- (djm) [kexc25519.c kexc25519c.c kexc25519s.c] Import missed files from

KEX/curve25519 change
This commit is contained in:
Damien Miller 2013-11-04 22:59:27 +11:00
parent ca67a7eaf8
commit 094003f545
4 changed files with 380 additions and 0 deletions

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@ -24,6 +24,8 @@
[roaming_common.c] [roaming_common.c]
fix a couple of function definitions foo() -> foo(void) fix a couple of function definitions foo() -> foo(void)
(-Wold-style-definition) (-Wold-style-definition)
- (djm) [kexc25519.c kexc25519c.c kexc25519s.c] Import missed files from
KEX/curve25519 change
20131103 20131103
- (dtucker) [openbsd-compat/bsd-misc.c] Include time.h for nanosleep. - (dtucker) [openbsd-compat/bsd-misc.c] Include time.h for nanosleep.

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/* $OpenBSD: kexc25519.c,v 1.2 2013/11/02 22:02:14 markus 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"
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);
}
BIGNUM *
kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
const u_char pub[CURVE25519_SIZE])
{
u_char shared_key[CURVE25519_SIZE];
BIGNUM *shared_secret;
crypto_scalarmult_curve25519(shared_key, key, pub);
#ifdef DEBUG_KEXECDH
dump_digest("shared secret", shared_key, CURVE25519_SIZE);
#endif
if ((shared_secret = BN_new()) == NULL)
fatal("%s: BN_new failed", __func__);
if (BN_bin2bn(shared_key, sizeof(shared_key), shared_secret) == NULL)
fatal("%s: BN_bin2bn failed", __func__);
memset(shared_key, 0, CURVE25519_SIZE); /* XXX explicit_bzero() */
return (shared_secret);
}
void
kex_c25519_hash(
const EVP_MD *evp_md,
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 BIGNUM *shared_secret,
u_char **hash, u_int *hashlen)
{
Buffer b;
EVP_MD_CTX md;
static u_char digest[EVP_MAX_MD_SIZE];
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_put_bignum2(&b, shared_secret);
#ifdef DEBUG_KEX
buffer_dump(&b);
#endif
EVP_DigestInit(&md, evp_md);
EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
EVP_DigestFinal(&md, digest, NULL);
buffer_free(&b);
#ifdef DEBUG_KEX
dump_digest("hash", digest, EVP_MD_size(evp_md));
#endif
*hash = digest;
*hashlen = EVP_MD_size(evp_md);
}

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/* $OpenBSD: kexc25519c.c,v 1.2 2013/11/02 22:02:14 markus Exp $ */
/*
* Copyright (c) 2001 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 <stdio.h>
#include <string.h>
#include <signal.h>
#include "xmalloc.h"
#include "buffer.h"
#include "key.h"
#include "cipher.h"
#include "kex.h"
#include "log.h"
#include "packet.h"
#include "ssh2.h"
void
kexc25519_client(Kex *kex)
{
BIGNUM *shared_secret;
Key *server_host_key;
u_char client_key[CURVE25519_SIZE];
u_char client_pubkey[CURVE25519_SIZE];
u_char *server_pubkey = NULL;
u_char *server_host_key_blob = NULL, *signature = NULL;
u_char *hash;
u_int slen, sbloblen, hashlen;
kexc25519_keygen(client_key, client_pubkey);
packet_start(SSH2_MSG_KEX_ECDH_INIT);
packet_put_string(client_pubkey, sizeof(client_pubkey));
packet_send();
debug("sending SSH2_MSG_KEX_ECDH_INIT");
#ifdef DEBUG_KEXECDH
dump_digest("client private key:", client_key, sizeof(client_key));
#endif
debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
packet_read_expect(SSH2_MSG_KEX_ECDH_REPLY);
/* hostkey */
server_host_key_blob = packet_get_string(&sbloblen);
server_host_key = key_from_blob(server_host_key_blob, sbloblen);
if (server_host_key == NULL)
fatal("cannot decode server_host_key_blob");
if (server_host_key->type != kex->hostkey_type)
fatal("type mismatch for decoded server_host_key_blob");
if (kex->verify_host_key == NULL)
fatal("cannot verify server_host_key");
if (kex->verify_host_key(server_host_key) == -1)
fatal("server_host_key verification failed");
/* Q_S, server public key */
server_pubkey = packet_get_string(&slen);
if (slen != CURVE25519_SIZE)
fatal("Incorrect size for server Curve25519 pubkey: %d", slen);
#ifdef DEBUG_KEXECDH
dump_digest("server public key:", server_pubkey, CURVE25519_SIZE);
#endif
/* signed H */
signature = packet_get_string(&slen);
packet_check_eom();
shared_secret = kexc25519_shared_key(client_key, server_pubkey);
/* calc and verify H */
kex_c25519_hash(
kex->evp_md,
kex->client_version_string,
kex->server_version_string,
buffer_ptr(&kex->my), buffer_len(&kex->my),
buffer_ptr(&kex->peer), buffer_len(&kex->peer),
server_host_key_blob, sbloblen,
client_pubkey,
server_pubkey,
shared_secret,
&hash, &hashlen
);
free(server_host_key_blob);
free(server_pubkey);
if (key_verify(server_host_key, signature, slen, hash, hashlen) != 1)
fatal("key_verify failed for server_host_key");
key_free(server_host_key);
free(signature);
/* save session id */
if (kex->session_id == NULL) {
kex->session_id_len = hashlen;
kex->session_id = xmalloc(kex->session_id_len);
memcpy(kex->session_id, hash, kex->session_id_len);
}
kex_derive_keys(kex, hash, hashlen, shared_secret);
BN_clear_free(shared_secret);
kex_finish(kex);
}

