Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libcrypto/crypto/../../libssl/src/crypto/ecdh/ech_key.c	Lines:	44	72	61.1 %
Date:	2016-12-06	Branches:	21	38	55.3 %


/* $OpenBSD: ech_key.c,v 1.6 2015/09/18 13:04:41 bcook Exp $ */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 *
 * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
 * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
 * to the OpenSSL project.
 *
 * The ECC Code is licensed pursuant to the OpenSSL open source
 * license provided below.
 *
 * The ECDH software is originally written by Douglas Stebila of
 * Sun Microsystems Laboratories.
 *
 */
/* ====================================================================
 * Copyright (c) 1998-2003 The OpenSSL Project.  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.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <limits.h>
#include <string.h>

#include <openssl/opensslconf.h>

#include <openssl/bn.h>
#include <openssl/err.h>
#include <openssl/obj_mac.h>
#include <openssl/sha.h>

#include "ech_locl.h"

static int ecdh_compute_key(void *out, size_t len, const EC_POINT *pub_key,
    EC_KEY *ecdh,
    void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen));

/*
 * This implementation is based on the following primitives in the IEEE 1363
 * standard:
 *  - ECKAS-DH1
 *  - ECSVDP-DH
 * Finally an optional KDF is applied.
 */
static int
ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
    EC_KEY *ecdh,
    void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen))
{
	BN_CTX *ctx;
	EC_POINT *tmp = NULL;
	BIGNUM *x = NULL, *y = NULL;
	const BIGNUM *priv_key;
	const EC_GROUP* group;
	int ret = -1;
	size_t buflen, len;
	unsigned char *buf = NULL;

	if (outlen > INT_MAX) {
		/* Sort of, anyway. */
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
		return -1;
	}

	if ((ctx = BN_CTX_new()) == NULL)
		goto err;
	BN_CTX_start(ctx);
	if ((x = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((y = BN_CTX_get(ctx)) == NULL)
		goto err;

	priv_key = EC_KEY_get0_private_key(ecdh);
	if (priv_key == NULL) {
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_NO_PRIVATE_VALUE);
		goto err;
	}

	group = EC_KEY_get0_group(ecdh);
	if ((tmp = EC_POINT_new(group)) == NULL) {
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
		goto err;
	}

	if (!EC_POINT_mul(group, tmp, NULL, pub_key, priv_key, ctx)) {
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,
		    ECDH_R_POINT_ARITHMETIC_FAILURE);
		goto err;
	}

	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) ==
	    NID_X9_62_prime_field) {
		if (!EC_POINT_get_affine_coordinates_GFp(group, tmp, x, y,
		    ctx)) {
			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,
			    ECDH_R_POINT_ARITHMETIC_FAILURE);
			goto err;
		}
	}
#ifndef OPENSSL_NO_EC2M
	else {
		if (!EC_POINT_get_affine_coordinates_GF2m(group, tmp, x, y,
		    ctx)) {
			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,
			    ECDH_R_POINT_ARITHMETIC_FAILURE);
			goto err;
		}
	}
#endif

	buflen = ECDH_size(ecdh);
	len = BN_num_bytes(x);
	if (len > buflen) {
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_INTERNAL_ERROR);
		goto err;
	}
	if (KDF == NULL && outlen < buflen) {
		/* The resulting key would be truncated. */
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_KEY_TRUNCATION);
		goto err;
	}
	if ((buf = malloc(buflen)) == NULL) {
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
		goto err;
	}

	memset(buf, 0, buflen - len);
	if (len != (size_t)BN_bn2bin(x, buf + buflen - len)) {
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_BN_LIB);
		goto err;
	}

	if (KDF != NULL) {
		if (KDF(buf, buflen, out, &outlen) == NULL) {
			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_KDF_FAILED);
			goto err;
		}
		ret = outlen;
	} else {
		/* No KDF, just copy out the key and zero the rest. */
		if (outlen > buflen) {
			memset((void *)((uintptr_t)out + buflen), 0, outlen - buflen);
			outlen = buflen;
		}
		memcpy(out, buf, outlen);
		ret = outlen;
	}

