Annotation of src/usr.bin/ssh/kex.c, Revision 1.72
1.72 ! stevesk 1: /* $OpenBSD: kex.c,v 1.71 2006/03/25 13:17:02 djm Exp $ */
1.1 markus 2: /*
1.36 markus 3: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.1 markus 4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: *
14: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24: */
25:
26: #include "includes.h"
1.18 markus 27:
28: #include <openssl/crypto.h>
1.72 ! stevesk 29:
! 30: #include <string.h>
1.1 markus 31:
32: #include "ssh2.h"
33: #include "xmalloc.h"
34: #include "buffer.h"
35: #include "bufaux.h"
1.7 markus 36: #include "packet.h"
1.1 markus 37: #include "compat.h"
1.18 markus 38: #include "cipher.h"
1.1 markus 39: #include "kex.h"
1.13 markus 40: #include "key.h"
1.18 markus 41: #include "log.h"
1.21 markus 42: #include "mac.h"
1.23 markus 43: #include "match.h"
1.26 markus 44: #include "dispatch.h"
1.48 provos 45: #include "monitor.h"
1.1 markus 46:
1.7 markus 47: #define KEX_COOKIE_LEN 16
1.48 provos 48:
1.66 djm 49: extern const EVP_MD *evp_ssh_sha256(void);
50:
1.35 itojun 51: /* prototype */
52: static void kex_kexinit_finish(Kex *);
53: static void kex_choose_conf(Kex *);
1.26 markus 54:
55: /* put algorithm proposal into buffer */
1.35 itojun 56: static void
1.26 markus 57: kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX])
1.1 markus 58: {
1.61 djm 59: u_int i;
1.26 markus 60:
61: buffer_clear(b);
1.49 markus 62: /*
63: * add a dummy cookie, the cookie will be overwritten by
64: * kex_send_kexinit(), each time a kexinit is set
65: */
66: for (i = 0; i < KEX_COOKIE_LEN; i++)
67: buffer_put_char(b, 0);
1.1 markus 68: for (i = 0; i < PROPOSAL_MAX; i++)
1.26 markus 69: buffer_put_cstring(b, proposal[i]);
70: buffer_put_char(b, 0); /* first_kex_packet_follows */
71: buffer_put_int(b, 0); /* uint32 reserved */
1.1 markus 72: }
73:
1.26 markus 74: /* parse buffer and return algorithm proposal */
1.35 itojun 75: static char **
1.53 markus 76: kex_buf2prop(Buffer *raw, int *first_kex_follows)
1.7 markus 77: {
1.26 markus 78: Buffer b;
1.7 markus 79: int i;
1.26 markus 80: char **proposal;
1.7 markus 81:
1.70 djm 82: proposal = xcalloc(PROPOSAL_MAX, sizeof(char *));
1.7 markus 83:
1.26 markus 84: buffer_init(&b);
85: buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
1.7 markus 86: /* skip cookie */
87: for (i = 0; i < KEX_COOKIE_LEN; i++)
1.26 markus 88: buffer_get_char(&b);
1.7 markus 89: /* extract kex init proposal strings */
90: for (i = 0; i < PROPOSAL_MAX; i++) {
1.26 markus 91: proposal[i] = buffer_get_string(&b,NULL);
92: debug2("kex_parse_kexinit: %s", proposal[i]);
1.7 markus 93: }
1.26 markus 94: /* first kex follows / reserved */
95: i = buffer_get_char(&b);
1.53 markus 96: if (first_kex_follows != NULL)
97: *first_kex_follows = i;
1.26 markus 98: debug2("kex_parse_kexinit: first_kex_follows %d ", i);
99: i = buffer_get_int(&b);
100: debug2("kex_parse_kexinit: reserved %d ", i);
101: buffer_free(&b);
102: return proposal;
1.1 markus 103: }
104:
1.35 itojun 105: static void
1.26 markus 106: kex_prop_free(char **proposal)
1.1 markus 107: {
1.61 djm 108: u_int i;
1.26 markus 109:
110: for (i = 0; i < PROPOSAL_MAX; i++)
111: xfree(proposal[i]);
112: xfree(proposal);
1.1 markus 113: }
114:
1.35 itojun 115: static void
1.41 markus 116: kex_protocol_error(int type, u_int32_t seq, void *ctxt)
1.1 markus 117: {
1.41 markus 118: error("Hm, kex protocol error: type %d seq %u", type, seq);
1.26 markus 119: }
1.1 markus 120:
1.35 itojun 121: static void
1.44 markus 122: kex_reset_dispatch(void)
1.29 markus 123: {
1.42 markus 124: dispatch_range(SSH2_MSG_TRANSPORT_MIN,
125: SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error);
