@Override
    protected void engineInit(AlgorithmParameterSpec algorithmParameterSpec)
            throws InvalidParameterSpecException {
        if (algorithmParameterSpec instanceof PSSParameterSpec) {
            this.spec = (PSSParameterSpec) algorithmParameterSpec;
        } else {
            throw new InvalidParameterSpecException("Only PSSParameterSpec is supported");
        }
    }
AlgorithmParameters implementation for PSS.  The only supported encoding format is ASN.1
(with X.509 accepted as an alias), as specified in RFC 4055 section 3.1.
common/src/main/java/org/conscrypt/PSSParameters.java