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-rw-r--r--crypto/openssh/kex.c564
1 files changed, 0 insertions, 564 deletions
diff --git a/crypto/openssh/kex.c b/crypto/openssh/kex.c
deleted file mode 100644
index bfc1c11..0000000
--- a/crypto/openssh/kex.c
+++ /dev/null
@@ -1,564 +0,0 @@
-/* $OpenBSD: kex.c,v 1.76 2006/08/03 03:34:42 deraadt Exp $ */
-/*
- * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "includes.h"
-
-#include <sys/param.h>
-
-#include <signal.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <openssl/crypto.h>
-
-#include "xmalloc.h"
-#include "ssh2.h"
-#include "buffer.h"
-#include "packet.h"
-#include "compat.h"
-#include "cipher.h"
-#include "key.h"
-#include "kex.h"
-#include "log.h"
-#include "mac.h"
-#include "match.h"
-#include "dispatch.h"
-#include "monitor.h"
-
-#define KEX_COOKIE_LEN 16
-
-#if OPENSSL_VERSION_NUMBER >= 0x00907000L
-# if defined(HAVE_EVP_SHA256)
-# define evp_ssh_sha256 EVP_sha256
-# else
-extern const EVP_MD *evp_ssh_sha256(void);
-# endif
-#endif
-
-/* prototype */
-static void kex_kexinit_finish(Kex *);
-static void kex_choose_conf(Kex *);
-
-/* put algorithm proposal into buffer */
-static void
-kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX])
-{
- u_int i;
-
- buffer_clear(b);
- /*
- * add a dummy cookie, the cookie will be overwritten by
- * kex_send_kexinit(), each time a kexinit is set
- */
- for (i = 0; i < KEX_COOKIE_LEN; i++)
- buffer_put_char(b, 0);
- for (i = 0; i < PROPOSAL_MAX; i++)
- buffer_put_cstring(b, proposal[i]);
- buffer_put_char(b, 0); /* first_kex_packet_follows */
- buffer_put_int(b, 0); /* uint32 reserved */
-}
-
-/* parse buffer and return algorithm proposal */
-static char **
-kex_buf2prop(Buffer *raw, int *first_kex_follows)
-{
- Buffer b;
- int i;
- char **proposal;
-
- proposal = xcalloc(PROPOSAL_MAX, sizeof(char *));
-
- buffer_init(&b);
- buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
- /* skip cookie */
- for (i = 0; i < KEX_COOKIE_LEN; i++)
- buffer_get_char(&b);
- /* extract kex init proposal strings */
- for (i = 0; i < PROPOSAL_MAX; i++) {
- proposal[i] = buffer_get_string(&b,NULL);
- debug2("kex_parse_kexinit: %s", proposal[i]);
- }
- /* first kex follows / reserved */
- i = buffer_get_char(&b);
- if (first_kex_follows != NULL)
- *first_kex_follows = i;
- debug2("kex_parse_kexinit: first_kex_follows %d ", i);
- i = buffer_get_int(&b);
- debug2("kex_parse_kexinit: reserved %d ", i);
- buffer_free(&b);
- return proposal;
-}
-
-static void
-kex_prop_free(char **proposal)
-{
- u_int i;
-
- for (i = 0; i < PROPOSAL_MAX; i++)
- xfree(proposal[i]);
- xfree(proposal);
-}
-
-static void
-kex_protocol_error(int type, u_int32_t seq, void *ctxt)
-{
- error("Hm, kex protocol error: type %d seq %u", type, seq);
-}
-
-static void
-kex_reset_dispatch(void)
-{
- dispatch_range(SSH2_MSG_TRANSPORT_MIN,
- SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error);
- dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
-}
-
-void
-kex_finish(Kex *kex)
-{
- kex_reset_dispatch();
-
- packet_start(SSH2_MSG_NEWKEYS);
- packet_send();
- /* packet_write_wait(); */
- debug("SSH2_MSG_NEWKEYS sent");
-
- debug("expecting SSH2_MSG_NEWKEYS");
- packet_read_expect(SSH2_MSG_NEWKEYS);
- packet_check_eom();
- debug("SSH2_MSG_NEWKEYS received");
-
- kex->done = 1;
- buffer_clear(&kex->peer);
- /* buffer_clear(&kex->my); */
- kex->flags &= ~KEX_INIT_SENT;
- xfree(kex->name);
