BigNumber.cpp

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/*
 * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "Cryptography/BigNumber.h"
#include "Errors.h"
#include <openssl/bn.h>
#include <algorithm>
#include <memory>
 
BigNumber::BigNumber()
 : _bn(BN_new())
{ }
 
BigNumber::BigNumber(BigNumber const& bn)
 : _bn(BN_dup(bn.BN()))
{ }
 
BigNumber::~BigNumber()
{
 BN_free(_bn);
}
 
void BigNumber::SetDword(int32 val)
{
 SetDword(uint32(abs(val)));
 if (val < 0)
 BN_set_negative(_bn, 1);
}
 
void BigNumber::SetDword(uint32 val)
{
 BN_set_word(_bn, val);
}
 
void BigNumber::SetQword(uint64 val)
{
 BN_set_word(_bn, (uint32)(val >> 32));
 BN_lshift(_bn, _bn, 32);
 BN_add_word(_bn, (uint32)(val & 0xFFFFFFFF));
}
 
void BigNumber::SetBinary(uint8 const* bytes, int32 len, bool littleEndian)
{
 if (littleEndian)
 BN_lebin2bn(bytes, len, _bn);
 else
 BN_bin2bn(bytes, len, _bn);
}
 
bool BigNumber::SetHexStr(char const* str)
{
 int n = BN_hex2bn(&_bn, str);
 return (n > 0);
}
 
void BigNumber::SetRand(int32 numbits)
{
 BN_rand(_bn, numbits, 0, 1);
}
 
BigNumber& BigNumber::operator=(BigNumber const& bn)
{
 if (this == &bn)
 return *this;
 
 BN_copy(_bn, bn._bn);
 return *this;
}
 
BigNumber& BigNumber::operator+=(BigNumber const& bn)
{
 BN_add(_bn, _bn, bn._bn);
 return *this;
}
 
BigNumber& BigNumber::operator-=(BigNumber const& bn)
{
 BN_sub(_bn, _bn, bn._bn);
 return *this;
}
 
BigNumber& BigNumber::operator*=(BigNumber const& bn)
{
 BN_CTX *bnctx;
 
 bnctx = BN_CTX_new();
 BN_mul(_bn, _bn, bn._bn, bnctx);
 BN_CTX_free(bnctx);
 
 return *this;
}
 
BigNumber& BigNumber::operator/=(BigNumber const& bn)
{
 BN_CTX *bnctx;
 
 bnctx = BN_CTX_new();
 BN_div(_bn, nullptr, _bn, bn._bn, bnctx);
 BN_CTX_free(bnctx);
 
 return *this;
}
 
BigNumber& BigNumber::operator%=(BigNumber const& bn)
{
 BN_CTX *bnctx;
 
 bnctx = BN_CTX_new();
 BN_nnmod(_bn, _bn, bn._bn, bnctx);
 BN_CTX_free(bnctx);
 
 return *this;
}
 
BigNumber& BigNumber::operator<<=(int n)
{
 BN_lshift(_bn, _bn, n);
 return *this;
}
 
int32 BigNumber::CompareTo(BigNumber const& bn) const
{
 return BN_cmp(_bn, bn._bn);
}
 
BigNumber BigNumber::Exp(BigNumber const& bn) const
{
 BigNumber ret;
 BN_CTX *bnctx;
 
 bnctx = BN_CTX_new();
 BN_exp(ret._bn, _bn, bn._bn, bnctx);
 BN_CTX_free(bnctx);
 
 return ret;
}
 
BigNumber BigNumber::ModExp(BigNumber const& bn1, BigNumber const& bn2) const
{
 BigNumber ret;
 BN_CTX *bnctx;
 
 bnctx = BN_CTX_new();
 BN_mod_exp(ret._bn, _bn, bn1._bn, bn2._bn, bnctx);
 BN_CTX_free(bnctx);
 
 return ret;
}
 
int32 BigNumber::GetNumBytes() const
{
 return BN_num_bytes(_bn);
}
 
int32 BigNumber::GetNumBits() const
{
 return BN_num_bits(_bn);
}
 
uint32 BigNumber::AsDword() const
{
 return (uint32)BN_get_word(_bn);
}
 
bool BigNumber::IsZero() const
{
 return BN_is_zero(_bn);
}
 
bool BigNumber::IsNegative() const
{
 return BN_is_negative(_bn);
}
 
void BigNumber::GetBytes(uint8* buf, size_t bufsize, bool littleEndian) const
{
 int res = littleEndian ? BN_bn2lebinpad(_bn, buf, bufsize) : BN_bn2binpad(_bn, buf, bufsize);
 ASSERT(res > 0, "Buffer of size %zu is too small to hold bignum with %d bytes.\n", bufsize, BN_num_bytes(_bn));
}
 
std::vector<uint8> BigNumber::ToByteVector(int32 minSize, bool littleEndian) const
{
 std::size_t length = std::max(GetNumBytes(), minSize);
 std::vector<uint8> v;
 v.resize(length);
 GetBytes(v.data(), length, littleEndian);
 return v;
}
 
std::string BigNumber::AsHexStr() const
{
 char* ch = BN_bn2hex(_bn);
 std::string ret = ch;
 OPENSSL_free(ch);
 return ret;
}
 
std::string BigNumber::AsDecStr() const
{
 char* ch = BN_bn2dec(_bn);
 std::string ret = ch;
 OPENSSL_free(ch);
 return ret;
}