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1   /*
2    * Copyright (c) 1997, 2009, 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   *
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24   */
25  
26  package sun.security.x509;
27  
28  import java.io.IOException;
29  import java.io.OutputStream;
30  import java.util.Enumeration;
31  
32  import sun.security.util.*;
33  
34  /**
35   * This class represents the Authority Key Identifier Extension.
36   *
37   * <p>The authority key identifier extension provides a means of
38   * identifying the particular public key used to sign a certificate.
39   * This extension would be used where an issuer has multiple signing
40   * keys (either due to multiple concurrent key pairs or due to
41   * changeover).
42   * <p>
43   * The ASN.1 syntax for this is:
44   * <pre>
45   * AuthorityKeyIdentifier ::= SEQUENCE {
46   *    keyIdentifier             [0] KeyIdentifier           OPTIONAL,
47   *    authorityCertIssuer       [1] GeneralNames            OPTIONAL,
48   *    authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL
49   * }
50   * KeyIdentifier ::= OCTET STRING
51   * </pre>
52   * @author Amit Kapoor
53   * @author Hemma Prafullchandra
54   * @see Extension
55   * @see CertAttrSet
56   */
57  public class AuthorityKeyIdentifierExtension extends Extension
58  implements CertAttrSet<String> {
59      /**
60       * Identifier for this attribute, to be used with the
61       * get, set, delete methods of Certificate, x509 type.
62       */
63      public static final String IDENT =
64                           "x509.info.extensions.AuthorityKeyIdentifier";
65      /**
66       * Attribute names.
67       */
68      public static final String NAME = "AuthorityKeyIdentifier";
69      public static final String KEY_ID = "key_id";
70      public static final String AUTH_NAME = "auth_name";
71      public static final String SERIAL_NUMBER = "serial_number";
72  
73      // Private data members
74      private static final byte TAG_ID = 0;
75      private static final byte TAG_NAMES = 1;
76      private static final byte TAG_SERIAL_NUM = 2;
77  
78      private KeyIdentifier       id = null;
79      private GeneralNames        names = null;
80      private SerialNumber        serialNum = null;
81  
82      // Encode only the extension value
83      private void encodeThis() throws IOException {
84          if (id == null && names == null && serialNum == null) {
85              this.extensionValue = null;
86              return;
87          }
88          DerOutputStream seq = new DerOutputStream();
89          DerOutputStream tmp = new DerOutputStream();
90          if (id != null) {
91              DerOutputStream tmp1 = new DerOutputStream();
92              id.encode(tmp1);
93              tmp.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,
94                                false, TAG_ID), tmp1);
95          }
96          try {
97              if (names != null) {
98                  DerOutputStream tmp1 = new DerOutputStream();
99                  names.encode(tmp1);
100                 tmp.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,
101                                   true, TAG_NAMES), tmp1);
102             }
103         } catch (Exception e) {
104             throw new IOException(e.toString());
105         }
106         if (serialNum != null) {
107             DerOutputStream tmp1 = new DerOutputStream();
108             serialNum.encode(tmp1);
109             tmp.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,
110                               false, TAG_SERIAL_NUM), tmp1);
111         }
112         seq.write(DerValue.tag_Sequence, tmp);
113         this.extensionValue = seq.toByteArray();
114     }
115 
116     /**
117      * The default constructor for this extension.  Null parameters make
118      * the element optional (not present).
119      *
120      * @param id the KeyIdentifier associated with this extension.
121      * @param names the GeneralNames associated with this extension
122      * @param serialNum the CertificateSerialNumber associated with
123      *         this extension.
124      * @exception IOException on error.
125      */
126     public AuthorityKeyIdentifierExtension(KeyIdentifier kid, GeneralNames name,
127                                            SerialNumber sn)
128     throws IOException {
129         this.id = kid;
130         this.names = name;
131         this.serialNum = sn;
132 
133         this.extensionId = PKIXExtensions.AuthorityKey_Id;
134         this.critical = false;
135         encodeThis();
136     }
137 
138     /**
139      * Create the extension from the passed DER encoded value of the same.
140      *
141      * @param critical true if the extension is to be treated as critical.
142      * @param value an array of DER encoded bytes of the actual value.
143      * @exception ClassCastException if value is not an array of bytes
144      * @exception IOException on error.
145      */
146     public AuthorityKeyIdentifierExtension(Boolean critical, Object value)
147     throws IOException {
148         this.extensionId = PKIXExtensions.AuthorityKey_Id;
149         this.critical = critical.booleanValue();
150 
151         this.extensionValue = (byte[]) value;
152         DerValue val = new DerValue(this.extensionValue);
153         if (val.tag != DerValue.tag_Sequence) {
154             throw new IOException("Invalid encoding for " +
155                                   "AuthorityKeyIdentifierExtension.");
156         }
157 
158         // Note that all the fields in AuthorityKeyIdentifier are defined as
159         // being OPTIONAL, i.e., there could be an empty SEQUENCE, resulting
160         // in val.data being null.
161         while ((val.data != null) && (val.data.available() != 0)) {
162             DerValue opt = val.data.getDerValue();
163 
164             // NB. this is always encoded with the IMPLICIT tag
165             // The checks only make sense if we assume implicit tagging,
166             // with explicit tagging the form is always constructed.