- kex->name = NULL;
-}
-
-void
-kex_send_kexinit(Kex *kex)
-{
- u_int32_t rnd = 0;
- u_char *cookie;
- u_int i;
-
- if (kex == NULL) {
- error("kex_send_kexinit: no kex, cannot rekey");
- return;
- }
- if (kex->flags & KEX_INIT_SENT) {
- debug("KEX_INIT_SENT");
- return;
- }
- kex->done = 0;
-
- /* generate a random cookie */
- if (buffer_len(&kex->my) < KEX_COOKIE_LEN)
- fatal("kex_send_kexinit: kex proposal too short");
- cookie = buffer_ptr(&kex->my);
- for (i = 0; i < KEX_COOKIE_LEN; i++) {
- if (i % 4 == 0)
- rnd = arc4random();
- cookie[i] = rnd;
- rnd >>= 8;
- }
- packet_start(SSH2_MSG_KEXINIT);
- packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my));
- packet_send();
- debug("SSH2_MSG_KEXINIT sent");
- kex->flags |= KEX_INIT_SENT;
-}
-
-void
-kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
-{
- char *ptr;
- u_int i, dlen;
- Kex *kex = (Kex *)ctxt;
-
- debug("SSH2_MSG_KEXINIT received");
- if (kex == NULL)
- fatal("kex_input_kexinit: no kex, cannot rekey");
-
- ptr = packet_get_raw(&dlen);
- buffer_append(&kex->peer, ptr, dlen);
-
- /* discard packet */
- for (i = 0; i < KEX_COOKIE_LEN; i++)
- packet_get_char();
- for (i = 0; i < PROPOSAL_MAX; i++)
- xfree(packet_get_string(NULL));
- (void) packet_get_char();
- (void) packet_get_int();
- packet_check_eom();
-
- kex_kexinit_finish(kex);
-}
-
-Kex *
-kex_setup(char *proposal[PROPOSAL_MAX])
-{
- Kex *kex;
-
- kex = xcalloc(1, sizeof(*kex));
- buffer_init(&kex->peer);
- buffer_init(&kex->my);
- kex_prop2buf(&kex->my, proposal);
- kex->done = 0;
-
- kex_send_kexinit(kex); /* we start */
- kex_reset_dispatch();
-
- return kex;
-}
-
-static void
-kex_kexinit_finish(Kex *kex)
-{
- if (!(kex->flags & KEX_INIT_SENT))
- kex_send_kexinit(kex);
-
- kex_choose_conf(kex);
-
- if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX &&
- kex->kex[kex->kex_type] != NULL) {
- (kex->kex[kex->kex_type])(kex);
- } else {
- fatal("Unsupported key exchange %d", kex->kex_type);
- }
-}
-
-static void
-choose_enc(Enc *enc, char *client, char *server)
-{
- char *name = match_list(client, server, NULL);
- if (name == NULL)
- fatal("no matching cipher found: client %s server %s", client, server);
- if ((enc->cipher = cipher_by_name(name)) == NULL)
- fatal("matching cipher is not supported: %s", name);
- enc->name = name;
- enc->enabled = 0;
- enc->iv = NULL;
- enc->key = NULL;
- enc->key_len = cipher_keylen(enc->cipher);
- enc->block_size = cipher_blocksize(enc->cipher);
-}
-
-static void
-choose_mac(Mac *mac, char *client, char *server)
-{
- char *name = match_list(client, server, NULL);
- if (name == NULL)
- fatal("no matching mac found: client %s server %s", client, server);
- if (mac_init(mac, name) < 0)
- fatal("unsupported mac %s", name);
- /* truncate the key */
- if (datafellows & SSH_BUG_HMAC)
- mac->key_len = 16;
- mac->name = name;
- mac->key = NULL;
- mac->enabled = 0;
-}
-
-static void
-choose_comp(Comp *comp, char *client, char *server)
-{
- char *name = match_list(client, server, NULL);
- if (name == NULL)
- fatal("no matching comp found: client %s server %s", client, server);
- if (strcmp(name, "zlib@openssh.com") == 0) {
- comp->type = COMP_DELAYED;
- } else if (strcmp(name, "zlib") == 0) {
- comp->type = COMP_ZLIB;
- } else if (strcmp(name, "none") == 0) {
- comp->type = COMP_NONE;
- } else {
- fatal("unsupported comp %s", name);
- }
- comp->name = name;
-}
-
-static void
-choose_kex(Kex *k, char *client, char *server)
