Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/ssh/lib/../kexc25519c.c	Lines:	0	67	0.0 %
Date:	2017-11-13	Branches:	0	42	0.0 %


/* $OpenBSD: kexc25519c.c,v 1.8 2017/05/31 04:17:12 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.
 *
 * 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 <sys/types.h>

#include <stdio.h>
#include <string.h>
#include <signal.h>

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

static int
input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh);

int
kexc25519_client(struct ssh *ssh)
{
	struct kex *kex = ssh->kex;
	int r;

	kexc25519_keygen(kex->c25519_client_key, kex->c25519_client_pubkey);
#ifdef DEBUG_KEXECDH
	dump_digest("client private key:", kex->c25519_client_key,
	    sizeof(kex->c25519_client_key));
#endif
	if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_INIT)) != 0 ||
	    (r = sshpkt_put_string(ssh, kex->c25519_client_pubkey,
	    sizeof(kex->c25519_client_pubkey))) != 0 ||
	    (r = sshpkt_send(ssh)) != 0)
		return r;

	debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
	ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_REPLY, &input_kex_c25519_reply);
	return 0;
}

static int
input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh)
{
	struct kex *kex = ssh->kex;
	struct sshkey *server_host_key = NULL;
	struct sshbuf *shared_secret = NULL;
	u_char *server_pubkey = NULL;
	u_char *server_host_key_blob = NULL, *signature = NULL;
	u_char hash[SSH_DIGEST_MAX_LENGTH];
	size_t slen, pklen, sbloblen, hashlen;
	int r;

	if (kex->verify_host_key == NULL) {
		r = SSH_ERR_INVALID_ARGUMENT;
		goto out;
	}

	/* hostkey */
	if ((r = sshpkt_get_string(ssh, &server_host_key_blob,
	    &sbloblen)) != 0 ||
	    (r = sshkey_from_blob(server_host_key_blob, sbloblen,
	    &server_host_key)) != 0)
		goto out;
	if (server_host_key->type != kex->hostkey_type ||
	    (kex->hostkey_type == KEY_ECDSA &&
	    server_host_key->ecdsa_nid != kex->hostkey_nid)) {
		r = SSH_ERR_KEY_TYPE_MISMATCH;
		goto out;
	}
	if (kex->verify_host_key(server_host_key, ssh) == -1) {
		r = SSH_ERR_SIGNATURE_INVALID;
		goto out;
	}

	/* Q_S, server public key */
	/* signed H */
	if ((r = sshpkt_get_string(ssh, &server_pubkey, &pklen)) != 0 ||
	    (r = sshpkt_get_string(ssh, &signature, &slen)) != 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("server public key:", server_pubkey, CURVE25519_SIZE);
#endif

	if ((shared_secret = sshbuf_new()) == NULL) {
		r = SSH_ERR_ALLOC_FAIL;
		goto out;
	}
	if ((r = kexc25519_shared_key(kex->c25519_client_key, server_pubkey,
	    shared_secret)) < 0)
		goto out;

	/* calc and verify H */
	hashlen = sizeof(hash);
	if ((r = kex_c25519_hash(
	    kex->hash_alg,
	    kex->client_version_string,
	    kex->server_version_string,
	    sshbuf_ptr(kex->my), sshbuf_len(kex->my),
	    sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
	    server_host_key_blob, sbloblen,
	    kex->c25519_client_pubkey,
	    server_pubkey,
	    sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
	    hash, &hashlen)) < 0)
		goto out;

	if ((r = sshkey_verify(server_host_key, signature, slen, hash, hashlen,
	    ssh->compat)) != 0)
		goto out;

	/* save session id */
	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);
	}

