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      1 /*
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      3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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      5  * This code is free software; you can redistribute it and/or modify it
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      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.
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     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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     17  * You should have received a copy of the GNU General Public License version
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     23  * questions.
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     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 represents the Subject Alternative Name Extension.
     36  *
     37  * This extension, if present, allows the subject to specify multiple
     38  * alternative names.
     39  *
     40  * <p>Extensions are represented as a sequence of the extension identifier
     41  * (Object Identifier), a boolean flag stating whether the extension is to
     42  * be treated as being critical and the extension value itself (this is again
     43  * a DER encoding of the extension value).
     44  * <p>
     45  * The ASN.1 syntax for this is:
     46  * <pre>
     47  * SubjectAltName ::= GeneralNames
     48  * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
     49  * </pre>
     50  * @author Amit Kapoor
     51  * @author Hemma Prafullchandra
     52  * @see Extension
     53  * @see CertAttrSet
     54  */
     55 public class SubjectAlternativeNameExtension extends Extension
     56 implements CertAttrSet<String> {
     57     /**
     58      * Identifier for this attribute, to be used with the
     59      * get, set, delete methods of Certificate, x509 type.
     60      */
     61     public static final String IDENT =
     62                          "x509.info.extensions.SubjectAlternativeName";
     63     /**
     64      * Attribute names.
     65      */
     66     public static final String NAME = "SubjectAlternativeName";
     67     public static final String SUBJECT_NAME = "subject_name";
     68 
     69     // private data members
     70     GeneralNames        names = null;
     71 
     72     // Encode this extension
     73     private void encodeThis() throws IOException {
     74         if (names == null || names.isEmpty()) {
     75             this.extensionValue = null;
     76             return;
     77         }
     78         DerOutputStream os = new DerOutputStream();
     79         names.encode(os);
     80         this.extensionValue = os.toByteArray();
     81     }
     82 
     83     /**
     84      * Create a SubjectAlternativeNameExtension with the passed GeneralNames.
     85      * The extension is marked non-critical.
     86      *
     87      * @param names the GeneralNames for the subject.
     88      * @exception IOException on error.
     89      */
     90     public SubjectAlternativeNameExtension(GeneralNames names)
     91     throws IOException {
     92         this(Boolean.FALSE, names);
     93     }
     94 
     95     /**
     96      * Create a SubjectAlternativeNameExtension with the specified
     97      * criticality and GeneralNames.
     98      *
     99      * @param critical true if the extension is to be treated as critical.
    100      * @param names the GeneralNames for the subject.
    101      * @exception IOException on error.
    102      */
    103     public SubjectAlternativeNameExtension(Boolean critical, GeneralNames names)
    104     throws IOException {
    105         this.names = names;
    106         this.extensionId = PKIXExtensions.SubjectAlternativeName_Id;
    107         this.critical = critical.booleanValue();
    108         encodeThis();
    109     }
    110 
    111     /**
    112      * Create a default SubjectAlternativeNameExtension. The extension
    113      * is marked non-critical.
    114      */
    115     public SubjectAlternativeNameExtension() {
    116         extensionId = PKIXExtensions.SubjectAlternativeName_Id;
    117         critical = false;
    118         names = new GeneralNames();
    119     }
    120 
    121     /**
    122      * Create the extension from the passed DER encoded value.
    123      *
    124      * @param critical true if the extension is to be treated as critical.
    125      * @param value an array of DER encoded bytes of the actual value.
    126      * @exception ClassCastException if value is not an array of bytes
    127      * @exception IOException on error.
    128      */
    129     public SubjectAlternativeNameExtension(Boolean critical, Object value)
    130     throws IOException {
    131         this.extensionId = PKIXExtensions.SubjectAlternativeName_Id;
    132         this.critical = critical.booleanValue();
    133 
    134         this.extensionValue = (byte[]) value;
    135         DerValue val = new DerValue(this.extensionValue);
    136         if (val.data == null) {
    137             names = new GeneralNames();
    138             return;
    139         }
    140 
    141         names = new GeneralNames(val);
    142     }
    143 
    144     /**
    145      * Returns a printable representation of the SubjectAlternativeName.
    146      */
    147     public String toString() {
    148 
    149         String result = super.toString() + "SubjectAlternativeName [\n";
    150         if(names == null) {
    151             result += "  null\n";
    152         } else {
    153             for(GeneralName name: names.names()) {
    154                 result += "  "+name+"\n";
    155             }
    156         }
    157         result += "]\n";
    158         return result;
    159     }
    160 
    161     /**
    162      * Write the extension to the OutputStream.
    163      *
    164      * @param out the OutputStream to write the extension to.
    165      * @exception IOException on encoding errors.
    166      */
    167     public void encode(OutputStream out) throws IOException {
    168         DerOutputStream tmp = new DerOutputStream();
    169         if (extensionValue == null) {
    170             extensionId = PKIXExtensions.SubjectAlternativeName_Id;
    171             critical = false;
    172             encodeThis();
    173         }
    174         super.encode(tmp);
    175         out.write(tmp.toByteArray());
    176     }
    177 
    178     /**
    179      * Set the attribute value.
    180      */
    181     public void set(String name, Object obj) throws IOException {
    182         if (name.equalsIgnoreCase(SUBJECT_NAME)) {
    183             if (!(obj instanceof GeneralNames)) {
    184               throw new IOException("Attribute value should be of " +
    185                                     "type GeneralNames.");
    186             }
    187             names = (GeneralNames)obj;
    188         } else {
    189           throw new IOException("Attribute name not recognized by " +
    190                         "CertAttrSet:SubjectAlternativeName.");
    191         }
    192         encodeThis();
    193     }
    194 
    195     /**
    196      * Get the attribute value.
    197      */
    198     public GeneralNames get(String name) throws IOException {
    199         if (name.equalsIgnoreCase(SUBJECT_NAME)) {
    200             return (names);
    201         } else {
    202           throw new IOException("Attribute name not recognized by " +
    203                         "CertAttrSet:SubjectAlternativeName.");
    204         }
    205     }
    206 
    207     /**
    208      * Delete the attribute value.
    209      */
    210     public void delete(String name) throws IOException {
    211         if (name.equalsIgnoreCase(SUBJECT_NAME)) {
    212             names = null;
    213         } else {
    214           throw new IOException("Attribute name not recognized by " +
    215                         "CertAttrSet:SubjectAlternativeName.");
    216         }
    217         encodeThis();
    218     }
    219 
    220     /**
    221      * Return an enumeration of names of attributes existing within this
    222      * attribute.
    223      */
    224     public Enumeration<String> getElements() {
    225         AttributeNameEnumeration elements = new AttributeNameEnumeration();
    226         elements.addElement(SUBJECT_NAME);
    227 
    228         return (elements.elements());
    229     }
    230 
    231     /**
    232      * Return the name of this attribute.
    233      */
    234     public String getName() {
    235         return (NAME);
    236     }
    237 }
    238