-{
- k->name = match_list(client, server, NULL);
- if (k->name == NULL)
- fatal("no kex alg");
- if (strcmp(k->name, KEX_DH1) == 0) {
- k->kex_type = KEX_DH_GRP1_SHA1;
- k->evp_md = EVP_sha1();
- } else if (strcmp(k->name, KEX_DH14) == 0) {
- k->kex_type = KEX_DH_GRP14_SHA1;
- k->evp_md = EVP_sha1();
- } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) {
- k->kex_type = KEX_DH_GEX_SHA1;
- k->evp_md = EVP_sha1();
-#if OPENSSL_VERSION_NUMBER >= 0x00907000L
- } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) {
- k->kex_type = KEX_DH_GEX_SHA256;
- k->evp_md = evp_ssh_sha256();
-#endif
- } else
- fatal("bad kex alg %s", k->name);
-}
-
-static void
-choose_hostkeyalg(Kex *k, char *client, char *server)
-{
- char *hostkeyalg = match_list(client, server, NULL);
- if (hostkeyalg == NULL)
- fatal("no hostkey alg");
- k->hostkey_type = key_type_from_name(hostkeyalg);
- if (k->hostkey_type == KEY_UNSPEC)
- fatal("bad hostkey alg '%s'", hostkeyalg);
- xfree(hostkeyalg);
-}
-
-static int
-proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX])
-{
- static int check[] = {
- PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1
- };
- int *idx;
- char *p;
-
- for (idx = &check[0]; *idx != -1; idx++) {
- if ((p = strchr(my[*idx], ',')) != NULL)
- *p = '\0';
- if ((p = strchr(peer[*idx], ',')) != NULL)
- *p = '\0';
- if (strcmp(my[*idx], peer[*idx]) != 0) {
- debug2("proposal mismatch: my %s peer %s",
- my[*idx], peer[*idx]);
- return (0);
- }
- }
- debug2("proposals match");
- return (1);
-}
-
-static void
-kex_choose_conf(Kex *kex)
-{
- Newkeys *newkeys;
- char **my, **peer;
- char **cprop, **sprop;
- int nenc, nmac, ncomp;
- u_int mode, ctos, need;
- int first_kex_follows, type;
-
- my = kex_buf2prop(&kex->my, NULL);
- peer = kex_buf2prop(&kex->peer, &first_kex_follows);
-
- if (kex->server) {
- cprop=peer;
- sprop=my;
- } else {
- cprop=my;
- sprop=peer;
- }
-
- /* Algorithm Negotiation */
- for (mode = 0; mode < MODE_MAX; mode++) {
- newkeys = xcalloc(1, sizeof(*newkeys));
- kex->newkeys[mode] = newkeys;
- ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
- nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
- nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
- ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
- choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]);
- choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]);
- choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
- debug("kex: %s %s %s %s",
- ctos ? "client->server" : "server->client",
- newkeys->enc.name,
- newkeys->mac.name,
- newkeys->comp.name);
- }
- choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
- choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
- sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
- need = 0;
- for (mode = 0; mode < MODE_MAX; mode++) {
- newkeys = kex->newkeys[mode];
- if (need < newkeys->enc.key_len)
- need = newkeys->enc.key_len;
- if (need < newkeys->enc.block_size)
- need = newkeys->enc.block_size;
- if (need < newkeys->mac.key_len)
- need = newkeys->mac.key_len;
- }
- /* XXX need runden? */
- kex->we_need = need;
-
- /* ignore the next message if the proposals do not match */
- if (first_kex_follows && !proposals_match(my, peer) &&
- !(datafellows & SSH_BUG_FIRSTKEX)) {
- type = packet_read();
- debug2("skipping next packet (type %u)", type);
- }
-
- kex_prop_free(my);
- kex_prop_free(peer);
-}
-
