J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.security.provider.certpath; |
| 27 | |
| 28 | import java.util.Collection; |
| 29 | import java.util.Collections; |
| 30 | import java.util.Set; |
| 31 | import java.util.HashSet; |
| 32 | import java.io.IOException; |
| 33 | import java.security.cert.Certificate; |
| 34 | import java.security.cert.CertificateException; |
| 35 | import java.security.cert.X509Certificate; |
| 36 | import java.security.cert.PKIXCertPathChecker; |
| 37 | import java.security.cert.CertPathValidatorException; |
| 38 | import sun.security.util.Debug; |
| 39 | import sun.security.x509.PKIXExtensions; |
| 40 | import sun.security.x509.NameConstraintsExtension; |
| 41 | import sun.security.x509.X509CertImpl; |
| 42 | |
| 43 | /** |
| 44 | * ConstraintsChecker is a <code>PKIXCertPathChecker</code> that checks |
| 45 | * constraints information on a PKIX certificate, namely basic constraints |
| 46 | * and name constraints. |
| 47 | * |
| 48 | * @since 1.4 |
| 49 | * @author Yassir Elley |
| 50 | */ |
| 51 | class ConstraintsChecker extends PKIXCertPathChecker { |
| 52 | |
| 53 | private static final Debug debug = Debug.getInstance("certpath"); |
| 54 | /* length of cert path */ |
| 55 | private final int certPathLength; |
| 56 | /* current maximum path length (as defined in PKIX) */ |
| 57 | private int maxPathLength; |
| 58 | /* current index of cert */ |
| 59 | private int i; |
| 60 | private NameConstraintsExtension prevNC; |
| 61 | |
| 62 | private static Set<String> supportedExts; |
| 63 | |
| 64 | /** |
| 65 | * Creates a ConstraintsChecker. |
| 66 | * |
| 67 | * @param certPathLength the length of the certification path |
| 68 | * @throws CertPathValidatorException if the checker cannot be initialized |
| 69 | */ |
| 70 | ConstraintsChecker(int certPathLength) throws CertPathValidatorException { |
| 71 | this.certPathLength = certPathLength; |
| 72 | init(false); |
| 73 | } |
| 74 | |
| 75 | public void init(boolean forward) throws CertPathValidatorException { |
| 76 | if (!forward) { |
| 77 | i = 0; |
| 78 | maxPathLength = certPathLength; |
| 79 | prevNC = null; |
| 80 | } else { |
| 81 | throw new CertPathValidatorException |
| 82 | ("forward checking not supported"); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | public boolean isForwardCheckingSupported() { |
| 87 | return false; |
| 88 | } |
| 89 | |
| 90 | public Set<String> getSupportedExtensions() { |
| 91 | if (supportedExts == null) { |
| 92 | supportedExts = new HashSet<String>(); |
| 93 | supportedExts.add(PKIXExtensions.BasicConstraints_Id.toString()); |
| 94 | supportedExts.add(PKIXExtensions.NameConstraints_Id.toString()); |
| 95 | supportedExts = Collections.unmodifiableSet(supportedExts); |
| 96 | } |
| 97 | return supportedExts; |
| 98 | } |
| 99 | |
| 100 | /** |
| 101 | * Performs the basic constraints and name constraints |
| 102 | * checks on the certificate using its internal state. |
| 103 | * |
| 104 | * @param cert the <code>Certificate</code> to be checked |
| 105 | * @param unresCritExts a <code>Collection</code> of OID strings |
| 106 | * representing the current set of unresolved critical extensions |
| 107 | * @throws CertPathValidatorException if the specified certificate |
| 108 | * does not pass the check |
| 109 | */ |
| 110 | public void check(Certificate cert, Collection<String> unresCritExts) |
| 111 | throws CertPathValidatorException |
| 112 | { |
| 113 | X509Certificate currCert = (X509Certificate) cert; |
| 114 | |
| 115 | i++; |
| 116 | // MUST run NC check second, since it depends on BC check to |
| 117 | // update remainingCerts |
| 118 | checkBasicConstraints(currCert); |
| 119 | verifyNameConstraints(currCert); |
| 120 | |
| 121 | if (unresCritExts != null && !unresCritExts.isEmpty()) { |
| 122 | unresCritExts.remove(PKIXExtensions.BasicConstraints_Id.toString()); |
| 123 | unresCritExts.remove(PKIXExtensions.NameConstraints_Id.toString()); |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * Internal method to check the name constraints against a cert |
| 129 | */ |
| 130 | private void verifyNameConstraints(X509Certificate currCert) |
| 131 | throws CertPathValidatorException |
| 132 | { |
| 133 | String msg = "name constraints"; |
| 134 | if (debug != null) { |
| 135 | debug.println("---checking " + msg + "..."); |
| 136 | } |
| 137 | |
| 138 | // check name constraints only if there is a previous name constraint |
| 139 | // and either the currCert is the final cert or the currCert is not |
| 140 | // self-issued |
| 141 | if (prevNC != null && ((i == certPathLength) || |
| 142 | !X509CertImpl.isSelfIssued(currCert))) { |
| 143 | if (debug != null) { |
| 144 | debug.println("prevNC = " + prevNC); |
| 145 | debug.println("currDN = " + currCert.getSubjectX500Principal()); |
