSG_FAILURE &&
1577 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1578 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1579 logevent("Requested CryptoCard authentication");
1580 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1582 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1583 logevent("CryptoCard authentication declined");
1584 c_write("CryptoCard authentication refused.\r\n", 29);
1586 int challengelen = ((pktin.body[0] << 24) |
1587 (pktin.body[1] << 16) |
1588 (pktin.body[2] << 8) |
1590 logevent("Received CryptoCard challenge");
1591 if (challengelen > sizeof(prompt)-1)
1592 challengelen = sizeof(prompt)-1; /* prevent overrun */
1593 memcpy(prompt, pktin.body+4, challengelen);
1594 strncpy(prompt + challengelen, "\r\nResponse : ",
1595 sizeof(prompt)-challengelen);
1596 prompt[sizeof(prompt)-1] = '\0';
1599 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1600 sprintf(prompt, "%.90s@%.90s's password: ",
1601 username, savedhost);
1603 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1604 char *comment = NULL;
1605 if (flags & FLAG_VERBOSE)
1606 c_write("Trying public key authentication.\r\n", 35);
1607 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1608 if (flags & FLAG_VERBOSE)
1609 c_write("No passphrase required.\r\n", 25);
1612 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1616 if (ssh_get_password) {
1617 if (!ssh_get_password(prompt, password, sizeof(password))) {
1619 * get_password failed to get a password (for
1620 * example because one was supplied on the command
1621 * line which has already failed to work).
1624 logevent("No more passwords to try");
1625 ssh_state = SSH_STATE_CLOSED;
1629 c_write(prompt, strlen(prompt));
1633 crWaitUntil(!ispkt);
1634 while (inlen--) switch (c = *in++) {
1651 if (((c >= ' ' && c <= '~') ||
1652 ((unsigned char)c >= 160)) && pos < sizeof(password))
1653 password[pos++] = c;
1661 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1663 * Try public key authentication with the specified
1666 static struct RSAKey pubkey;
1667 static Bignum challenge, response;
1669 static unsigned char buffer[32];
1671 tried_publickey = 1;
1672 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
1674 c_write("Couldn't load public key from ", 30);
1675 c_write(cfg.keyfile, strlen(cfg.keyfile));
1676 c_write(".\r\n", 3);
1677 continue; /* go and try password */
1680 c_write("Wrong passphrase.\r\n", 19);
1681 tried_publickey = 0;
1682 continue; /* try again */
1686 * Send a public key attempt.
1688 send_packet(SSH1_CMSG_AUTH_RSA,
1689 PKT_BIGNUM, pubkey.modulus, PKT_END);
1692 if (pktin.type == SSH1_SMSG_FAILURE) {
1693 c_write("Server refused our public key.\r\n", 32);
1694 continue; /* go and try password */
1696 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1697 bombout(("Bizarre response to offer of public key"));
1700 ssh1_read_bignum(pktin.body, &challenge);
1701 response = rsadecrypt(challenge, &pubkey);
1702 freebn(pubkey.private_exponent); /* burn the evidence */
1704 for (i = 0; i < 32; i += 2) {
1705 buffer[i] = response[16-i/2] >> 8;
1706 buffer[i+1] = response[16-i/2] & 0xFF;
1710 MD5Update(&md5c, buffer, 32);
1711 MD5Update(&md5c, session_id, 16);
1712 MD5Final(buffer, &md5c);
1714 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1715 PKT_DATA, buffer, 16, PKT_END);
1718 if (pktin.type == SSH1_SMSG_FAILURE) {
1719 if (flags & FLAG_VERBOSE)
1720 c_write("Failed to authenticate with our public key.\r\n",
1722 continue; /* go and try password */
1723 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1724 bombout(("Bizarre response to RSA authentication response"));
1728 break; /* we're through! */
1730 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1732 logevent("Sent password");
1733 memset(password, 0, strlen(password));
1735 if (pktin.type == SSH1_SMSG_FAILURE) {
1736 if (flags & FLAG_VERBOSE)
1737 c_write("Access denied\r\n", 15);
1738 logevent("Authentication refused");
1739 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1740 logevent("Received disconnect request");
1741 ssh_state = SSH_STATE_CLOSED;
1743 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1744 bombout(("Strange packet received, type %d", pktin.type));
1749 logevent("Authentication successful");
1754 void sshfwd_close(struct ssh_channel *c) {
1756 if (ssh_version == 1) {
1757 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1759 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1760 ssh2_pkt_adduint32(c->remoteid);
1764 if (c->type == CHAN_X11) {
1766 logevent("X11 connection terminated");
1771 void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
1772 if (ssh_version == 1) {
