content: /*
   * Copyright (C) 2018 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.ike.ikev2;
  
  import android.annotation.IntDef;
  import android.util.ArraySet;
  
  import com.android.ike.ikev2.exceptions.AuthenticationFailedException;
  
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.net.Inet4Address;
  import java.net.Inet6Address;
  import java.net.UnknownHostException;
  import java.util.Objects;
  import java.util.Set;
  
  /**
   * IkeIdentification is abstract base class that represents the common information for all types of
   * IKE entity identification.
   *
   * <p>IkeIdentification can be user configured or be constructed from an inbound packet.
   *
   * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.5">RFC 7296, Internet Key Exchange
   *     Protocol Version 2 (IKEv2)</a>
   */
  public abstract class IkeIdentification {
      // Set of supported ID types.
      private static final Set<Integer> SUPPORTED_ID_TYPES;
  
      @Retention(RetentionPolicy.SOURCE)
      @IntDef({
          ID_TYPE_IPV4_ADDR,
          ID_TYPE_FQDN,
          ID_TYPE_RFC822_ADDR,
          ID_TYPE_IPV6_ADDR,
          ID_TYPE_DER_ASN1_DN,
          ID_TYPE_DER_ASN1_GN,
          ID_TYPE_KEY_ID
      })
      public @interface IdType {}
  
      public static final int ID_TYPE_IPV4_ADDR = 1;
      public static final int ID_TYPE_FQDN = 2;
      public static final int ID_TYPE_RFC822_ADDR = 3;
      public static final int ID_TYPE_IPV6_ADDR = 5;
      public static final int ID_TYPE_DER_ASN1_DN = 9;
      public static final int ID_TYPE_DER_ASN1_GN = 10;
      public static final int ID_TYPE_KEY_ID = 11;
  
      static {
          SUPPORTED_ID_TYPES = new ArraySet();
          SUPPORTED_ID_TYPES.add(ID_TYPE_IPV4_ADDR);
          SUPPORTED_ID_TYPES.add(ID_TYPE_FQDN);
          SUPPORTED_ID_TYPES.add(ID_TYPE_RFC822_ADDR);
          SUPPORTED_ID_TYPES.add(ID_TYPE_IPV6_ADDR);
          SUPPORTED_ID_TYPES.add(ID_TYPE_DER_ASN1_DN);
          SUPPORTED_ID_TYPES.add(ID_TYPE_DER_ASN1_GN);
          SUPPORTED_ID_TYPES.add(ID_TYPE_KEY_ID);
      }
  
      public final int idType;
  
      protected IkeIdentification(@IdType int type) {
          idType = type;
      }
  
      /**
       * Return the encoded identification data in a byte array.
       *
       * @return the encoded identification data.
       */
      public abstract byte[] getEncodedIdData();
  
      /** IkeIpv4AddrIdentification represents ID information in IPv4 address ID type. */
      public static class IkeIpv4AddrIdentification extends IkeIdentification {
          public final Inet4Address ipv4Address;
  
          /**
           * Construct an instance of IkeIpv4AddrIdentification from decoding an inbound packet.
           *
           * @param ipv4AddrBytes IPv4 address in byte array.
           * @throws AuthenticationFailedException for decoding bytes error.
           */
          public IkeIpv4AddrIdentification(byte[] ipv4AddrBytes)
                  throws AuthenticationFailedException {
              super(ID_TYPE_IPV4_ADDR);
              try {
                  ipv4Address = (Inet4Address) (Inet4Address.getByAddress(ipv4AddrBytes));
              } catch (ClassCastException | UnknownHostException e) {
                  throw new AuthenticationFailedException(e);
              }
          }
  
          /**
           * Construct an instance of IkeIpv4AddrIdentification with user provided IPv4 address for
           * building outbound packet.
           *
           * @param address user provided IPv4 address
           */
          public IkeIpv4AddrIdentification(Inet4Address address) {
              super(ID_TYPE_IPV4_ADDR);
              ipv4Address = address;
          }
  
          @Override
          public int hashCode() {
              return Objects.hash(idType, ipv4Address);
          }
  
          @Override
          public boolean equals(Object o) {
              if (!(o instanceof IkeIpv4AddrIdentification)) return false;
  
              return ipv4Address.equals(((IkeIpv4AddrIdentification) o).ipv4Address);
          }
  
          /**
           * Retrieve the byte-representation of the IPv4 address.
           *
           * @return the byte-representation of the IPv4 address.
           */
          @Override
          public byte[] getEncodedIdData() {
              return ipv4Address.getAddress();
          }
      }
  
      /** IkeIpv6AddrIdentification represents ID information in IPv6 address ID type. */
      public static class IkeIpv6AddrIdentification extends IkeIdentification {
          public final Inet6Address ipv6Address;
  
          /**
           * Construct an instance of IkeIpv6AddrIdentification from decoding an inbound packet.
           *
           * @param ipv6AddrBytes IPv6 address in byte array.
           * @throws AuthenticationFailedException for decoding bytes error.
           */
          public IkeIpv6AddrIdentification(byte[] ipv6AddrBytes)
                  throws AuthenticationFailedException {
              super(ID_TYPE_IPV6_ADDR);
              try {
                  ipv6Address = (Inet6Address) (Inet6Address.getByAddress(ipv6AddrBytes));
              } catch (ClassCastException | UnknownHostException e) {
                  throw new AuthenticationFailedException(e);
              }
          }
  
          /**
           * Construct an instance of IkeIpv6AddrIdentification with user provided IPv6 address for
           * building outbound packet.
           *
           * @param address user provided IPv6 address
           */
          public IkeIpv6AddrIdentification(Inet6Address address) {
              super(ID_TYPE_IPV6_ADDR);
              ipv6Address = address;
          }
  
          @Override
          public int hashCode() {
              return Objects.hash(idType, ipv6Address);
          }
  
          @Override
          public boolean equals(Object o) {
              if (!(o instanceof IkeIpv6AddrIdentification)) return false;
  
              return ipv6Address.equals(((IkeIpv6AddrIdentification) o).ipv6Address);
          }
  
          /**
           * Retrieve the byte-representation of the IPv6 address.
           *
           * @return the byte-representation of the IPv6 address.
           */
          @Override
          public byte[] getEncodedIdData() {
              return ipv6Address.getAddress();
          }
      }
  }
  