/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 okhttp3.internal.tls;

import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.List;
import javax.net.ssl.SSLPeerUnverifiedException;
import javax.net.ssl.X509TrustManager;
import okhttp3.internal.platform.Platform;

Computes the effective certificate chain from the raw array returned by Java's built in TLS APIs. Cleaning a chain returns a list of certificates where the first element is chain[0], each certificate is signed by the certificate that follows, and the last certificate is a trusted CA certificate. 
Use of the chain cleaner is necessary to omit unexpected certificates that aren't relevant to
the TLS handshake and to extract the trusted CA certificate for the benefit of certificate
pinning.
/**
 * Computes the effective certificate chain from the raw array returned by Java's built in TLS APIs.
 * Cleaning a chain returns a list of certificates where the first element is {@code chain[0]}, each
 * certificate is signed by the certificate that follows, and the last certificate is a trusted CA
 * certificate.
 *
 * <p>Use of the chain cleaner is necessary to omit unexpected certificates that aren't relevant to
 * the TLS handshake and to extract the trusted CA certificate for the benefit of certificate
 * pinning.
 */
public abstract class CertificateChainCleaner {
  public abstract List<Certificate> clean(List<Certificate> chain, String hostname)
      throws SSLPeerUnverifiedException;

  public static CertificateChainCleaner get(X509TrustManager trustManager) {
    return Platform.get().buildCertificateChainCleaner(trustManager);
  }

  public static CertificateChainCleaner get(X509Certificate... caCerts) {
    return new BasicCertificateChainCleaner(new BasicTrustRootIndex(caCerts));
  }
}