/*
 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
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 *
 */

package java.security;

import java.io.*;
import java.security.cert.CertPath;

/**
 * This class encapsulates information about a code signer.
 * It is immutable.
 *
 * @since 1.5
 * @author Vincent Ryan
 */

public final class CodeSigner implements Serializable {

 private static final long serialVersionUID = 6819288105193937581L;

 /**
 * The signer's certificate path.
 *
 * @serial
 */
 private CertPath signerCertPath;

 /*
 * The signature timestamp.
 *
 * @serial
 */
 private Timestamp timestamp;

 /*
 * Hash code for this code signer.
 */
 private transient int myhash = -1;

 /**
 * Constructs a CodeSigner object.
 *
 * @param signerCertPath The signer's certificate path.
 * It must not be {@code null}.
 * @param timestamp A signature timestamp.
 * If {@code null} then no timestamp was generated
 * for the signature.
 * @throws NullPointerException if {@code signerCertPath} is
 * {@code null}.
 */
 public CodeSigner(CertPath signerCertPath, Timestamp timestamp) {
 if (signerCertPath == null) {
 throw new NullPointerException();
 }
 this.signerCertPath = signerCertPath;
 this.timestamp = timestamp;
 }

 /**
 * Returns the signer's certificate path.
 *
 * @return A certificate path.
 */
 public CertPath getSignerCertPath() {
 return signerCertPath;
 }

 /**
 * Returns the signature timestamp.
 *
 * @return The timestamp or {@code null} if none is present.
 */
 public Timestamp getTimestamp() {
 return timestamp;
 }

 /**
 * Returns the hash code value for this code signer.
 * The hash code is generated using the signer's certificate path and the
 * timestamp, if present.
 *
 * @return a hash code value for this code signer.
 */
 public int hashCode() {
 if (myhash == -1) {
 if (timestamp == null) {
 myhash = signerCertPath.hashCode();
 } else {
 myhash = signerCertPath.hashCode() + timestamp.hashCode();
 }
 }
 return myhash;
 }

 /**
 * Tests for equality between the specified object and this
 * code signer. Two code signers are considered equal if their
 * signer certificate paths are equal and if their timestamps are equal,
 * if present in both.
 *
 * @param obj the object to test for equality with this object.
 *
 * @return true if the objects are considered equal, false otherwise.
 */
 public boolean equals(Object obj) {
 if (obj == null || (!(obj instanceof CodeSigner))) {
 return false;
 }
 CodeSigner that = (CodeSigner)obj;

 if (this == that) {
 return true;
 }
 Timestamp thatTimestamp = that.getTimestamp();
 if (timestamp == null) {
 if (thatTimestamp != null) {
 return false;
 }
 } else {
 if (thatTimestamp == null ||
 (! timestamp.equals(thatTimestamp))) {
 return false;
 }
 }
 return signerCertPath.equals(that.getSignerCertPath());
 }

 /**
 * Returns a string describing this code signer.
 *
 * @return A string comprising the signer's certificate and a timestamp,
 * if present.
 */
 public String toString() {
 StringBuilder sb = new StringBuilder();
 sb.append("(");
 sb.append("Signer: " + signerCertPath.getCertificates().get(0));
 if (timestamp != null) {
 sb.append("timestamp: " + timestamp);
 }
 sb.append(")");
 return sb.toString();
 }

 // Explicitly reset hash code value to -1
 private void readObject(ObjectInputStream ois)
 throws IOException, ClassNotFoundException {
 ois.defaultReadObject();
 myhash = -1;
 }
}