1773 send_packet(SSH1_MSG_CHANNEL_DATA,
1774 PKT_INT, c->remoteid,
1779 ssh2_add_channel_data(c, buf, len);
1784 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
1789 while (!do_ssh1_login(in, inlen, ispkt)) {
1792 if (ssh_state == SSH_STATE_CLOSED)
1795 if (cfg.agentfwd && agent_exists()) {
1796 logevent("Requesting agent forwarding");
1797 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1798 do { crReturnV; } while (!ispkt);
1799 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1800 bombout(("Protocol confusion"));
1802 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1803 logevent("Agent forwarding refused");
1805 logevent("Agent forwarding enabled");
1806 ssh_agentfwd_enabled = TRUE;
1810 if (cfg.x11_forward) {
1811 char proto[20], data[64];
1812 logevent("Requesting X11 forwarding");
1813 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1814 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1815 PKT_STR, proto, PKT_STR, data,
1818 do { crReturnV; } while (!ispkt);
1819 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1820 bombout(("Protocol confusion"));
1822 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1823 logevent("X11 forwarding refused");
1825 logevent("X11 forwarding enabled");
1826 ssh_X11_fwd_enabled = TRUE;
1831 send_packet(SSH1_CMSG_REQUEST_PTY,
1832 PKT_STR, cfg.termtype,
1833 PKT_INT, rows, PKT_INT, cols,
1834 PKT_INT, 0, PKT_INT, 0,
1837 ssh_state = SSH_STATE_INTERMED;
1838 do { crReturnV; } while (!ispkt);
1839 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1840 bombout(("Protocol confusion"));
1842 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1843 c_write("Server refused to allocate pty\r\n", 32);
1844 ssh_editing = ssh_echoing = 1;
1846 logevent("Allocated pty");
1848 ssh_editing = ssh_echoing = 1;
1851 if (cfg.compression) {
1852 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1853 do { crReturnV; } while (!ispkt);
1854 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1855 bombout(("Protocol confusion"));
1857 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1858 c_write("Server refused to compress\r\n", 32);
1860 logevent("Started compression");
1861 ssh1_compressing = TRUE;
1862 zlib_compress_init();
1863 zlib_decompress_init();
1866 if (*cfg.remote_cmd)
1867 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1869 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
1870 logevent("Started session");
1872 ssh_state = SSH_STATE_SESSION;
1876 ssh_special(TS_EOF);
1878 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
1880 ssh_channels = newtree234(ssh_channelcmp);
1884 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1885 pktin.type == SSH1_SMSG_STDERR_DATA) {
1886 long len = GET_32BIT(pktin.body);
1887 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1889 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
1890 ssh_state = SSH_STATE_CLOSED;
1891 logevent("Received disconnect request");
1893 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1894 /* Remote side is trying to open a channel to talk to our
1895 * X-Server. Give them back a local channel number. */
1897 struct ssh_channel *c, *d;
1900 logevent("Received X11 connect request");
1901 /* Refuse if X11 forwarding is disabled. */
1902 if (!ssh_X11_fwd_enabled) {
1903 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1904 PKT_INT, GET_32BIT(pktin.body),
1906 logevent("Rejected X11 connect request");
1908 c = smalloc(sizeof(struct ssh_channel));
1910 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
1911 logevent("opening X11 forward connection failed");
1913 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1914 PKT_INT, GET_32BIT(pktin.body),
1917 logevent("opening X11 forward connection succeeded");
1918 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
1920 break; /* found a free number */
1923 c->remoteid = GET_32BIT(pktin.body);
1926 c->type = CHAN_X11; /* identify channel type */
1927 add234(ssh_channels, c);
1928 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1929 PKT_INT, c->remoteid, PKT_INT, c->localid,
1931 logevent("Opened X11 forward channel");
1934 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1935 /* Remote side is trying to open a channel to talk to our
1936 * agent. Give them back a local channel number. */
1938 struct ssh_channel *c;
1941 /* Refuse if agent forwarding is disabled. */
1942 if (!ssh_agentfwd_enabled) {
1943 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1944 PKT_INT, GET_32BIT(pktin.body),
1948 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1950 break; /* found a free number */
1953 c = smalloc(sizeof(struct ssh_channel));
1954 c->remoteid = GET_32BIT(pktin.body);
