kex.c revision 181111
1181111Sdes/* $OpenBSD: kex.c,v 1.79 2007/06/05 06:52:37 djm Exp $ */ 260573Skris/* 392555Sdes * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 460573Skris * 560573Skris * Redistribution and use in source and binary forms, with or without 660573Skris * modification, are permitted provided that the following conditions 760573Skris * are met: 860573Skris * 1. Redistributions of source code must retain the above copyright 960573Skris * notice, this list of conditions and the following disclaimer. 1060573Skris * 2. Redistributions in binary form must reproduce the above copyright 1160573Skris * notice, this list of conditions and the following disclaimer in the 1260573Skris * documentation and/or other materials provided with the distribution. 1360573Skris * 1460573Skris * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1560573Skris * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1660573Skris * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1760573Skris * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1860573Skris * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1960573Skris * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2060573Skris * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2160573Skris * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2260573Skris * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2360573Skris * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2460573Skris */ 2560573Skris 2660573Skris#include "includes.h" 2760573Skris 28162852Sdes#include <sys/param.h> 29162852Sdes 30162852Sdes#include <signal.h> 31162852Sdes#include <stdarg.h> 32162852Sdes#include <stdio.h> 33162852Sdes#include <stdlib.h> 34162852Sdes#include <string.h> 35162852Sdes 3676259Sgreen#include <openssl/crypto.h> 3776259Sgreen 38162852Sdes#include "xmalloc.h" 3960573Skris#include "ssh2.h" 4060573Skris#include "buffer.h" 4161209Skris#include "packet.h" 4260573Skris#include "compat.h" 4376259Sgreen#include "cipher.h" 44162852Sdes#include "key.h" 4560573Skris#include "kex.h" 4676259Sgreen#include "log.h" 4776259Sgreen#include "mac.h" 4876259Sgreen#include "match.h" 4976259Sgreen#include "dispatch.h" 5098675Sdes#include "monitor.h" 5160573Skris 5261209Skris#define KEX_COOKIE_LEN 16 5361209Skris 54162852Sdes#if OPENSSL_VERSION_NUMBER >= 0x00907000L 55162852Sdes# if defined(HAVE_EVP_SHA256) 56162852Sdes# define evp_ssh_sha256 EVP_sha256 57162852Sdes# else 58162852Sdesextern const EVP_MD *evp_ssh_sha256(void); 59162852Sdes# endif 60162852Sdes#endif 61162852Sdes 6292555Sdes/* prototype */ 6392555Sdesstatic void kex_kexinit_finish(Kex *); 6492555Sdesstatic void kex_choose_conf(Kex *); 6576259Sgreen 6676259Sgreen/* put algorithm proposal into buffer */ 6792555Sdesstatic void 6876259Sgreenkex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX]) 6960573Skris{ 70149749Sdes u_int i; 7176259Sgreen 7276259Sgreen buffer_clear(b); 7398675Sdes /* 7498675Sdes * add a dummy cookie, the cookie will be overwritten by 7598675Sdes * kex_send_kexinit(), each time a kexinit is set 7698675Sdes */ 7798675Sdes for (i = 0; i < KEX_COOKIE_LEN; i++) 7898675Sdes buffer_put_char(b, 0); 7960573Skris for (i = 0; i < PROPOSAL_MAX; i++) 8076259Sgreen buffer_put_cstring(b, proposal[i]); 8176259Sgreen buffer_put_char(b, 0); /* first_kex_packet_follows */ 8276259Sgreen buffer_put_int(b, 0); /* uint32 reserved */ 8360573Skris} 8460573Skris 8576259Sgreen/* parse buffer and return algorithm proposal */ 8692555Sdesstatic char ** 87113908Sdeskex_buf2prop(Buffer *raw, int *first_kex_follows) 8861209Skris{ 8976259Sgreen