More thorough testing

[NegaScout]

current test suits are just sanity checks, the do not cover whole imput range

[NegaScout]

• https://cryptography.io/en/44.0.1/development/test-vectors/
• https://www.ietf.org/archive/id/draft-irtf-cfrg-rsa-guidance-01.html
• https://github.com/C2SP/wycheproof