1957 c->type = CHAN_AGENT; /* identify channel type */
1958 c->u.a.lensofar = 0;
1959 add234(ssh_channels, c);
1960 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1961 PKT_INT, c->remoteid, PKT_INT, c->localid,
1964 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1965 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1966 /* Remote side closes a channel. */
1967 unsigned i = GET_32BIT(pktin.body);
1968 struct ssh_channel *c;
1969 c = find234(ssh_channels, &i, ssh_channelfind);
1972 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1973 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1974 if ((c->closes == 0) && (c->type == CHAN_X11)) {
1975 logevent("X11 connection closed");
1976 assert(c->u.x11.s != NULL);
1977 x11_close(c->u.x11.s);
1980 c->closes |= closetype;
1981 if (c->closes == 3) {
1982 del234(ssh_channels, c);
1986 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1987 /* Data sent down one of our channels. */
1988 int i = GET_32BIT(pktin.body);
1989 int len = GET_32BIT(pktin.body+4);
1990 unsigned char *p = pktin.body+8;
1991 struct ssh_channel *c;
1992 c = find234(ssh_channels, &i, ssh_channelfind);
1996 x11_send(c->u.x11.s, p, len);
1999 /* Data for an agent message. Buffer it. */
2001 if (c->u.a.lensofar < 4) {
2002 int l = min(4 - c->u.a.lensofar, len);
2003 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2004 p += l; len -= l; c->u.a.lensofar += l;
2006 if (c->u.a.lensofar == 4) {
2007 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
2008 c->u.a.message = smalloc(c->u.a.totallen);
2009 memcpy(c->u.a.message, c->u.a.msglen, 4);
2011 if (c->u.a.lensofar >= 4 && len > 0) {
2012 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2013 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2014 p += l; len -= l; c->u.a.lensofar += l;
2016 if (c->u.a.lensofar == c->u.a.totallen) {
2017 void *reply, *sentreply;
2019 agent_query(c->u.a.message, c->u.a.totallen,
2024 /* Fake SSH_AGENT_FAILURE. */
2025 sentreply = "\0\0\0\1\5";
2028 send_packet(SSH1_MSG_CHANNEL_DATA,
2029 PKT_INT, c->remoteid,
2031 PKT_DATA, sentreply, replylen,
2035 sfree(c->u.a.message);
2036 c->u.a.lensofar = 0;
2042 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2043 /* may be from EXEC_SHELL on some servers */
2044 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2045 /* may be from EXEC_SHELL on some servers
2046 * if no pty is available or in other odd cases. Ignore */
2047 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2048 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2050 bombout(("Strange packet received: type %d", pktin.type));
2055 int len = min(inlen, 512);
2056 send_packet(SSH1_CMSG_STDIN_DATA,
2057 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2068 * Utility routine for decoding comma-separated strings in KEXINIT.
2070 static int in_commasep_string(char *needle, char *haystack, int haylen) {
2071 int needlen = strlen(needle);
2074 * Is it at the start of the string?
2076 if (haylen >= needlen && /* haystack is long enough */
2077 !memcmp(needle, haystack, needlen) && /* initial match */
2078 (haylen == needlen || haystack[needlen] == ',')
2079 /* either , or EOS follows */
2083 * If not, search for the next comma and resume after that.
2084 * If no comma found, terminate.
2086 while (haylen > 0 && *haystack != ',')
2087 haylen--, haystack++;
2090 haylen--, haystack++; /* skip over comma itself */
2095 * SSH2 key creation method.
2097 static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
2099 /* First 20 bytes. */
2102 SHA_Bytes(&s, H, 20);
2103 SHA_Bytes(&s, &chr, 1);
2104 SHA_Bytes(&s, H, 20);
2105 SHA_Final(&s, keyspace);
2106 /* Next 20 bytes. */
2109 SHA_Bytes(&s, H, 20);
2110 SHA_Bytes(&s, keyspace, 20);
2111 SHA_Final(&s, keyspace+20);
2115 * Handle the SSH2 transport layer.
2117 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2121 static Bignum e, f, K;
2122 static const struct ssh_mac **maclist;
2124 static const struct ssh_cipher *cscipher_tobe = NULL;
2125 static const struct ssh_cipher *sccipher_tobe = NULL;
2126 static const struct ssh_mac *csmac_tobe = NULL;
2127 static const struct ssh_mac *scmac_tobe = NULL;
2128 static const struct ssh_compress *cscomp_tobe = NULL;
2129 static const struct ssh_compress *sccomp_tobe = NULL;
2130 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2131 static int hostkeylen, siglen;
2132 static void *hkey; /* actual host key */
2133 static unsigned char exchange_hash[20];
2134 static unsigned char keyspace[40];
2135 static const struct ssh_cipher *preferred_cipher;
2136 static const struct ssh_compress *preferred_comp;
2137 static int first_kex;
2144 * Set up the preferred cipher and compression.