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/* $OpenBSD: kexc25519s.c,v 1.2 2013/11/02 22:02:14 markus Exp $ */
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2010 Damien Miller. All rights reserved.
* Copyright (c) 2013 Aris Adamantiadis. All rights reserved.
*
* 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 <string.h>
#include <signal.h>
#include "xmalloc.h"
#include "buffer.h"
#include "key.h"
#include "cipher.h"
#include "kex.h"
#include "log.h"
#include "packet.h"
#include "ssh2.h"
void
kexc25519_server(Kex *kex)
{
BIGNUM *shared_secret;
Key *server_host_private, *server_host_public;
u_char *server_host_key_blob = NULL, *signature = NULL;
u_char server_key[CURVE25519_SIZE];
u_char *client_pubkey = NULL;
u_char server_pubkey[CURVE25519_SIZE];
u_char *hash;
u_int slen, sbloblen, hashlen;
/* generate private key */
kexc25519_keygen(server_key, server_pubkey);
#ifdef DEBUG_KEXECDH
dump_digest("server private key:", server_key, sizeof(server_key));
#endif
if (kex->load_host_public_key == NULL ||
kex->load_host_private_key == NULL)
fatal("Cannot load hostkey");
server_host_public = kex->load_host_public_key(kex->hostkey_type);
if (server_host_public == NULL)
fatal("Unsupported hostkey type %d", kex->hostkey_type);
server_host_private = kex->load_host_private_key(kex->hostkey_type);
debug("expecting SSH2_MSG_KEX_ECDH_INIT");
packet_read_expect(SSH2_MSG_KEX_ECDH_INIT);
client_pubkey = packet_get_string(&slen);
if (slen != CURVE25519_SIZE)
fatal("Incorrect size for server Curve25519 pubkey: %d", slen);
packet_check_eom();
#ifdef DEBUG_KEXECDH
dump_digest("client public key:", client_pubkey, CURVE25519_SIZE);
#endif
shared_secret = kexc25519_shared_key(server_key, client_pubkey);
/* calc H */
key_to_blob(server_host_public, &server_host_key_blob, &sbloblen);
kex_c25519_hash(
kex->evp_md,
kex->client_version_string,
kex->server_version_string,
buffer_ptr(&kex->peer), buffer_len(&kex->peer),
buffer_ptr(&kex->my), buffer_len(&kex->my),
server_host_key_blob, sbloblen,
client_pubkey,
server_pubkey,
shared_secret,
&hash, &hashlen
);
/* save session id := H */
if (kex->session_id == NULL) {
kex->session_id_len = hashlen;
kex->session_id = xmalloc(kex->session_id_len);
memcpy(kex->session_id, hash, kex->session_id_len);
}
/* sign H */
kex->sign(server_host_private, server_host_public, &signature, &slen,
hash, hashlen);
/* destroy_sensitive_data(); */
/* send server hostkey, ECDH pubkey 'Q_S' and signed H */
packet_start(SSH2_MSG_KEX_ECDH_REPLY);
packet_put_string(server_host_key_blob, sbloblen);
packet_put_string(server_pubkey, sizeof(server_pubkey));
packet_put_string(signature, slen);
packet_send();
free(signature);
free(server_host_key_blob);
/* have keys, free server key */
free(client_pubkey);
kex_derive_keys(kex, hash, hashlen, shared_secret);
BN_clear_free(shared_secret);
kex_finish(kex);
}