J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2003 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.*; |
| 29 | import java.security.cert.*; |
| 30 | |
| 31 | import sun.security.util.Debug; |
| 32 | import sun.security.x509.PKIXExtensions; |
| 33 | |
| 34 | /** |
| 35 | * KeyChecker is a <code>PKIXCertPathChecker</code> that checks that the |
| 36 | * keyCertSign bit is set in the keyUsage extension in an intermediate CA |
| 37 | * certificate. It also checks whether the final certificate in a |
| 38 | * certification path meets the specified target constraints specified as |
| 39 | * a CertSelector in the PKIXParameters passed to the CertPathValidator. |
| 40 | * |
| 41 | * @since 1.4 |
| 42 | * @author Yassir Elley |
| 43 | */ |
| 44 | class KeyChecker extends PKIXCertPathChecker { |
| 45 | |
| 46 | private static final Debug debug = Debug.getInstance("certpath"); |
| 47 | // the index of keyCertSign in the boolean KeyUsage array |
| 48 | private static final int keyCertSign = 5; |
| 49 | private final int certPathLen; |
| 50 | private CertSelector targetConstraints; |
| 51 | private int remainingCerts; |
| 52 | |
| 53 | private static Set<String> supportedExts; |
| 54 | |
| 55 | /** |
| 56 | * Default Constructor |
| 57 | * |
| 58 | * @param certPathLen allowable cert path length |
| 59 | * @param targetCertSel a CertSelector object specifying the constraints |
| 60 | * on the target certificate |
| 61 | */ |
| 62 | KeyChecker(int certPathLen, CertSelector targetCertSel) |
| 63 | throws CertPathValidatorException |
| 64 | { |
| 65 | this.certPathLen = certPathLen; |
| 66 | this.targetConstraints = targetCertSel; |
| 67 | init(false); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Initializes the internal state of the checker from parameters |
| 72 | * specified in the constructor |
| 73 | */ |
| 74 | public void init(boolean forward) throws CertPathValidatorException { |
| 75 | if (!forward) { |
| 76 | remainingCerts = certPathLen; |
| 77 | } else { |
| 78 | throw new CertPathValidatorException("forward checking not supported"); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | public boolean isForwardCheckingSupported() { |
| 83 | return false; |
| 84 | } |
| 85 | |
| 86 | public Set<String> getSupportedExtensions() { |
| 87 | if (supportedExts == null) { |
| 88 | supportedExts = new HashSet<String>(); |
| 89 | supportedExts.add(PKIXExtensions.KeyUsage_Id.toString()); |
| 90 | supportedExts.add(PKIXExtensions.ExtendedKeyUsage_Id.toString()); |
| 91 | supportedExts.add(PKIXExtensions.SubjectAlternativeName_Id.toString()); |
| 92 | supportedExts = Collections.unmodifiableSet(supportedExts); |
| 93 | } |
| 94 | return supportedExts; |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * Checks that keyUsage and target constraints are satisfied by |
| 99 | * the specified certificate. |
| 100 | * |
| 101 | * @param cert the Certificate |
| 102 | * @param unresolvedCritExts the unresolved critical extensions |
| 103 | * @exception CertPathValidatorException Exception thrown if certificate |
| 104 | * does not verify |
| 105 | */ |
| 106 | public void check(Certificate cert, Collection<String> unresCritExts) |
| 107 | throws CertPathValidatorException |
| 108 | { |
| 109 | X509Certificate currCert = (X509Certificate) cert; |
| 110 | |
| 111 | remainingCerts--; |
| 112 | |
| 113 | // if final certificate, check that target constraints are satisfied |
| 114 | if (remainingCerts == 0) { |
| 115 | if ((targetConstraints != null) && |
| 116 | (targetConstraints.match(currCert) == false)) { |
| 117 | throw new CertPathValidatorException("target certificate " + |
| 118 | "constraints check failed"); |
| 119 | } |
| 120 | } else { |
| 121 | // otherwise, verify that keyCertSign bit is set in CA certificate |
| 122 | verifyCAKeyUsage(currCert); |
| 123 | } |
| 124 | |
| 125 | // remove the extensions that we have checked |
| 126 | if (unresCritExts != null && !unresCritExts.isEmpty()) { |
| 127 | unresCritExts.remove(PKIXExtensions.KeyUsage_Id.toString()); |
| 128 | unresCritExts.remove(PKIXExtensions.ExtendedKeyUsage_Id.toString()); |
| 129 | unresCritExts.remove( |
| 130 | PKIXExtensions.SubjectAlternativeName_Id.toString()); |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Static method to verify that the key usage and extended key usage |
| 136 | * extension in a CA cert. The key usage extension, if present, must |
| 137 | * assert the keyCertSign bit. The extended key usage extension, if |
| 138 | * present, must include anyExtendedKeyUsage. |
| 139 | */ |
| 140 | static void verifyCAKeyUsage(X509Certificate cert) |
| 141 | throws CertPathValidatorException { |
| 142 | String msg = "CA key usage"; |
| 143 | if (debug != null) { |
| 144 | debug.println("KeyChecker.verifyCAKeyUsage() ---checking " + msg |
| 145 | + "..."); |
| 146 | } |
| 147 | |
| 148 | boolean[] keyUsageBits = cert.getKeyUsage(); |
| 149 | |
| 150 | // getKeyUsage returns null if the KeyUsage extension is not present |
| 151 | // in the certificate - in which case there is nothing to check |
| 152 | if (keyUsageBits == null) { |
| 153 | return; |
| 154 | } |
| 155 | |
| 156 | // throw an exception if the keyCertSign bit is not set |
| 157 | if (!keyUsageBits[keyCertSign]) { |
| 158 | throw new CertPathValidatorException(msg + " check failed: " |
| 159 | + "keyCertSign bit is not set"); |
| 160 | } |
| 161 | |
| 162 | if (debug != null) { |
| 163 | debug.println("KeyChecker.verifyCAKeyUsage() " + msg |
| 164 | + " verified."); |
| 165 | } |
| 166 | } |
| 167 | } |