2146 if (cfg.cipher == CIPHER_BLOWFISH) {
2147 preferred_cipher = &ssh_blowfish_ssh2;
2148 } else if (cfg.cipher == CIPHER_DES) {
2149 logevent("Single DES not supported in SSH2; using 3DES");
2150 preferred_cipher = &ssh_3des_ssh2;
2151 } else if (cfg.cipher == CIPHER_3DES) {
2152 preferred_cipher = &ssh_3des_ssh2;
2154 /* Shouldn't happen, but we do want to initialise to _something_. */
2155 preferred_cipher = &ssh_3des_ssh2;
2157 if (cfg.compression)
2158 preferred_comp = &ssh_zlib;
2160 preferred_comp = &ssh_comp_none;
2163 * Be prepared to work around the buggy MAC problem.
2166 maclist = buggymacs, nmacs = lenof(buggymacs);
2168 maclist = macs, nmacs = lenof(macs);
2172 * Construct and send our key exchange packet.
2174 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2175 for (i = 0; i < 16; i++)
2176 ssh2_pkt_addbyte((unsigned char)random_byte());
2177 /* List key exchange algorithms. */
2178 ssh2_pkt_addstring_start();
2179 for (i = 0; i < lenof(kex_algs); i++) {
2180 ssh2_pkt_addstring_str(kex_algs[i]->name);
2181 if (i < lenof(kex_algs)-1)
2182 ssh2_pkt_addstring_str(",");
2184 /* List server host key algorithms. */
2185 ssh2_pkt_addstring_start();
2186 for (i = 0; i < lenof(hostkey_algs); i++) {
2187 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2188 if (i < lenof(hostkey_algs)-1)
2189 ssh2_pkt_addstring_str(",");
2191 /* List client->server encryption algorithms. */
2192 ssh2_pkt_addstring_start();
2193 for (i = 0; i < lenof(ciphers)+1; i++) {
2194 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2195 ssh2_pkt_addstring_str(c->name);
2196 if (i < lenof(ciphers))
2197 ssh2_pkt_addstring_str(",");
2199 /* List server->client encryption algorithms. */
2200 ssh2_pkt_addstring_start();
2201 for (i = 0; i < lenof(ciphers)+1; i++) {
2202 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2203 ssh2_pkt_addstring_str(c->name);
2204 if (i < lenof(ciphers))
2205 ssh2_pkt_addstring_str(",");
2207 /* List client->server MAC algorithms. */
2208 ssh2_pkt_addstring_start();
2209 for (i = 0; i < nmacs; i++) {
2210 ssh2_pkt_addstring_str(maclist[i]->name);
2212 ssh2_pkt_addstring_str(",");
2214 /* List server->client MAC algorithms. */
2215 ssh2_pkt_addstring_start();
2216 for (i = 0; i < nmacs; i++) {
2217 ssh2_pkt_addstring_str(maclist[i]->name);
2219 ssh2_pkt_addstring_str(",");
2221 /* List client->server compression algorithms. */
2222 ssh2_pkt_addstring_start();
2223 for (i = 0; i < lenof(compressions)+1; i++) {
2224 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2225 ssh2_pkt_addstring_str(c->name);
2226 if (i < lenof(compressions))
2227 ssh2_pkt_addstring_str(",");
2229 /* List server->client compression algorithms. */
2230 ssh2_pkt_addstring_start();
2231 for (i = 0; i < lenof(compressions)+1; i++) {
2232 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2233 ssh2_pkt_addstring_str(c->name);
2234 if (i < lenof(compressions))
2235 ssh2_pkt_addstring_str(",");
2237 /* List client->server languages. Empty list. */
2238 ssh2_pkt_addstring_start();
2239 /* List server->client languages. Empty list. */
2240 ssh2_pkt_addstring_start();
2241 /* First KEX packet does _not_ follow, because we're not that brave. */
2242 ssh2_pkt_addbool(FALSE);
2244 ssh2_pkt_adduint32(0);
2246 exhash = exhashbase;
2247 sha_string(&exhash, pktout.data+5, pktout.length-5);
2251 if (!ispkt) crWaitUntil(ispkt);
2252 sha_string(&exhash, pktin.data+5, pktin.length-5);
2255 * Now examine the other side's KEXINIT to see what we're up
2258 if (pktin.type != SSH2_MSG_KEXINIT) {
2259 bombout(("expected key exchange packet from server"));
2262 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2263 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2264 pktin.savedpos += 16; /* skip garbage cookie */
2265 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2266 for (i = 0; i < lenof(kex_algs); i++) {
2267 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2272 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2273 for (i = 0; i < lenof(hostkey_algs); i++) {
2274 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2275 hostkey = hostkey_algs[i];
2279 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
2280 for (i = 0; i < lenof(ciphers)+1; i++) {
2281 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2282 if (in_commasep_string(c->name, str, len)) {
2287 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
2288 for (i = 0; i < lenof(ciphers)+1; i++) {
2289 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
2290 if (in_commasep_string(c->name, str, len)) {
2295 ssh2_pkt_getstring(&str, &len); /* client->server mac */
2296 for (i = 0; i < nmacs; i++) {
2297 if (in_commasep_string(maclist[i]->name, str, len)) {
2298 csmac_tobe = maclist[i];
2302 ssh2_pkt_getstring(&str, &len); /* server->client mac */
2303 for (i = 0; i < nmacs; i++) {
2304 if (in_commasep_string(maclist[i]->name, str, len)) {
2305 scmac_tobe = maclist[i];
2309 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2310 for (i = 0; i < lenof(compressions)+1; i++) {
2311 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2312 if (in_commasep_string(c->name, str, len)) {
2317 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2318 for (i = 0; i < lenof(compressions)+1; i++) {
2319 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2320 if (in_commasep_string(c->name, str, len)) {
2327 * Currently we only support Diffie-Hellman and DSS, so let's
2328 * bomb out if those aren't selected.
