GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libcrypto/crypto/../../libssl/src/crypto/dh/dh_check.c Lines: 34 50 68.0 %
Date: 2016-12-06 Branches: 15 36 41.7 %

Line Branch Exec Source
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/* $OpenBSD: dh_check.c,v 1.16 2016/07/05 02:54:35 bcook Exp $ */
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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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 * All rights reserved.
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 *
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 * This package is an SSL implementation written
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 * by Eric Young (eay@cryptsoft.com).
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 * The implementation was written so as to conform with Netscapes SSL.
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 *
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 * This library is free for commercial and non-commercial use as long as
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 * the following conditions are aheared to.  The following conditions
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 * apply to all code found in this distribution, be it the RC4, RSA,
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 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
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 * included with this distribution is covered by the same copyright terms
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 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
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 *
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 * Copyright remains Eric Young's, and as such any Copyright notices in
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 * the code are not to be removed.
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 * If this package is used in a product, Eric Young should be given attribution
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 * as the author of the parts of the library used.
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 * This can be in the form of a textual message at program startup or
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 * in documentation (online or textual) provided with the package.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. All advertising materials mentioning features or use of this software
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 *    must display the following acknowledgement:
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 *    "This product includes cryptographic software written by
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 *     Eric Young (eay@cryptsoft.com)"
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 *    The word 'cryptographic' can be left out if the rouines from the library
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 *    being used are not cryptographic related :-).
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 * 4. If you include any Windows specific code (or a derivative thereof) from
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 *    the apps directory (application code) you must include an acknowledgement:
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 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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 *
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 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 *
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 * The licence and distribution terms for any publically available version or
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 * derivative of this code cannot be changed.  i.e. this code cannot simply be
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 * copied and put under another distribution licence
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 * [including the GNU Public Licence.]
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 */
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#include <stdio.h>
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#include <openssl/bn.h>
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#include <openssl/dh.h>
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/*
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 * Check that p is a safe prime and
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 * if g is 2, 3 or 5, check that it is a suitable generator
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 * where
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 * for 2, p mod 24 == 11
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 * for 3, p mod 12 == 5
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 * for 5, p mod 10 == 3 or 7
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 * should hold.
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 */
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int
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DH_check(const DH *dh, int *ret)
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1
{
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1
	int ok = 0;
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1
	BN_CTX *ctx = NULL;
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	BN_ULONG l;
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1
	BIGNUM *q = NULL;
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1
	*ret = 0;
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1
	ctx = BN_CTX_new();
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1
	if (ctx == NULL)
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		goto err;
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1
	q = BN_new();
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1
	if (q == NULL)
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		goto err;
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	if (BN_is_word(dh->g, DH_GENERATOR_2)) {
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		l = BN_mod_word(dh->p, 24);
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		if (l == (BN_ULONG)-1)
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			goto err;
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		if (l != 11)
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			*ret |= DH_NOT_SUITABLE_GENERATOR;
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1
	} else if (BN_is_word(dh->g, DH_GENERATOR_5)) {
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1
		l = BN_mod_word(dh->p, 10);
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1
		if (l == (BN_ULONG)-1)
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			goto err;
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1
		if (l != 3 && l != 7)
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			*ret |= DH_NOT_SUITABLE_GENERATOR;
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	} else
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		*ret |= DH_UNABLE_TO_CHECK_GENERATOR;
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1
	if (!BN_is_prime_ex(dh->p, BN_prime_checks, ctx, NULL))
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		*ret |= DH_CHECK_P_NOT_PRIME;
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	else {
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1
		if (!BN_rshift1(q, dh->p))
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			goto err;
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1
		if (!BN_is_prime_ex(q, BN_prime_checks, ctx, NULL))
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			*ret |= DH_CHECK_P_NOT_SAFE_PRIME;
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	}
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1
	ok = 1;
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1
err:
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1
	BN_CTX_free(ctx);
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1
	BN_free(q);
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1
	return ok;
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}
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int
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DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret)
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18
{
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	BIGNUM *q = NULL;
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	*ret = 0;
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18
	q = BN_new();
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18
	if (q == NULL)
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		return 0;
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18
	BN_set_word(q, 1);
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18
	if (BN_cmp(pub_key, q) <= 0)
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		*ret |= DH_CHECK_PUBKEY_TOO_SMALL;
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18
	BN_copy(q, dh->p);
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18
	BN_sub_word(q, 1);
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18
	if (BN_cmp(pub_key, q) >= 0)
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		*ret |= DH_CHECK_PUBKEY_TOO_LARGE;
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	BN_free(q);
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	return 1;
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}