ladybird/Userland/Libraries/LibCrypto/BigInt/Algorithms/GCD.cpp
DexesTTP 5963f6f9ff LibCrypto: Split BigInteger operations into an Algorithms class
Since the operations are already complicated and will become even more
so soon, let's split them into their own files. We can also integrate
the NumberTheory operations that would better fit there into this class
as well.

This commit doesn't change behaviors, but moves the allocation of some
variables into caller classes.
2021-05-13 19:18:07 +01:00

43 lines
1.2 KiB
C++

/*
* Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
* Copyright (c) 2020-2021, Dex♪ <dexes.ttp@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "UnsignedBigIntegerAlgorithms.h"
namespace Crypto {
void UnsignedBigIntegerAlgorithms::destructive_GCD_without_allocation(
UnsignedBigInteger& temp_a,
UnsignedBigInteger& temp_b,
UnsignedBigInteger& temp_1,
UnsignedBigInteger& temp_2,
UnsignedBigInteger& temp_3,
UnsignedBigInteger& temp_4,
UnsignedBigInteger& temp_quotient,
UnsignedBigInteger& temp_remainder,
UnsignedBigInteger& output)
{
for (;;) {
if (temp_a == 0) {
output.set_to(temp_b);
return;
}
// temp_b %= temp_a
divide_without_allocation(temp_b, temp_a, temp_1, temp_2, temp_3, temp_4, temp_quotient, temp_remainder);
temp_b.set_to(temp_remainder);
if (temp_b == 0) {
output.set_to(temp_a);
return;
}
// temp_a %= temp_b
divide_without_allocation(temp_a, temp_b, temp_1, temp_2, temp_3, temp_4, temp_quotient, temp_remainder);
temp_a.set_to(temp_remainder);
}
}
}