167             if (opt.isContextSpecific(TAG_ID) && !opt.isConstructed()) {
168                 if (id != null)
169                     throw new IOException("Duplicate KeyIdentifier in " +
170                                           "AuthorityKeyIdentifier.");
171                 opt.resetTag(DerValue.tag_OctetString);
172                 id = new KeyIdentifier(opt);
173 
174             } else if (opt.isContextSpecific(TAG_NAMES) &&
175                        opt.isConstructed()) {
176                 if (names != null)
177                     throw new IOException("Duplicate GeneralNames in " +
178                                           "AuthorityKeyIdentifier.");
179                 opt.resetTag(DerValue.tag_Sequence);
180                 names = new GeneralNames(opt);
181 
182             } else if (opt.isContextSpecific(TAG_SERIAL_NUM) &&
183                        !opt.isConstructed()) {
184                 if (serialNum != null)
185                     throw new IOException("Duplicate SerialNumber in " +
186                                           "AuthorityKeyIdentifier.");
187                 opt.resetTag(DerValue.tag_Integer);
188                 serialNum = new SerialNumber(opt);
189             } else
190                 throw new IOException("Invalid encoding of " +
191                                       "AuthorityKeyIdentifierExtension.");
192         }
193     }
194 
195     /**
196      * Return the object as a string.
197      */
198     public String toString() {
199         String s = super.toString() + "AuthorityKeyIdentifier [\n";
200         if (id != null) {
201             s += id.toString();     // id already has a newline
202         }
203         if (names != null) {
204             s += names.toString() + "\n";
205         }
206         if (serialNum != null) {
207             s += serialNum.toString() + "\n";
208         }
209         return (s + "]\n");
210     }
211 
212     /**
213      * Write the extension to the OutputStream.
214      *
215      * @param out the OutputStream to write the extension to.
216      * @exception IOException on error.
217      */
218     public void encode(OutputStream out) throws IOException {
219         DerOutputStream tmp = new DerOutputStream();
220         if (this.extensionValue == null) {
221             extensionId = PKIXExtensions.AuthorityKey_Id;
222             critical = false;
223             encodeThis();
224         }
225         super.encode(tmp);
226         out.write(tmp.toByteArray());
227     }
228 
229     /**
230      * Set the attribute value.
231      */
232     public void set(String name, Object obj) throws IOException {
233         if (name.equalsIgnoreCase(KEY_ID)) {
234             if (!(obj instanceof KeyIdentifier)) {
235               throw new IOException("Attribute value should be of " +
236                                     "type KeyIdentifier.");
237             }
238             id = (KeyIdentifier)obj;
239         } else if (name.equalsIgnoreCase(AUTH_NAME)) {
240             if (!(obj instanceof GeneralNames)) {
241               throw new IOException("Attribute value should be of " +
242                                     "type GeneralNames.");
243             }
244             names = (GeneralNames)obj;
245         } else if (name.equalsIgnoreCase(SERIAL_NUMBER)) {
246             if (!(obj instanceof SerialNumber)) {
247               throw new IOException("Attribute value should be of " +
248                                     "type SerialNumber.");
249             }
250             serialNum = (SerialNumber)obj;
251         } else {
252           throw new IOException("Attribute name not recognized by " +
253                         "CertAttrSet:AuthorityKeyIdentifier.");
254         }
255         encodeThis();
256     }
257 
258     /**
259      * Get the attribute value.
260      */
261     public Object get(String name) throws IOException {
262         if (name.equalsIgnoreCase(KEY_ID)) {
263             return (id);
264         } else if (name.equalsIgnoreCase(AUTH_NAME)) {
265             return (names);
266         } else if (name.equalsIgnoreCase(SERIAL_NUMBER)) {
267             return (serialNum);
268         } else {
269           throw new IOException("Attribute name not recognized by " +
270                         "CertAttrSet:AuthorityKeyIdentifier.");
271         }
272     }
273 
274     /**
275      * Delete the attribute value.
276      */
277     public void delete(String name) throws IOException {
278         if (name.equalsIgnoreCase(KEY_ID)) {
279             id = null;
280         } else if (name.equalsIgnoreCase(AUTH_NAME)) {
281             names = null;
282         } else if (name.equalsIgnoreCase(SERIAL_NUMBER)) {
283             serialNum = null;
284         } else {
285           throw new IOException("Attribute name not recognized by " +
286                         "CertAttrSet:AuthorityKeyIdentifier.");
287         }
288         encodeThis();
289     }
290 
291     /**
292      * Return an enumeration of names of attributes existing within this
293      * attribute.
294      */
295     public Enumeration<String> getElements() {
296         AttributeNameEnumeration elements = new AttributeNameEnumeration();
297         elements.addElement(KEY_ID);
298         elements.addElement(AUTH_NAME);
299         elements.addElement(SERIAL_NUMBER);
300 
301         return (elements.elements());
302     }
303 
304     /**
305      * Return the name of this attribute.
306      */
307     public String getName() {
308         return (NAME);
309     }
310 }