org.bouncycastle.asn1.pkcs.RSAPublicKey.java Source code

Introduction

Here is the source code for org.bouncycastle.asn1.pkcs.RSAPublicKey.java

Source

package org.bouncycastle.asn1.pkcs;

import java.math.BigInteger;
import java.util.Enumeration;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DERSequence;

public class RSAPublicKey extends ASN1Object {
    private BigInteger modulus;
    private BigInteger publicExponent;

    public static RSAPublicKey getInstance(ASN1TaggedObject obj, boolean explicit) {
        return getInstance(ASN1Sequence.getInstance(obj, explicit));
    }

    public static RSAPublicKey getInstance(Object obj) {
        if (obj instanceof RSAPublicKey) {
            return (RSAPublicKey) obj;
        }

        if (obj != null) {
            return new RSAPublicKey(ASN1Sequence.getInstance(obj));
        }

        return null;
    }

    public RSAPublicKey(BigInteger modulus, BigInteger publicExponent) {
        this.modulus = modulus;
        this.publicExponent = publicExponent;
    }

    private RSAPublicKey(ASN1Sequence seq) {
        if (seq.size() != 2) {
            throw new IllegalArgumentException("Bad sequence size: " + seq.size());
        }

        Enumeration e = seq.getObjects();

        modulus = ASN1Integer.getInstance(e.nextElement()).getPositiveValue();
        publicExponent = ASN1Integer.getInstance(e.nextElement()).getPositiveValue();
    }

    public BigInteger getModulus() {
        return modulus;
    }

    public BigInteger getPublicExponent() {
        return publicExponent;
    }

    /**
     * This outputs the key in PKCS1v2 format.
     * <pre>
     *      RSAPublicKey ::= SEQUENCE {
     *                          modulus INTEGER, -- n
     *                          publicExponent INTEGER, -- e
     *                      }
     * </pre>
     * <p>
     */
    public ASN1Primitive toASN1Primitive() {
        ASN1EncodableVector v = new ASN1EncodableVector(2);

        v.add(new ASN1Integer(getModulus()));
        v.add(new ASN1Integer(getPublicExponent()));

        return new DERSequence(v);
    }
}