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

signCtx :: ( EllipticCurveEdDSA curve
           , HashAlgorithm hash
           , HashDigestSize hash ~ CurveDigestSize curve
           , ByteArrayAccess ctx
           , ByteArrayAccess msg
           )
        => proxy curve -> ctx -> SecretKey curve -> PublicKey curve hash -> msg -> Signature curve hash
signCtx prx = signPhCtx prx False
signCtx prx = signPhCtx prx False