GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libcrypto/bn/bn_rand.c Lines: 57 77 74.0 %
Date: 2017-11-13 Branches: 42 56 75.0 %

Line Branch Exec Source
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/* $OpenBSD: bn_rand.c,v 1.20 2017/05/02 03:59:44 deraadt 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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/* ====================================================================
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 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
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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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 *
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 *
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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
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 *    the documentation and/or other materials provided with the
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 *    distribution.
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 *
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 * 3. All advertising materials mentioning features or use of this
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 *    software must display the following acknowledgment:
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 *    "This product includes software developed by the OpenSSL Project
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 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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 *
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 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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 *    endorse or promote products derived from this software without
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 *    prior written permission. For written permission, please contact
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 *    openssl-core@openssl.org.
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 *
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 * 5. Products derived from this software may not be called "OpenSSL"
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 *    nor may "OpenSSL" appear in their names without prior written
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 *    permission of the OpenSSL Project.
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 *
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 * 6. Redistributions of any form whatsoever must retain the following
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 *    acknowledgment:
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 *    "This product includes software developed by the OpenSSL Project
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 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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 * OF THE POSSIBILITY OF SUCH DAMAGE.
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 * ====================================================================
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 *
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 * This product includes cryptographic software written by Eric Young
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 * (eay@cryptsoft.com).  This product includes software written by Tim
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 * Hudson (tjh@cryptsoft.com).
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 *
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <openssl/err.h>
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#include "bn_lcl.h"
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static int
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bnrand(int pseudorand, BIGNUM *rnd, int bits, int top, int bottom)
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{
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	unsigned char *buf = NULL;
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	int ret = 0, bit, bytes, mask;
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134816
	if (rnd == NULL) {
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		BNerror(ERR_R_PASSED_NULL_PARAMETER);
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		return (0);
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	}
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67408
	if (bits == 0) {
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		BN_zero(rnd);
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		return (1);
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	}
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67408
	bytes = (bits + 7) / 8;
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67408
	bit = (bits - 1) % 8;
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67408
	mask = 0xff << (bit + 1);
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67408
	buf = malloc(bytes);
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67408
	if (buf == NULL) {
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		BNerror(ERR_R_MALLOC_FAILURE);
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		goto err;
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	}
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	/* make a random number and set the top and bottom bits */
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67408
	arc4random_buf(buf, bytes);
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#if 1
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67408
	if (pseudorand == 2) {
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		/* generate patterns that are more likely to trigger BN
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		   library bugs */
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		int i;
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10157
		unsigned char c;
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2171511
		for (i = 0; i < bytes; i++) {
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762474
			arc4random_buf(&c, 1);
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762474
			if (c >= 128 && i > 0)
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376595
				buf[i] = buf[i - 1];
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385879
			else if (c < 42)
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124797
				buf[i] = 0;
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261082
			else if (c < 84)
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124857
				buf[i] = 255;
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		}
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10157
	}
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#endif
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67408
	if (top != -1) {
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31355
		if (top) {
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1485
			if (bit == 0) {
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				buf[0] = 1;
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				buf[1] |= 0x80;
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			} else {
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1485
				buf[0] |= (3 << (bit - 1));
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			}
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		} else {
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29870
			buf[0] |= (1 << bit);
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		}
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31355
	}
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67408
	buf[0] &= ~mask;
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67408
	if (bottom) /* set bottom bit if requested */
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20560
		buf[bytes - 1] |= 1;
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67408
	if (BN_bin2bn(buf, bytes, rnd) == NULL)
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		goto err;
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67408
	ret = 1;
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err:
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67408
	freezero(buf, bytes);
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	bn_check_top(rnd);
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67408
	return (ret);
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67408
}
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int
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BN_rand(BIGNUM *rnd, int bits, int top, int bottom)
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{
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52636
	return bnrand(0, rnd, bits, top, bottom);
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}
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int
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BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom)
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{
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61866
	return bnrand(1, rnd, bits, top, bottom);
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}
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#if 1
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int
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BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom)
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{
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20314
	return bnrand(2, rnd, bits, top, bottom);
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}
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#endif
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/* random number r:  0 <= r < range */
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static int
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bn_rand_range(int pseudo, BIGNUM *r, const BIGNUM *range)
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{
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56862
	int (*bn_rand)(BIGNUM *, int, int, int) = pseudo ? BN_pseudo_rand : BN_rand;
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	int n;
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	int count = 100;
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56862
	if (range->neg || BN_is_zero(range)) {
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		BNerror(BN_R_INVALID_RANGE);
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		return 0;
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	}
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28431
	n = BN_num_bits(range); /* n > 0 */
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	/* BN_is_bit_set(range, n - 1) always holds */
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28431
	if (n == 1)
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		BN_zero(r);
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41117
	else if (!BN_is_bit_set(range, n - 2) && !BN_is_bit_set(range, n - 3)) {
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		/* range = 100..._2,
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		 * so  3*range (= 11..._2)  is exactly one bit longer than  range */
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6643
		do {
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7935
			if (!bn_rand(r, n + 1, -1, 0))
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				return 0;
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			/* If  r < 3*range,  use  r := r MOD range
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			 * (which is either  r, r - range,  or  r - 2*range).
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			 * Otherwise, iterate once more.
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			 * Since  3*range = 11..._2, each iteration succeeds with
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			 * probability >= .75. */
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7935
			if (BN_cmp(r, range) >= 0) {
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5695
				if (!BN_sub(r, r, range))
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					return 0;
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5695
				if (BN_cmp(r, range) >= 0)
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3493
					if (!BN_sub(r, r, range))
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						return 0;
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			}
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253
7935
			if (!--count) {
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				BNerror(BN_R_TOO_MANY_ITERATIONS);
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				return 0;
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			}
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258
7935
		} while (BN_cmp(r, range) >= 0);
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	} else {
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21788
		do {
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			/* range = 11..._2  or  range = 101..._2 */
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26772
			if (!bn_rand(r, n, -1, 0))
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				return 0;
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265
26772
			if (!--count) {
266
				BNerror(BN_R_TOO_MANY_ITERATIONS);
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				return 0;
268
			}
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26772
		} while (BN_cmp(r, range) >= 0);
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	}
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272
	bn_check_top(r);
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28431
	return 1;
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28431
}
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276
int
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BN_rand_range(BIGNUM *r, const BIGNUM *range)
278
{
279
6572
	return bn_rand_range(0, r, range);
280
}
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282
int
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BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range)
284
{
285
50290
	return bn_rand_range(1, r, range);
286
}