258 lines
8.4 KiB
C++
258 lines
8.4 KiB
C++
#define GALOIS_API
|
|
|
|
#include "Galois.h"
|
|
#include <string.h>
|
|
|
|
namespace CryptoCPP{
|
|
namespace Math{
|
|
size_t _ceil(double d)
|
|
{
|
|
return (size_t)d + (d > (size_t)d ? 1 : 0);
|
|
}
|
|
|
|
size_t block_count(size_t bin_block_size, size_t bufs)
|
|
{
|
|
return (bufs * 8) / bin_block_size;
|
|
}
|
|
|
|
void* do_copy(void* v, size_t size)
|
|
{
|
|
char * c = new char[size];
|
|
memcpy(c, v, size);
|
|
return c;
|
|
}
|
|
|
|
GALOIS_API Galois::Galois(
|
|
size_t characteristic,
|
|
size_t exponent,
|
|
size_t * irreducible,
|
|
size_t irreducible_size,
|
|
size_t * value
|
|
) :
|
|
characteristic(characteristic),
|
|
exponent(exponent),
|
|
irreducible(irreducible),
|
|
irreducible_size(irreducible_size),
|
|
binary_block_size(_ceil(characteristic/2.0)),
|
|
data_size(binary_block_size * exponent)
|
|
{
|
|
data = value;
|
|
}
|
|
|
|
GALOIS_API Galois::Galois(const Galois & copy) :
|
|
characteristic(copy.characteristic),
|
|
exponent(copy.exponent),
|
|
irreducible(new size_t[copy.irreducible_size]),
|
|
irreducible_size(copy.irreducible_size),
|
|
binary_block_size(copy.binary_block_size),
|
|
data_size(copy.data_size)
|
|
{
|
|
data = new size_t[data_size];
|
|
memcpy(irreducible, copy.irreducible, irreducible_size * sizeof(size_t));
|
|
memcpy(data, copy.data, data_size * sizeof(size_t));
|
|
}
|
|
|
|
GALOIS_API Galois::~Galois()
|
|
{
|
|
delete[] irreducible;
|
|
delete[] data;
|
|
}
|
|
|
|
GALOIS_API Galois * Galois::add(const Galois * value) const
|
|
{
|
|
bool imSmaller = value->data_size > data_size;
|
|
size_t state_size = imSmaller ? value->data_size : data_size;
|
|
size_t * state = new size_t[state_size];
|
|
memset(state, 0, state_size * sizeof(size_t));
|
|
memcpy(state, imSmaller ? value->data : data, state_size * sizeof(size_t));
|
|
|
|
iadd(imSmaller ? data : value->data, imSmaller ? data_size : value->data_size, binary_block_size, state, state_size, characteristic);
|
|
|
|
return new Galois(characteristic, exponent, (size_t *)do_copy(irreducible, irreducible_size * sizeof(size_t)), irreducible_size, state);
|
|
}
|
|
|
|
GALOIS_API Galois * Galois::sub(const Galois * value) const
|
|
{
|
|
bool imSmaller = value->data_size > data_size;
|
|
size_t state_size = imSmaller ? value->data_size : data_size;
|
|
size_t * state = new size_t[state_size];
|
|
memset(state, 0, state_size * sizeof(size_t));
|
|
memcpy(state, data, data_size * sizeof(size_t));
|
|
|
|
isub(value->data, value->data_size, binary_block_size, state, state_size, characteristic);
|
|
|
|
return new Galois(characteristic, exponent, (size_t *)do_copy(irreducible, irreducible_size * sizeof(size_t)), irreducible_size, state);
|
|
}
|
|
|
|
GALOIS_API Galois * Galois::mul(const Galois * value) const
|
|
{
|
|
bool nb1, nb2;
|
|
size_t
|
|
h1 = high_factor(data, data_size, binary_block_size, &nb1),
|
|
h2 = high_factor(value->data, value->data_size, value->binary_block_size, &nb2);
|
|
|
|
// If one of the values is 0, return a zero-Galois
|
|
if (nb1 || nb2) return new Galois(characteristic, exponent, (size_t *)do_copy(irreducible, irreducible_size * sizeof(size_t)), irreducible_size, (size_t*)memset(new size_t[1], 0, sizeof(size_t)));
|
|
|
|
// The product of two values with the same base is represented as the sum of their exponents
|
|
size_t * state = new size_t[h1 + h2];
|
|
memset(state, 0, (h1 + h2) * sizeof(size_t));
|
|
|
|
imul(value->data, value->data_size, binary_block_size, state, h1 + h2, characteristic, h1, h2);
|
|
|
|
return new Galois(characteristic, exponent, (size_t *)do_copy(irreducible, irreducible_size * sizeof(size_t)), irreducible_size, state);
|
|
}
|
|
|
|
GALOIS_API Galois * Galois::inv() const
|
|
{
|
|
|
|
}
|
|
|
|
// These internal functions assume that an adequate state size has been chose
|
|
GALOIS_API void Galois::iadd(size_t * data, size_t data_size, size_t bin_size, size_t * state, size_t state_size, size_t characteristic)
|
|
{
|
|
for (size_t t = block_count(bin_size, data_size); t > 0; --t)
|
|
set_value(
|
|
t - 1,
|
|
(
|
|
get_value(t-1, bin_size, state) +
|
|
get_value(t - 1, bin_size, data)
|
|
) % characteristic,
|
|
bin_size,
|
|
characteristic,
|
|
state
|
|
);
|
|
}
|
|
|
|
GALOIS_API void Galois::isub(size_t * data, size_t data_size, size_t bin_size, size_t * state, size_t state_size, size_t characteristic)
|
|
{
|
|
for (size_t t = block_count(bin_size, data_size); t > 0; --t)