2330 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2331 bombout(("internal fault: chaos in SSH 2 transport layer"));
2336 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2339 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2344 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
2345 bombout(("expected key exchange packet from server"));
2348 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2349 f = ssh2_pkt_getmp();
2350 ssh2_pkt_getstring(&sigdata, &siglen);
2354 sha_string(&exhash, hostkeydata, hostkeylen);
2355 sha_mpint(&exhash, e);
2356 sha_mpint(&exhash, f);
2357 sha_mpint(&exhash, K);
2358 SHA_Final(&exhash, exchange_hash);
2361 debug(("Exchange hash is:\r\n"));
2362 for (i = 0; i < 20; i++)
2363 debug((" %02x", exchange_hash[i]));
2367 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2368 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
2369 bombout(("Server failed host key check"));
2374 * Expect SSH2_MSG_NEWKEYS from server.
2377 if (pktin.type != SSH2_MSG_NEWKEYS) {
2378 bombout(("expected new-keys packet from server"));
2383 * Authenticate remote host: verify host key. (We've already
2384 * checked the signature of the exchange hash.)
2386 keystr = hostkey->fmtkey(hkey);
2387 fingerprint = hostkey->fingerprint(hkey);
2388 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2389 keystr, fingerprint);
2390 logevent("Host key fingerprint is:");
2391 logevent(fingerprint);
2394 hostkey->freekey(hkey);
2397 * Send SSH2_MSG_NEWKEYS.
2399 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2403 * Create and initialise session keys.
2405 cscipher = cscipher_tobe;
2406 sccipher = sccipher_tobe;
2409 cscomp = cscomp_tobe;
2410 sccomp = sccomp_tobe;
2411 cscomp->compress_init();
2412 sccomp->decompress_init();
2414 * Set IVs after keys.
2416 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2417 ssh2_mkkey(K, exchange_hash, 'D', keyspace); sccipher->setsckey(keyspace);
2418 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2419 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2420 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2421 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2424 * If this is the first key exchange phase, we must pass the
2425 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2426 * wants to see it but because it will need time to initialise
2427 * itself before it sees an actual packet. In subsequent key
2428 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2429 * it would only confuse the layer above.
2437 * Now we're encrypting. Begin returning 1 to the protocol main
2438 * function so that other things can run on top of the
2439 * transport. If we ever see a KEXINIT, we must go back to the
2444 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2445 goto begin_key_exchange;
2451 * Add data to an SSH2 channel output buffer.
2453 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2454 if (c->v2.outbufsize <
2455 c->v2.outbuflen + len) {
2457 c->v2.outbuflen + len + 1024;
2458 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2461 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2463 c->v2.outbuflen += len;
2467 * Attempt to send data on an SSH2 channel.
2469 static void ssh2_try_send(struct ssh_channel *c) {
2470 while (c->v2.remwindow > 0 &&
2471 c->v2.outbuflen > 0) {
2472 unsigned len = c->v2.remwindow;
2473 if (len > c->v2.outbuflen)
2474 len = c->v2.outbuflen;
2475 if (len > c->v2.remmaxpkt)
2476 len = c->v2.remmaxpkt;
2477 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2478 ssh2_pkt_adduint32(c->remoteid);
2479 ssh2_pkt_addstring_start();
2480 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2482 c->v2.outbuflen -= len;
2483 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2485 c->v2.remwindow -= len;
2490 * Handle the SSH2 userauth and connection layers.
2492 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2494 static unsigned long remote_winsize;
2495 static unsigned long remote_maxpkt;
2500 * Request userauth protocol, and await a response to it.
