001/* PKIXCertPathChecker.java -- checks X.509 certificate paths. 002 Copyright (C) 2003 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.security.cert; 040 041import java.util.Collection; 042import java.util.Set; 043 044/** 045 * A validator for X.509 certificates when approving certificate chains. 046 * 047 * <p>Concrete subclasses can be passed to the {@link 048 * PKIXParameters#setCertPathCheckers(java.util.List)} and {@link 049 * PKIXParameters#addCertPathChecker(java.security.cert.PKIXCertPathChecker)} 050 * methods, which are then used to set up PKIX certificate chain 051 * builders or validators. These classes then call the {@link 052 * #check(java.security.cert.Certificate,java.util.Collection)} method 053 * of this class, performing whatever checks on the certificate, 054 * throwing an exception if any check fails. 055 * 056 * <p>Subclasses of this must be able to perform their checks in the 057 * backward direction -- from the most-trusted certificate to the target 058 * -- and may optionally support forward checking -- from the target to 059 * the most-trusted certificate. 060 * 061 * @see PKIXParameters 062 * @since 1.4 063 */ 064public abstract class PKIXCertPathChecker implements Cloneable 065{ 066 067 // Constructor. 068 // ------------------------------------------------------------------------ 069 070 /** Default constructor. */ 071 protected PKIXCertPathChecker() 072 { 073 super(); 074 } 075 076 // Cloneable interface. 077 // ------------------------------------------------------------------------ 078 079 public Object clone() 080 { 081 try 082 { 083 return super.clone(); 084 } 085 catch (CloneNotSupportedException cnse) 086 { 087 throw new InternalError(cnse.getMessage()); 088 } 089 } 090 091 // Abstract methods. 092 // ------------------------------------------------------------------------ 093 094 /** 095 * Initialize this PKIXCertPathChecker. If subclasses support forward 096 * checking, a value of true can be passed to this method, and 097 * certificates can be validated from the target certificate to the 098 * most-trusted certifcate. 099 * 100 * @param forward The direction of this PKIXCertPathChecker. 101 * @throws CertPathValidatorException If <i>forward</i> is true and 102 * this class does not support forward checking. 103 */ 104 public abstract void init(boolean forward) throws CertPathValidatorException; 105 106 /** 107 * Returns whether or not this class supports forward checking. 108 * 109 * @return Whether or not this class supports forward checking. 110 */ 111 public abstract boolean isForwardCheckingSupported(); 112 113 /** 114 * Returns an immutable set of X.509 extension object identifiers (OIDs) 115 * supported by this PKIXCertPathChecker. 116 * 117 * @return An immutable set of Strings of the supported X.509 OIDs, or 118 * null if no extensions are supported. 119 */ 120 public abstract Set<String> getSupportedExtensions(); 121 122 /** 123 * Checks a certificate, removing any critical extensions that are 124 * resolved in this check. 125 * 126 * @param cert The certificate to check. 127 * @param unresolvedCritExts The (mutable) collection of as-of-yet 128 * unresolved critical extensions, as OID strings. 129 * @throws CertPathValidatorException If this certificate fails this 130 * check. 131 */ 132 public abstract void check(Certificate cert, Collection<String> unresolvedCritExts) 133 throws CertPathValidatorException; 134}