1 /*
2  * Copyright 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package org.conscrypt;
18 
19 import java.util.regex.Pattern;
20 
21 /**
22  * Utilities to check whether IP addresses meet some criteria.
23  */
24 final class AddressUtils {
25     /*
26      * Regex that matches valid IPv4 and IPv6 addresses.
27      */
28     private static final String IP_PATTERN = "^(?:(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9]))|"
29             + "(?i:(?:(?:[0-9a-f]{1,4}:){7}(?:[0-9a-f]{1,4}|:))|(?:(?:[0-9a-f]{1,4}:){6}(?::[0-9a-f]{1,4}|(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3})|:))|(?:(?:[0-9a-f]{1,4}:){5}(?:(?:(?::[0-9a-f]{1,4}){1,2})|:(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3})|:))|(?:(?:[0-9a-f]{1,4}:){4}(?:(?:(?::[0-9a-f]{1,4}){1,3})|(?:(?::[0-9a-f]{1,4})?:(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(?:(?:[0-9a-f]{1,4}:){3}(?:(?:(?::[0-9a-f]{1,4}){1,4})|(?:(?::[0-9a-f]{1,4}){0,2}:(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(?:(?:[0-9a-f]{1,4}:){2}(?:(?:(?::[0-9a-f]{1,4}){1,5})|(?:(?::[0-9a-f]{1,4}){0,3}:(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(?:(?:[0-9a-f]{1,4}:){1}(?:(?:(?::[0-9a-f]{1,4}){1,6})|(?:(?::[0-9a-f]{1,4}){0,4}:(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(?::(?:(?:(?::[0-9a-f]{1,4}){1,7})|(?:(?::[0-9a-f]{1,4}){0,5}:(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:)))(?:%.+)?$";
30 
31     private static Pattern ipPattern;
32 
AddressUtils()33     private AddressUtils() {}
34 
35     /**
36      * Returns true when the supplied hostname is valid for SNI purposes.
37      */
isValidSniHostname(String sniHostname)38     static boolean isValidSniHostname(String sniHostname) {
39         if (sniHostname == null) {
40             return false;
41         }
42 
43         // Must be a FQDN that does not have a trailing dot.
44         return (sniHostname.equalsIgnoreCase("localhost")
45                     || sniHostname.indexOf('.') != -1)
46                 && !isLiteralIpAddress(sniHostname)
47                 && !sniHostname.endsWith(".")
48                 && sniHostname.indexOf('\0') == -1;
49     }
50 
51     /**
52      * Returns true if the supplied hostname is an literal IP address.
53      */
isLiteralIpAddress(String hostname)54     static boolean isLiteralIpAddress(String hostname) {
55         /* This is here for backwards compatibility for pre-Honeycomb devices. */
56         Pattern ipPattern = AddressUtils.ipPattern;
57         if (ipPattern == null) {
58             AddressUtils.ipPattern = ipPattern = Pattern.compile(IP_PATTERN);
59         }
60         return ipPattern.matcher(hostname).matches();
61     }
62 }
63