| 146 | } |
| 147 | |
| 148 | try { |
| 149 | if (!prevNC.verify(currCert)) { |
| 150 | throw new CertPathValidatorException(msg + " check failed"); |
| 151 | } |
| 152 | } catch (IOException ioe) { |
| 153 | throw new CertPathValidatorException(ioe); |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | // merge name constraints regardless of whether cert is self-issued |
| 158 | prevNC = mergeNameConstraints(currCert, prevNC); |
| 159 | |
| 160 | if (debug != null) |
| 161 | debug.println(msg + " verified."); |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Helper to fold sets of name constraints together |
| 166 | */ |
| 167 | static NameConstraintsExtension |
| 168 | mergeNameConstraints(X509Certificate currCert, |
| 169 | NameConstraintsExtension prevNC) throws CertPathValidatorException |
| 170 | { |
| 171 | X509CertImpl currCertImpl; |
| 172 | try { |
| 173 | currCertImpl = X509CertImpl.toImpl(currCert); |
| 174 | } catch (CertificateException ce) { |
| 175 | throw new CertPathValidatorException(ce); |
| 176 | } |
| 177 | |
| 178 | NameConstraintsExtension newConstraints = |
| 179 | currCertImpl.getNameConstraintsExtension(); |
| 180 | |
| 181 | if (debug != null) { |
| 182 | debug.println("prevNC = " + prevNC); |
| 183 | debug.println("newNC = " + String.valueOf(newConstraints)); |
| 184 | } |
| 185 | |
| 186 | // if there are no previous name constraints, we just return the |
| 187 | // new name constraints. |
| 188 | if (prevNC == null) { |
| 189 | if (debug != null) { |
| 190 | debug.println("mergedNC = " + String.valueOf(newConstraints)); |
| 191 | } |
| 192 | if (newConstraints == null) { |
| 193 | return newConstraints; |
| 194 | } else { |
| 195 | // Make sure we do a clone here, because we're probably |
| 196 | // going to modify this object later and we don't want to |
| 197 | // be sharing it with a Certificate object! |
| 198 | return (NameConstraintsExtension) newConstraints.clone(); |
| 199 | } |
| 200 | } else { |
| 201 | try { |
| 202 | // after merge, prevNC should contain the merged constraints |
| 203 | prevNC.merge(newConstraints); |
| 204 | } catch (IOException ioe) { |
| 205 | throw new CertPathValidatorException(ioe); |
| 206 | } |
| 207 | if (debug != null) { |
| 208 | debug.println("mergedNC = " + prevNC); |
| 209 | } |
| 210 | return prevNC; |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | /** |
| 215 | * Internal method to check that a given cert meets basic constraints. |
| 216 | */ |
| 217 | private void checkBasicConstraints(X509Certificate currCert) |
| 218 | throws CertPathValidatorException |
| 219 | { |
| 220 | String msg = "basic constraints"; |
| 221 | if (debug != null) { |
| 222 | debug.println("---checking " + msg + "..."); |
| 223 | debug.println("i = " + i); |
| 224 | debug.println("maxPathLength = " + maxPathLength); |
| 225 | } |
| 226 | |
| 227 | /* check if intermediate cert */ |
| 228 | if (i < certPathLength) { |
| 229 | int pathLenConstraint = currCert.getBasicConstraints(); |
| 230 | if (pathLenConstraint == -1) { |
| 231 | throw new CertPathValidatorException(msg + " check failed: " |
| 232 | + "this is not a CA certificate"); |
| 233 | } |
| 234 | |
| 235 | if (!X509CertImpl.isSelfIssued(currCert)) { |
| 236 | if (maxPathLength <= 0) { |
| 237 | throw new CertPathValidatorException |
| 238 | (msg + " check failed: pathLenConstraint violated - " |
| 239 | + "this cert must be the last cert in the " |
| 240 | + "certification path"); |
| 241 | } |
| 242 | maxPathLength--; |
| 243 | } |
| 244 | if (pathLenConstraint < maxPathLength) |
| 245 | maxPathLength = pathLenConstraint; |
| 246 | } |
| 247 | |
| 248 | if (debug != null) { |
| 249 | debug.println("after processing, maxPathLength = " + maxPathLength); |
| 250 | debug.println(msg + " verified."); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | /** |
| 255 | * Merges the specified maxPathLength with the pathLenConstraint |
| 256 | * obtained from the certificate. |
| 257 | * |
| 258 | * @param cert the <code>X509Certificate</code> |
| 259 | * @param maxPathLength the previous maximum path length |
| 260 | * @return the new maximum path length constraint (-1 means no more |
| 261 | * certificates can follow, Integer.MAX_VALUE means path length is |
| 262 | * unconstrained) |
| 263 | */ |
| 264 | static int mergeBasicConstraints(X509Certificate cert, int maxPathLength) { |
| 265 | |
| 266 | int pathLenConstraint = cert.getBasicConstraints(); |
| 267 | |
| 268 | if (!X509CertImpl.isSelfIssued(cert)) { |
| 269 | maxPathLength--; |
| 270 | } |
| 271 | |
| 272 | if (pathLenConstraint < maxPathLength) { |
| 273 | maxPathLength = pathLenConstraint; |
| 274 | } |
| 275 | |
| 276 | return maxPathLength; |
| 277 | } |
| 278 | } |