feather/src/monero_seed/galois_field.cpp
2022-12-21 16:21:27 +01:00

32 lines
666 B
C++

/*
Copyright (c) 2020 tevador <tevador@gmail.com>
All rights reserved.
*/
#include <monero_seed/galois_field.hpp>
template<unsigned bits, gf_item primitive>
galois_field<bits, primitive>::galois_field() {
gf_item b = 1;
for (gf_item i = 0; i < size_; ++i) {
log_table[b] = i;
exp_table[i] = b;
b <<= 1;
if ((b & size_) != 0)
b ^= primitive;
}
for (auto i = size_ - 1; i < (2 * size_); ++i) {
exp_table[i] = exp_table[i - (size_ - 1)];
}
for (gf_item i = 2; i < size_; i++) {
for (gf_item j = 2; j < size_; j++) {
auto p = mult(i, j);
if (p == 1) {
inv_table[i] = j;
break;
}
}
}
}
template class galois_field<11, 2053>;