2502 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2503 ssh2_pkt_addstring("ssh-userauth");
2505 crWaitUntilV(ispkt);
2506 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2507 bombout(("Server refused user authentication protocol"));
2512 * FIXME: currently we support only password authentication.
2513 * (This places us technically in violation of the SSH2 spec.
2514 * We must fix this.)
2518 * Get a username and a password.
2520 static char username[100];
2521 static char password[100];
2525 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2526 c_write("login as: ", 10);
2529 crWaitUntilV(!ispkt);
2530 while (inlen--) switch (c = *in++) {
2537 c_write("\b \b", 3);
2543 c_write("\b \b", 3);
2552 if (((c >= ' ' && c <= '~') ||
2553 ((unsigned char)c >= 160)) && pos < 40) {
2554 username[pos++] = c;
2561 username[strcspn(username, "\n\r")] = '\0';
2564 strncpy(username, cfg.username, 99);
2565 username[99] = '\0';
2566 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
2567 sprintf(stuff, "Using username \"%s\".\r\n", username);
2568 c_write(stuff, strlen(stuff));
2572 if (ssh_get_password) {
2574 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
2575 if (!ssh_get_password(prompt, password, sizeof(password))) {
2577 * get_password failed to get a password (for
2578 * example because one was supplied on the command
2579 * line which has already failed to work).
2582 logevent("No more passwords to try");
2583 ssh_state = SSH_STATE_CLOSED;
2587 c_write("password: ", 10);
2592 crWaitUntilV(!ispkt);
2593 while (inlen--) switch (c = *in++) {
2610 if (((c >= ' ' && c <= '~') ||
2611 ((unsigned char)c >= 160)) && pos < 40)
2612 password[pos++] = c;
2619 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2620 ssh2_pkt_addstring(username);
2621 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2622 ssh2_pkt_addstring("password");
2623 ssh2_pkt_addbool(FALSE);
2624 ssh2_pkt_addstring(password);
2627 crWaitUntilV(ispkt);
2628 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2629 c_write("Access denied\r\n", 15);
2630 logevent("Authentication refused");
2636 * Now we're authenticated for the connection protocol. The
2637 * connection protocol will automatically have started at this
2638 * point; there's no need to send SERVICE_REQUEST.
2642 * So now create a channel with a session in it.
2644 mainchan = smalloc(sizeof(struct ssh_channel));
2645 mainchan->localid = 100; /* as good as any */
2646 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2647 ssh2_pkt_addstring("session");
2648 ssh2_pkt_adduint32(mainchan->localid);
2649 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2650 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2652 crWaitUntilV(ispkt);
2653 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2654 bombout(("Server refused to open a session"));
2656 /* FIXME: error data comes back in FAILURE packet */
2658 if (ssh2_pkt_getuint32() != mainchan->localid) {
2659 bombout(("Server's channel confirmation cited wrong channel"));
2662 mainchan->remoteid = ssh2_pkt_getuint32();
2663 mainchan->type = CHAN_MAINSESSION;
2664 mainchan->closes = 0;
2665 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2666 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2667 mainchan->v2.outbuffer = NULL;
2668 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2669 ssh_channels = newtree234(ssh_channelcmp);
2670 add234(ssh_channels, mainchan);
2671 logevent("Opened channel for session");
2674 * Potentially enable X11 forwarding.
2676 if (cfg.x11_forward) {
2677 char proto[20], data[64];
2678 logevent("Requesting X11 forwarding");
2679 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2680 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2681 ssh2_pkt_adduint32(mainchan->remoteid);
2682 ssh2_pkt_addstring("x11-req");
2683 ssh2_pkt_addbool(1); /* want reply */
2684 ssh2_pkt_addbool(0); /* many connections */
2685 ssh2_pkt_addstring(proto);
2686 ssh2_pkt_addstring(data);
2687 ssh2_pkt_adduint32(0); /* screen number */
2691 crWaitUntilV(ispkt);
2692 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2693 unsigned i = ssh2_pkt_getuint32();
2694 struct ssh_channel *c;
2695 c = find234(ssh_channels, &i, ssh_channelfind);
2697 continue; /* nonexistent channel */
2698 c->v2.remwindow += ssh2_pkt_getuint32();
2700 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2702 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2703 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2704 bombout(("Server got confused by X11 forwarding request"));
2707 logevent("X11 forwarding refused");
2709 logevent("X11 forwarding enabled");
2710 ssh_X11_fwd_enabled = TRUE;
2715 * Now allocate a pty for the session.