Buffer b; 90181111Sdes u_int i; 9176259Sgreen char **proposal; 9261209Skris 93162852Sdes proposal = xcalloc(PROPOSAL_MAX, sizeof(char *)); 9461209Skris 9576259Sgreen buffer_init(&b); 9676259Sgreen buffer_append(&b, buffer_ptr(raw), buffer_len(raw)); 9761209Skris /* skip cookie */ 9861209Skris for (i = 0; i < KEX_COOKIE_LEN; i++) 9976259Sgreen buffer_get_char(&b); 10061209Skris /* extract kex init proposal strings */ 10161209Skris for (i = 0; i < PROPOSAL_MAX; i++) { 10276259Sgreen proposal[i] = buffer_get_string(&b,NULL); 10376259Sgreen debug2("kex_parse_kexinit: %s", proposal[i]); 10461209Skris } 10576259Sgreen /* first kex follows / reserved */ 10676259Sgreen i = buffer_get_char(&b); 107113908Sdes if (first_kex_follows != NULL) 108113908Sdes *first_kex_follows = i; 10976259Sgreen debug2("kex_parse_kexinit: first_kex_follows %d ", i); 11076259Sgreen i = buffer_get_int(&b); 111181111Sdes debug2("kex_parse_kexinit: reserved %u ", i); 11276259Sgreen buffer_free(&b); 11376259Sgreen return proposal; 11461209Skris} 11561209Skris 11692555Sdesstatic void 11776259Sgreenkex_prop_free(char **proposal) 11860573Skris{ 119149749Sdes u_int i; 12060573Skris 12176259Sgreen for (i = 0; i < PROPOSAL_MAX; i++) 12276259Sgreen xfree(proposal[i]); 12376259Sgreen xfree(proposal); 12460573Skris} 12560573Skris 126181111Sdes/* ARGSUSED */ 12792555Sdesstatic void 12892555Sdeskex_protocol_error(int type, u_int32_t seq, void *ctxt) 12960573Skris{ 13092555Sdes error("Hm, kex protocol error: type %d seq %u", type, seq); 13160573Skris} 13260573Skris 13392555Sdesstatic void 13492555Sdeskex_reset_dispatch(void) 13569587Sgreen{ 13692555Sdes dispatch_range(SSH2_MSG_TRANSPORT_MIN, 13792555Sdes SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error); 13892555Sdes dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); 13969587Sgreen} 14069587Sgreen 14176259Sgreenvoid 14276259Sgreenkex_finish(Kex *kex) 14369587Sgreen{ 14492555Sdes kex_reset_dispatch(); 14569587Sgreen 14676259Sgreen packet_start(SSH2_MSG_NEWKEYS); 14776259Sgreen packet_send(); 14876259Sgreen /* packet_write_wait(); */ 14976259Sgreen debug("SSH2_MSG_NEWKEYS sent"); 15069587Sgreen 151113908Sdes debug("expecting SSH2_MSG_NEWKEYS"); 15292555Sdes packet_read_expect(SSH2_MSG_NEWKEYS); 15392555Sdes packet_check_eom(); 15476259Sgreen debug("SSH2_MSG_NEWKEYS received"); 15569587Sgreen 15676259Sgreen kex->done = 1; 15776259Sgreen buffer_clear(&kex->peer); 15876259Sgreen /* buffer_clear(&kex->my); */ 15976259Sgreen kex->flags &= ~KEX_INIT_SENT; 16076259Sgreen xfree(kex->name); 16176259Sgreen kex->name = NULL; 16269587Sgreen} 16369587Sgreen 16460573Skrisvoid 16576259Sgreenkex_send_kexinit(Kex *kex) 16660573Skris{ 167137015Sdes u_int32_t rnd = 0; 16898675Sdes u_char *cookie; 169149749Sdes u_int i; 17098675Sdes 17176259Sgreen if (kex == NULL) { 17276259Sgreen error("kex_send_kexinit: no kex, cannot rekey"); 17376259Sgreen return; 17460573Skris } 17576259Sgreen if (kex->flags & KEX_INIT_SENT) { 17676259Sgreen debug("KEX_INIT_SENT"); 17776259Sgreen return; 17876259Sgreen } 17976259Sgreen kex->done = 0; 18098675Sdes 18198675Sdes /* generate a random cookie */ 18298675Sdes if (buffer_len(&kex->my) < KEX_COOKIE_LEN) 18398675Sdes fatal("kex_send_kexinit: kex proposal too short"); 18498675Sdes cookie = buffer_ptr(&kex->my); 18598675Sdes for (i = 0; i < KEX_COOKIE_LEN; i++) { 18698675Sdes if (i % 4 == 0) 187137015Sdes rnd = arc4random(); 188137015Sdes cookie[i] = rnd; 189137015Sdes rnd >>= 8; 19098675Sdes } 19176259Sgreen packet_start(SSH2_MSG_KEXINIT); 19276259Sgreen packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my)); 