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/*==LICENSE==*
CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.
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 3 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/>.
You can contact Cyan Worlds, Inc. by email legal@cyan.com
or by snail mail at:
Cyan Worlds, Inc.
14617 N Newport Hwy
Mead, WA 99021
*==LICENSE==*/
/*****************************************************************************
*
* $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtBigNum.h
*
***/
#ifdef PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTBIGNUM_H
#error "Header $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtBigNum.h included more than once"
#endif
#define PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTBIGNUM_H
/*****************************************************************************
*
* BigNum class
*
***/
#include <openssl/bn.h>
class BigNum {
private:
BIGNUM m_number;
mutable BN_CTX * m_context;
BN_CTX * GetContext () const
{
if (!m_context)
m_context = BN_CTX_new();
return m_context;
}
public:
BigNum ();
BigNum (const BigNum & a);
BigNum (unsigned a);
BigNum (unsigned bytes, const void * data, bool le=false);
~BigNum ();
BigNum & operator= (const BigNum & a)
{
BN_copy(&m_number, &a.m_number);
return *this;
}
// Constant parameters need not be distinct from the destination or from
// each other
void Add (const BigNum & a, dword b)
{
// this = a + b
BN_copy(&m_number, &a.m_number);
BN_add_word(&m_number, b);
}
void Add (const BigNum & a, const BigNum & b)
{
// this = a + b
BN_add(&m_number, &a.m_number, &b.m_number);
}
int Compare (dword a) const;
int Compare (const BigNum & a) const
{
return BN_cmp(&m_number, &a.m_number);
}
void Div (const BigNum & a, dword b, dword * remainder)
{
// this = a / b, remainder = a % b
BN_copy(&m_number, &a.m_number);
*remainder = (dword)BN_div_word(&m_number, b);
}
void Div (const BigNum & a, const BigNum & b, BigNum * remainder)
{
// this = a / b, remainder = a % b
// either this or remainder may be nil
BN_div(this ? &m_number : nil, remainder ? &remainder->m_number : nil,
&a.m_number, &b.m_number, GetContext());
}
void FromData_BE (unsigned bytes, const void * data)
{
BN_bin2bn((const unsigned char *)data, bytes, &m_number);
}
void FromData_LE (unsigned bytes, const void * data);
unsigned char * GetData_BE (unsigned * bytes) const;
unsigned char * GetData_LE (unsigned * bytes) const;
bool IsPrime () const
{
// Cyan's code uses 3 checks, so we'll follow suit.
// This provides an accurate answer to p < 0.015625
return BN_is_prime_fasttest(&m_number, 3, nil, GetContext(), nil, 1) > 0;
}
void Mod (const BigNum & a, const BigNum & b)
{
// this = a % b
BN_div(nil, &m_number, &a.m_number, &b.m_number, GetContext());
}
void Mul (const BigNum & a, dword b)
{
// this = a * b
BN_copy(&m_number, &a.m_number);
BN_mul_word(&m_number, b);
}
void Mul (const BigNum & a, const BigNum & b)
{
// this = a * b
BN_mul(&m_number, &a.m_number, &b.m_number, GetContext());
}
void PowMod (dword a, const BigNum & b, const BigNum & c)
{
// this = a ^ b % c
PowMod(BigNum(a), b, c);
}
void PowMod (const BigNum & a, const BigNum & b, const BigNum & c)
{
// this = a ^ b % c
BN_mod_exp(&m_number, &a.m_number, &b.m_number, &c.m_number, GetContext());
}
void Rand (const BigNum & a, BigNum * seed)
{
// this = random number less than a
unsigned bits = BN_num_bits(&a.m_number);
do
Rand(bits, seed);
while (Compare(a) >= 0);
}
void Rand (unsigned bits, BigNum * seed);
void RandPrime (unsigned bits, BigNum * seed)
{
BN_generate_prime(&m_number, bits, 1, nil, nil, nil, nil);
}
void Set (const BigNum & a)
{
BN_copy(&m_number, &a.m_number);
}
void Set (unsigned a)
{
BN_set_word(&m_number, a);
}
void SetOne () { Set(1); }
void SetZero () { Set(0); }
void Shl (const BigNum & a, unsigned b)
{
// this = a << b
BN_lshift(&m_number, &a.m_number, b);
}
void Shr (const BigNum & a, unsigned b)
{
// this = a >> b
BN_rshift(&m_number, &a.m_number, b);
}
void Sub (const BigNum & a, dword b)
{
// this = a - b
BN_copy(&m_number, &a.m_number);
BN_sub_word(&m_number, b);
}
void Sub (const BigNum & a, const BigNum & b)
{
// this = a - b
BN_sub(&m_number, &a.m_number, &b.m_number);
}
};