diff options
Diffstat (limited to 'src/lib/math/numbertheory/powm_mnt.cpp')
| -rw-r--r-- | src/lib/math/numbertheory/powm_mnt.cpp | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/lib/math/numbertheory/powm_mnt.cpp b/src/lib/math/numbertheory/powm_mnt.cpp index 572f0de98..546a2739a 100644 --- a/src/lib/math/numbertheory/powm_mnt.cpp +++ b/src/lib/math/numbertheory/powm_mnt.cpp @@ -41,7 +41,7 @@ void Montgomery_Exponentiator::set_base(const BigInt& base) workspace.data()); m_g[0] = z; - m_g[1] = (base >= m_modulus) ? (base % m_modulus) : base; + m_g[1] = m_reducer.reduce(base); bigint_monty_mul(z, m_g[1], m_R2_mod, m_modulus.data(), m_mod_words, m_mod_prime, @@ -112,6 +112,7 @@ BigInt Montgomery_Exponentiator::execute() const Montgomery_Exponentiator::Montgomery_Exponentiator(const BigInt& mod, Power_Mod::Usage_Hints hints) : m_modulus(mod), + m_reducer(m_modulus), m_mod_words(m_modulus.sig_words()), m_window_bits(1), m_hints(hints) @@ -123,8 +124,8 @@ Montgomery_Exponentiator::Montgomery_Exponentiator(const BigInt& mod, m_mod_prime = monty_inverse(mod.word_at(0)); const BigInt r = BigInt::power_of_2(m_mod_words * BOTAN_MP_WORD_BITS); - m_R_mod = r % m_modulus; - m_R2_mod = (m_R_mod * m_R_mod) % m_modulus; + m_R_mod = m_reducer.reduce(r); + m_R2_mod = m_reducer.square(m_R_mod); m_exp_bits = 0; } |