/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.server.wifi.hotspot2;

import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.KeyStore;
import java.security.cert.CertPath;
import java.security.cert.CertPathValidator;
import java.security.cert.CertificateFactory;
import java.security.cert.PKIXParameters;
import java.security.cert.X509Certificate;
import java.util.Arrays;

/**
 * Utility class used for verifying certificates against the pre-loaded public CAs in the
 * system key store.  This class is created to allow the certificate verification to be mocked in
 * unit tests.
 */
public class CertificateVerifier {

    /**
     * Verify that the given certificate is trusted by one of the pre-loaded public CAs in the
     * system key store.
     *
     * @param caCert The CA Certificate to verify
     * @throws GeneralSecurityException
     * @throws IOException
     */
    public void verifyCaCert(X509Certificate caCert)
            throws GeneralSecurityException, IOException {
        CertificateFactory factory = CertificateFactory.getInstance("X.509");
        CertPathValidator validator =
                CertPathValidator.getInstance(CertPathValidator.getDefaultType());
        CertPath path = factory.generateCertPath(
                Arrays.asList(caCert));
        KeyStore ks = KeyStore.getInstance("AndroidCAStore");
        ks.load(null, null);
        PKIXParameters params = new PKIXParameters(ks);
        params.setRevocationEnabled(false);
        validator.validate(path, params);
    }
}