amxmodx/third_party/hashing/hashers/keccak.cpp

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// //////////////////////////////////////////////////////////
// keccak.cpp
// Copyright (c) 2014 Stephan Brumme. All rights reserved.
// see http://create.stephan-brumme.com/disclaimer.html
//
#include "keccak.h"
/// same as reset()
Keccak::Keccak(Bits bits)
: m_blockSize(200 - 2 * (bits / 8)),
m_bits(bits)
{
reset();
}
/// same as reset()
void Keccak::changeBits(Bits bits)
{
m_blockSize = (200 - 2 * (bits / 8));
m_bits = bits;
reset();
}
/// restart
void Keccak::reset()
{
for (size_t i = 0; i < StateSize; i++)
m_hash[i] = 0;
m_numBytes = 0;
m_bufferSize = 0;
}
/// constants and local helper functions
namespace
{
const unsigned int KeccakRounds = 24;
const uint64_t XorMasks[KeccakRounds] =
{
0x0000000000000001ULL, 0x0000000000008082ULL, 0x800000000000808aULL,
0x8000000080008000ULL, 0x000000000000808bULL, 0x0000000080000001ULL,
0x8000000080008081ULL, 0x8000000000008009ULL, 0x000000000000008aULL,
0x0000000000000088ULL, 0x0000000080008009ULL, 0x000000008000000aULL,
0x000000008000808bULL, 0x800000000000008bULL, 0x8000000000008089ULL,
0x8000000000008003ULL, 0x8000000000008002ULL, 0x8000000000000080ULL,
0x000000000000800aULL, 0x800000008000000aULL, 0x8000000080008081ULL,
0x8000000000008080ULL, 0x0000000080000001ULL, 0x8000000080008008ULL
};
/// rotate left and wrap around to the right
inline uint64_t rotateLeft(uint64_t x, uint8_t numBits)
{
return (x << numBits) | (x >> (64 - numBits));
}
/// convert litte vs big endian
inline uint64_t swap(uint64_t x)
{
#if defined(__GNUC__) || defined(__clang__)
return __builtin_bswap64(x);
#endif
#ifdef _MSC_VER
return _byteswap_uint64(x);
#endif
return (x >> 56) |
((x >> 40) & 0x000000000000FF00ULL) |
((x >> 24) & 0x0000000000FF0000ULL) |
((x >> 8) & 0x00000000FF000000ULL) |
((x << 8) & 0x000000FF00000000ULL) |
((x << 24) & 0x0000FF0000000000ULL) |
((x << 40) & 0x00FF000000000000ULL) |
(x << 56);
}
/// return x % 5 for 0 <= x <= 9
unsigned int mod5(unsigned int x)
{
if (x < 5)
return x;
return x - 5;
}
}
/// process a full block
void Keccak::processBlock(const void* data)
{
#if defined(__BYTE_ORDER) && (__BYTE_ORDER != 0) && (__BYTE_ORDER == __BIG_ENDIAN)
#define LITTLEENDIAN(x) swap(x)
#else
#define LITTLEENDIAN(x) (x)
#endif
const uint64_t* data64 = (const uint64_t*) data;
// mix data into state
for (unsigned int i = 0; i < m_blockSize / 8; i++)
m_hash[i] ^= LITTLEENDIAN(data64[i]);
// re-compute state
for (unsigned int round = 0; round < KeccakRounds; round++)
{
// Theta
uint64_t coefficients[5];
for (unsigned int i = 0; i < 5; i++)
coefficients[i] = m_hash[i] ^ m_hash[i + 5] ^ m_hash[i + 10] ^ m_hash[i + 15] ^ m_hash[i + 20];
for (unsigned int i = 0; i < 5; i++)
{
uint64_t one = coefficients[mod5(i + 4)] ^ rotateLeft(coefficients[mod5(i + 1)], 1);
m_hash[i ] ^= one;
m_hash[i + 5] ^= one;
m_hash[i + 10] ^= one;
m_hash[i + 15] ^= one;
m_hash[i + 20] ^= one;
}
// temporary
uint64_t one;
// Rho Pi
uint64_t last = m_hash[1];
one = m_hash[10]; m_hash[10] = rotateLeft(last, 1); last = one;
one = m_hash[ 7]; m_hash[ 7] = rotateLeft(last, 3); last = one;
one = m_hash[11]; m_hash[11] = rotateLeft(last, 6); last = one;
one = m_hash[17]; m_hash[17] = rotateLeft(last, 10); last = one;
one = m_hash[18]; m_hash[18] = rotateLeft(last, 15); last = one;
one = m_hash[ 3]; m_hash[ 3] = rotateLeft(last, 21); last = one;
one = m_hash[ 5]; m_hash[ 5] = rotateLeft(last, 28); last = one;
one = m_hash[16]; m_hash[16] = rotateLeft(last, 36); last = one;
