1 /* 2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.security.cert; 27 28 import java.security.KeyStore; 29 import java.security.KeyStoreException; 30 import java.security.InvalidAlgorithmParameterException; 31 import java.security.InvalidParameterException; 32 import java.util.Set; 33 34 /** 35 * Parameters used as input for the PKIX {@code CertPathBuilder} 36 * algorithm. 37 * <p> 38 * A PKIX {@code CertPathBuilder} uses these parameters to {@link 39 * CertPathBuilder#build build} a {@code CertPath} which has been 40 * validated according to the PKIX certification path validation algorithm. 41 * 42 * <p>To instantiate a {@code PKIXBuilderParameters} object, an 43 * application must specify one or more <i>most-trusted CAs</i> as defined by 44 * the PKIX certification path validation algorithm. The most-trusted CA 45 * can be specified using one of two constructors. An application 46 * can call {@link #PKIXBuilderParameters(Set, CertSelector) 47 * PKIXBuilderParameters(Set, CertSelector)}, specifying a 48 * {@code Set} of {@code TrustAnchor} objects, each of which 49 * identifies a most-trusted CA. Alternatively, an application can call 50 * {@link #PKIXBuilderParameters(KeyStore, CertSelector) 51 * PKIXBuilderParameters(KeyStore, CertSelector)}, specifying a 52 * {@code KeyStore} instance containing trusted certificate entries, each 53 * of which will be considered as a most-trusted CA. 54 * 55 * <p>In addition, an application must specify constraints on the target 56 * certificate that the {@code CertPathBuilder} will attempt 57 * to build a path to. The constraints are specified as a 58 * {@code CertSelector} object. These constraints should provide the 59 * {@code CertPathBuilder} with enough search criteria to find the target 60 * certificate. Minimal criteria for an {@code X509Certificate} usually 61 * include the subject name and/or one or more subject alternative names. 62 * If enough criteria is not specified, the {@code CertPathBuilder} 63 * may throw a {@code CertPathBuilderException}. 64 * <p> 65 * <b>Concurrent Access</b> 66 * <p> 67 * Unless otherwise specified, the methods defined in this class are not 68 * thread-safe. Multiple threads that need to access a single 69 * object concurrently should synchronize amongst themselves and 70 * provide the necessary locking. Multiple threads each manipulating 71 * separate objects need not synchronize. 72 * 73 * @see CertPathBuilder 74 * 75 * @since 1.4 76 * @author Sean Mullan 77 */ 78 public class PKIXBuilderParameters extends PKIXParameters { 79 80 private int maxPathLength = 5; 81 82 /** 83 * Creates an instance of {@code PKIXBuilderParameters} with 84 * the specified {@code Set} of most-trusted CAs. 85 * Each element of the set is a {@link TrustAnchor TrustAnchor}. 86 * 87 * <p>Note that the {@code Set} is copied to protect against 88 * subsequent modifications. 89 * 90 * @param trustAnchors a {@code Set} of {@code TrustAnchor}s 91 * @param targetConstraints a {@code CertSelector} specifying the 92 * constraints on the target certificate 93 * @throws InvalidAlgorithmParameterException if {@code trustAnchors} 94 * is empty {@code (trustAnchors.isEmpty() == true)} 95 * @throws NullPointerException if {@code trustAnchors} is 96 * {@code null} 97 * @throws ClassCastException if any of the elements of 98 * {@code trustAnchors} are not of type 99 * {@code java.security.cert.TrustAnchor} 100 */ 101 public PKIXBuilderParameters(Set<TrustAnchor> trustAnchors, CertSelector 102 targetConstraints) throws InvalidAlgorithmParameterException 103 { 104 super(trustAnchors); 105 setTargetCertConstraints(targetConstraints); 106 } 107 108 /** 109 * Creates an instance of {@code PKIXBuilderParameters} that 110 * populates the set of most-trusted CAs from the trusted 111 * certificate entries contained in the specified {@code KeyStore}. 112 * Only keystore entries that contain trusted {@code X509Certificate}s 113 * are considered; all other certificate types are ignored. 114 * 115 * @param keystore a {@code KeyStore} from which the set of 116 * most-trusted CAs will be populated 117 * @param targetConstraints a {@code CertSelector} specifying the 118 * constraints on the target certificate 119 * @throws KeyStoreException if {@code keystore} has not been 120 * initialized 121 * @throws InvalidAlgorithmParameterException if {@code keystore} does 122 * not contain at least one trusted certificate entry 123 * @throws NullPointerException if {@code keystore} is 124 * {@code null} 125 */ 126 public PKIXBuilderParameters(KeyStore keystore, 127 CertSelector targetConstraints) 128 throws KeyStoreException, InvalidAlgorithmParameterException 129 { 130 super(keystore); 131 setTargetCertConstraints(targetConstraints); 132 } 133 134 /** 135 * Sets the value of the maximum number of non-self-issued intermediate 136 * certificates that may exist in a certification path. A certificate 137 * is self-issued if the DNs that appear in the subject and issuer 138 * fields are identical and are not empty. Note that the last certificate 139 * in a certification path is not an intermediate certificate, and is not 140 * included in this limit. Usually the last certificate is an end entity 141 * certificate, but it can be a CA certificate. A PKIX 142 * {@code CertPathBuilder} instance must not build 143 * paths longer than the length specified. 144 * 145 * <p> A value of 0 implies that the path can only contain 146 * a single certificate. A value of -1 implies that the 147 * path length is unconstrained (i.e. there is no maximum). 148 * The default maximum path length, if not specified, is 5. 149 * Setting a value less than -1 will cause an exception to be thrown. 150 * 151 * <p> If any of the CA certificates contain the 152 * {@code BasicConstraintsExtension}, the value of the 153 * {@code pathLenConstraint} field of the extension overrides 154 * the maximum path length parameter whenever the result is a 155 * certification path of smaller length. 156 * 157 * @param maxPathLength the maximum number of non-self-issued intermediate 158 * certificates that may exist in a certification path 159 * @throws InvalidParameterException if {@code maxPathLength} is set 160 * to a value less than -1 161 * 162 * @see #getMaxPathLength 163 */ 164 public void setMaxPathLength(int maxPathLength) { 165 if (maxPathLength < -1) { 166 throw new InvalidParameterException("the maximum path " 167 + "length parameter can not be less than -1"); 168 } 169 this.maxPathLength = maxPathLength; 170 } 171 172 /** 173 * Returns the value of the maximum number of intermediate non-self-issued 174 * certificates that may exist in a certification path. See 175 * the {@link #setMaxPathLength} method for more details. 176 * 177 * @return the maximum number of non-self-issued intermediate certificates 178 * that may exist in a certification path, or -1 if there is no limit 179 * 180 * @see #setMaxPathLength 181 */ 182 public int getMaxPathLength() { 183 return maxPathLength; 184 } 185 186 /** 187 * Returns a formatted string describing the parameters. 188 * 189 * @return a formatted string describing the parameters 190 */ 191 public String toString() { 192 StringBuffer sb = new StringBuffer(); 193 sb.append("[\n"); 194 sb.append(super.toString()); 195 sb.append(" Maximum Path Length: " + maxPathLength + "\n"); 196 sb.append("]\n"); 197 return sb.toString(); 198 } 199 } 200
