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 java.security.cert; |
| 27 | |
| 28 | import java.io.ByteArrayInputStream; |
| 29 | import java.io.NotSerializableException; |
| 30 | import java.io.ObjectStreamException; |
| 31 | import java.io.Serializable; |
| 32 | import java.util.Iterator; |
| 33 | import java.util.List; |
| 34 | |
| 35 | /** |
| 36 | * An immutable sequence of certificates (a certification path). |
| 37 | * <p> |
| 38 | * This is an abstract class that defines the methods common to all |
| 39 | * <code>CertPath</code>s. Subclasses can handle different kinds of |
| 40 | * certificates (X.509, PGP, etc.). |
| 41 | * <p> |
| 42 | * All <code>CertPath</code> objects have a type, a list of |
| 43 | * <code>Certificate</code>s, and one or more supported encodings. Because the |
| 44 | * <code>CertPath</code> class is immutable, a <code>CertPath</code> cannot |
| 45 | * change in any externally visible way after being constructed. This |
| 46 | * stipulation applies to all public fields and methods of this class and any |
| 47 | * added or overridden by subclasses. |
| 48 | * <p> |
| 49 | * The type is a <code>String</code> that identifies the type of |
| 50 | * <code>Certificate</code>s in the certification path. For each |
| 51 | * certificate <code>cert</code> in a certification path <code>certPath</code>, |
| 52 | * <code>cert.getType().equals(certPath.getType())</code> must be |
| 53 | * <code>true</code>. |
| 54 | * <p> |
| 55 | * The list of <code>Certificate</code>s is an ordered <code>List</code> of |
| 56 | * zero or more <code>Certificate</code>s. This <code>List</code> and all |
| 57 | * of the <code>Certificate</code>s contained in it must be immutable. |
| 58 | * <p> |
| 59 | * Each <code>CertPath</code> object must support one or more encodings |
| 60 | * so that the object can be translated into a byte array for storage or |
| 61 | * transmission to other parties. Preferably, these encodings should be |
| 62 | * well-documented standards (such as PKCS#7). One of the encodings supported |
| 63 | * by a <code>CertPath</code> is considered the default encoding. This |
| 64 | * encoding is used if no encoding is explicitly requested (for the |
| 65 | * {@link #getEncoded() getEncoded()} method, for instance). |
| 66 | * <p> |
| 67 | * All <code>CertPath</code> objects are also <code>Serializable</code>. |
| 68 | * <code>CertPath</code> objects are resolved into an alternate |
| 69 | * {@link CertPathRep CertPathRep} object during serialization. This allows |
| 70 | * a <code>CertPath</code> object to be serialized into an equivalent |
| 71 | * representation regardless of its underlying implementation. |
| 72 | * <p> |
| 73 | * <code>CertPath</code> objects can be created with a |
| 74 | * <code>CertificateFactory</code> or they can be returned by other classes, |
| 75 | * such as a <code>CertPathBuilder</code>. |
| 76 | * <p> |
| 77 | * By convention, X.509 <code>CertPath</code>s (consisting of |
| 78 | * <code>X509Certificate</code>s), are ordered starting with the target |
| 79 | * certificate and ending with a certificate issued by the trust anchor. That |
| 80 | * is, the issuer of one certificate is the subject of the following one. The |
| 81 | * certificate representing the {@link TrustAnchor TrustAnchor} should not be |
| 82 | * included in the certification path. Unvalidated X.509 <code>CertPath</code>s |
| 83 | * may not follow these conventions. PKIX <code>CertPathValidator</code>s will |
| 84 | * detect any departure from these conventions that cause the certification |
| 85 | * path to be invalid and throw a <code>CertPathValidatorException</code>. |
| 86 | * <p> |
| 87 | * <b>Concurrent Access</b> |
| 88 | * <p> |
| 89 | * All <code>CertPath</code> objects must be thread-safe. That is, multiple |
| 90 | * threads may concurrently invoke the methods defined in this class on a |
| 91 | * single <code>CertPath</code> object (or more than one) with no |
| 92 | * ill effects. This is also true for the <code>List</code> returned by |
| 93 | * <code>CertPath.getCertificates</code>. |
| 94 | * <p> |
| 95 | * Requiring <code>CertPath</code> objects to be immutable and thread-safe |
| 96 | * allows them to be passed around to various pieces of code without worrying |
| 97 | * about coordinating access. Providing this thread-safety is |
| 98 | * generally not difficult, since the <code>CertPath</code> and |
| 99 | * <code>List</code> objects in question are immutable. |
| 100 | * |
| 101 | * @see CertificateFactory |
| 102 | * @see CertPathBuilder |