1.44 markus 126: dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1.29 markus 127: }
128:
129: void
1.28 markus 130: kex_finish(Kex *kex)
1.26 markus 131: {
1.44 markus 132: kex_reset_dispatch();
1.28 markus 133:
1.26 markus 134: packet_start(SSH2_MSG_NEWKEYS);
135: packet_send();
136: /* packet_write_wait(); */
137: debug("SSH2_MSG_NEWKEYS sent");
1.19 stevesk 138:
1.52 markus 139: debug("expecting SSH2_MSG_NEWKEYS");
1.40 markus 140: packet_read_expect(SSH2_MSG_NEWKEYS);
1.46 markus 141: packet_check_eom();
1.26 markus 142: debug("SSH2_MSG_NEWKEYS received");
1.32 markus 143:
1.30 markus 144: kex->done = 1;
1.26 markus 145: buffer_clear(&kex->peer);
1.27 markus 146: /* buffer_clear(&kex->my); */
1.26 markus 147: kex->flags &= ~KEX_INIT_SENT;
1.32 markus 148: xfree(kex->name);
149: kex->name = NULL;
1.26 markus 150: }
1.1 markus 151:
1.26 markus 152: void
153: kex_send_kexinit(Kex *kex)
154: {
1.60 avsm 155: u_int32_t rnd = 0;
1.49 markus 156: u_char *cookie;
1.61 djm 157: u_int i;
1.49 markus 158:
1.29 markus 159: if (kex == NULL) {
160: error("kex_send_kexinit: no kex, cannot rekey");
161: return;
162: }
1.28 markus 163: if (kex->flags & KEX_INIT_SENT) {
164: debug("KEX_INIT_SENT");
165: return;
166: }
1.30 markus 167: kex->done = 0;
1.49 markus 168:
169: /* generate a random cookie */
170: if (buffer_len(&kex->my) < KEX_COOKIE_LEN)
171: fatal("kex_send_kexinit: kex proposal too short");
172: cookie = buffer_ptr(&kex->my);
173: for (i = 0; i < KEX_COOKIE_LEN; i++) {
174: if (i % 4 == 0)
1.60 avsm 175: rnd = arc4random();
176: cookie[i] = rnd;
177: rnd >>= 8;
1.49 markus 178: }
1.26 markus 179: packet_start(SSH2_MSG_KEXINIT);
180: packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my));
181: packet_send();
182: debug("SSH2_MSG_KEXINIT sent");
183: kex->flags |= KEX_INIT_SENT;
1.1 markus 184: }
185:
1.26 markus 186: void
1.41 markus 187: kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
1.11 provos 188: {
1.26 markus 189: char *ptr;
1.61 djm 190: u_int i, dlen;
1.26 markus 191: Kex *kex = (Kex *)ctxt;
1.11 provos 192:
1.26 markus 193: debug("SSH2_MSG_KEXINIT received");
1.29 markus 194: if (kex == NULL)
195: fatal("kex_input_kexinit: no kex, cannot rekey");
1.11 provos 196:
1.26 markus 197: ptr = packet_get_raw(&dlen);
198: buffer_append(&kex->peer, ptr, dlen);
1.31 markus 199:
200: /* discard packet */
201: for (i = 0; i < KEX_COOKIE_LEN; i++)
202: packet_get_char();
203: for (i = 0; i < PROPOSAL_MAX; i++)
204: xfree(packet_get_string(NULL));
1.51 markus 205: (void) packet_get_char();
206: (void) packet_get_int();
1.39 markus 207: packet_check_eom();
1.19 stevesk 208:
1.26 markus 209: kex_kexinit_finish(kex);
210: }
1.11 provos 211:
1.26 markus 212: Kex *
1.28 markus 213: kex_setup(char *proposal[PROPOSAL_MAX])
1.26 markus 214: {
215: Kex *kex;
1.11 provos 216:
1.70 djm 217: kex = xcalloc(1, sizeof(*kex));
1.26 markus 218: buffer_init(&kex->peer);
219: buffer_init(&kex->my);
220: kex_prop2buf(&kex->my, proposal);
1.30 markus 221: kex->done = 0;
1.26 markus 222:
223: kex_send_kexinit(kex); /* we start */
1.44 markus 224: kex_reset_dispatch();
1.26 markus 225:
226: return kex;
1.11 provos 227: }
228:
1.35 itojun 229: static void
1.26 markus 230: kex_kexinit_finish(Kex *kex)
1.1 markus 231: {
1.26 markus 232: if (!(kex->flags & KEX_INIT_SENT))
233: kex_send_kexinit(kex);
1.1 markus 234:
1.26 markus 235: kex_choose_conf(kex);
1.1 markus 236:
1.54 markus 237: if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX &&
238: kex->kex[kex->kex_type] != NULL) {
239: (kex->kex[kex->kex_type])(kex);
240: } else {
1.26 markus 241: fatal("Unsupported key exchange %d", kex->kex_type);