	if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
		r = kex_send_newkeys(ssh);
out:
	explicit_bzero(hash, sizeof(hash));
	explicit_bzero(kex->c25519_client_key, sizeof(kex->c25519_client_key));
	free(server_host_key_blob);
	free(server_pubkey);
	free(signature);
	sshkey_free(server_host_key);
	sshbuf_free(shared_secret);
	return r;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: kexc25519c.c,v 1.8 2017/05/31 04:17:12 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			* Redistribution and use in source and binary forms, with or without
8			* modification, are permitted provided that the following conditions
9			* are met:
10			* 1. Redistributions of source code must retain the above copyright
11			* notice, this list of conditions and the following disclaimer.
12			* 2. Redistributions in binary form must reproduce the above copyright
13			* notice, this list of conditions and the following disclaimer in the
14			* documentation and/or other materials provided with the distribution.
15			*
16			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17			* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19			* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20			* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22			* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24			* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25			* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26			*/
27
28			#include <sys/types.h>
29
30			#include <stdio.h>
31			#include <string.h>
32			#include <signal.h>
33
34			#include "sshkey.h"
35			#include "cipher.h"
36			#include "kex.h"
37			#include "log.h"
38			#include "packet.h"
39			#include "ssh2.h"
40			#include "sshbuf.h"
41			#include "digest.h"
42			#include "ssherr.h"
43
44			static int
45			input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh);
46
47			int
48			kexc25519_client(struct ssh *ssh)
49			{
50			struct kex *kex = ssh->kex;
51			int r;
52
53			kexc25519_keygen(kex->c25519_client_key, kex->c25519_client_pubkey);
54			#ifdef DEBUG_KEXECDH
55			dump_digest("client private key:", kex->c25519_client_key,
56			sizeof(kex->c25519_client_key));
57			#endif
58			if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_INIT)) != 0 \|\|
59			(r = sshpkt_put_string(ssh, kex->c25519_client_pubkey,
60			sizeof(kex->c25519_client_pubkey))) != 0 \|\|
61			(r = sshpkt_send(ssh)) != 0)
62			return r;
63
64			debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
65			ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_REPLY, &input_kex_c25519_reply);
66			return 0;
67			}
68
69			static int
70			input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh)
71			{
72			struct kex *kex = ssh->kex;
73			struct sshkey *server_host_key = NULL;
74			struct sshbuf *shared_secret = NULL;
75			u_char *server_pubkey = NULL;
76			u_char server_host_key_blob = NULL, signature = NULL;
77			u_char hash[SSH_DIGEST_MAX_LENGTH];
78			size_t slen, pklen, sbloblen, hashlen;
79			int r;
80
81			if (kex->verify_host_key == NULL) {
82			r = SSH_ERR_INVALID_ARGUMENT;
83			goto out;
84			}
85
86			/* hostkey */
87			if ((r = sshpkt_get_string(ssh, &server_host_key_blob,
88			&sbloblen)) != 0 \|\|
89			(r = sshkey_from_blob(server_host_key_blob, sbloblen,
90			&server_host_key)) != 0)
91			goto out;
92			if (server_host_key->type != kex->hostkey_type \|\|
93			(kex->hostkey_type == KEY_ECDSA &&
94			server_host_key->ecdsa_nid != kex->hostkey_nid)) {
95			r = SSH_ERR_KEY_TYPE_MISMATCH;
96			goto out;
97			}
98			if (kex->verify_host_key(server_host_key, ssh) == -1) {
99			r = SSH_ERR_SIGNATURE_INVALID;
100			goto out;
101			}
102
103			/* Q_S, server public key */
104			/* signed H */
105			if ((r = sshpkt_get_string(ssh, &server_pubkey, &pklen)) != 0 \|\|
106			(r = sshpkt_get_string(ssh, &signature, &slen)) != 0 \|\|
107			(r = sshpkt_get_end(ssh)) != 0)
108			goto out;
109			if (pklen != CURVE25519_SIZE) {
110			r = SSH_ERR_SIGNATURE_INVALID;
111			goto out;
112			}
113
114			#ifdef DEBUG_KEXECDH
115			dump_digest("server public key:", server_pubkey, CURVE25519_SIZE);
116			#endif
117
118			if ((shared_secret = sshbuf_new()) == NULL) {
119			r = SSH_ERR_ALLOC_FAIL;
120			goto out;
121			}
122			if ((r = kexc25519_shared_key(kex->c25519_client_key, server_pubkey,
123			shared_secret)) < 0)
124			goto out;
125
126			/* calc and verify H */
127			hashlen = sizeof(hash);
128			if ((r = kex_c25519_hash(
129			kex->hash_alg,
130			kex->client_version_string,
131			kex->server_version_string,
132			sshbuf_ptr(kex->my), sshbuf_len(kex->my),
133			sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
134			server_host_key_blob, sbloblen,
135			kex->c25519_client_pubkey,
136			server_pubkey,
137			sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
138			hash, &hashlen)) < 0)
139			goto out;
140
141			if ((r = sshkey_verify(server_host_key, signature, slen, hash, hashlen,
142			ssh->compat)) != 0)
143			goto out;
144
145			/* save session id */
146			if (kex->session_id == NULL) {
147			kex->session_id_len = hashlen;
148			kex->session_id = malloc(kex->session_id_len);
149			if (kex->session_id == NULL) {
150			r = SSH_ERR_ALLOC_FAIL;
151			goto out;
152			}
153			memcpy(kex->session_id, hash, kex->session_id_len);
154			}
155
156			if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
157			r = kex_send_newkeys(ssh);
158			out:
159			explicit_bzero(hash, sizeof(hash));
160			explicit_bzero(kex->c25519_client_key, sizeof(kex->c25519_client_key));
161			free(server_host_key_blob);
162			free(server_pubkey);
163			free(signature);
164			sshkey_free(server_host_key);
165			sshbuf_free(shared_secret);
166			return r;
167			}