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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.validator.routines;
19  
20  import java.io.Serializable;
21  import java.util.ArrayList;
22  import java.util.Arrays;
23  import java.util.List;
24  import java.util.regex.Pattern;
25  
26  import org.apache.commons.validator.GenericValidator;
27  
28  /**
29   * <p><strong>InetAddress</strong> validation and conversion routines ({@code java.net.InetAddress}).</p>
30   *
31   * <p>This class provides methods to validate a candidate IP address.
32   *
33   * <p>
34   * This class is a Singleton; you can retrieve the instance via the {@link #getInstance()} method.
35   * </p>
36   *
37   * @since 1.4
38   */
39  public class InetAddressValidator implements Serializable {
40  
41      private static final int MAX_BYTE = 128;
42  
43      private static final int IPV4_MAX_OCTET_VALUE = 255;
44  
45      private static final int MAX_UNSIGNED_SHORT = 0xffff;
46  
47      private static final int BASE_16 = 16;
48  
49      private static final long serialVersionUID = -919201640201914789L;
50  
51      private static final String IPV4_REGEX = "^(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})$";
52  
53      // Max number of hex groups (separated by :) in an IPV6 address
54      private static final int IPV6_MAX_HEX_GROUPS = 8;
55  
56      // Max hex digits in each IPv6 group
57      private static final int IPV6_MAX_HEX_DIGITS_PER_GROUP = 4;
58  
59      /**
60       * Singleton instance of this class.
61       */
62      private static final InetAddressValidator VALIDATOR = new InetAddressValidator();
63  
64      private static final Pattern DIGITS_PATTERN = Pattern.compile("\\d{1,3}");
65  
66      private static final Pattern ID_CHECK_PATTERN = Pattern.compile("[^\\s/%]+");
67  
68      /** IPv4 RegexValidator */
69      private static final RegexValidator IPV4_VALIDATOR = new RegexValidator(IPV4_REGEX);
70  
71      /**
72       * Returns the singleton instance of this validator.
73       *
74       * @return the singleton instance of this validator
75       */
76      public static InetAddressValidator getInstance() {
77          return VALIDATOR;
78      }
79  
80      /**
81       * Constructs a new instance.
82       */
83      public InetAddressValidator() {
84          // empty
85      }
86  
87      /**
88       * Checks if the specified string is a valid IPv4 or IPv6 address.
89       *
90       * @param inetAddress the string to validate
91       * @return true if the string validates as an IP address
92       */
93      public boolean isValid(final String inetAddress) {
94          return isValidInet4Address(inetAddress) || isValidInet6Address(inetAddress);
95      }
96  
97      /**
98       * Validates an IPv4 address. Returns true if valid.
99       *
100      * @param inet4Address the IPv4 address to validate
101      * @return true if the argument contains a valid IPv4 address
102      */
103     public boolean isValidInet4Address(final String inet4Address) {
104         // verify that address conforms to generic IPv4 format
105         final String[] groups = IPV4_VALIDATOR.match(inet4Address);
106         if (groups == null) {
107             return false;
108         }
109         // verify that address subgroups are legal
110         for (final String ipSegment : groups) {
111             if (GenericValidator.isBlankOrNull(ipSegment)) {
112                 return false;
113             }
114             int iIpSegment = 0;
115             try {
116                 iIpSegment = Integer.parseInt(ipSegment);
117             } catch (final NumberFormatException e) {
118                 return false;
119             }
120             if (iIpSegment > IPV4_MAX_OCTET_VALUE || ipSegment.length() > 1 && ipSegment.startsWith("0")) {
121                 return false;
122             }
123         }
124         return true;
125     }
126 
127     /**
128      * Validates an IPv6 address. Returns true if valid.
129      *
130      * @param inet6Address the IPv6 address to validate
131      * @return true if the argument contains a valid IPv6 address
132      * @since 1.4.1
133      */
134     public boolean isValidInet6Address(String inet6Address) {
135         String[] parts;
136         // remove prefix size. This will appear after the zone id (if any)
137         parts = inet6Address.split("/", -1);
138         if (parts.length > 2) {
139             return false; // can only have one prefix specifier
140         }
141         if (parts.length == 2) {
142             if (!DIGITS_PATTERN.matcher(parts[1]).matches()) {
143                 return false; // not a valid number
144             }
145             final int bits = Integer.parseInt(parts[1]); // cannot fail because of RE check
146             if (bits < 0 || bits > MAX_BYTE) {
147                 return false; // out of range
148             }
149         }
150         // remove zone-id
151         parts = parts[0].split("%", -1);
152         // The id syntax is implementation independent, but it presumably cannot allow:
153         // whitespace, '/' or '%'
154         if (parts.length > 2 || parts.length == 2 && !ID_CHECK_PATTERN.matcher(parts[1]).matches()) {
155             return false; // invalid id
156         }
157         inet6Address = parts[0];
158         final boolean containsCompressedZeroes = inet6Address.contains("::");
159         if (containsCompressedZeroes && inet6Address.indexOf("::") != inet6Address.lastIndexOf("::")) {
160             return false;
161         }
162         final boolean startsWithCompressed = inet6Address.startsWith("::");
163         final boolean endsWithCompressed = inet6Address.endsWith("::");
164         final boolean endsWithSep = inet6Address.endsWith(":");
165         if (inet6Address.startsWith(":") && !startsWithCompressed || endsWithSep && !endsWithCompressed) {
166             return false;
167         }
168         String[] octets = inet6Address.split(":");
169         if (containsCompressedZeroes) {
170             final List<String> octetList = new ArrayList<>(Arrays.asList(octets));
171             if (endsWithCompressed) {
172                 // String.split() drops ending empty segments
173                 octetList.add("");
174             } else if (startsWithCompressed && !octetList.isEmpty()) {
175                 octetList.remove(0);
176             }
177             octets = octetList.toArray(new String[0]);
178         }
179         if (octets.length > IPV6_MAX_HEX_GROUPS) {
180             return false;
181         }
182         int validOctets = 0;
183         int emptyOctets = 0; // consecutive empty chunks
184         for (int index = 0; index < octets.length; index++) {
185             final String octet = octets[index];
186             if (GenericValidator.isBlankOrNull(octet)) {
187                 emptyOctets++;
188                 if (emptyOctets > 1) {
189                     return false;
190                 }
191             } else {
192                 emptyOctets = 0;
193                 // Is last chunk an IPv4 address?
194                 if (index == octets.length - 1 && octet.contains(".")) {
195                     if (!isValidInet4Address(octet)) {
196                         return false;
197                     }
198                     validOctets += 2;
199                     continue;
200                 }
201                 if (octet.length() > IPV6_MAX_HEX_DIGITS_PER_GROUP) {
202                     return false;
203                 }
204                 int octetInt = 0;
205                 try {
206                     octetInt = Integer.parseInt(octet, BASE_16);
207                 } catch (final NumberFormatException e) {
208                     return false;
209                 }
210                 if (octetInt < 0 || octetInt > MAX_UNSIGNED_SHORT) {
211                     return false;
212                 }
213             }
214             validOctets++;
215         }
216         if (validOctets > IPV6_MAX_HEX_GROUPS || validOctets < IPV6_MAX_HEX_GROUPS && !containsCompressedZeroes) {
217             return false;
218         }
219         return true;
220     }
221 }