Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libcrypto/dh/dh_check.c	Lines:	31	38	81.6 %
Date:	2017-11-07	Branches:	19	36	52.8 %


/* $OpenBSD: dh_check.c,v 1.16 2016/07/05 02:54:35 bcook Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 OR 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>

#include <openssl/bn.h>
#include <openssl/dh.h>

/*
 * Check that p is a safe prime and
 * if g is 2, 3 or 5, check that it is a suitable generator
 * where
 * for 2, p mod 24 == 11
 * for 3, p mod 12 == 5
 * for 5, p mod 10 == 3 or 7
 * should hold.
 */

int
DH_check(const DH *dh, int *ret)
{
	int ok = 0;
	BN_CTX *ctx = NULL;
	BN_ULONG l;
	BIGNUM *q = NULL;

	*ret = 0;
	ctx = BN_CTX_new();
	if (ctx == NULL)
		goto err;
	q = BN_new();
	if (q == NULL)
		goto err;

	if (BN_is_word(dh->g, DH_GENERATOR_2)) {
		l = BN_mod_word(dh->p, 24);
		if (l == (BN_ULONG)-1)
			goto err;
		if (l != 11)
			*ret |= DH_NOT_SUITABLE_GENERATOR;
	} else if (BN_is_word(dh->g, DH_GENERATOR_5)) {
		l = BN_mod_word(dh->p, 10);
		if (l == (BN_ULONG)-1)
			goto err;
		if (l != 3 && l != 7)
			*ret |= DH_NOT_SUITABLE_GENERATOR;
	} else
		*ret |= DH_UNABLE_TO_CHECK_GENERATOR;

	if (!BN_is_prime_ex(dh->p, BN_prime_checks, ctx, NULL))
		*ret |= DH_CHECK_P_NOT_PRIME;
	else {
		if (!BN_rshift1(q, dh->p))
			goto err;
		if (!BN_is_prime_ex(q, BN_prime_checks, ctx, NULL))
			*ret |= DH_CHECK_P_NOT_SAFE_PRIME;
	}
	ok = 1;
err:
	BN_CTX_free(ctx);
	BN_free(q);
	return ok;
}

int
DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret)
{
	BIGNUM *q = NULL;

	*ret = 0;
	q = BN_new();
	if (q == NULL)
		return 0;
	BN_set_word(q, 1);
	if (BN_cmp(pub_key, q) <= 0)
		*ret |= DH_CHECK_PUBKEY_TOO_SMALL;
	BN_copy(q, dh->p);
	BN_sub_word(q, 1);
	if (BN_cmp(pub_key, q) >= 0)
		*ret |= DH_CHECK_PUBKEY_TOO_LARGE;

