288 lines
8.9 KiB
C
288 lines
8.9 KiB
C
/* crypto/bn/bn_rand.c */
|
|
/* 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.]
|
|
*/
|
|
/* ====================================================================
|
|
* Copyright (c) 1998-2001 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 <stdio.h>
|
|
#include <time.h>
|
|
#include "cryptlib.h"
|
|
#include "bn_lcl.h"
|
|
#include <openssl/rand.h>
|
|
|
|
static int bnrand(int pseudorand, BIGNUM *rnd, int bits, int top, int bottom)
|
|
{
|
|
unsigned char *buf=NULL;
|
|
int ret=0,bit,bytes,mask;
|
|
time_t tim;
|
|
|
|
if (bits == 0)
|
|
{
|
|
BN_zero(rnd);
|
|
return 1;
|
|
}
|
|
|
|
bytes=(bits+7)/8;
|
|
bit=(bits-1)%8;
|
|
mask=0xff<<(bit+1);
|
|
|
|
buf=(unsigned char *)OPENSSL_malloc(bytes);
|
|
if (buf == NULL)
|
|
{
|
|
BNerr(BN_F_BN_RAND,ERR_R_MALLOC_FAILURE);
|
|
goto err;
|
|
}
|
|
|
|
/* make a random number and set the top and bottom bits */
|
|
time(&tim);
|
|
RAND_add(&tim,sizeof(tim),0);
|
|
|
|
if (pseudorand)
|
|
{
|
|
if (RAND_pseudo_bytes(buf, bytes) == -1)
|
|
goto err;
|
|
}
|
|
else
|
|
{
|
|
if (RAND_bytes(buf, bytes) <= 0)
|
|
goto err;
|
|
}
|
|
|
|
#if 1
|
|
if (pseudorand == 2)
|
|
{
|
|
/* generate patterns that are more likely to trigger BN
|
|
library bugs */
|
|
int i;
|
|
unsigned char c;
|
|
|
|
for (i = 0; i < bytes; i++)
|
|
{
|
|
RAND_pseudo_bytes(&c, 1);
|
|
if (c >= 128 && i > 0)
|
|
buf[i] = buf[i-1];
|
|
else if (c < 42)
|
|
buf[i] = 0;
|
|
else if (c < 84)
|
|
buf[i] = 255;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (top != -1)
|
|
{
|
|
if (top)
|
|
{
|
|
if (bit == 0)
|
|
{
|
|
buf[0]=1;
|
|
buf[1]|=0x80;
|
|
}
|
|
else
|
|
{
|
|
buf[0]|=(3<<(bit-1));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
buf[0]|=(1<<bit);
|
|
}
|
|
}
|
|
buf[0] &= ~mask;
|
|
if (bottom) /* set bottom bit if requested */
|
|
buf[bytes-1]|=1;
|
|
if (!BN_bin2bn(buf,bytes,rnd)) goto err;
|
|
ret=1;
|
|
err:
|
|
if (buf != NULL)
|
|
{
|
|
memset(buf,0,bytes);
|
|
OPENSSL_free(buf);
|
|
}
|
|
return(ret);
|
|
}
|
|
|
|
int BN_rand(BIGNUM *rnd, int bits, int top, int bottom)
|
|
{
|
|
return bnrand(0, rnd, bits, top, bottom);
|
|
}
|
|
|
|
int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom)
|
|
{
|
|
return bnrand(1, rnd, bits, top, bottom);
|
|
}
|
|
|
|
#if 1
|
|
int BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom)
|
|
{
|
|
return bnrand(2, rnd, bits, top, bottom);
|
|
}
|
|
#endif
|
|
|
|
/* random number r: 0 <= r < range */
|
|
static int bn_rand_range(int pseudo, BIGNUM *r, BIGNUM *range)
|
|
{
|
|
int (*bn_rand)(BIGNUM *, int, int, int) = pseudo ? BN_pseudo_rand : BN_rand;
|
|
int n;
|
|
|
|
if (range->neg || BN_is_zero(range))
|
|
{
|
|
BNerr(BN_F_BN_RAND_RANGE, BN_R_INVALID_RANGE);
|
|
return 0;
|
|
}
|
|
|
|
n = BN_num_bits(range); /* n > 0 */
|
|
|
|
if (n == 1)
|
|
{
|
|
if (!BN_zero(r)) return 0;
|
|
}
|
|
else if (BN_is_bit_set(range, n - 2))
|
|
{
|
|
do
|
|
{
|
|
/* range = 11..._2, so each iteration succeeds with probability >= .75 */
|
|
if (!bn_rand(r, n, -1, 0)) return 0;
|
|
}
|
|
while (BN_cmp(r, range) >= 0);
|
|
}
|
|
else
|
|
{
|
|
/* range = 10..._2,
|
|
* so 3*range (= 11..._2) is exactly one bit longer than range */
|
|
do
|
|
{
|
|
if (!bn_rand(r, n + 1, -1, 0)) return 0;
|
|
/* If r < 3*range, use r := r MOD range
|
|
* (which is either r, r - range, or r - 2*range).
|
|
* Otherwise, iterate once more.
|
|
* Since 3*range = 11..._2, each iteration succeeds with
|
|
* probability >= .75. */
|
|
if (BN_cmp(r ,range) >= 0)
|
|
{
|
|
if (!BN_sub(r, r, range)) return 0;
|
|
if (BN_cmp(r, range) >= 0)
|
|
if (!BN_sub(r, r, range)) return 0;
|
|
}
|
|
}
|
|
while (BN_cmp(r, range) >= 0);
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
int BN_rand_range(BIGNUM *r, BIGNUM *range)
|
|
{
|
|
return bn_rand_range(0, r, range);
|
|
}
|
|
|
|
int BN_pseudo_rand_range(BIGNUM *r, BIGNUM *range)
|
|
{
|
|
return bn_rand_range(1, r, range);
|
|
}
|