src/org/bouncycastle/asn1/x509/SubjectKeyIdentifier.java

   1 package org.bouncycastle.asn1.x509;
   2
   3 import org.bouncycastle.crypto.Digest;
   4 import org.bouncycastle.crypto.digests.SHA1Digest;
   5 import org.bouncycastle.asn1.*;
   6
   7 /**
   8  * <pre>
   9  * SubjectKeyIdentifier::= OCTET STRING
  10  * </pre>
  11  */
  12 public class SubjectKeyIdentifier
  13     implements DEREncodable
  14 {
  15         private byte[] keyidentifier;
  16
  17     public static SubjectKeyIdentifier getInstance(
  18         ASN1TaggedObject obj,
  19         boolean          explicit)
  20     {
  21         return getInstance(ASN1OctetString.getInstance(obj, explicit));
  22     }
  23
  24     public static SubjectKeyIdentifier getInstance(
  25         Object obj)
  26     {
  27         if(obj == null || obj instanceof SubjectKeyIdentifier)
  28         {
  29             return (SubjectKeyIdentifier)obj;
  30         }
  31
  32         if(obj instanceof SubjectPublicKeyInfo)
  33         {
  34             return new SubjectKeyIdentifier((SubjectPublicKeyInfo)obj);
  35         }
  36
  37         if(obj instanceof ASN1OctetString)
  38         {
  39             return new SubjectKeyIdentifier((ASN1OctetString)obj);
  40         }
  41
  42         throw new IllegalArgumentException("Invalid SubjectKeyIdentifier: " + obj.getClass().getName());
  43     }
  44
  45     public SubjectKeyIdentifier(
  46         byte[] keyid)
  47     {
  48         this.keyidentifier=keyid;
  49     }
  50
  51     public SubjectKeyIdentifier(
  52         ASN1OctetString  keyid)
  53     {
  54                 this.keyidentifier=keyid.getOctets();
  55
  56     }
  57
  58         /**
  59          *
  60          * Calulates the keyidentifier using a SHA1 hash over the BIT STRING
  61          * from SubjectPublicKeyInfo as defined in RFC2459.
  62          *
  63          **/
  64         public SubjectKeyIdentifier(
  65                 SubjectPublicKeyInfo    spki)
  66         {
  67                 Digest  digest = new SHA1Digest();
  68                 byte[]  resBuf = new byte[digest.getDigestSize()];
  69
  70                 byte[] bytes = spki.getPublicKeyData().getBytes();
  71                 digest.update(bytes, 0, bytes.length);
  72                 digest.doFinal(resBuf, 0);
  73                 this.keyidentifier=resBuf;
  74         }
  75
  76     public byte[] getKeyIdentifier()
  77     {
  78         return keyidentifier;
  79     }
  80
  81      /**
  82      * <pre>
  83      * SubjectKeyIdentifier := OCTET STRING
  84      * </pre>
  85      */
  86     public DERObject getDERObject()
  87     {
  88         return new DEROctetString(keyidentifier);
  89     }
  90 }