- | Sign a prehashed message using the key pair under context @ctx@
signPh :: ( EllipticCurveEdDSA curve
          , HashAlgorithm hash
          , HashDigestSize hash ~ CurveDigestSize curve
          , ByteArrayAccess ctx
          )
       => proxy curve -> ctx -> SecretKey curve -> PublicKey curve hash -> Digest prehash -> Signature curve hash
signPh prx = signPhCtx prx True

signPh :: ( EllipticCurveEdDSA curve
          , HashAlgorithm hash
          , HashDigestSize hash ~ CurveDigestSize curve
          , ByteArrayAccess ctx
          )
       => proxy curve -> ctx -> SecretKey curve -> PublicKey curve hash -> Digest prehash -> Signature curve hash
signPh prx = signPhCtx prx True
signPh prx = signPhCtx prx True