From 094003f5454a9f5a607674b2739824a7e91835f4 Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Mon, 4 Nov 2013 22:59:27 +1100 Subject: - (djm) [kexc25519.c kexc25519c.c kexc25519s.c] Import missed files from KEX/curve25519 change --- kexc25519c.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 kexc25519c.c (limited to 'kexc25519c.c') diff --git a/kexc25519c.c b/kexc25519c.c new file mode 100644 index 000000000..f741566cc --- /dev/null +++ b/kexc25519c.c @@ -0,0 +1,128 @@ +/* $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 + +#include +#include +#include + +#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); +} -- cgit v1.2.3