mirror of git://anongit.mindrot.org/openssh.git
123 lines
4.1 KiB
C
123 lines
4.1 KiB
C
/* $OpenBSD: kexc25519.c,v 1.5 2014/01/31 16:39:19 tedu Exp $ */
|
|
/*
|
|
* Copyright (c) 2001, 2013 Markus Friedl. All rights reserved.
|
|
* Copyright (c) 2010 Damien Miller. All rights reserved.
|
|
* Copyright (c) 2013 Aris Adamantiadis. 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/types.h>
|
|
|
|
#include <signal.h>
|
|
#include <string.h>
|
|
|
|
#include <openssl/bn.h>
|
|
#include <openssl/evp.h>
|
|
|
|
#include "buffer.h"
|
|
#include "ssh2.h"
|
|
#include "key.h"
|
|
#include "cipher.h"
|
|
#include "kex.h"
|
|
#include "log.h"
|
|
#include "digest.h"
|
|
|
|
extern int crypto_scalarmult_curve25519(u_char a[CURVE25519_SIZE],
|
|
const u_char b[CURVE25519_SIZE], const u_char c[CURVE25519_SIZE])
|
|
__attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
|
|
__attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)))
|
|
__attribute__((__bounded__(__minbytes__, 3, CURVE25519_SIZE)));
|
|
|
|
void
|
|
kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
|
|
{
|
|
static const u_char basepoint[CURVE25519_SIZE] = {9};
|
|
|
|
arc4random_buf(key, CURVE25519_SIZE);
|
|
crypto_scalarmult_curve25519(pub, key, basepoint);
|
|
}
|
|
|
|
void
|
|
kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
|
|
const u_char pub[CURVE25519_SIZE], Buffer *out)
|
|
{
|
|
u_char shared_key[CURVE25519_SIZE];
|
|
|
|
crypto_scalarmult_curve25519(shared_key, key, pub);
|
|
#ifdef DEBUG_KEXECDH
|
|
dump_digest("shared secret", shared_key, CURVE25519_SIZE);
|
|
#endif
|
|
buffer_clear(out);
|
|
buffer_put_bignum2_from_string(out, shared_key, CURVE25519_SIZE);
|
|
explicit_bzero(shared_key, CURVE25519_SIZE);
|
|
}
|
|
|
|
void
|
|
kex_c25519_hash(
|
|
int hash_alg,
|
|
char *client_version_string,
|
|
char *server_version_string,
|
|
char *ckexinit, int ckexinitlen,
|
|
char *skexinit, int skexinitlen,
|
|
u_char *serverhostkeyblob, int sbloblen,
|
|
const u_char client_dh_pub[CURVE25519_SIZE],
|
|
const u_char server_dh_pub[CURVE25519_SIZE],
|
|
const u_char *shared_secret, u_int secretlen,
|
|
u_char **hash, u_int *hashlen)
|
|
{
|
|
Buffer b;
|
|
static u_char digest[SSH_DIGEST_MAX_LENGTH];
|
|
|
|
buffer_init(&b);
|
|
buffer_put_cstring(&b, client_version_string);
|
|
buffer_put_cstring(&b, server_version_string);
|
|
|
|
/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
|
|
buffer_put_int(&b, ckexinitlen+1);
|
|
buffer_put_char(&b, SSH2_MSG_KEXINIT);
|
|
buffer_append(&b, ckexinit, ckexinitlen);
|
|
buffer_put_int(&b, skexinitlen+1);
|
|
buffer_put_char(&b, SSH2_MSG_KEXINIT);
|
|
buffer_append(&b, skexinit, skexinitlen);
|
|
|
|
buffer_put_string(&b, serverhostkeyblob, sbloblen);
|
|
buffer_put_string(&b, client_dh_pub, CURVE25519_SIZE);
|
|
buffer_put_string(&b, server_dh_pub, CURVE25519_SIZE);
|
|
buffer_append(&b, shared_secret, secretlen);
|
|
|
|
#ifdef DEBUG_KEX
|
|
buffer_dump(&b);
|
|
#endif
|
|
if (ssh_digest_buffer(hash_alg, &b, digest, sizeof(digest)) != 0)
|
|
fatal("%s: digest_buffer failed", __func__);
|
|
|
|
buffer_free(&b);
|
|
|
|
#ifdef DEBUG_KEX
|
|
dump_digest("hash", digest, ssh_digest_bytes(hash_alg));
|
|
#endif
|
|
*hash = digest;
|
|
*hashlen = ssh_digest_bytes(hash_alg);
|
|
}
|