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/* * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.security.cert; import java.io.ByteArrayInputStream; import java.io.NotSerializableException; import java.io.ObjectStreamException; import java.io.Serializable; import java.util.Iterator; import java.util.List; /** * An immutable sequence of certificates (a certification path). * <p> * This is an abstract class that defines the methods common to all * {@code CertPath}s. Subclasses can handle different kinds of * certificates (X.509, PGP, etc.). * <p> * All {@code CertPath} objects have a type, a list of * {@code Certificate}s, and one or more supported encodings. Because the * {@code CertPath} class is immutable, a {@code CertPath} cannot * change in any externally visible way after being constructed. This * stipulation applies to all public fields and methods of this class and any * added or overridden by subclasses. * <p> * The type is a {@code String} that identifies the type of * {@code Certificate}s in the certification path. For each * certificate {@code cert} in a certification path {@code certPath}, * {@code cert.getType().equals(certPath.getType())} must be * {@code true}. * <p> * The list of {@code Certificate}s is an ordered {@code List} of * zero or more {@code Certificate}s. This {@code List} and all * of the {@code Certificate}s contained in it must be immutable. * <p> * Each {@code CertPath} object must support one or more encodings * so that the object can be translated into a byte array for storage or * transmission to other parties. Preferably, these encodings should be * well-documented standards (such as PKCS#7). One of the encodings supported * by a {@code CertPath} is considered the default encoding. This * encoding is used if no encoding is explicitly requested (for the * {@link #getEncoded() getEncoded()} method, for instance). * <p> * All {@code CertPath} objects are also {@code Serializable}. * {@code CertPath} objects are resolved into an alternate * {@link CertPathRep CertPathRep} object during serialization. This allows * a {@code CertPath} object to be serialized into an equivalent * representation regardless of its underlying implementation. * <p> * {@code CertPath} objects can be created with a * {@code CertificateFactory} or they can be returned by other classes, * such as a {@code CertPathBuilder}. * <p> * By convention, X.509 {@code CertPath}s (consisting of * {@code X509Certificate}s), are ordered starting with the target * certificate and ending with a certificate issued by the trust anchor. That * is, the issuer of one certificate is the subject of the following one. The * certificate representing the {@link TrustAnchor TrustAnchor} should not be * included in the certification path. Unvalidated X.509 {@code CertPath}s * may not follow these conventions. PKIX {@code CertPathValidator}s will * detect any departure from these conventions that cause the certification * path to be invalid and throw a {@code CertPathValidatorException}. * * <p> Every implementation of the Java platform is required to support the * following standard {@code CertPath} encodings: * <ul> * <li>{@code PKCS7}</li> * <li>{@code PkiPath}</li> * </ul> * These encodings are described in the <a href= * "{@docRoot}/../specs/security/standard-names.html#certpath-encodings"> * CertPath Encodings section</a> of the * Java Security Standard Algorithm Names Specification. * Consult the release documentation for your implementation to see if any * other encodings are supported. * <p> * <b>Concurrent Access</b> * <p> * All {@code CertPath} objects must be thread-safe. That is, multiple * threads may concurrently invoke the methods defined in this class on a * single {@code CertPath} object (or more than one) with no * ill effects. This is also true for the {@code List} returned by * {@code CertPath.getCertificates}. * <p> * Requiring {@code CertPath} objects to be immutable and thread-safe * allows them to be passed around to various pieces of code without worrying * about coordinating access. Providing this thread-safety is * generally not difficult, since the {@code CertPath} and * {@code List} objects in question are immutable. * * @see CertificateFactory * @see CertPathBuilder * * @author Yassir Elley * @since 1.4 */ public abstract class CertPath implements Serializable { private static final long serialVersionUID = 6068470306649138683L; private String type; // the type of certificates in this chain /** * Creates a {@code CertPath} of the specified type. * <p> * This constructor is protected because most users should use a * {@code CertificateFactory} to create {@code CertPath}s. * * @param type the standard name of the type of * {@code Certificate}s in this path */ protected CertPath(String type) { this.type = type; } /** * Returns the type of {@code Certificate}s in this certification * path. This is the same string that would be returned by * {@link java.security.cert.Certificate#getType() cert.getType()} * for all {@code Certificate}s in the certification path. * * @return the type of {@code Certificate}s in this certification * path (never null) */ public String getType() { return type; } /** * Returns an iteration of the encodings supported by this certification * path, with the default encoding first. Attempts to modify the returned * {@code Iterator} via its {@code remove} method result in an * {@code UnsupportedOperationException}. * * @return