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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/ssh/lib/../kexc25519s.c	Lines:	0	63	0.0 %
Date:	2017-11-13	Branches:	0	38	0.0 %


/* $OpenBSD: kexc25519s.c,v 1.11 2017/05/31 04:19:28 djm 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 <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>

#include "sshkey.h"
#include "cipher.h"
#include "digest.h"
#include "kex.h"
#include "log.h"
#include "packet.h"
#include "ssh2.h"
#include "sshbuf.h"
#include "ssherr.h"

static int input_kex_c25519_init(int, u_int32_t, struct ssh *);

int
kexc25519_server(struct ssh *ssh)
{
	debug("expecting SSH2_MSG_KEX_ECDH_INIT");
	ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_INIT, &input_kex_c25519_init);
	return 0;
}

static int
input_kex_c25519_init(int type, u_int32_t seq, struct ssh *ssh)
{
	struct kex *kex = ssh->kex;
	struct sshkey *server_host_private, *server_host_public;
	struct sshbuf *shared_secret = NULL;
	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[SSH_DIGEST_MAX_LENGTH];
	size_t slen, pklen, sbloblen, hashlen;
	int r;

	/* 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) {
		r = SSH_ERR_INVALID_ARGUMENT;
		goto out;
	}
	server_host_public = kex->load_host_public_key(kex->hostkey_type,
	    kex->hostkey_nid, ssh);
	server_host_private = kex->load_host_private_key(kex->hostkey_type,
	    kex->hostkey_nid, ssh);
	if (server_host_public == NULL) {
		r = SSH_ERR_NO_HOSTKEY_LOADED;
		goto out;
	}

	if ((r = sshpkt_get_string(ssh, &client_pubkey, &pklen)) != 0 ||
	    (r = sshpkt_get_end(ssh)) != 0)
		goto out;
	if (pklen != CURVE25519_SIZE) {
		r = SSH_ERR_SIGNATURE_INVALID;
		goto out;
	}
#ifdef DEBUG_KEXECDH
	dump_digest("client public key:", client_pubkey, CURVE25519_SIZE);
#endif

	if ((shared_secret = sshbuf_new()) == NULL) {
		r = SSH_ERR_ALLOC_FAIL;
		goto out;
	}
	if ((r = kexc25519_shared_key(server_key, client_pubkey,
	    shared_secret)) < 0)
		goto out;

	/* calc H */
	if ((r = sshkey_to_blob(server_host_public, &server_host_key_blob,
	    &sbloblen)) != 0)
		goto out;
	hashlen = sizeof(hash);
	if ((r = kex_c25519_hash(
	    kex->hash_alg,
	    kex->client_version_string,
	    kex->server_version_string,
	    sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
	    sshbuf_ptr(kex->my), sshbuf_len(kex->my),
	    server_host_key_blob, sbloblen,
	    client_pubkey,
	    server_pubkey,
	    sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
	    hash, &hashlen)) < 0)
		goto out;

	/* save session id := H */
	if (kex->session_id == NULL) {
		kex->session_id_len = hashlen;
		kex->session_id = malloc(kex->session_id_len);
		if (kex->session_id == NULL) {
			r = SSH_ERR_ALLOC_FAIL;
			goto out;
		}
		memcpy(kex->session_id, hash, kex->session_id_len);
	}

	/* sign H */
	if ((r = kex->sign(server_host_private, server_host_public, &signature,
	     &slen, hash, hashlen, kex->hostkey_alg, ssh->compat)) < 0)
		goto out;

	/* send server hostkey, ECDH pubkey 'Q_S' and signed H */
	if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_REPLY)) != 0 ||
	    (r = sshpkt_put_string(ssh, server_host_key_blob, sbloblen)) != 0 ||
	    (r = sshpkt_put_string(ssh, server_pubkey, sizeof(server_pubkey))) != 0 ||
	    (r = sshpkt_put_string(ssh, signature, slen)) != 0 ||
	    (r = sshpkt_send(ssh)) != 0)
		goto out;

