Avoid using old pow_mod interface in RSA

On its own gives a modest speedup (3-5%) to RSA sign/decrypt, and it
is needed for another more complicated optimization.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/lib/math/numbertheory/monty.cpp b/src/lib/math/numbertheory/monty.cpp
index f2a31d8e1..b05bdd30b 100644
--- a/src/lib/math/numbertheory/monty.cpp
+++ b/src/lib/math/numbertheory/monty.cpp
@@ -39,6 +39,7 @@ Montgomery_Params::Montgomery_Params(const BigInt& p)
 
    const BigInt r = BigInt::power_of_2(m_p_words * BOTAN_MP_WORD_BITS);
 
+   // It might be faster to use ct_modulo here vs setting up Barrett reduction?
    Modular_Reducer mod_p(p);
 
    m_r1 = mod_p.reduce(r);