@Override
    public void initialize(int keysize, SecureRandom random) {
        if (keysize != 255) {
            throw new IllegalArgumentException("EdDSA only supports key size 255");
        }
    }
An implementation of {@link KeyPairGenerator} for XDH keys which uses BoringSSL to perform all
the operations. This only supports EdDSA keys.
common/src/main/java/org/conscrypt/OpenSslEdDsaKeyPairGenerator.java