|
|
set_value(
|
|
t - 1,
|
|
(
|
|
characteristic +
|
|
get_value(t - 1, bin_size, state) -
|
|
get_value(t - 1, bin_size, data)
|
|
) % characteristic,
|
|
bin_size,
|
|
characteristic,
|
|
state
|
|
);
|
|
}
|
|
|
|
GALOIS_API void Galois::imul(size_t * data, size_t data_size, size_t bin_size, size_t * state, size_t state_size, size_t characteristic, size_t high1, size_t high2)
|
|
{
|
|
size_t * temp = new size_t[high1 + high2];
|
|
memset(temp, 0, (high1 + high2) * sizeof(size_t));
|
|
|
|
size_t data_blocks = block_count(bin_size, data_size);
|
|
|
|
for (size_t t = block_count(bin_size, state_size); t > 0; --t)
|
|
{
|
|
memcpy(temp, data, data_size * sizeof(size_t));
|
|
ilsh(temp, data_size + (t*bin_size), t);
|
|
|
|
for (size_t tblk = 0; tblk < data_blocks; ++tblk) // Multiply each element
|
|
set_value(tblk, get_value(tblk, bin_size, data) * get_value(t - 1, bin_size, state), bin_size, characteristic, temp);
|
|
|
|
// Add shifted and multiplied value to state
|
|
iadd(state, data_size + (t*bin_size), bin_size, state, state_size, characteristic);
|
|
}
|
|
}
|
|
|
|
GALOIS_API void Galois::iinv(size_t * state, size_t state_size)
|
|
{
|
|
|
|
}
|
|
|
|
GALOIS_API void Galois::ilsh(size_t * state, size_t state_size, size_t bin_size, size_t characteristic, size_t shiftc)
|
|
{
|
|
for (size_t t = block_count(bin_size, state_size); t > shiftc; --t)
|
|
set_value(t - 1, get_value(t - 1 - shiftc, bin_size, state), bin_size, characteristic, state);
|
|
for (size_t t = shiftc; t > 0; --t)
|
|
set_value(t - 1, 0, bin_size, characteristic, state);
|
|
}
|
|
|
|
GALOIS_API size_t Galois::_mask(size_t bits, bool side)
|
|
{
|
|
size_t result = 0;
|
|
for(size_t t = 0; t<bits; ++t) result = side?(result<<1)|1:(result>>1)|high_bit;
|
|
return result;
|
|
}
|
|
|
|
GALOIS_API size_t Galois::get_value(size_t index, size_t block_size, size_t * from)
|
|
{
|
|
// Compute block/sub-block indexing
|
|
size_t upper_bit_size = ((block_size*index)%(8*sizeof(size_t)))% block_size;
|
|
size_t upper_block_index = (index*block_size)/8;
|
|
size_t lower_block_index = ((index - upper_bit_size)*block_size)/8;
|
|
|
|
// Boundary disparity check
|
|
if(upper_block_index!=lower_block_index)
|
|
{
|
|
// Get block values
|
|
size_t upper_block = from[upper_block_index] & _mask(upper_bit_size, true);
|
|
size_t lower_block = from[lower_block_index] & _mask(block_size -upper_bit_size, false);
|
|
|
|
// Do alignment
|
|
size_t block = (upper_block << (block_size - upper_bit_size)) | (lower_block >> ((sizeof(size_t)*8)-upper_bit_size));
|
|
|
|
return block;
|
|
}
|
|
else
|
|
{
|
|
// Passed: no boundary disparity
|
|
size_t shift = (block_size * index) % (8 * sizeof(size_t));
|
|
size_t block_index = (block_size * index) / (8 * sizeof(size_t));
|
|
|
|
// Get and mask
|
|
return from[block_index] >> shift & _mask(block_size, true);
|
|
}
|
|
}
|
|
|
|
GALOIS_API void Galois::set_value(size_t index, size_t value, size_t block_size, size_t characteristic, size_t * to)
|
|
{
|
|
value = value % characteristic;
|
|
|
|
// Compute block/sub-block indexing
|
|
size_t upper_bit_size = ((block_size*index)%(8*sizeof(size_t)))%block_size;
|
|
size_t upper_block_index = (index*block_size)/8;
|
|
size_t lower_block_index = ((index - upper_bit_size)*block_size)/8;
|
|
|
|
// Boundary disparity check
|
|
if(upper_block_index!=lower_block_index)
|
|
{
|
|
// Mask bits
|
|
to[upper_block_index] &= ~_mask(upper_bit_size, false);
|
|
to[lower_block_index] &= ~_mask(block_size -upper_bit_size, true);
|
|
|
|
// Get block values
|
|
to[upper_block_index] = value >> (block_size - upper_bit_size);
|
|
to[lower_block_index] = (value & _mask(block_size -upper_bit_size, false)) << ((8 * sizeof(size_t)) - (block_size - upper_bit_size));
|
|
}
|
|
else
|
|
{
|
|
// Passed: no boundary disparity
|
|
size_t shift = (block_size * index) % (8 * sizeof(size_t));
|
|
size_t block_index = (block_size * index) / (8 * sizeof(size_t));
|
|
|
|
// Mask bits
|
|
to[block_index] &= ~_mask(block_size, false) << shift;
|
|
|
|
// Apply shift
|
|
to[block_index] = value << shift;
|
|
}
|
|
}
|
|
|
|
GALOIS_API size_t Galois::high_factor(size_t * state, size_t state_size, size_t bin_size, bool * noBits)
|
|
{
|
|
*noBits = false;
|
|
for (size_t t = block_count(bin_size, state_size); t > 0; --t)
|
|
if (get_value(t - 1, bin_size, state))
|
|
return t - 1;
|
|
*noBits = true;
|
|
return 0;
|
|
}
|
|
}
|
|
}
|