private void configureSigningParametersForDecoding() {
        val result = findRsaJsonWebKeyByProvidedKeyId(webKeySet.getJsonWebKeys());
        if (result.isEmpty()) {
            throw new IllegalArgumentException("Could not locate RSA JSON web key from keystore");
        }
        val key = result.get();
        if (key.getPublicKey() == null) {
            throw new IllegalArgumentException("Public key located from keystore for key id " + key.getKeyId() + " is undefined");
        }
        setSigningKey(key.getPublicKey());
    }
This is {@link JsonWebKeySetStringCipherExecutor}.

@author Misagh Moayyed
@since 5.3.0
core/cas-server-core-util-api/src/main/java/org/apereo/cas/util/cipher/JsonWebKeySetStringCipherExecutor.java