2718 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2719 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2720 ssh2_pkt_addstring("pty-req");
2721 ssh2_pkt_addbool(1); /* want reply */
2722 ssh2_pkt_addstring(cfg.termtype);
2723 ssh2_pkt_adduint32(cols);
2724 ssh2_pkt_adduint32(rows);
2725 ssh2_pkt_adduint32(0); /* pixel width */
2726 ssh2_pkt_adduint32(0); /* pixel height */
2727 ssh2_pkt_addstring_start();
2728 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2730 ssh_state = SSH_STATE_INTERMED;
2733 crWaitUntilV(ispkt);
2734 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2735 unsigned i = ssh2_pkt_getuint32();
2736 struct ssh_channel *c;
2737 c = find234(ssh_channels, &i, ssh_channelfind);
2739 continue; /* nonexistent channel */
2740 c->v2.remwindow += ssh2_pkt_getuint32();
2742 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2744 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2745 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2746 bombout(("Server got confused by pty request"));
2749 c_write("Server refused to allocate pty\r\n", 32);
2750 ssh_editing = ssh_echoing = 1;
2752 logevent("Allocated pty");
2755 ssh_editing = ssh_echoing = 1;
2759 * Start a shell or a remote command.
2761 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2762 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2763 if (*cfg.remote_cmd) {
2764 ssh2_pkt_addstring("exec");
2765 ssh2_pkt_addbool(1); /* want reply */
2766 ssh2_pkt_addstring(cfg.remote_cmd);
2768 ssh2_pkt_addstring("shell");
2769 ssh2_pkt_addbool(1); /* want reply */
2773 crWaitUntilV(ispkt);
2774 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2775 unsigned i = ssh2_pkt_getuint32();
2776 struct ssh_channel *c;
2777 c = find234(ssh_channels, &i, ssh_channelfind);
2779 continue; /* nonexistent channel */
2780 c->v2.remwindow += ssh2_pkt_getuint32();
2782 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2783 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2784 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2785 bombout(("Server got confused by shell/command request"));
2788 bombout(("Server refused to start a shell/command"));
2791 logevent("Started a shell/command");
2794 ssh_state = SSH_STATE_SESSION;
2798 ssh_special(TS_EOF);
2803 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2806 static int try_send;
2810 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2811 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2814 unsigned i = ssh2_pkt_getuint32();
2815 struct ssh_channel *c;
2816 c = find234(ssh_channels, &i, ssh_channelfind);
2818 continue; /* nonexistent channel */
2819 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2820 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2821 continue; /* extended but not stderr */
2822 ssh2_pkt_getstring(&data, &length);
2825 case CHAN_MAINSESSION:
2826 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2830 x11_send(c->u.x11.s, data, length);
2834 * Enlarge the window again at the remote
2835 * side, just in case it ever runs down and
2836 * they fail to send us any more data.
2838 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2839 ssh2_pkt_adduint32(c->remoteid);
2840 ssh2_pkt_adduint32(length);
2843 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2844 ssh_state = SSH_STATE_CLOSED;
2845 logevent("Received disconnect message");
2847 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2848 continue; /* exit status et al; ignore (FIXME?) */
2849 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2850 unsigned i = ssh2_pkt_getuint32();
2851 struct ssh_channel *c;
2853 c = find234(ssh_channels, &i, ssh_channelfind);
2855 continue; /* nonexistent channel */
2857 if (c->type == CHAN_X11) {
2859 * Remote EOF on an X11 channel means we should
2860 * wrap up and close the channel ourselves.
2862 x11_close(c->u.x11.s);
2865 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2866 unsigned i = ssh2_pkt_getuint32();
2867 struct ssh_channel *c;
2870 c = find234(ssh_channels, &i, ssh_channelfind);
2872 continue; /* nonexistent channel */
2873 if (c->closes == 0) {
2874 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2875 ssh2_pkt_adduint32(c->remoteid);
2878 /* Do pre-close processing on the channel. */
2880 case CHAN_MAINSESSION:
2881 break; /* nothing to see here, move along */
2885 del234(ssh_channels, c);
2886 sfree(c->v2.outbuffer);
2890 * See if that was the last channel left open.
