1 /* 2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/conn/ssl/AbstractVerifier.java $ 3 * $Revision: 653041 $ 4 * $Date: 2008-05-03 03:39:28 -0700 (Sat, 03 May 2008) $ 5 * 6 * ==================================================================== 7 * Licensed to the Apache Software Foundation (ASF) under one 8 * or more contributor license agreements. See the NOTICE file 9 * distributed with this work for additional information 10 * regarding copyright ownership. The ASF licenses this file 11 * to you under the Apache License, Version 2.0 (the 12 * "License"); you may not use this file except in compliance 13 * with the License. You may obtain a copy of the License at 14 * 15 * http://www.apache.org/licenses/LICENSE-2.0 16 * 17 * Unless required by applicable law or agreed to in writing, 18 * software distributed under the License is distributed on an 19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 20 * KIND, either express or implied. See the License for the 21 * specific language governing permissions and limitations 22 * under the License. 23 * ==================================================================== 24 * 25 * This software consists of voluntary contributions made by many 26 * individuals on behalf of the Apache Software Foundation. For more 27 * information on the Apache Software Foundation, please see 28 * <http://www.apache.org/>. 29 * 30 */ 31 32 package org.apache.http.conn.ssl; 33 34 import org.apache.http.conn.util.InetAddressUtils; 35 36 import java.io.IOException; 37 import java.io.InputStream; 38 import java.security.cert.Certificate; 39 import java.security.cert.CertificateParsingException; 40 import java.security.cert.X509Certificate; 41 import java.util.Arrays; 42 import java.util.Collection; 43 import java.util.Iterator; 44 import java.util.LinkedList; 45 import java.util.List; 46 import java.util.Locale; 47 import java.util.StringTokenizer; 48 import java.util.logging.Logger; 49 import java.util.logging.Level; 50 51 import javax.net.ssl.SSLException; 52 import javax.net.ssl.SSLSession; 53 import javax.net.ssl.SSLSocket; 54 55 /** 56 * Abstract base class for all standard {@link X509HostnameVerifier} 57 * implementations. 58 * 59 * @author Julius Davies 60 */ 61 public abstract class AbstractVerifier implements X509HostnameVerifier { 62 63 /** 64 * This contains a list of 2nd-level domains that aren't allowed to 65 * have wildcards when combined with country-codes. 66 * For example: [*.co.uk]. 67 * <p/> 68 * The [*.co.uk] problem is an interesting one. Should we just hope 69 * that CA's would never foolishly allow such a certificate to happen? 70 * Looks like we're the only implementation guarding against this. 71 * Firefox, Curl, Sun Java 1.4, 5, 6 don't bother with this check. 72 */ 73 private final static String[] BAD_COUNTRY_2LDS = 74 { "ac", "co", "com", "ed", "edu", "go", "gouv", "gov", "info", 75 "lg", "ne", "net", "or", "org" }; 76 77 static { 78 // Just in case developer forgot to manually sort the array. :-) 79 Arrays.sort(BAD_COUNTRY_2LDS); 80 } 81 82 public AbstractVerifier() { 83 super(); 84 } 85 86 public final void verify(String host, SSLSocket ssl) 87 throws IOException { 88 if(host == null) { 89 throw new NullPointerException("host to verify is null"); 90 } 91 92 SSLSession session = ssl.getSession(); 93 Certificate[] certs = session.getPeerCertificates(); 94 X509Certificate x509 = (X509Certificate) certs[0]; 95 verify(host, x509); 96 } 97 98 public final boolean verify(String host, SSLSession session) { 99 try { 100 Certificate[] certs = session.getPeerCertificates(); 101 X509Certificate x509 = (X509Certificate) certs[0]; 102 verify(host, x509); 103 return true; 104 } 105 catch(SSLException e) { 106 return false; 107 } 108 } 109 110 public final void verify(String host, X509Certificate cert) 111 throws SSLException { 112 String[] cns = getCNs(cert); 113 String[] subjectAlts = getDNSSubjectAlts(cert); 114 verify(host, cns, subjectAlts); 115 } 116 117 public final void verify(final String host, final String[] cns, 118 final String[] subjectAlts, 119 final boolean strictWithSubDomains) 120 throws SSLException { 121 122 // Build the list of names we're going to check. Our DEFAULT and 123 // STRICT implementations of the HostnameVerifier only use the 124 // first CN provided. All other CNs are ignored. 125 // (Firefox, wget, curl, Sun Java 1.4, 5, 6 all work this way). 126 LinkedList<String> names = new LinkedList<String>(); 127 if(cns != null && cns.length > 0 && cns[0] != null) { 128 names.add(cns[0]); 129 } 130 if(subjectAlts != null) { 131 for (String subjectAlt : subjectAlts) { 132 if (subjectAlt != null) { 133 names.add(subjectAlt); 134 } 135 } 136 } 137 138 if(names.isEmpty()) { 139 String msg = "Certificate for <" + host + "> doesn't contain CN or DNS subjectAlt"; 140 throw new SSLException(msg); 141 } 142 143 // StringBuffer for building the error message. 