19376259Sgreen packet_send(); 19476259Sgreen debug("SSH2_MSG_KEXINIT sent"); 19576259Sgreen kex->flags |= KEX_INIT_SENT; 19660573Skris} 19760573Skris 198181111Sdes/* ARGSUSED */ 19976259Sgreenvoid 20092555Sdeskex_input_kexinit(int type, u_int32_t seq, void *ctxt) 20160573Skris{ 20276259Sgreen char *ptr; 203149749Sdes u_int i, dlen; 20476259Sgreen Kex *kex = (Kex *)ctxt; 20560573Skris 20676259Sgreen debug("SSH2_MSG_KEXINIT received"); 20776259Sgreen if (kex == NULL) 20876259Sgreen fatal("kex_input_kexinit: no kex, cannot rekey"); 20960573Skris 21076259Sgreen ptr = packet_get_raw(&dlen); 21176259Sgreen buffer_append(&kex->peer, ptr, dlen); 21260573Skris 21376259Sgreen /* discard packet */ 21476259Sgreen for (i = 0; i < KEX_COOKIE_LEN; i++) 21576259Sgreen packet_get_char(); 21676259Sgreen for (i = 0; i < PROPOSAL_MAX; i++) 21776259Sgreen xfree(packet_get_string(NULL)); 21899060Sdes (void) packet_get_char(); 21999060Sdes (void) packet_get_int(); 22092555Sdes packet_check_eom(); 22160573Skris 22276259Sgreen kex_kexinit_finish(kex); 22360573Skris} 22460573Skris 22576259SgreenKex * 22676259Sgreenkex_setup(char *proposal[PROPOSAL_MAX]) 22769587Sgreen{ 22876259Sgreen Kex *kex; 22969587Sgreen 230162852Sdes kex = xcalloc(1, sizeof(*kex)); 23176259Sgreen buffer_init(&kex->peer); 23276259Sgreen buffer_init(&kex->my); 23376259Sgreen kex_prop2buf(&kex->my, proposal); 23476259Sgreen kex->done = 0; 23569587Sgreen 23676259Sgreen kex_send_kexinit(kex); /* we start */ 23792555Sdes kex_reset_dispatch(); 23869587Sgreen 23976259Sgreen return kex; 24069587Sgreen} 24169587Sgreen 24292555Sdesstatic void 24376259Sgreenkex_kexinit_finish(Kex *kex) 24460573Skris{ 24576259Sgreen if (!(kex->flags & KEX_INIT_SENT)) 24676259Sgreen kex_send_kexinit(kex); 24760573Skris 24876259Sgreen kex_choose_conf(kex); 24960573Skris 250113908Sdes if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX && 251113908Sdes kex->kex[kex->kex_type] != NULL) { 252113908Sdes (kex->kex[kex->kex_type])(kex); 253113908Sdes } else { 25476259Sgreen fatal("Unsupported key exchange %d", kex->kex_type); 25560573Skris } 25660573Skris} 25760573Skris 25892555Sdesstatic void 25960573Skrischoose_enc(Enc *enc, char *client, char *server) 26060573Skris{ 26176259Sgreen char *name = match_list(client, server, NULL); 26260573Skris if (name == NULL) 263181111Sdes fatal("no matching cipher found: client %s server %s", 264181111Sdes client, server); 26592555Sdes if ((enc->cipher = cipher_by_name(name)) == NULL) 26669587Sgreen fatal("matching cipher is not supported: %s", name); 26760573Skris enc->name = name; 26860573Skris enc->enabled = 0; 26960573Skris enc->iv = NULL; 27060573Skris enc->key = NULL; 27192555Sdes enc->key_len = cipher_keylen(enc->cipher); 27292555Sdes enc->block_size = cipher_blocksize(enc->cipher); 27360573Skris} 274162852Sdes 27592555Sdesstatic void 27660573Skrischoose_mac(Mac *mac, char *client, char *server) 27760573Skris{ 27876259Sgreen char *name = match_list(client, server, NULL); 27960573Skris if (name == NULL) 280181111Sdes fatal("no matching mac found: client %s server %s", 281181111Sdes client, server); 282181111Sdes if (mac_setup(mac, name) < 0) 28360573Skris fatal("unsupported mac %s", name); 28476259Sgreen /* truncate the key */ 28576259Sgreen if (datafellows & SSH_BUG_HMAC) 28676259Sgreen mac->key_len = 16; 28760573Skris mac->name = name; 28860573Skris mac->key = NULL; 28960573Skris mac->enabled = 0; 29060573Skris} 291162852Sdes 29292555Sdesstatic void 29360573Skrischoose_comp(Comp *comp, char *client, char *server) 29460573Skris{ 29576259Sgreen