mirror of
https://github.com/openssl/openssl.git
synced 2025-01-18 13:44:20 +08:00
dd1d7bcb69
FIPS 186-4 has 5 different algorithms for key generation, and all of them rely on testing GCD(a,n) == 1 many times. Cachegrind was showing that during a RSA keygen operation, the function BN_gcd() was taking a considerable percentage of the total cycles. The default provider uses multiprime keygen, which seemed to be much faster. This is because it uses BN_mod_inverse() instead. For a 4096 bit key, the entropy of a key that was taking a long time to generate was recorded and fed back into subsequent runs. Roughly 40% of the cycle time was BN_gcd() with most of the remainder in the prime testing. Changing to use the inverse resulted in the cycle count being 96% in the prime testing. Reviewed-by: Paul Dale <pauli@openssl.org> Reviewed-by: Tomas Mraz <tomas@openssl.org> (Merged from https://github.com/openssl/openssl/pull/19578) |
||
|---|---|---|
| .. | ||
| crypto | ||
| internal | ||
| openssl | ||