| 103 | * |
| 104 | * @author Yassir Elley |
| 105 | * @since 1.4 |
| 106 | */ |
| 107 | public abstract class CertPath implements Serializable { |
| 108 | |
| 109 | private static final long serialVersionUID = 6068470306649138683L; |
| 110 | |
| 111 | private String type; // the type of certificates in this chain |
| 112 | |
| 113 | /** |
| 114 | * Creates a <code>CertPath</code> of the specified type. |
| 115 | * <p> |
| 116 | * This constructor is protected because most users should use a |
| 117 | * <code>CertificateFactory</code> to create <code>CertPath</code>s. |
| 118 | * |
| 119 | * @param type the standard name of the type of |
| 120 | * <code>Certificate</code>s in this path |
| 121 | */ |
| 122 | protected CertPath(String type) { |
| 123 | this.type = type; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Returns the type of <code>Certificate</code>s in this certification |
| 128 | * path. This is the same string that would be returned by |
| 129 | * {@link java.security.cert.Certificate#getType() cert.getType()} |
| 130 | * for all <code>Certificate</code>s in the certification path. |
| 131 | * |
| 132 | * @return the type of <code>Certificate</code>s in this certification |
| 133 | * path (never null) |
| 134 | */ |
| 135 | public String getType() { |
| 136 | return type; |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Returns an iteration of the encodings supported by this certification |
| 141 | * path, with the default encoding first. Attempts to modify the returned |
| 142 | * <code>Iterator</code> via its <code>remove</code> method result in an |
| 143 | * <code>UnsupportedOperationException</code>. |
| 144 | * |
| 145 | * @return an <code>Iterator</code> over the names of the supported |
| 146 | * encodings (as Strings) |
| 147 | */ |
| 148 | public abstract Iterator<String> getEncodings(); |
| 149 | |
| 150 | /** |
| 151 | * Compares this certification path for equality with the specified |
| 152 | * object. Two <code>CertPath</code>s are equal if and only if their |
| 153 | * types are equal and their certificate <code>List</code>s (and by |
| 154 | * implication the <code>Certificate</code>s in those <code>List</code>s) |
| 155 | * are equal. A <code>CertPath</code> is never equal to an object that is |
| 156 | * not a <code>CertPath</code>. |
| 157 | * <p> |
| 158 | * This algorithm is implemented by this method. If it is overridden, |
| 159 | * the behavior specified here must be maintained. |
| 160 | * |
| 161 | * @param other the object to test for equality with this certification path |
| 162 | * @return true if the specified object is equal to this certification path, |
| 163 | * false otherwise |
| 164 | */ |
| 165 | public boolean equals(Object other) { |
| 166 | if (this == other) |
| 167 | return true; |
| 168 | |
| 169 | if (! (other instanceof CertPath)) |
| 170 | return false; |
| 171 | |
| 172 | CertPath otherCP = (CertPath) other; |
| 173 | if (! otherCP.getType().equals(type)) |
| 174 | return false; |
| 175 | |
| 176 | List<? extends Certificate> thisCertList = this.getCertificates(); |
| 177 | List<? extends Certificate> otherCertList = otherCP.getCertificates(); |
| 178 | return(thisCertList.equals(otherCertList)); |
| 179 | } |
| 180 | |
| 181 | /** |
| 182 | * Returns the hashcode for this certification path. The hash code of |
| 183 | * a certification path is defined to be the result of the following |
| 184 | * calculation: |
| 185 | * <pre><code> |
| 186 | * hashCode = path.getType().hashCode(); |
| 187 | * hashCode = 31*hashCode + path.getCertificates().hashCode(); |
| 188 | * </code></pre> |
| 189 | * This ensures that <code>path1.equals(path2)</code> implies that |
| 190 | * <code>path1.hashCode()==path2.hashCode()</code> for any two certification |
| 191 | * paths, <code>path1</code> and <code>path2</code>, as required by the |
| 192 | * general contract of <code>Object.hashCode</code>. |
| 193 | * |
| 194 | * @return the hashcode value for this certification path |
| 195 | */ |
| 196 | public int hashCode() { |
| 197 | int hashCode = type.hashCode(); |
| 198 | hashCode = 31*hashCode + getCertificates().hashCode(); |
| 199 | return hashCode; |
| 200 | } |
| 201 | |
| 202 | /** |
| 203 | * Returns a string representation of this certification path. |
| 204 | * This calls the <code>toString</code> method on each of the |
| 205 | * <code>Certificate</code>s in the path. |
| 206 | * |
| 207 | * @return a string representation of this certification path |
| 208 | */ |
| 209 | public String toString() { |