1.1 markus 242: }
243: }
244:
1.35 itojun 245: static void
1.1 markus 246: choose_enc(Enc *enc, char *client, char *server)
247: {
1.23 markus 248: char *name = match_list(client, server, NULL);
1.1 markus 249: if (name == NULL)
250: fatal("no matching cipher found: client %s server %s", client, server);
1.45 markus 251: if ((enc->cipher = cipher_by_name(name)) == NULL)
1.12 markus 252: fatal("matching cipher is not supported: %s", name);
1.1 markus 253: enc->name = name;
254: enc->enabled = 0;
255: enc->iv = NULL;
256: enc->key = NULL;
1.45 markus 257: enc->key_len = cipher_keylen(enc->cipher);
258: enc->block_size = cipher_blocksize(enc->cipher);
1.1 markus 259: }
1.69 deraadt 260:
1.35 itojun 261: static void
1.1 markus 262: choose_mac(Mac *mac, char *client, char *server)
263: {
1.23 markus 264: char *name = match_list(client, server, NULL);
1.1 markus 265: if (name == NULL)
266: fatal("no matching mac found: client %s server %s", client, server);
1.21 markus 267: if (mac_init(mac, name) < 0)
1.1 markus 268: fatal("unsupported mac %s", name);
1.21 markus 269: /* truncate the key */
270: if (datafellows & SSH_BUG_HMAC)
271: mac->key_len = 16;
1.1 markus 272: mac->name = name;
273: mac->key = NULL;
274: mac->enabled = 0;
275: }
1.69 deraadt 276:
1.35 itojun 277: static void
1.1 markus 278: choose_comp(Comp *comp, char *client, char *server)
279: {
1.23 markus 280: char *name = match_list(client, server, NULL);
1.1 markus 281: if (name == NULL)
282: fatal("no matching comp found: client %s server %s", client, server);
1.64 markus 283: if (strcmp(name, "zlib@openssh.com") == 0) {
284: comp->type = COMP_DELAYED;
285: } else if (strcmp(name, "zlib") == 0) {
286: comp->type = COMP_ZLIB;
1.1 markus 287: } else if (strcmp(name, "none") == 0) {
1.64 markus 288: comp->type = COMP_NONE;
1.1 markus 289: } else {
290: fatal("unsupported comp %s", name);
291: }
292: comp->name = name;
293: }
1.69 deraadt 294:
1.35 itojun 295: static void
1.1 markus 296: choose_kex(Kex *k, char *client, char *server)
297: {
1.23 markus 298: k->name = match_list(client, server, NULL);
1.1 markus 299: if (k->name == NULL)
300: fatal("no kex alg");
1.11 provos 301: if (strcmp(k->name, KEX_DH1) == 0) {
1.54 markus 302: k->kex_type = KEX_DH_GRP1_SHA1;
1.65 djm 303: k->evp_md = EVP_sha1();
1.59 djm 304: } else if (strcmp(k->name, KEX_DH14) == 0) {
305: k->kex_type = KEX_DH_GRP14_SHA1;
1.65 djm 306: k->evp_md = EVP_sha1();
307: } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) {
1.54 markus 308: k->kex_type = KEX_DH_GEX_SHA1;
1.65 djm 309: k->evp_md = EVP_sha1();
1.66 djm 310: } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) {
311: k->kex_type = KEX_DH_GEX_SHA256;
312: k->evp_md = evp_ssh_sha256();
1.11 provos 313: } else
1.1 markus 314: fatal("bad kex alg %s", k->name);
315: }
1.65 djm 316:
1.35 itojun 317: static void
1.1 markus 318: choose_hostkeyalg(Kex *k, char *client, char *server)
319: {
1.23 markus 320: char *hostkeyalg = match_list(client, server, NULL);
1.13 markus 321: if (hostkeyalg == NULL)
1.1 markus 322: fatal("no hostkey alg");
1.13 markus 323: k->hostkey_type = key_type_from_name(hostkeyalg);
324: if (k->hostkey_type == KEY_UNSPEC)
325: fatal("bad hostkey alg '%s'", hostkeyalg);
1.17 markus 326: xfree(hostkeyalg);
1.1 markus 327: }
328:
1.56 djm 329: static int
1.53 markus 330: proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX])
331: {
332: static int check[] = {
333: PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1
334: };
335: int *idx;
336: char *p;
337:
338: for (idx = &check[0]; *idx != -1; idx++) {
339: if ((p = strchr(my[*idx], ',')) != NULL)
340: *p = '\0';