char *name = match_list(client, server, NULL); 29660573Skris if (name == NULL) 29760573Skris fatal("no matching comp found: client %s server %s", client, server); 298149749Sdes if (strcmp(name, "zlib@openssh.com") == 0) { 299149749Sdes comp->type = COMP_DELAYED; 300149749Sdes } else if (strcmp(name, "zlib") == 0) { 301149749Sdes comp->type = COMP_ZLIB; 30260573Skris } else if (strcmp(name, "none") == 0) { 303149749Sdes comp->type = COMP_NONE; 30460573Skris } else { 30560573Skris fatal("unsupported comp %s", name); 30660573Skris } 30760573Skris comp->name = name; 30860573Skris} 309162852Sdes 31092555Sdesstatic void 31160573Skrischoose_kex(Kex *k, char *client, char *server) 31260573Skris{ 31376259Sgreen k->name = match_list(client, server, NULL); 31460573Skris if (k->name == NULL) 315181111Sdes fatal("Unable to negotiate a key exchange method"); 31669587Sgreen if (strcmp(k->name, KEX_DH1) == 0) { 317113908Sdes k->kex_type = KEX_DH_GRP1_SHA1; 318157016Sdes k->evp_md = EVP_sha1(); 319137015Sdes } else if (strcmp(k->name, KEX_DH14) == 0) { 320137015Sdes k->kex_type = KEX_DH_GRP14_SHA1; 321157016Sdes k->evp_md = EVP_sha1(); 322157016Sdes } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) { 323113908Sdes k->kex_type = KEX_DH_GEX_SHA1; 324157016Sdes k->evp_md = EVP_sha1(); 325162852Sdes#if OPENSSL_VERSION_NUMBER >= 0x00907000L 326162852Sdes } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) { 327162852Sdes k->kex_type = KEX_DH_GEX_SHA256; 328162852Sdes k->evp_md = evp_ssh_sha256(); 329162852Sdes#endif 33069587Sgreen } else 33160573Skris fatal("bad kex alg %s", k->name); 33260573Skris} 333157016Sdes 33492555Sdesstatic void 33560573Skrischoose_hostkeyalg(Kex *k, char *client, char *server) 33660573Skris{ 33776259Sgreen char *hostkeyalg = match_list(client, server, NULL); 33876259Sgreen if (hostkeyalg == NULL) 33960573Skris fatal("no hostkey alg"); 34076259Sgreen k->hostkey_type = key_type_from_name(hostkeyalg); 34176259Sgreen if (k->hostkey_type == KEY_UNSPEC) 34276259Sgreen fatal("bad hostkey alg '%s'", hostkeyalg); 34376259Sgreen xfree(hostkeyalg); 34460573Skris} 34560573Skris 346126274Sdesstatic int 347113908Sdesproposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX]) 348113908Sdes{ 349113908Sdes static int check[] = { 350113908Sdes PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1 351113908Sdes }; 352113908Sdes int *idx; 353113908Sdes char *p; 354113908Sdes 355113908Sdes for (idx = &check[0]; *idx != -1; idx++) { 356113908Sdes if ((p = strchr(my[*idx], ',')) != NULL) 357113908Sdes *p = '\0'; 358113908Sdes if ((p = strchr(peer[*idx], ',')) != NULL) 359113908Sdes *p = '\0'; 360113908Sdes if (strcmp(my[*idx], peer[*idx]) != 0) { 361113908Sdes debug2("proposal mismatch: my %s peer %s", 362113908Sdes my[*idx], peer[*idx]); 363113908Sdes return (0); 364113908Sdes } 365113908Sdes } 366113908Sdes debug2("proposals match"); 367113908Sdes return (1); 368113908Sdes} 369113908Sdes 37092555Sdesstatic void 37176259Sgreenkex_choose_conf(Kex *kex) 37260573Skris{ 37376259Sgreen Newkeys *newkeys; 37476259Sgreen char **my, **peer; 37576259Sgreen char **cprop, **sprop; 37676259Sgreen int nenc, nmac, ncomp; 377149749Sdes u_int mode, ctos, need; 378113908Sdes int first_kex_follows, type; 37960573Skris 380113908Sdes my = kex_buf2prop(&kex->my, NULL); 381113908Sdes peer = kex_buf2prop(&kex->peer, &first_kex_follows); 38260573Skris 38376259Sgreen if (kex->server) { 38476259Sgreen cprop=peer; 38576259Sgreen sprop=my; 38676259Sgreen } else { 38776259Sgreen cprop=my; 38876259Sgreen sprop=peer; 38976259Sgreen } 39076259Sgreen 39176259Sgreen /* Algorithm Negotiation */ 39260573Skris for (mode = 0; mode < MODE_MAX; mode++) { 393162852Sdes newkeys = xcalloc(1, sizeof(*newkeys)); 39476259Sgreen kex->newkeys[mode] = newkeys; 395181111Sdes ctos = (!kex->server && mode == MODE_OUT) || 396181111Sdes (kex->server && mode == MODE_IN); 39760573Skris nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC; 39860573Skris nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC; 39960573Skris ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC; 40076259Sgreen choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]); 40176259Sgreen choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]); 40276259Sgreen choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]); 40360573Skris debug("kex: %s %s %s %s", 40460573Skris ctos ? "client->server" : "server->client", 40576259Sgreen newkeys->enc.name, 40676259Sgreen newkeys->mac.name, 40776259Sgreen newkeys->comp.name); 40860573Skris } 40976259Sgreen choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]); 41076259Sgreen choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS], 41160573Skris sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]); 41260573Skris need = 0; 41360573Skris for (mode = 0; mode < MODE_MAX; mode++) { 41476259Sgreen newkeys = kex->newkeys[mode]; 41592555Sdes if (need < newkeys->enc.key_len) 41692555Sdes need = newkeys->enc.key_len; 41792555Sdes if (need < newkeys->enc.block_size) 41892555Sdes need = newkeys->enc.block_size; 41976259Sgreen if (need < newkeys->mac.key_len) 42076259Sgreen need = newkeys->mac.key_len; 42160573Skris } 42261209Skris /* XXX need runden? */ 42376259Sgreen kex->we_need = need; 42476259Sgreen 425113908Sdes /* ignore the next message if the proposals do not match */ 426126274Sdes if (first_kex_follows && !proposals_match(my, peer) && 427149749Sdes !(datafellows & SSH_BUG_FIRSTKEX)) { 428113908Sdes type = packet_read(); 429113908Sdes debug2("skipping next packet (type %u)", type); 430113908Sdes } 431113908Sdes 43276259Sgreen kex_prop_free(my); 43376259Sgreen kex_prop_free(peer); 43460573Skris} 43560573Skris 43692555Sdesstatic u_char * 437157016Sdesderive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen, 438157016Sdes BIGNUM *shared_secret) 43960573Skris{ 44076259Sgreen Buffer b; 44176259Sgreen EVP_MD_CTX md; 44276259Sgreen char c = id; 443149749Sdes u_int have; 444157016Sdes int mdsz; 445149749Sdes u_char *digest; 44660573Skris 447157016Sdes if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0) 448157016Sdes fatal("bad kex md size %d", mdsz); 449162852Sdes digest = xmalloc(roundup(need, mdsz)); 450149749Sdes 45176259Sgreen buffer_init(&b); 45276259Sgreen buffer_put_bignum2(&b, shared_secret); 45376259Sgreen 45476259Sgreen /* K1 = HASH(K || H || "A" || session_id) */ 455157016Sdes EVP_DigestInit(&md, kex->evp_md); 45692555Sdes if (!(datafellows & SSH_BUG_DERIVEKEY)) 45792555Sdes EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 458157016Sdes EVP_DigestUpdate(&md, hash, hashlen); 45976259Sgreen EVP_DigestUpdate(&md, &c, 1); 46076259Sgreen EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len); 46176259Sgreen EVP_DigestFinal(&md, digest, NULL); 46276259Sgreen 46376259Sgreen /* 46476259Sgreen * expand key: 46576259Sgreen * Kn = HASH(K || H || K1 || K2 || ... || Kn-1) 46676259Sgreen * Key = K1 || K2 || ... || Kn 46776259Sgreen */ 46876259Sgreen for (have = mdsz; need > have; have += mdsz) { 469157016Sdes EVP_DigestInit(&md, kex->evp_md); 47092555Sdes if (!