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

   1 package org.bouncycastle.asn1.x509;
   2
   3 import java.util.Enumeration;
   4 import java.math.BigInteger;
   5
   6 import org.bouncycastle.asn1.*;
   7
   8 public class RSAPublicKeyStructure
   9     implements DEREncodable
  10 {
  11     private BigInteger  modulus;
  12     private BigInteger  publicExponent;
  13
  14     public static RSAPublicKeyStructure getInstance(
  15         ASN1TaggedObject obj,
  16         boolean          explicit)
  17     {
  18         return getInstance(ASN1Sequence.getInstance(obj, explicit));
  19     }
  20
  21     public static RSAPublicKeyStructure getInstance(
  22         Object obj)
  23     {
  24         if(obj == null || obj instanceof RSAPublicKeyStructure)
  25         {
  26             return (RSAPublicKeyStructure)obj;
  27         }
  28
  29         if(obj instanceof ASN1Sequence)
  30         {
  31             return new RSAPublicKeyStructure((ASN1Sequence)obj);
  32         }
  33
  34         throw new IllegalArgumentException("Invalid RSAPublicKeyStructure: " + obj.getClass().getName());
  35     }
  36
  37     public RSAPublicKeyStructure(
  38         BigInteger  modulus,
  39         BigInteger  publicExponent)
  40     {
  41         this.modulus = modulus;
  42         this.publicExponent = publicExponent;
  43     }
  44
  45     public RSAPublicKeyStructure(
  46         ASN1Sequence  seq)
  47     {
  48         Enumeration e = seq.getObjects();
  49
  50         modulus = ((DERInteger)e.nextElement()).getValue();
  51         publicExponent = ((DERInteger)e.nextElement()).getValue();
  52     }
  53
  54     public BigInteger getModulus()
  55     {
  56         return modulus;
  57     }
  58
  59     public BigInteger getPublicExponent()
  60     {
  61         return publicExponent;
  62     }
  63
  64     /**
  65      * This outputs the key in PKCS1v2 format.
  66      * <pre>
  67      *      RSAPublicKey ::= SEQUENCE {
  68      *                          modulus INTEGER, -- n
  69      *                          publicExponent INTEGER, -- e
  70      *                      }
  71      * </pre>
  72      * <p>
  73      */
  74     public DERObject getDERObject()
  75     {
  76         DERConstructedSequence  seq = new DERConstructedSequence();
  77
  78         seq.addObject(new DERInteger(getModulus()));
  79         seq.addObject(new DERInteger(getPublicExponent()));
  80
  81         return seq;
  82     }
  83 }