1/*
2 * Copyright (c) 1997, 2017, 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).
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24 */
25
26package java.security.cert;
27
28import java.util.Arrays;
29
30import java.security.Provider;
31import java.security.PublicKey;
32import java.security.NoSuchAlgorithmException;
33import java.security.NoSuchProviderException;
34import java.security.InvalidKeyException;
35import java.security.SignatureException;
36
37import sun.security.x509.X509CertImpl;
38
39/**
40 * <p>Abstract class for managing a variety of identity certificates.
41 * An identity certificate is a binding of a principal to a public key which
42 * is vouched for by another principal.  (A principal represents
43 * an entity such as an individual user, a group, or a corporation.)
44 * <p>
45 * This class is an abstraction for certificates that have different
46 * formats but important common uses.  For example, different types of
47 * certificates, such as X.509 and PGP, share general certificate
48 * functionality (like encoding and verifying) and
49 * some types of information (like a public key).
50 * <p>
51 * X.509, PGP, and SDSI certificates can all be implemented by
52 * subclassing the Certificate class, even though they contain different
53 * sets of information, and they store and retrieve the information in
54 * different ways.
55 *
56 * @see X509Certificate
57 * @see CertificateFactory
58 *
59 * @author Hemma Prafullchandra
60 * @since 1.2
61 */
62
63public abstract class Certificate implements java.io.Serializable {
64
65    private static final long serialVersionUID = -3585440601605666277L;
66
67    // the certificate type
68    private final String type;
69
70    /** Cache the hash code for the certiticate */
71    private int hash = -1; // Default to -1
72
73    /**
74     * Creates a certificate of the specified type.
75     *
76     * @param type the standard name of the certificate type.
77     * See the CertificateFactory section in the <a href=
78     * "{@docRoot}/../specs/security/standard-names.html#certificatefactory-types">
79     * Java Security Standard Algorithm Names Specification</a>
80     * for information about standard certificate types.
81     */
82    protected Certificate(String type) {
83        this.type = type;
84    }
85
86    /**
87     * Returns the type of this certificate.
88     *
89     * @return the type of this certificate.
90     */
91    public final String getType() {
92        return this.type;
93    }
94
95    /**
96     * Compares this certificate for equality with the specified
97     * object. If the {@code other} object is an
98     * {@code instanceof} {@code Certificate}, then
99     * its encoded form is retrieved and compared with the
100     * encoded form of this certificate.
101     *
102     * @param other the object to test for equality with this certificate.
103     * @return true iff the encoded forms of the two certificates
104     * match, false otherwise.
105     */
106    public boolean equals(Object other) {
107        if (this == other) {
108            return true;
109        }
110        if (!(other instanceof Certificate)) {
111            return false;
112        }
113        try {
114            byte[] thisCert = X509CertImpl.getEncodedInternal(this);
115            byte[] otherCert = X509CertImpl.getEncodedInternal((Certificate)other);
116
117            return Arrays.equals(thisCert, otherCert);
118        } catch (CertificateException e) {
119            return false;
120        }
121    }
122
123    /**
124     * Returns a hashcode value for this certificate from its
125     * encoded form.
126     *
127     * @return the hashcode value.
128     */
129    public int hashCode() {
130        int h = hash;
131        if (h == -1) {
132            try {
133                h = Arrays.hashCode(X509CertImpl.getEncodedInternal(this));
134            } catch (CertificateException e) {
135                h = 0;
136            }
137            hash = h;
138        }
139        return h;
140    }
141
142    /**
143     * Returns the encoded form of this certificate. It is
144     * assumed that each certificate type would have only a single
145     * form of encoding; for example, X.509 certificates would
146     * be encoded as ASN.1 DER.
147     *
148     * @return the encoded form of this certificate
149     *
150     * @exception CertificateEncodingException if an encoding error occurs.
151     */
152    public abstract byte[] getEncoded()
153        throws CertificateEncodingException;
154
155    /**
156     * Verifies that this certificate was signed using the
157     * private key that corresponds to the specified public key.
158     *
159     * @param key the PublicKey used to carry out the verification.
160     *
161     * @exception NoSuchAlgorithmException on unsupported signature
162     * algorithms.
163     * @exception InvalidKeyException on incorrect key.
164     * @exception NoSuchProviderException if there's no default provider.
165     * @exception SignatureException on signature errors.
166     * @exception CertificateException on encoding errors.
