/*
* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <assert.h>
#include <limits.h>
#include "internal/cryptlib.h"
#include "internal/endian.h"
#include "bn_local.h"
#include <openssl/opensslconf.h>
#include "internal/constant_time.h"
/* This stuff appears to be completely unused, so is deprecated */
#ifndef OPENSSL_NO_DEPRECATED_0_9_8
/*-
* For a 32 bit machine
* 2 - 4 == 128
* 3 - 8 == 256
* 4 - 16 == 512
* 5 - 32 == 1024
* 6 - 64 == 2048
* 7 - 128 == 4096
* 8 - 256 == 8192
*/
static int bn_limit_bits = 0;
static int bn_limit_num = 8; /* (1<<bn_limit_bits) */
static int bn_limit_bits_low = 0;
static int bn_limit_num_low = 8; /* (1<<bn_limit_bits_low) */
static int bn_limit_bits_high = 0;
static int bn_limit_num_high = 8; /* (1<<bn_limit_bits_high) */
static int bn_limit_bits_mont = 0;
static int bn_limit_num_mont = 8; /* (1<<bn_limit_bits_mont) */
void BN_set_params(int mult, int high, int low, int mont)
{
if (mult >= 0) {
if (mult > (int)(sizeof(int) * 8) - 1)
mult = sizeof(int) * 8 - 1;
bn_limit_bits = mult;
bn_limit_num = 1 << mult;
}
if (high >= 0) {
if (high > (int)(sizeof(int) * 8) - 1)
high = sizeof(int) * 8 - 1;
bn_limit_bits_high = high;
bn_limit_num_high = 1 << high;
}
if (low >= 0) {
if (low > (int)(sizeof(int) * 8) - 1)
low = sizeof(int) * 8 - 1;
bn_limit_bits_low = low;
bn_limit_num_low = 1 << low;
}
if (mont >= 0) {
if (mont > (int)(sizeof(int) * 8) - 1)
mont = sizeof(int) * 8 - 1;
bn_limit_bits_mont = mont;
bn_limit_num_mont = 1 << mont;
}
}
int BN_get_params(int which)
{
if (which == 0)
return bn_limit_bits;
else if (which == 1)
return bn_limit_bits_high;
else if (which == 2)
return bn_limit_bits_low;
else if (which == 3)
return bn_limit_bits_mont;
else
return 0;
}
#endif
const BIGNUM *BN_value_one(void)
{
static const BN_ULONG data_one = 1L;
static const BIGNUM const_one =
{ (BN_ULONG *)&data_one, 1, 1, 0, BN_FLG_STATIC_DATA };
return &const_one;
}
/*
* Old Visual Studio ARM compiler miscompiles BN_num_bits_word()
* https://mta.openssl.org/pipermail/openssl-users/2018-August/008465.html
*/
#if defined(_MSC_VER) && defined(_ARM_) && defined(_WIN32_WCE) \
&& _MSC_VER>=1400 && _MSC_VER<1501
# define MS_BROKEN_BN_num_bits_word
# pragma optimize("", off)
#endif
int BN_num_bits_word(BN_ULONG l)
{
BN_ULONG x, mask;
int bits = (l != 0);
#if BN_BITS2 > 32
x = l >> 32;
mask = (0 - x) & BN_MASK2;
mask = (0 - (mask >> (BN_BITS2 - 1)));
bits += 32 & mask;
l ^= (x ^ l) &<