The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 2 | * Copyright (C) 2010 The Android Open Source Project |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 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 | */ |
Dianne Hackborn | 2269d157 | 2010-02-24 19:54:22 -0800 | [diff] [blame] | 16 | package com.android.internal.net; |
| 17 | |
Robert Greenwalt | e590373 | 2011-02-22 16:00:42 -0800 | [diff] [blame] | 18 | import android.net.NetworkUtils; |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 19 | import android.util.Config; |
| 20 | import android.util.Log; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 21 | |
| 22 | import java.net.InetAddress; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 23 | import java.security.cert.CertificateParsingException; |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 24 | import java.security.cert.X509Certificate; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 25 | import java.util.Collection; |
| 26 | import java.util.Iterator; |
| 27 | import java.util.List; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 28 | import java.util.regex.Pattern; |
| 29 | import java.util.regex.PatternSyntaxException; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 30 | |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 31 | import javax.security.auth.x500.X500Principal; |
| 32 | |
Dianne Hackborn | 2269d157 | 2010-02-24 19:54:22 -0800 | [diff] [blame] | 33 | /** @hide */ |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 34 | public class DomainNameValidator { |
| 35 | private final static String TAG = "DomainNameValidator"; |
| 36 | |
| 37 | private static final boolean DEBUG = false; |
| 38 | private static final boolean LOG_ENABLED = DEBUG ? Config.LOGD : Config.LOGV; |
| 39 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 40 | private static final int ALT_DNS_NAME = 2; |
| 41 | private static final int ALT_IPA_NAME = 7; |
| 42 | |
| 43 | /** |
| 44 | * Checks the site certificate against the domain name of the site being visited |
| 45 | * @param certificate The certificate to check |
| 46 | * @param thisDomain The domain name of the site being visited |
| 47 | * @return True iff if there is a domain match as specified by RFC2818 |
| 48 | */ |
| 49 | public static boolean match(X509Certificate certificate, String thisDomain) { |
| 50 | if (certificate == null || thisDomain == null || thisDomain.length() == 0) { |
| 51 | return false; |
| 52 | } |
| 53 | |
| 54 | thisDomain = thisDomain.toLowerCase(); |
| 55 | if (!isIpAddress(thisDomain)) { |
| 56 | return matchDns(certificate, thisDomain); |
| 57 | } else { |
| 58 | return matchIpAddress(certificate, thisDomain); |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * @return True iff the domain name is specified as an IP address |
| 64 | */ |
| 65 | private static boolean isIpAddress(String domain) { |
| 66 | boolean rval = (domain != null && domain.length() != 0); |
| 67 | if (rval) { |
| 68 | try { |
| 69 | // do a quick-dirty IP match first to avoid DNS lookup |
Robert Greenwalt | e590373 | 2011-02-22 16:00:42 -0800 | [diff] [blame] | 70 | rval = domain.equals( |
| 71 | NetworkUtils.numericToInetAddress(domain).getHostAddress()); |
| 72 | } catch (IllegalArgumentException e) { |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 73 | if (LOG_ENABLED) { |
Robert Greenwalt | e590373 | 2011-02-22 16:00:42 -0800 | [diff] [blame] | 74 | Log.v(TAG, "DomainNameValidator.isIpAddress(): " + e); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 75 | } |
| 76 | |
| 77 | rval = false; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | return rval; |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Checks the site certificate against the IP domain name of the site being visited |
| 86 | * @param certificate The certificate to check |