144 StringBuffer buf = new StringBuffer(); 145 146 // We're can be case-insensitive when comparing the host we used to 147 // establish the socket to the hostname in the certificate. 148 String hostName = host.trim().toLowerCase(Locale.ENGLISH); 149 boolean match = false; 150 for(Iterator<String> it = names.iterator(); it.hasNext();) { 151 // Don't trim the CN, though! 152 String cn = it.next(); 153 cn = cn.toLowerCase(Locale.ENGLISH); 154 // Store CN in StringBuffer in case we need to report an error. 155 buf.append(" <"); 156 buf.append(cn); 157 buf.append('>'); 158 if(it.hasNext()) { 159 buf.append(" OR"); 160 } 161 162 // The CN better have at least two dots if it wants wildcard 163 // action. It also can't be [*.co.uk] or [*.co.jp] or 164 // [*.org.uk], etc... 165 boolean doWildcard = cn.startsWith("*.") && 166 cn.indexOf('.', 2) != -1 && 167 acceptableCountryWildcard(cn) && 168 !InetAddressUtils.isIPv4Address(host); 169 170 if(doWildcard) { 171 match = hostName.endsWith(cn.substring(1)); 172 if(match && strictWithSubDomains) { 173 // If we're in strict mode, then [*.foo.com] is not 174 // allowed to match [a.b.foo.com] 175 match = countDots(hostName) == countDots(cn); 176 } 177 } else { 178 match = hostName.equals(cn); 179 } 180 if(match) { 181 break; 182 } 183 } 184 if(!match) { 185 throw new SSLException("hostname in certificate didn't match: <" + host + "> !=" + buf); 186 } 187 } 188 189 public static boolean acceptableCountryWildcard(String cn) { 190 int cnLen = cn.length(); 191 if(cnLen >= 7 && cnLen <= 9) { 192 // Look for the '.' in the 3rd-last position: 193 if(cn.charAt(cnLen - 3) == '.') { 194 // Trim off the [*.] and the [.XX]. 195 String s = cn.substring(2, cnLen - 3); 196 // And test against the sorted array of bad 2lds: 197 int x = Arrays.binarySearch(BAD_COUNTRY_2LDS, s); 198 return x < 0; 199 } 200 } 201 return true; 202 } 203 204 public static String[] getCNs(X509Certificate cert) { 205 LinkedList<String> cnList = new LinkedList<String>(); 206 /* 207 Sebastian Hauer's original StrictSSLProtocolSocketFactory used 208 getName() and had the following comment: 209 210 Parses a X.500 distinguished name for the value of the 211 "Common Name" field. This is done a bit sloppy right 212 now and should probably be done a bit more according to 213 <code>RFC 2253</code>. 214 215 I've noticed that toString() seems to do a better job than 216 getName() on these X500Principal objects, so I'm hoping that 217 addresses Sebastian's concern. 218 219 For example, getName() gives me this: 220 1.2.840.113549.1.9.1=#16166a756c6975736461766965734063756362632e636f6d 221 222 whereas toString() gives me this: 223 EMAILADDRESS=juliusdavies (at) cucbc.com 224 225 Looks like toString() even works with non-ascii domain names! 226 I tested it with "花子.co.jp" and it worked fine. 227 */ 228 String subjectPrincipal = cert.getSubjectX500Principal().toString(); 229 StringTokenizer st = new StringTokenizer(subjectPrincipal, ","); 230 while(st.hasMoreTokens()) { 231 String tok = st.nextToken(); 232 int x = tok.indexOf("CN="); 233 if(x >= 0) { 234 cnList.add(tok.substring(x + 3)); 235 } 236 } 237 if(!cnList.isEmpty()) { 238 String[] cns = new String[cnList.size()]; 239 cnList.toArray(cns); 240 return cns; 241 } else { 242 return null; 243 } 244 } 245 246 247 /** 248 * Extracts the array of SubjectAlt DNS names from an X509Certificate. 249 * Returns null if there aren't any. 250 * <p/> 251 * Note: Java doesn't appear able to extract international characters 252 * from the SubjectAlts. It can only extract international characters 253 * from the CN field. 254 * <p/> 255 * (Or maybe the version of OpenSSL I'm using to test isn't storing the 256 * international characters correctly in the SubjectAlts?). 257 * 258 * @param cert X509Certificate 259 * @return Array of SubjectALT DNS names stored in the certificate. 260 */ 261 public static String[] getDNSSubjectAlts(X509Certificate cert) { 262 LinkedList<String> subjectAltList = new LinkedList<String>(); 263 Collection<List<?>> c = null; 264 try { 265 c = cert.getSubjectAlternativeNames(); 266 } 267 catch(CertificateParsingException cpe) { 268 Logger.getLogger(AbstractVerifier.class.getName()) 269 .log(Level.FINE, "Error parsing certificate.", cpe); 270 } 271 if(c != null) { 272 for (List<?> aC : c) { 273 List<?> list = aC; 274 int type = ((Integer) list.get(0)).intValue(); 275 // If type is 2, then we've got a dNSName 276 if (type == 2) { 277 String s = (String) list.get(1); 278 subjectAltList.add(s); 279 } 280 } 281 } 282 if(!subjectAltList.isEmpty()) { 283 String[] subjectAlts = new String[subjectAltList.size()]; 284 subjectAltList.toArray(subjectAlts); 285 return subjectAlts; 286 } else { 287 return null; 288 } 289 } 290 291 /** 292 * Counts the number of dots "." in a string. 293 * @param s string to count dots from 294 * @return number of dots 295 */ 296 public static int countDots(final String s) { 297 int count = 0; 298 for(int i = 0; i < s.length(); i++) { 299 if(s.charAt(i) == '.') { 300 count++; 301 } 302 } 303 return count; 304 } 305 306 } 307
