LibCrypto: Update ModularInverse implementation to use extended GCD

The previous implementation of `ModularInverse` was flaky and did not
compute the correct value in many occasions, especially with big numbers
like in RSA.

Also added a bunch of tests with big numbers.
This commit is contained in:
devgianlu 2024-12-15 16:06:14 +01:00 committed by Ali Mohammad Pur
commit f49a55d089
Notes: github-actions[bot] 2024-12-15 22:32:53 +00:00
4 changed files with 65 additions and 80 deletions

View file

@ -29,7 +29,7 @@ public:
static void extended_GCD_without_allocation(UnsignedBigInteger const& a, UnsignedBigInteger const& b, UnsignedBigInteger& x, UnsignedBigInteger& y, UnsignedBigInteger& gcd, UnsignedBigInteger& temp_quotient, UnsignedBigInteger& temp_1, UnsignedBigInteger& temp_2, UnsignedBigInteger& temp_shift_result, UnsignedBigInteger& temp_shift_plus, UnsignedBigInteger& temp_shift, UnsignedBigInteger& temp_r, UnsignedBigInteger& temp_s, UnsignedBigInteger& temp_t);
static void destructive_GCD_without_allocation(UnsignedBigInteger& temp_a, UnsignedBigInteger& temp_b, UnsignedBigInteger& temp_quotient, UnsignedBigInteger& temp_remainder, UnsignedBigInteger& output);
static void modular_inverse_without_allocation(UnsignedBigInteger const& a_, UnsignedBigInteger const& b, UnsignedBigInteger& temp_1, UnsignedBigInteger& temp_minus, UnsignedBigInteger& temp_quotient, UnsignedBigInteger& temp_d, UnsignedBigInteger& temp_u, UnsignedBigInteger& temp_v, UnsignedBigInteger& temp_x, UnsignedBigInteger& result);
static void modular_inverse_without_allocation(UnsignedBigInteger const& a, UnsignedBigInteger const& b, UnsignedBigInteger& result, UnsignedBigInteger& temp_y, UnsignedBigInteger& temp_gcd, UnsignedBigInteger& temp_quotient, UnsignedBigInteger& temp_1, UnsignedBigInteger& temp_2, UnsignedBigInteger& temp_shift_result, UnsignedBigInteger& temp_shift_plus, UnsignedBigInteger& temp_shift, UnsignedBigInteger& temp_r, UnsignedBigInteger& temp_s, UnsignedBigInteger& temp_t);
static void destructive_modular_power_without_allocation(UnsignedBigInteger& ep, UnsignedBigInteger& base, UnsignedBigInteger const& m, UnsignedBigInteger& temp_1, UnsignedBigInteger& temp_2, UnsignedBigInteger& temp_3, UnsignedBigInteger& temp_multiply, UnsignedBigInteger& temp_quotient, UnsignedBigInteger& temp_remainder, UnsignedBigInteger& result);
static void montgomery_modular_power_with_minimal_allocations(UnsignedBigInteger const& base, UnsignedBigInteger const& exponent, UnsignedBigInteger const& modulo, UnsignedBigInteger& temp_z0, UnsignedBigInteger& temp_rr, UnsignedBigInteger& temp_one, UnsignedBigInteger& temp_z, UnsignedBigInteger& temp_zz, UnsignedBigInteger& temp_x, UnsignedBigInteger& temp_extra, UnsignedBigInteger& result);