341: if ((p = strchr(peer[*idx], ',')) != NULL)
342: *p = '\0';
343: if (strcmp(my[*idx], peer[*idx]) != 0) {
344: debug2("proposal mismatch: my %s peer %s",
345: my[*idx], peer[*idx]);
346: return (0);
347: }
348: }
349: debug2("proposals match");
350: return (1);
351: }
352:
1.35 itojun 353: static void
1.27 markus 354: kex_choose_conf(Kex *kex)
1.1 markus 355: {
1.27 markus 356: Newkeys *newkeys;
1.26 markus 357: char **my, **peer;
358: char **cprop, **sprop;
1.27 markus 359: int nenc, nmac, ncomp;
1.61 djm 360: u_int mode, ctos, need;
1.53 markus 361: int first_kex_follows, type;
1.1 markus 362:
1.53 markus 363: my = kex_buf2prop(&kex->my, NULL);
364: peer = kex_buf2prop(&kex->peer, &first_kex_follows);
1.26 markus 365:
1.27 markus 366: if (kex->server) {
1.26 markus 367: cprop=peer;
368: sprop=my;
369: } else {
370: cprop=my;
371: sprop=peer;
372: }
1.1 markus 373:
1.30 markus 374: /* Algorithm Negotiation */
1.1 markus 375: for (mode = 0; mode < MODE_MAX; mode++) {
1.70 djm 376: newkeys = xcalloc(1, sizeof(*newkeys));
1.30 markus 377: kex->newkeys[mode] = newkeys;
1.27 markus 378: ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
1.1 markus 379: nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
380: nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
381: ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
1.27 markus 382: choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]);
383: choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]);
384: choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
1.2 markus 385: debug("kex: %s %s %s %s",
1.1 markus 386: ctos ? "client->server" : "server->client",
1.27 markus 387: newkeys->enc.name,
388: newkeys->mac.name,
389: newkeys->comp.name);
1.1 markus 390: }
1.27 markus 391: choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
392: choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
1.1 markus 393: sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
394: need = 0;
395: for (mode = 0; mode < MODE_MAX; mode++) {
1.30 markus 396: newkeys = kex->newkeys[mode];
1.45 markus 397: if (need < newkeys->enc.key_len)
398: need = newkeys->enc.key_len;
399: if (need < newkeys->enc.block_size)
400: need = newkeys->enc.block_size;
1.27 markus 401: if (need < newkeys->mac.key_len)
402: need = newkeys->mac.key_len;
1.1 markus 403: }
1.7 markus 404: /* XXX need runden? */
1.27 markus 405: kex->we_need = need;
1.53 markus 406:
407: /* ignore the next message if the proposals do not match */
1.56 djm 408: if (first_kex_follows && !proposals_match(my, peer) &&
1.63 djm 409: !(datafellows & SSH_BUG_FIRSTKEX)) {
1.53 markus 410: type = packet_read();
411: debug2("skipping next packet (type %u)", type);
412: }
1.26 markus 413:
414: kex_prop_free(my);
415: kex_prop_free(peer);
416: }
417:
1.35 itojun 418: static u_char *
1.65 djm 419: derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen,
420: BIGNUM *shared_secret)
1.26 markus 421: {
422: Buffer b;
423: EVP_MD_CTX md;
424: char c = id;
1.61 djm 425: u_int have;
1.65 djm 426: int mdsz;
1.61 djm 427: u_char *digest;
1.62 djm 428:
1.65 djm 429: if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0)
430: fatal("bad kex md size %d", mdsz);
1.68 deraadt 431: digest = xmalloc(roundup(need, mdsz));
1.26 markus 432:
433: buffer_init(&b);
434: buffer_put_bignum2(&b, shared_secret);
435:
1.30 markus 436: /* K1 = HASH(K || H || "A" || session_id) */
1.65 djm 437: EVP_DigestInit(&md, kex->evp_md);
1.34 markus 438: if (!(datafellows & SSH_BUG_DERIVEKEY))
439: EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
1.65 djm 440: EVP_DigestUpdate(&md, hash, hashlen);
1.30 markus 441: EVP_DigestUpdate(&md, &c, 1);