one = m_hash[ 8]; m_hash[ 8] = rotateLeft(last, 45); last = one;
one = m_hash[21]; m_hash[21] = rotateLeft(last, 55); last = one;
one = m_hash[24]; m_hash[24] = rotateLeft(last, 2); last = one;
one = m_hash[ 4]; m_hash[ 4] = rotateLeft(last, 14); last = one;
one = m_hash[15]; m_hash[15] = rotateLeft(last, 27); last = one;
one = m_hash[23]; m_hash[23] = rotateLeft(last, 41); last = one;
one = m_hash[19]; m_hash[19] = rotateLeft(last, 56); last = one;
one = m_hash[13]; m_hash[13] = rotateLeft(last, 8); last = one;
one = m_hash[12]; m_hash[12] = rotateLeft(last, 25); last = one;
one = m_hash[ 2]; m_hash[ 2] = rotateLeft(last, 43); last = one;
one = m_hash[20]; m_hash[20] = rotateLeft(last, 62); last = one;
one = m_hash[14]; m_hash[14] = rotateLeft(last, 18); last = one;
one = m_hash[22]; m_hash[22] = rotateLeft(last, 39); last = one;
one = m_hash[ 9]; m_hash[ 9] = rotateLeft(last, 61); last = one;
one = m_hash[ 6]; m_hash[ 6] = rotateLeft(last, 20); last = one;
m_hash[ 1] = rotateLeft(last, 44);
// Chi
for (unsigned int j = 0; j < 25; j += 5)
{
// temporaries
uint64_t one = m_hash[j];
uint64_t two = m_hash[j + 1];
m_hash[j] ^= m_hash[j + 2] & ~two;
m_hash[j + 1] ^= m_hash[j + 3] & ~m_hash[j + 2];
m_hash[j + 2] ^= m_hash[j + 4] & ~m_hash[j + 3];
m_hash[j + 3] ^= one & ~m_hash[j + 4];
m_hash[j + 4] ^= two & ~one;
}
// Iota
m_hash[0] ^= XorMasks[round];
}
}
/// add arbitrary number of bytes
void Keccak::add(const void* data, size_t numBytes)
{
const uint8_t* current = (const uint8_t*) data;
if (m_bufferSize > 0)
{
while (numBytes > 0 && m_bufferSize < m_blockSize)
{
m_buffer[m_bufferSize++] = *current++;
numBytes--;
}
}
// full buffer
if (m_bufferSize == m_blockSize)
{
processBlock((void*)m_buffer);
m_numBytes += m_blockSize;
m_bufferSize = 0;
}
// no more data ?
if (numBytes == 0)
return;
// process full blocks
while (numBytes >= m_blockSize)
{
processBlock(current);
current += m_blockSize;
m_numBytes += m_blockSize;
numBytes -= m_blockSize;
}
// keep remaining bytes in buffer
while (numBytes > 0)
{
m_buffer[m_bufferSize++] = *current++;
numBytes--;
}
}
/// process everything left in the internal buffer
void Keccak::processBuffer()
{
unsigned int blockSize = 200 - 2 * (m_bits / 8);
// add padding
size_t offset = m_bufferSize;
// add a "1" byte
m_buffer[offset++] = 1;
// fill with zeros
while (offset < blockSize - 1)
m_buffer[offset++] = 0;
// and add a single set bit
m_buffer[blockSize - 1] = 0x80;
processBlock(m_buffer);
}
/// return latest hash as 16 hex characters
const char* Keccak::getHash()
{
// process remaining bytes
processBuffer();
// convert hash to string
static const char dec2hex[16 + 1] = "0123456789abcdef";
// number of significant elements in hash (uint64_t)
unsigned int hashLength = m_bits / 64;
static char result[128+1];
size_t written = 0;
for (unsigned int i = 0; i < hashLength; i++)
for (unsigned int j = 0; j < 8; j++) // 64 bits => 8 bytes
{
// convert a byte to hex
unsigned char oneByte = (unsigned char) (m_hash[i] >> (8 * j));
result[written++] = dec2hex[oneByte >> 4];
result[written++] = dec2hex[oneByte & 15];
}
result[written] = 0;
return (const char *)result;
}
/// compute Keccak hash of a memory block
const char* Keccak::operator()(const void* data, size_t numBytes)
{
reset();
add(data, numBytes);
return getHash();
}
/// compute Keccak hash of a string, excluding final zero
const char* Keccak::operator()(const char* text, size_t size)
{
reset();
add(text, size);
return getHash();
}