| 87 | * @param thisDomain The DNS domain name of the site being visited |
| 88 | * @return True iff if there is a domain match as specified by RFC2818 |
| 89 | */ |
| 90 | private static boolean matchIpAddress(X509Certificate certificate, String thisDomain) { |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 91 | if (LOG_ENABLED) { |
| 92 | Log.v(TAG, "DomainNameValidator.matchIpAddress(): this domain: " + thisDomain); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 93 | } |
| 94 | |
| 95 | try { |
| 96 | Collection subjectAltNames = certificate.getSubjectAlternativeNames(); |
| 97 | if (subjectAltNames != null) { |
| 98 | Iterator i = subjectAltNames.iterator(); |
| 99 | while (i.hasNext()) { |
| 100 | List altNameEntry = (List)(i.next()); |
| 101 | if (altNameEntry != null && 2 <= altNameEntry.size()) { |
| 102 | Integer altNameType = (Integer)(altNameEntry.get(0)); |
| 103 | if (altNameType != null) { |
| 104 | if (altNameType.intValue() == ALT_IPA_NAME) { |
| 105 | String altName = (String)(altNameEntry.get(1)); |
| 106 | if (altName != null) { |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 107 | if (LOG_ENABLED) { |
| 108 | Log.v(TAG, "alternative IP: " + altName); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 109 | } |
| 110 | if (thisDomain.equalsIgnoreCase(altName)) { |
| 111 | return true; |
| 112 | } |
| 113 | } |
| 114 | } |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | } |
| 119 | } catch (CertificateParsingException e) {} |
| 120 | |
| 121 | return false; |
| 122 | } |
| 123 | |
| 124 | /** |
| 125 | * Checks the site certificate against the DNS domain name of the site being visited |
| 126 | * @param certificate The certificate to check |
| 127 | * @param thisDomain The DNS domain name of the site being visited |
| 128 | * @return True iff if there is a domain match as specified by RFC2818 |
| 129 | */ |
| 130 | private static boolean matchDns(X509Certificate certificate, String thisDomain) { |
| 131 | boolean hasDns = false; |
| 132 | try { |
| 133 | Collection subjectAltNames = certificate.getSubjectAlternativeNames(); |
| 134 | if (subjectAltNames != null) { |
| 135 | Iterator i = subjectAltNames.iterator(); |
| 136 | while (i.hasNext()) { |
| 137 | List altNameEntry = (List)(i.next()); |
| 138 | if (altNameEntry != null && 2 <= altNameEntry.size()) { |
| 139 | Integer altNameType = (Integer)(altNameEntry.get(0)); |
| 140 | if (altNameType != null) { |
| 141 | if (altNameType.intValue() == ALT_DNS_NAME) { |
| 142 | hasDns = true; |
| 143 | String altName = (String)(altNameEntry.get(1)); |
| 144 | if (altName != null) { |
| 145 | if (matchDns(thisDomain, altName)) { |
| 146 | return true; |
| 147 | } |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | } |
| 152 | } |
| 153 | } |
| 154 | } catch (CertificateParsingException e) { |
Makoto Onuki | 2683c6f | 2010-01-20 09:56:01 -0800 | [diff] [blame] | 155 | String errorMessage = e.getMessage(); |
| 156 | if (errorMessage == null) { |
| 157 | errorMessage = "failed to parse certificate"; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 158 | } |
Makoto Onuki | 2683c6f | 2010-01-20 09:56:01 -0800 | [diff] [blame] | 159 | |
| 160 | Log.w(TAG, "DomainNameValidator.matchDns(): " + errorMessage); |
| 161 | return false; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 162 | } |
| 163 | |
| 164 | if (!hasDns) { |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 165 | final String cn = new DNParser(certificate.getSubjectX500Principal()) |
| 166 | .find("cn"); |
| 167 | if (LOG_ENABLED) { |
| 168 | Log.v(TAG, "Validating subject: DN:" |
| 169 | + certificate.getSubjectX500Principal().getName(X500Principal.CANONICAL) |
| 170 | + " CN:" + cn); |
| 171 | } |
| 172 | if (cn != null) { |
| 173 | return matchDns(thisDomain, cn); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 174 | } |