	if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
		r = kex_send_newkeys(ssh);
out:
	explicit_bzero(hash, sizeof(hash));
	explicit_bzero(server_key, sizeof(server_key));
	free(server_host_key_blob);
	free(signature);
	free(client_pubkey);
	sshbuf_free(shared_secret);
	return r;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: kexc25519s.c,v 1.11 2017/05/31 04:19:28 djm Exp $ */
2			/*
3			* Copyright (c) 2001 Markus Friedl. All rights reserved.
4			* Copyright (c) 2010 Damien Miller. All rights reserved.
5			* Copyright (c) 2013 Aris Adamantiadis. All rights reserved.
6			*
7			* modification, are permitted provided that the following conditions
8			* are met:
9			* 1. Redistributions of source code must retain the above copyright
10			* notice, this list of conditions and the following disclaimer.
11			* 2. Redistributions in binary form must reproduce the above copyright
12			* notice, this list of conditions and the following disclaimer in the
13			* documentation and/or other materials provided with the distribution.
14			*
15			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16			* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18			* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19			* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21			* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23			* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24			* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25			*/
26
27			#include <sys/types.h>
28			#include <stdio.h>
29			#include <string.h>
30			#include <signal.h>
31
32			#include "sshkey.h"
33			#include "cipher.h"
34			#include "digest.h"
35			#include "kex.h"
36			#include "log.h"
37			#include "packet.h"
38			#include "ssh2.h"
39			#include "sshbuf.h"
40			#include "ssherr.h"
41
42			static int input_kex_c25519_init(int, u_int32_t, struct ssh *);
43
44			int
45			kexc25519_server(struct ssh *ssh)
46			{
47			debug("expecting SSH2_MSG_KEX_ECDH_INIT");
48			ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_INIT, &input_kex_c25519_init);
49			return 0;
50			}
51
52			static int
53			input_kex_c25519_init(int type, u_int32_t seq, struct ssh *ssh)
54			{
55			struct kex *kex = ssh->kex;
56			struct sshkey server_host_private, server_host_public;
57			struct sshbuf *shared_secret = NULL;
58			u_char server_host_key_blob = NULL, signature = NULL;
59			u_char server_key[CURVE25519_SIZE];
60			u_char *client_pubkey = NULL;
61			u_char server_pubkey[CURVE25519_SIZE];
62			u_char hash[SSH_DIGEST_MAX_LENGTH];
63			size_t slen, pklen, sbloblen, hashlen;
64			int r;
65
66			/* generate private key */
67			kexc25519_keygen(server_key, server_pubkey);
68			#ifdef DEBUG_KEXECDH
69			dump_digest("server private key:", server_key, sizeof(server_key));
70			#endif
71			if (kex->load_host_public_key == NULL \|\|
72			kex->load_host_private_key == NULL) {
73			r = SSH_ERR_INVALID_ARGUMENT;
74			goto out;
75			}
76			server_host_public = kex->load_host_public_key(kex->hostkey_type,
77			kex->hostkey_nid, ssh);
78			server_host_private = kex->load_host_private_key(kex->hostkey_type,
79			kex->hostkey_nid, ssh);
80			if (server_host_public == NULL) {
81			r = SSH_ERR_NO_HOSTKEY_LOADED;
82			goto out;
83			}
84
85			if ((r = sshpkt_get_string(ssh, &client_pubkey, &pklen)) != 0 \|\|
86			(r = sshpkt_get_end(ssh)) != 0)
87			goto out;
88			if (pklen != CURVE25519_SIZE) {
89			r = SSH_ERR_SIGNATURE_INVALID;
90			goto out;
91			}
92			#ifdef DEBUG_KEXECDH
93			dump_digest("client public key:", client_pubkey, CURVE25519_SIZE);
94			#endif
95
96			if ((shared_secret = sshbuf_new()) == NULL) {
97			r = SSH_ERR_ALLOC_FAIL;
98			goto out;
99			}
100			if ((r = kexc25519_shared_key(server_key, client_pubkey,
101			shared_secret)) < 0)
102			goto out;
103
104			/* calc H */
105			if ((r = sshkey_to_blob(server_host_public, &server_host_key_blob,
106			&sbloblen)) != 0)
107			goto out;
108			hashlen = sizeof(hash);
109			if ((r = kex_c25519_hash(
110			kex->hash_alg,
111			kex->client_version_string,
112			kex->server_version_string,
113			sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
114			sshbuf_ptr(kex->my), sshbuf_len(kex->my),
115			server_host_key_blob, sbloblen,
116			client_pubkey,
117			server_pubkey,
118			sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
119			hash, &hashlen)) < 0)
120			goto out;
121
122			/* save session id := H */
123			if (kex->session_id == NULL) {
124			kex->session_id_len = hashlen;
125			kex->session_id = malloc(kex->session_id_len);
126			if (kex->session_id == NULL) {
127			r = SSH_ERR_ALLOC_FAIL;
128			goto out;
129			}
130			memcpy(kex->session_id, hash, kex->session_id_len);
131			}
132
133			/* sign H */
134			if ((r = kex->sign(server_host_private, server_host_public, &signature,
135			&slen, hash, hashlen, kex->hostkey_alg, ssh->compat)) < 0)
136			goto out;
137
138			/* send server hostkey, ECDH pubkey 'Q_S' and signed H */
139			if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_REPLY)) != 0 \|\|
140			(r = sshpkt_put_string(ssh, server_host_key_blob, sbloblen)) != 0 \|\|
141			(r = sshpkt_put_string(ssh, server_pubkey, sizeof(server_pubkey))) != 0 \|\|
142			(r = sshpkt_put_string(ssh, signature, slen)) != 0 \|\|
143			(r = sshpkt_send(ssh)) != 0)
144			goto out;
145
146			if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
147			r = kex_send_newkeys(ssh);
148			out:
149			explicit_bzero(hash, sizeof(hash));
150			explicit_bzero(server_key, sizeof(server_key));
151			free(server_host_key_blob);
152			free(signature);
153			free(client_pubkey);
154			sshbuf_free(shared_secret);
155			return r;
156			}