err:
	EC_POINT_free(tmp);
	if (ctx)
		BN_CTX_end(ctx);
	BN_CTX_free(ctx);
	free(buf);
	return (ret);
}

static ECDH_METHOD openssl_ecdh_meth = {
	.name = "OpenSSL ECDH method",
	.compute_key = ecdh_compute_key
};

const ECDH_METHOD *
ECDH_OpenSSL(void)
{
	return &openssl_ecdh_meth;
}

int
ECDH_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
    EC_KEY *eckey,
    void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen))
{
	ECDH_DATA *ecdh = ecdh_check(eckey);
	if (ecdh == NULL)
		return 0;
	return ecdh->meth->compute_key(out, outlen, pub_key, eckey, KDF);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: ech_key.c,v 1.6 2015/09/18 13:04:41 bcook Exp $ */
2			/* ====================================================================
3			* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
4			*
5			* The Elliptic Curve Public-Key Crypto Library (ECC Code) included
6			* herein is developed by SUN MICROSYSTEMS, INC., and is contributed
7			* to the OpenSSL project.
8			*
9			* The ECC Code is licensed pursuant to the OpenSSL open source
10			* license provided below.
11			*
12			* The ECDH software is originally written by Douglas Stebila of
13			* Sun Microsystems Laboratories.
14			*
15			*/
16			/* ====================================================================
17			* Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved.
18			*
19			* Redistribution and use in source and binary forms, with or without
20			* modification, are permitted provided that the following conditions
21			* are met:
22			*
23			* 1. Redistributions of source code must retain the above copyright
24			* notice, this list of conditions and the following disclaimer.
25			*
26			* 2. Redistributions in binary form must reproduce the above copyright
27			* notice, this list of conditions and the following disclaimer in
28			* the documentation and/or other materials provided with the
29			* distribution.
30			*
31			* 3. All advertising materials mentioning features or use of this
32			* software must display the following acknowledgment:
33			* "This product includes software developed by the OpenSSL Project
34			* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
35			*
36			* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
37			* endorse or promote products derived from this software without
38			* prior written permission. For written permission, please contact
39			* openssl-core@OpenSSL.org.
40			*
41			* 5. Products derived from this software may not be called "OpenSSL"
42			* nor may "OpenSSL" appear in their names without prior written
43			* permission of the OpenSSL Project.
44			*
45			* 6. Redistributions of any form whatsoever must retain the following
46			* acknowledgment:
47			* "This product includes software developed by the OpenSSL Project
48			* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
49			*
50			* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
51			* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
53			* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
54			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
55			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
56			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
57			* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
59			* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
60			* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
61			* OF THE POSSIBILITY OF SUCH DAMAGE.
62			* ====================================================================
63			*
64			* This product includes cryptographic software written by Eric Young
65			* (eay@cryptsoft.com). This product includes software written by Tim
66			* Hudson (tjh@cryptsoft.com).
67			*
68			*/
69
70			#include <limits.h>
71			#include <string.h>
72
73			#include <openssl/opensslconf.h>
74
75			#include <openssl/bn.h>
76			#include <openssl/err.h>
77			#include <openssl/obj_mac.h>
78			#include <openssl/sha.h>
79
80			#include "ech_locl.h"
81
82			static int ecdh_compute_key(void out, size_t len, const EC_POINT pub_key,
83			EC_KEY *ecdh,
84			void (KDF)(const void in, size_t inlen, void out, size_t *outlen));
