bn_rand.c revision e915367e40b579d18ac13c9c58c15fec614d9890
#include "../rename.h"
/* 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.]
*/
#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;
bytes=(bits+7)/8;
bit=(bits-1)%8;
mask=0xff<<bit;
buf=(unsigned char *)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 (top)
{
if (bit == 0)
{
buf[0]=1;
buf[1]|=0x80;
}
else
{
buf[0]|=(3<<(bit-1));
buf[0]&= ~(mask<<1);
}
}
else
{
buf[0]|=(1<<bit);
buf[0]&= ~(mask<<1);
}
if (bottom) /* set bottom bits to whatever odd is */
buf[bytes-1]|=1;
if (!BN_bin2bn(buf,bytes,rnd)) goto err;
ret=1;
err:
if (buf != NULL)
{
memset(buf,0,bytes);
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);
}