| 175 | } |
| 176 | |
| 177 | return false; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * @param thisDomain The domain name of the site being visited |
| 182 | * @param thatDomain The domain name from the certificate |
| 183 | * @return True iff thisDomain matches thatDomain as specified by RFC2818 |
| 184 | */ |
Makoto Onuki | 8f028a9 | 2010-01-08 13:34:57 -0800 | [diff] [blame] | 185 | // not private for testing |
| 186 | public static boolean matchDns(String thisDomain, String thatDomain) { |
| 187 | if (LOG_ENABLED) { |
| 188 | Log.v(TAG, "DomainNameValidator.matchDns():" + |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 189 | " this domain: " + thisDomain + |
| 190 | " that domain: " + thatDomain); |
| 191 | } |
| 192 | |
| 193 | if (thisDomain == null || thisDomain.length() == 0 || |
| 194 | thatDomain == null || thatDomain.length() == 0) { |
| 195 | return false; |
| 196 | } |
| 197 | |
| 198 | thatDomain = thatDomain.toLowerCase(); |
| 199 | |
| 200 | // (a) domain name strings are equal, ignoring case: X matches X |
| 201 | boolean rval = thisDomain.equals(thatDomain); |
| 202 | if (!rval) { |
| 203 | String[] thisDomainTokens = thisDomain.split("\\."); |
| 204 | String[] thatDomainTokens = thatDomain.split("\\."); |
| 205 | |
| 206 | int thisDomainTokensNum = thisDomainTokens.length; |
| 207 | int thatDomainTokensNum = thatDomainTokens.length; |
| 208 | |
| 209 | // (b) OR thatHost is a '.'-suffix of thisHost: Z.Y.X matches X |
| 210 | if (thisDomainTokensNum >= thatDomainTokensNum) { |
| 211 | for (int i = thatDomainTokensNum - 1; i >= 0; --i) { |
| 212 | rval = thisDomainTokens[i].equals(thatDomainTokens[i]); |
| 213 | if (!rval) { |
| 214 | // (c) OR we have a special *-match: |
Grace Kloba | 106f9b2 | 2010-01-05 10:50:39 -0800 | [diff] [blame] | 215 | // *.Y.X matches Z.Y.X but *.X doesn't match Z.Y.X |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 216 | rval = (i == 0 && thisDomainTokensNum == thatDomainTokensNum); |
| 217 | if (rval) { |
| 218 | rval = thatDomainTokens[0].equals("*"); |
| 219 | if (!rval) { |
| 220 | // (d) OR we have a *-component match: |
| 221 | // f*.com matches foo.com but not bar.com |
| 222 | rval = domainTokenMatch( |
| 223 | thisDomainTokens[0], thatDomainTokens[0]); |
| 224 | } |
| 225 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 226 | break; |
| 227 | } |
| 228 | } |
Grace Kloba | 106f9b2 | 2010-01-05 10:50:39 -0800 | [diff] [blame] | 229 | } else { |
| 230 | // (e) OR thatHost has a '*.'-prefix of thisHost: |
| 231 | // *.Y.X matches Y.X |
| 232 | rval = thatDomain.equals("*." + thisDomain); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 233 | } |
| 234 | } |
| 235 | |
| 236 | return rval; |
| 237 | } |
| 238 | |
| 239 | /** |
| 240 | * @param thisDomainToken The domain token from the current domain name |
| 241 | * @param thatDomainToken The domain token from the certificate |
| 242 | * @return True iff thisDomainToken matches thatDomainToken, using the |
| 243 | * wildcard match as specified by RFC2818-3.1. For example, f*.com must |
| 244 | * match foo.com but not bar.com |
| 245 | */ |
| 246 | private static boolean domainTokenMatch(String thisDomainToken, String thatDomainToken) { |
| 247 | if (thisDomainToken != null && thatDomainToken != null) { |
| 248 | int starIndex = thatDomainToken.indexOf('*'); |
| 249 | if (starIndex >= 0) { |
| 250 | if (thatDomainToken.length() - 1 <= thisDomainToken.length()) { |
| 251 | String prefix = thatDomainToken.substring(0, starIndex); |
| 252 | String suffix = thatDomainToken.substring(starIndex + 1); |
| 253 | |
| 254 | return thisDomainToken.startsWith(prefix) && thisDomainToken.endsWith(suffix); |
| 255 | } |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | return false; |
| 260 | } |
| 261 | } |