an {@code Iterator} over the names of the supported * encodings (as Strings) */ public abstract Iterator<String> getEncodings(); /** * Compares this certification path for equality with the specified * object. Two {@code CertPath}s are equal if and only if their * types are equal and their certificate {@code List}s (and by * implication the {@code Certificate}s in those {@code List}s) * are equal. A {@code CertPath} is never equal to an object that is * not a {@code CertPath}. * <p> * This algorithm is implemented by this method. If it is overridden, * the behavior specified here must be maintained. * * @param other the object to test for equality with this certification path * @return true if the specified object is equal to this certification path, * false otherwise */ public boolean equals(Object other) { if (this == other) return true; if (!(other instanceof CertPath)) return false; CertPath otherCP = (CertPath) other; if (!otherCP.getType().equals(type)) return false; List<? extends Certificate> thisCertList = this.getCertificates(); List<? extends Certificate> otherCertList = otherCP.getCertificates(); return (thisCertList.equals(otherCertList)); } /** * Returns the hashcode for this certification path. The hash code of * a certification path is defined to be the result of the following * calculation: * <pre>{@code * hashCode = path.getType().hashCode(); * hashCode = 31*hashCode + path.getCertificates().hashCode(); * }</pre> * This ensures that {@code path1.equals(path2)} implies that * {@code path1.hashCode()==path2.hashCode()} for any two certification * paths, {@code path1} and {@code path2}, as required by the * general contract of {@code Object.hashCode}. * * @return the hashcode value for this certification path */ public int hashCode() { int hashCode = type.hashCode(); hashCode = 31 * hashCode + getCertificates().hashCode(); return hashCode; } /** * Returns a string representation of this certification path. * This calls the {@code toString} method on each of the * {@code Certificate}s in the path. * * @return a string representation of this certification path */ public String toString() { StringBuilder sb = new StringBuilder(); Iterator<? extends Certificate> stringIterator = getCertificates().iterator(); sb.append("\n" + type + " Cert Path: length = " + getCertificates().size() + ".\n"); sb.append("[\n"); int i = 1; while (stringIterator.hasNext()) { sb.append( "==========================================" + "===============Certificate " + i + " start.\n"); Certificate stringCert = stringIterator.next(); sb.append(stringCert.toString()); sb.append("\n========================================" + "=================Certificate " + i + " end.\n\n\n"); i++; } sb.append("\n]"); return sb.toString(); } /** * Returns the encoded form of this certification path, using the default * encoding. * * @return the encoded bytes * @exception CertificateEncodingException if an encoding error occurs */ public abstract byte[] getEncoded() throws CertificateEncodingException; /** * Returns the encoded form of this certification path, using the * specified encoding. * * @param encoding the name of the encoding to use * @return the encoded bytes * @exception CertificateEncodingException if an encoding error occurs or * the encoding requested is not supported */ public abstract byte[] getEncoded(String encoding) throws CertificateEncodingException; /** * Returns the list of certificates in this certification path. * The {@code List} returned must be immutable and thread-safe. * * @return an immutable {@code List} of {@code Certificate}s * (may be empty, but not null) */ public abstract List<? extends Certificate> getCertificates(); /** * Replaces the {@code CertPath} to be serialized with a * {@code CertPathRep} object. * * @return the {@code CertPathRep} to be serialized * * @throws ObjectStreamException if a {@code CertPathRep} object * representing this certification path could not be created */ protected Object writeReplace() throws ObjectStreamException { try { return new CertPathRep(type, getEncoded()); } catch (CertificateException ce) { NotSerializableException nse = new NotSerializableException("java.security.cert.CertPath: " + type); nse.initCause(ce); throw nse; } } /** * Alternate {@code CertPath} class for serialization. * @since 1.4 */ protected static class CertPathRep implements Serializable { private static final long serialVersionUID = 3015633072427920915L; /** The Certificate type */ private String type; /** The encoded form of the cert path */ private byte[] data; /** * Creates a {@code CertPathRep} with the specified * type and encoded form of a certification path. * * @param type the standard name of a {@code CertPath} type * @param data the encoded form of the certification path */ protected CertPathRep(String type, byte[] data) { this.type = type; this.data = data; } /** * Returns a {@code CertPath} constructed from the type and data. * * @return the resolved {@code CertPath} object * * @throws ObjectStreamException if a {@code CertPath} could not * be constructed */ protected Object readResolve() throws ObjectStreamException { try { CertificateFactory cf = CertificateFactory.getInstance(type); return cf.generateCertPath(new ByteArrayInputStream(data)); } catch (CertificateException ce) { NotSerializableException nse = new NotSerializableException("java.security.cert.CertPath: " + type); nse.initCause(ce); throw nse; } } } }