| 210 | StringBuffer sb = new StringBuffer(); |
| 211 | Iterator<? extends Certificate> stringIterator = |
| 212 | getCertificates().iterator(); |
| 213 | |
| 214 | sb.append("\n" + type + " Cert Path: length = " |
| 215 | + getCertificates().size() + ".\n"); |
| 216 | sb.append("[\n"); |
| 217 | int i = 1; |
| 218 | while (stringIterator.hasNext()) { |
| 219 | sb.append("==========================================" |
| 220 | + "===============Certificate " + i + " start.\n"); |
| 221 | Certificate stringCert = stringIterator.next(); |
| 222 | sb.append(stringCert.toString()); |
| 223 | sb.append("\n========================================" |
| 224 | + "=================Certificate " + i + " end.\n\n\n"); |
| 225 | i++; |
| 226 | } |
| 227 | |
| 228 | sb.append("\n]"); |
| 229 | return sb.toString(); |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * Returns the encoded form of this certification path, using the default |
| 234 | * encoding. |
| 235 | * |
| 236 | * @return the encoded bytes |
| 237 | * @exception CertificateEncodingException if an encoding error occurs |
| 238 | */ |
| 239 | public abstract byte[] getEncoded() |
| 240 | throws CertificateEncodingException; |
| 241 | |
| 242 | /** |
| 243 | * Returns the encoded form of this certification path, using the |
| 244 | * specified encoding. |
| 245 | * |
| 246 | * @param encoding the name of the encoding to use |
| 247 | * @return the encoded bytes |
| 248 | * @exception CertificateEncodingException if an encoding error occurs or |
| 249 | * the encoding requested is not supported |
| 250 | */ |
| 251 | public abstract byte[] getEncoded(String encoding) |
| 252 | throws CertificateEncodingException; |
| 253 | |
| 254 | /** |
| 255 | * Returns the list of certificates in this certification path. |
| 256 | * The <code>List</code> returned must be immutable and thread-safe. |
| 257 | * |
| 258 | * @return an immutable <code>List</code> of <code>Certificate</code>s |
| 259 | * (may be empty, but not null) |
| 260 | */ |
| 261 | public abstract List<? extends Certificate> getCertificates(); |
| 262 | |
| 263 | /** |
| 264 | * Replaces the <code>CertPath</code> to be serialized with a |
| 265 | * <code>CertPathRep</code> object. |
| 266 | * |
| 267 | * @return the <code>CertPathRep</code> to be serialized |
| 268 | * |
| 269 | * @throws ObjectStreamException if a <code>CertPathRep</code> object |
| 270 | * representing this certification path could not be created |
| 271 | */ |
| 272 | protected Object writeReplace() throws ObjectStreamException { |
| 273 | try { |
| 274 | return new CertPathRep(type, getEncoded()); |
| 275 | } catch (CertificateException ce) { |
| 276 | NotSerializableException nse = |
| 277 | new NotSerializableException |
| 278 | ("java.security.cert.CertPath: " + type); |
| 279 | nse.initCause(ce); |
| 280 | throw nse; |
| 281 | } |
| 282 | } |
| 283 | |
| 284 | /** |
| 285 | * Alternate <code>CertPath</code> class for serialization. |
| 286 | * @since 1.4 |
| 287 | */ |
| 288 | protected static class CertPathRep implements Serializable { |
| 289 | |
| 290 | private static final long serialVersionUID = 3015633072427920915L; |
| 291 | |
| 292 | /** The Certificate type */ |
| 293 | private String type; |
| 294 | /** The encoded form of the cert path */ |
| 295 | private byte[] data; |
| 296 | |
| 297 | /** |
| 298 | * Creates a <code>CertPathRep</code> with the specified |
| 299 | * type and encoded form of a certification path. |
| 300 | * |
| 301 | * @param type the standard name of a <code>CertPath</code> type |
| 302 | * @param data the encoded form of the certification path |
| 303 | */ |
| 304 | protected CertPathRep(String type, byte[] data) { |
| 305 | this.type = type; |
| 306 | this.data = data; |
| 307 | } |
| 308 | |
| 309 | /** |
| 310 | * Returns a <code>CertPath</code> constructed from the type and data. |
| 311 | * |
| 312 | * @return the resolved <code>CertPath</code> object |
| 313 | * |
| 314 | * @throws ObjectStreamException if a <code>CertPath</code> could not |
| 315 | * be constructed |
| 316 | */ |
| 317 | protected Object readResolve() throws ObjectStreamException { |
| 318 | try { |
| 319 | CertificateFactory cf = CertificateFactory.getInstance(type); |
| 320 | return cf.generateCertPath(new ByteArrayInputStream(data)); |
| 321 | } catch (CertificateException ce) { |
| 322 | NotSerializableException nse = |
| 323 | new NotSerializableException |
| 324 | ("java.security.cert.CertPath: " + type); |
| 325 | nse.initCause(ce); |
| 326 | throw nse; |
| 327 | } |
| 328 | } |
| 329 | } |
| 330 | } |