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

   1 package org.bouncycastle.asn1.x509;
   2
   3 import java.util.Enumeration;
   4
   5 import org.bouncycastle.asn1.*;
   6 import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
   7
   8 /**
   9  * <pre>
  10  * DigestInfo::=SEQUENCE{
  11  *          digestAlgorithm  AlgorithmIdentifier,
  12  *          digest OCTET STRING }
  13  * </pre>
  14  */
  15 public class DigestInfo
  16     implements DEREncodable
  17 {
  18     private byte[]                  digest;
  19     private AlgorithmIdentifier     algId;
  20
  21     public static DigestInfo getInstance(
  22         ASN1TaggedObject obj,
  23         boolean          explicit)
  24     {
  25         return getInstance(ASN1Sequence.getInstance(obj, explicit));
  26     }
  27
  28     public static DigestInfo getInstance(
  29         Object  obj)
  30     {
  31         if (obj instanceof DigestInfo)
  32         {
  33             return (DigestInfo)obj;
  34         }
  35         else if (obj instanceof ASN1Sequence)
  36         {
  37             return new DigestInfo((ASN1Sequence)obj);
  38         }
  39
  40         throw new IllegalArgumentException("unknown object in factory");
  41     }
  42
  43     public DigestInfo(
  44         AlgorithmIdentifier  algId,
  45         byte[]               digest)
  46     {
  47         this.digest = digest;
  48         this.algId = algId;
  49     }
  50
  51     public DigestInfo(
  52         ASN1Sequence  obj)
  53     {
  54         Enumeration             e = obj.getObjects();
  55
  56         algId = AlgorithmIdentifier.getInstance(e.nextElement());
  57         digest = ((ASN1OctetString)e.nextElement()).getOctets();
  58     }
  59
  60     public AlgorithmIdentifier getAlgorithmId()
  61     {
  62         return algId;
  63     }
  64
  65     public byte[] getDigest()
  66     {
  67         return digest;
  68     }
  69
  70     public DERObject getDERObject()
  71     {
  72         DEREncodableVector  v = new DEREncodableVector();
  73
  74         v.add(algId);
  75         v.add(new DEROctetString(digest));
  76
  77         return new DERSequence(v);
  78     }
  79 }