optional: Add support for ed448
ed448 is a signing algorithm being standardized by CFRG which operates similarly to ed25519 but has a higher security level. This algorithm is part of TLS 1.3.
This is a nice to have feature, rather than requirement.
- Add in nettle
- Add as a general signature algorithm in gnutls (X.509/PKCS#7)
- Add in TLS
- Test suite for nettle
- Test suite for X.509/PKCS#7 verification / generation
- Test suite for TLS use