167     */
168    public abstract void verify(PublicKey key)
169        throws CertificateException, NoSuchAlgorithmException,
170        InvalidKeyException, NoSuchProviderException,
171        SignatureException;
172
173    /**
174     * Verifies that this certificate was signed using the
175     * private key that corresponds to the specified public key.
176     * This method uses the signature verification engine
177     * supplied by the specified provider.
178     *
179     * @param key the PublicKey used to carry out the verification.
180     * @param sigProvider the name of the signature provider.
181     *
182     * @exception NoSuchAlgorithmException on unsupported signature
183     * algorithms.
184     * @exception InvalidKeyException on incorrect key.
185     * @exception NoSuchProviderException on incorrect provider.
186     * @exception SignatureException on signature errors.
187     * @exception CertificateException on encoding errors.
188     */
189    public abstract void verify(PublicKey key, String sigProvider)
190        throws CertificateException, NoSuchAlgorithmException,
191        InvalidKeyException, NoSuchProviderException,
192        SignatureException;
193
194    /**
195     * Verifies that this certificate was signed using the
196     * private key that corresponds to the specified public key.
197     * This method uses the signature verification engine
198     * supplied by the specified provider. Note that the specified
199     * Provider object does not have to be registered in the provider list.
200     *
201     * <p> This method was added to version 1.8 of the Java Platform
202     * Standard Edition. In order to maintain backwards compatibility with
203     * existing service providers, this method cannot be {@code abstract}
204     * and by default throws an {@code UnsupportedOperationException}.
205     *
206     * @param key the PublicKey used to carry out the verification.
207     * @param sigProvider the signature provider.
208     *
209     * @exception NoSuchAlgorithmException on unsupported signature
210     * algorithms.
211     * @exception InvalidKeyException on incorrect key.
212     * @exception SignatureException on signature errors.
213     * @exception CertificateException on encoding errors.
214     * @exception UnsupportedOperationException if the method is not supported
215     * @since 1.8
216     */
217    public void verify(PublicKey key, Provider sigProvider)
218        throws CertificateException, NoSuchAlgorithmException,
219        InvalidKeyException, SignatureException {
220        throw new UnsupportedOperationException();
221    }
222
223    /**
224     * Returns a string representation of this certificate.
225     *
226     * @return a string representation of this certificate.
227     */
228    public abstract String toString();
229
230    /**
231     * Gets the public key from this certificate.
232     *
233     * @return the public key.
234     */
235    public abstract PublicKey getPublicKey();
236
237    /**
238     * Alternate Certificate class for serialization.
239     * @since 1.3
240     */
241    protected static class CertificateRep implements java.io.Serializable {
242
243        private static final long serialVersionUID = -8563758940495660020L;
244
245        private String type;
246        private byte[] data;
247
248        /**
249         * Construct the alternate Certificate class with the Certificate
250         * type and Certificate encoding bytes.
251         *
252         * @param type the standard name of the Certificate type.
253         *
254         * @param data the Certificate data.
255         */
256        protected CertificateRep(String type, byte[] data) {
257            this.type = type;
258            this.data = data;
259        }
260
261        /**
262         * Resolve the Certificate Object.
263         *
264         * @return the resolved Certificate Object
265         *
266         * @throws java.io.ObjectStreamException if the Certificate
267         *      could not be resolved
268         */
269        protected Object readResolve() throws java.io.ObjectStreamException {
270            try {
271                CertificateFactory cf = CertificateFactory.getInstance(type);
272                return cf.generateCertificate
273                        (new java.io.ByteArrayInputStream(data));
274            } catch (CertificateException e) {
275                throw new java.io.NotSerializableException
276                                ("java.security.cert.Certificate: " +
277                                type +
278                                ": " +
279                                e.getMessage());
280            }
281        }
282    }
283
284    /**
285     * Replace the Certificate to be serialized.
286     *
287     * @return the alternate Certificate object to be serialized
288     *
289     * @throws java.io.ObjectStreamException if a new object representing
290     * this Certificate could not be created
291     * @since 1.3
292     */
293    protected Object writeReplace() throws java.io.ObjectStreamException {
294        try {
295            return new CertificateRep(type, getEncoded());
296        } catch (CertificateException e) {
297            throw new java.io.NotSerializableException
298                                ("java.security.cert.Certificate: " +
299                                type +
300                                ": " +
301                                e.getMessage());
302        }
303    }
304}
305