	BN_free(q);
	return 1;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: dh_check.c,v 1.16 2016/07/05 02:54:35 bcook Exp $ */
2			/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3			* All rights reserved.
4			*
5			* This package is an SSL implementation written
6			* by Eric Young (eay@cryptsoft.com).
7			* The implementation was written so as to conform with Netscapes SSL.
8			*
9			* This library is free for commercial and non-commercial use as long as
10			* the following conditions are aheared to. The following conditions
11			* apply to all code found in this distribution, be it the RC4, RSA,
12			* lhash, DES, etc., code; not just the SSL code. The SSL documentation
13			* included with this distribution is covered by the same copyright terms
14			* except that the holder is Tim Hudson (tjh@cryptsoft.com).
15			*
16			* Copyright remains Eric Young's, and as such any Copyright notices in
17			* the code are not to be removed.
18			* If this package is used in a product, Eric Young should be given attribution
19			* as the author of the parts of the library used.
20			* This can be in the form of a textual message at program startup or
21			* in documentation (online or textual) provided with the package.
22			*
23			* Redistribution and use in source and binary forms, with or without
24			* modification, are permitted provided that the following conditions
25			* are met:
26			* 1. Redistributions of source code must retain the copyright
27			* notice, this list of conditions and the following disclaimer.
28			* 2. Redistributions in binary form must reproduce the above copyright
29			* notice, this list of conditions and the following disclaimer in the
30			* documentation and/or other materials provided with the distribution.
31			* 3. All advertising materials mentioning features or use of this software
32			* must display the following acknowledgement:
33			* "This product includes cryptographic software written by
34			* Eric Young (eay@cryptsoft.com)"
35			* The word 'cryptographic' can be left out if the rouines from the library
36			* being used are not cryptographic related :-).
37			* 4. If you include any Windows specific code (or a derivative thereof) from
38			* the apps directory (application code) you must include an acknowledgement:
39			* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40			*
41			* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44			* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51			* SUCH DAMAGE.
52			*
53			* The licence and distribution terms for any publically available version or
54			* derivative of this code cannot be changed. i.e. this code cannot simply be
55			* copied and put under another distribution licence
56			* [including the GNU Public Licence.]
57			*/
58
59			#include <stdio.h>
60
61			#include <openssl/bn.h>
62			#include <openssl/dh.h>
63
64			/*
65			* Check that p is a safe prime and
66			* if g is 2, 3 or 5, check that it is a suitable generator
67			* where
68			* for 2, p mod 24 == 11
69			* for 3, p mod 12 == 5
70			* for 5, p mod 10 == 3 or 7
71			* should hold.
72			*/
73
74			int
75			DH_check(const DH dh, int ret)
76			{
77			int ok = 0;
78			BN_CTX *ctx = NULL;
79			BN_ULONG l;
80			BIGNUM *q = NULL;
81
82		20	*ret = 0;
83		10	ctx = BN_CTX_new();
84	✓✗	10	if (ctx == NULL)
85			goto err;
86		10	q = BN_new();
87	✓✗	10	if (q == NULL)
88			goto err;
89
90	✓✗✓✓ ✓✗	24	if (BN_is_word(dh->g, DH_GENERATOR_2)) {
91		4	l = BN_mod_word(dh->p, 24);
92	✓✗	4	if (l == (BN_ULONG)-1)
93			goto err;
94	✗✓	4	if (l != 11)
95			*ret \|= DH_NOT_SUITABLE_GENERATOR;
96	✓✗✓✗ ✓✗	18	} else if (BN_is_word(dh->g, DH_GENERATOR_5)) {
97		6	l = BN_mod_word(dh->p, 10);
98	✓✗	6	if (l == (BN_ULONG)-1)
99			goto err;
100	✗✓	6	if (l != 3 && l != 7)
101			*ret \|= DH_NOT_SUITABLE_GENERATOR;
102			} else
103			*ret \|= DH_UNABLE_TO_CHECK_GENERATOR;
104
105	✗✓	10	if (!BN_is_prime_ex(dh->p, BN_prime_checks, ctx, NULL))
106			*ret \|= DH_CHECK_P_NOT_PRIME;
107			else {
108	✓✗	10	if (!BN_rshift1(q, dh->p))
109			goto err;
110	✗✓	10	if (!BN_is_prime_ex(q, BN_prime_checks, ctx, NULL))
111			*ret \|= DH_CHECK_P_NOT_SAFE_PRIME;
112			}
113		10	ok = 1;
114			err:
115		10	BN_CTX_free(ctx);
116		10	BN_free(q);
117		10	return ok;
118			}
119
120			int
121			DH_check_pub_key(const DH dh, const BIGNUM pub_key, int *ret)
122			{
123			BIGNUM *q = NULL;
124
125		712	*ret = 0;
126		356	q = BN_new();
127	✗✓	356	if (q == NULL)
128			return 0;
129		356	BN_set_word(q, 1);
130	✗✓	356	if (BN_cmp(pub_key, q) <= 0)
131			*ret \|= DH_CHECK_PUBKEY_TOO_SMALL;
132		356	BN_copy(q, dh->p);
133		356	BN_sub_word(q, 1);
134	✗✓	356	if (BN_cmp(pub_key, q) >= 0)
135			*ret \|= DH_CHECK_PUBKEY_TOO_LARGE;
136
137		356	BN_free(q);
138		356	return 1;
139		356	}