(datafellows & SSH_BUG_DERIVEKEY)) 47192555Sdes EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); 472157016Sdes EVP_DigestUpdate(&md, hash, hashlen); 47376259Sgreen EVP_DigestUpdate(&md, digest, have); 47476259Sgreen EVP_DigestFinal(&md, digest + have, NULL); 47576259Sgreen } 47676259Sgreen buffer_free(&b); 47776259Sgreen#ifdef DEBUG_KEX 47876259Sgreen fprintf(stderr, "key '%c'== ", c); 47976259Sgreen dump_digest("key", digest, need); 48076259Sgreen#endif 48176259Sgreen return digest; 48276259Sgreen} 48376259Sgreen 48476259SgreenNewkeys *current_keys[MODE_MAX]; 48576259Sgreen 48676259Sgreen#define NKEYS 6 48776259Sgreenvoid 488157016Sdeskex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret) 48976259Sgreen{ 49076259Sgreen u_char *keys[NKEYS]; 491149749Sdes u_int i, mode, ctos; 49276259Sgreen 493157016Sdes for (i = 0; i < NKEYS; i++) { 494157016Sdes keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen, 495157016Sdes shared_secret); 496157016Sdes } 49760573Skris 498113908Sdes debug2("kex_derive_keys"); 49960573Skris for (mode = 0; mode < MODE_MAX; mode++) { 50076259Sgreen current_keys[mode] = kex->newkeys[mode]; 50176259Sgreen kex->newkeys[mode] = NULL; 502162852Sdes ctos = (!kex->server && mode == MODE_OUT) || 503162852Sdes (kex->server && mode == MODE_IN); 50476259Sgreen current_keys[mode]->enc.iv = keys[ctos ? 0 : 1]; 50576259Sgreen current_keys[mode]->enc.key = keys[ctos ? 2 : 3]; 50676259Sgreen current_keys[mode]->mac.key = keys[ctos ? 4 : 5]; 50760573Skris } 50860573Skris} 50976259Sgreen 51076259SgreenNewkeys * 51176259Sgreenkex_get_newkeys(int mode) 51276259Sgreen{ 51376259Sgreen Newkeys *ret; 51476259Sgreen 51576259Sgreen ret = current_keys[mode]; 51676259Sgreen current_keys[mode] = NULL; 51776259Sgreen return ret; 51876259Sgreen} 51976259Sgreen 520137015Sdesvoid 521137015Sdesderive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus, 522137015Sdes u_int8_t cookie[8], u_int8_t id[16]) 523137015Sdes{ 524137015Sdes const EVP_MD *evp_md = EVP_md5(); 525137015Sdes EVP_MD_CTX md; 526137015Sdes u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE]; 527137015Sdes int len; 528137015Sdes 529137015Sdes EVP_DigestInit(&md, evp_md); 530137015Sdes 531137015Sdes len = BN_num_bytes(host_modulus); 532149749Sdes if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) 533137015Sdes fatal("%s: bad host modulus (len %d)", __func__, len); 534137015Sdes BN_bn2bin(host_modulus, nbuf); 535137015Sdes EVP_DigestUpdate(&md, nbuf, len); 536137015Sdes 537137015Sdes len = BN_num_bytes(server_modulus); 538149749Sdes if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) 539137015Sdes fatal("%s: bad server modulus (len %d)", __func__, len); 540137015Sdes BN_bn2bin(server_modulus, nbuf); 541137015Sdes EVP_DigestUpdate(&md, nbuf, len); 542137015Sdes 543137015Sdes EVP_DigestUpdate(&md, cookie, 8); 544137015Sdes 545137015Sdes EVP_DigestFinal(&md, obuf, NULL); 546137015Sdes memcpy(id, obuf, 16); 547137015Sdes 548137015Sdes memset(nbuf, 0, sizeof(nbuf)); 549137015Sdes memset(obuf, 0, sizeof(obuf)); 550137015Sdes memset(&md, 0, sizeof(md)); 551137015Sdes} 552137015Sdes 55376259Sgreen#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) 55476259Sgreenvoid 55576259Sgreendump_digest(char *msg, u_char *digest, int len) 55676259Sgreen{ 557149749Sdes u_int i; 55876259Sgreen 55976259Sgreen fprintf(stderr, "%s\n", msg); 560181111Sdes for (i = 0; i < len; i++) { 56176259Sgreen fprintf(stderr, "%02x", digest[i]); 56276259Sgreen if (i%32 == 31) 56376259Sgreen fprintf(stderr, "\n"); 56476259Sgreen else if (i%8 == 7) 56576259Sgreen fprintf(stderr, " "); 56676259Sgreen } 56776259Sgreen fprintf(stderr, "\n"); 56876259Sgreen} 56976259Sgreen#endif 570