-static u_char *
-derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen,
- BIGNUM *shared_secret)
-{
- Buffer b;
- EVP_MD_CTX md;
- char c = id;
- u_int have;
- int mdsz;
- u_char *digest;
-
- if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0)
- fatal("bad kex md size %d", mdsz);
- digest = xmalloc(roundup(need, mdsz));
-
- buffer_init(&b);
- buffer_put_bignum2(&b, shared_secret);
-
- /* K1 = HASH(K || H || "A" || session_id) */
- EVP_DigestInit(&md, kex->evp_md);
- if (!(datafellows & SSH_BUG_DERIVEKEY))
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestUpdate(&md, hash, hashlen);
- EVP_DigestUpdate(&md, &c, 1);
- EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
- EVP_DigestFinal(&md, digest, NULL);
-
- /*
- * expand key:
- * Kn = HASH(K || H || K1 || K2 || ... || Kn-1)
- * Key = K1 || K2 || ... || Kn
- */
- for (have = mdsz; need > have; have += mdsz) {
- EVP_DigestInit(&md, kex->evp_md);
- if (!(datafellows & SSH_BUG_DERIVEKEY))
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestUpdate(&md, hash, hashlen);
- EVP_DigestUpdate(&md, digest, have);
- EVP_DigestFinal(&md, digest + have, NULL);
- }
- buffer_free(&b);
-#ifdef DEBUG_KEX
- fprintf(stderr, "key '%c'== ", c);
- dump_digest("key", digest, need);
-#endif
- return digest;
-}
-
-Newkeys *current_keys[MODE_MAX];
-
-#define NKEYS 6
-void
-kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret)
-{
- u_char *keys[NKEYS];
- u_int i, mode, ctos;
-
- for (i = 0; i < NKEYS; i++) {
- keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen,
- shared_secret);
- }
-
- debug2("kex_derive_keys");
- for (mode = 0; mode < MODE_MAX; mode++) {
- current_keys[mode] = kex->newkeys[mode];
- kex->newkeys[mode] = NULL;
- ctos = (!kex->server && mode == MODE_OUT) ||
- (kex->server && mode == MODE_IN);
- current_keys[mode]->enc.iv = keys[ctos ? 0 : 1];
- current_keys[mode]->enc.key = keys[ctos ? 2 : 3];
- current_keys[mode]->mac.key = keys[ctos ? 4 : 5];
- }
-}
-
-Newkeys *
-kex_get_newkeys(int mode)
-{
- Newkeys *ret;
-
- ret = current_keys[mode];
- current_keys[mode] = NULL;
- return ret;
-}
-
-void
-derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus,
- u_int8_t cookie[8], u_int8_t id[16])
-{
- const EVP_MD *evp_md = EVP_md5();
- EVP_MD_CTX md;
- u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE];
- int len;
-
- EVP_DigestInit(&md, evp_md);
-
- len = BN_num_bytes(host_modulus);
- if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
- fatal("%s: bad host modulus (len %d)", __func__, len);
- BN_bn2bin(host_modulus, nbuf);
- EVP_DigestUpdate(&md, nbuf, len);
-
- len = BN_num_bytes(server_modulus);
- if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
- fatal("%s: bad server modulus (len %d)", __func__, len);
- BN_bn2bin(server_modulus, nbuf);
- EVP_DigestUpdate(&md, nbuf, len);
-
- EVP_DigestUpdate(&md, cookie, 8);
-
- EVP_DigestFinal(&md, obuf, NULL);
- memcpy(id, obuf, 16);
-
- memset(nbuf, 0, sizeof(nbuf));
- memset(obuf, 0, sizeof(obuf));
- memset(&md, 0, sizeof(md));
-}
-
-#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
-void
-dump_digest(char *msg, u_char *digest, int len)
-{
- u_int i;
-
- fprintf(stderr, "%s\n", msg);
- for (i = 0; i< len; i++) {
- fprintf(stderr, "%02x", digest[i]);
- if (i%32 == 31)
- fprintf(stderr, "\n");
- else if (i%8 == 7)
- fprintf(stderr, " ");
- }
- fprintf(stderr, "\n");
-}
-#endif
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