85
86			/*
87			* This implementation is based on the following primitives in the IEEE 1363
88			* standard:
89			* - ECKAS-DH1
90			* - ECSVDP-DH
91			* Finally an optional KDF is applied.
92			*/
93			static int
94			ecdh_compute_key(void out, size_t outlen, const EC_POINT pub_key,
95			EC_KEY *ecdh,
96			void (KDF)(const void in, size_t inlen, void out, size_t *outlen))
97		38	{
98			BN_CTX *ctx;
99		38	EC_POINT *tmp = NULL;
100		38	BIGNUM x = NULL, y = NULL;
101			const BIGNUM *priv_key;
102			const EC_GROUP* group;
103		38	int ret = -1;
104			size_t buflen, len;
105		38	unsigned char *buf = NULL;
106
107	✗✓	38	if (outlen > INT_MAX) {
108			/* Sort of, anyway. */
109			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
110			return -1;
111			}
112
113	✗✓	38	if ((ctx = BN_CTX_new()) == NULL)
114			goto err;
115		38	BN_CTX_start(ctx);
116	✗✓	38	if ((x = BN_CTX_get(ctx)) == NULL)
117			goto err;
118	✗✓	38	if ((y = BN_CTX_get(ctx)) == NULL)
119			goto err;
120
121		38	priv_key = EC_KEY_get0_private_key(ecdh);
122	✗✓	38	if (priv_key == NULL) {
123			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_NO_PRIVATE_VALUE);
124			goto err;
125			}
126
127		38	group = EC_KEY_get0_group(ecdh);
128	✗✓	38	if ((tmp = EC_POINT_new(group)) == NULL) {
129			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
130			goto err;
131			}
132
133	✗✓	38	if (!EC_POINT_mul(group, tmp, NULL, pub_key, priv_key, ctx)) {
134			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,
135			ECDH_R_POINT_ARITHMETIC_FAILURE);
136			goto err;
137			}
138
139	✓✓	38	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) ==
140			NID_X9_62_prime_field) {
141	✗✓	18	if (!EC_POINT_get_affine_coordinates_GFp(group, tmp, x, y,
142			ctx)) {
143			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,
144			ECDH_R_POINT_ARITHMETIC_FAILURE);
145			goto err;
146			}
147			}
148			#ifndef OPENSSL_NO_EC2M
149			else {
150	✗✓	20	if (!EC_POINT_get_affine_coordinates_GF2m(group, tmp, x, y,
151			ctx)) {
152			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,
153			ECDH_R_POINT_ARITHMETIC_FAILURE);
154			goto err;
155			}
156			}
157			#endif
158
159		38	buflen = ECDH_size(ecdh);
160		38	len = BN_num_bytes(x);
161	✗✓	38	if (len > buflen) {
162			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_INTERNAL_ERROR);
163			goto err;
164			}
165	✗✓	38	if (KDF == NULL && outlen < buflen) {
166			/* The resulting key would be truncated. */
167			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_KEY_TRUNCATION);
168			goto err;
169			}
170	✗✓	38	if ((buf = malloc(buflen)) == NULL) {
171			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
172			goto err;
173			}
174
175		38	memset(buf, 0, buflen - len);
176	✗✓	38	if (len != (size_t)BN_bn2bin(x, buf + buflen - len)) {
177			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_BN_LIB);
178			goto err;
179			}
180
181	✓✓	38	if (KDF != NULL) {
182	✗✓	30	if (KDF(buf, buflen, out, &outlen) == NULL) {
183			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_KDF_FAILED);
184			goto err;
185			}
186		30	ret = outlen;
187			} else {
188			/* No KDF, just copy out the key and zero the rest. */
189	✗✓	8	if (outlen > buflen) {
190			memset((void *)((uintptr_t)out + buflen), 0, outlen - buflen);
191			outlen = buflen;
192			}
193		8	memcpy(out, buf, outlen);
194		8	ret = outlen;
195			}
196
197		38	err:
198		38	EC_POINT_free(tmp);
199	✓✗	38	if (ctx)
200		38	BN_CTX_end(ctx);
201		38	BN_CTX_free(ctx);
202		38	free(buf);
203		38	return (ret);
204			}
205
206			static ECDH_METHOD openssl_ecdh_meth = {
207			.name = "OpenSSL ECDH method",
208			.compute_key = ecdh_compute_key
209			};
210
211			const ECDH_METHOD *
212			ECDH_OpenSSL(void)
213		3	{
214		3	return &openssl_ecdh_meth;
215			}
216
217			int
218			ECDH_compute_key(void out, size_t outlen, const EC_POINT pub_key,
219			EC_KEY *eckey,
220			void (KDF)(const void in, size_t inlen, void out, size_t *outlen))
221		38	{
222		38	ECDH_DATA *ecdh = ecdh_check(eckey);
223	✗✓	38	if (ecdh == NULL)
224			return 0;
225		38	return ecdh->meth->compute_key(out, outlen, pub_key, eckey, KDF);
226			}