2892 c = first234(ssh_channels, &e);
2894 logevent("All channels closed. Disconnecting");
2895 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2896 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2897 ssh2_pkt_addstring("All open channels closed");
2898 ssh2_pkt_addstring("en"); /* language tag */
2900 ssh_state = SSH_STATE_CLOSED;
2903 continue; /* remote sends close; ignore (FIXME) */
2904 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2905 unsigned i = ssh2_pkt_getuint32();
2906 struct ssh_channel *c;
2907 c = find234(ssh_channels, &i, ssh_channelfind);
2909 continue; /* nonexistent channel */
2910 mainchan->v2.remwindow += ssh2_pkt_getuint32();
2912 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
2916 struct ssh_channel *c;
2917 ssh2_pkt_getstring(&type, &typelen);
2918 c = smalloc(sizeof(struct ssh_channel));
2920 if (typelen == 3 && !memcmp(type, "x11", 3)) {
2921 if (!ssh_X11_fwd_enabled)
2922 error = "X11 forwarding is not enabled";
2923 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
2924 error = "Unable to open an X11 connection";
2929 error = "Unsupported channel type requested";
2932 c->remoteid = ssh2_pkt_getuint32();
2934 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2935 ssh2_pkt_adduint32(c->remoteid);
2936 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
2937 ssh2_pkt_addstring(error);
2938 ssh2_pkt_addstring("en"); /* language tag */
2942 struct ssh_channel *d;
2946 for (i=1, d = first234(ssh_channels, &e); d;
2949 break; /* found a free number */
2954 c->v2.remwindow = ssh2_pkt_getuint32();
2955 c->v2.remmaxpkt = ssh2_pkt_getuint32();
2956 c->v2.outbuffer = NULL;
2957 c->v2.outbuflen = c->v2.outbufsize = 0;
2958 add234(ssh_channels, c);
2959 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2960 ssh2_pkt_adduint32(c->remoteid);
2961 ssh2_pkt_adduint32(c->localid);
2962 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2963 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2967 bombout(("Strange packet received: type %d", pktin.type));
2972 * We have spare data. Add it to the channel buffer.
2974 ssh2_add_channel_data(mainchan, in, inlen);
2979 struct ssh_channel *c;
2981 * Try to send data on all channels if we can.
2983 for (c = first234(ssh_channels, &e); c; c = next234(&e))
2992 * Handle the top-level SSH2 protocol.
2994 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2996 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2998 do_ssh2_authconn(in, inlen, ispkt);
3002 * Called to set up the connection.
3004 * Returns an error message, or NULL on success.
3006 static char *ssh_init (char *host, int port, char **realhost) {
3010 if(crypto_startup() == 0)
3011 return "Microsoft high encryption pack not installed!";
3018 p = connect_to_host(host, port, realhost);
3026 * Called to send data down the Telnet connection.
3028 static void ssh_send (char *buf, int len) {
3029 if (s == NULL || ssh_protocol == NULL)
3032 ssh_protocol(buf, len, 0);
3036 * Called to set the size of the window from SSH's POV.
3038 static void ssh_size(void) {
3039 switch (ssh_state) {
3040 case SSH_STATE_BEFORE_SIZE:
3041 case SSH_STATE_PREPACKET:
3042 case SSH_STATE_CLOSED:
3043 break; /* do nothing */
3044 case SSH_STATE_INTERMED:
3045 size_needed = TRUE; /* buffer for later */
3047 case SSH_STATE_SESSION:
3049 if (ssh_version == 1) {
3050 send_packet(SSH1_CMSG_WINDOW_SIZE,
3051 PKT_INT, rows, PKT_INT, cols,
3052 PKT_INT, 0, PKT_INT, 0, PKT_END);
3054 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3055 ssh2_pkt_adduint32(mainchan->remoteid);
3056 ssh2_pkt_addstring("window-change");
3057 ssh2_pkt_addbool(0);
3058 ssh2_pkt_adduint32(cols);
3059 ssh2_pkt_adduint32(rows);
3060 ssh2_pkt_adduint32(0);
3061 ssh2_pkt_adduint32(0);
3070 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3071 * can send an EOF and collect resulting output (e.g. `plink
3074 static void ssh_special (Telnet_Special code) {
3075 if (code == TS_EOF) {
3076 if (ssh_state != SSH_STATE_SESSION) {
3078 * Buffer the EOF in case we are pre-SESSION, so we can
3079 * send it as soon as we reach SESSION.
3085 if (ssh_version == 1) {
3086 send_packet(SSH1_CMSG_EOF, PKT_END);
3088 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
3089 ssh2_pkt_adduint32(mainchan->remoteid);
3092 logevent("Sent EOF message");
3093 } else if (code == TS_PING) {
3094 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3096 if (ssh_version == 1) {
3097 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3099 ssh2_pkt_init(SSH2_MSG_IGNORE);
3100 ssh2_pkt_addstring_start();
3108 static Socket ssh_socket(void) { return s; }
3110 static int ssh_sendok(void) { return ssh_send_ok; }
3112 static int ssh_ldisc(int option) {
3113 if (option == LD_ECHO) return ssh_echoing;
3114 if (option == LD_EDIT) return ssh_editing;
3118 Backend ssh_backend = {