1.27 markus 442: EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
1.26 markus 443: EVP_DigestFinal(&md, digest, NULL);
444:
1.30 markus 445: /*
446: * expand key:
447: * Kn = HASH(K || H || K1 || K2 || ... || Kn-1)
448: * Key = K1 || K2 || ... || Kn
449: */
1.26 markus 450: for (have = mdsz; need > have; have += mdsz) {
1.65 djm 451: EVP_DigestInit(&md, kex->evp_md);
1.34 markus 452: if (!(datafellows & SSH_BUG_DERIVEKEY))
453: EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
1.65 djm 454: EVP_DigestUpdate(&md, hash, hashlen);
1.26 markus 455: EVP_DigestUpdate(&md, digest, have);
456: EVP_DigestFinal(&md, digest + have, NULL);
457: }
458: buffer_free(&b);
459: #ifdef DEBUG_KEX
460: fprintf(stderr, "key '%c'== ", c);
461: dump_digest("key", digest, need);
462: #endif
463: return digest;
1.1 markus 464: }
465:
1.30 markus 466: Newkeys *current_keys[MODE_MAX];
1.27 markus 467:
1.23 markus 468: #define NKEYS 6
1.26 markus 469: void
1.65 djm 470: kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret)
1.1 markus 471: {
1.15 markus 472: u_char *keys[NKEYS];
1.61 djm 473: u_int i, mode, ctos;
1.1 markus 474:
1.65 djm 475: for (i = 0; i < NKEYS; i++) {
476: keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen,
477: shared_secret);
478: }
1.1 markus 479:
1.52 markus 480: debug2("kex_derive_keys");
1.1 markus 481: for (mode = 0; mode < MODE_MAX; mode++) {
1.30 markus 482: current_keys[mode] = kex->newkeys[mode];
483: kex->newkeys[mode] = NULL;
1.69 deraadt 484: ctos = (!kex->server && mode == MODE_OUT) ||
485: (kex->server && mode == MODE_IN);
1.30 markus 486: current_keys[mode]->enc.iv = keys[ctos ? 0 : 1];
487: current_keys[mode]->enc.key = keys[ctos ? 2 : 3];
488: current_keys[mode]->mac.key = keys[ctos ? 4 : 5];
1.1 markus 489: }
1.27 markus 490: }
491:
492: Newkeys *
493: kex_get_newkeys(int mode)
494: {
1.30 markus 495: Newkeys *ret;
496:
497: ret = current_keys[mode];
498: current_keys[mode] = NULL;
499: return ret;
1.57 djm 500: }
501:
502: void
503: derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus,
504: u_int8_t cookie[8], u_int8_t id[16])
505: {
506: const EVP_MD *evp_md = EVP_md5();
507: EVP_MD_CTX md;
508: u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE];
509: int len;
510:
511: EVP_DigestInit(&md, evp_md);
512:
513: len = BN_num_bytes(host_modulus);
1.61 djm 514: if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
1.57 djm 515: fatal("%s: bad host modulus (len %d)", __func__, len);
516: BN_bn2bin(host_modulus, nbuf);
517: EVP_DigestUpdate(&md, nbuf, len);
518:
519: len = BN_num_bytes(server_modulus);
1.61 djm 520: if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
1.57 djm 521: fatal("%s: bad server modulus (len %d)", __func__, len);
522: BN_bn2bin(server_modulus, nbuf);
523: EVP_DigestUpdate(&md, nbuf, len);
524:
525: EVP_DigestUpdate(&md, cookie, 8);
526:
1.58 djm 527: EVP_DigestFinal(&md, obuf, NULL);
1.57 djm 528: memcpy(id, obuf, 16);
529:
530: memset(nbuf, 0, sizeof(nbuf));
531: memset(obuf, 0, sizeof(obuf));
532: memset(&md, 0, sizeof(md));
1.1 markus 533: }
1.26 markus 534:
535: #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
536: void
537: dump_digest(char *msg, u_char *digest, int len)
538: {
1.61 djm 539: u_int i;
1.26 markus 540:
541: fprintf(stderr, "%s\n", msg);
1.37 deraadt 542: for (i = 0; i< len; i++) {
1.26 markus 543: fprintf(stderr, "%02x", digest[i]);
544: if (i%32 == 31)
545: fprintf(stderr, "\n");
546: else if (i%8 == 7)
547: fprintf(stderr, " ");
548: }
549: fprintf(stderr, "\n");
550: }
551: #endif
![[BACK]](/icons/back.gif){kind=icon}
Return to kex.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh