x509encodedkeyspecexample.java

sip CMSEnvelopedData

package chapter5;

import java.security.*;
import java.security.spec.X509EncodedKeySpec;

import org.bouncycastle.asn1.ASN1InputStream;

import org.bouncycastle.asn1.util.ASN1Dump;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;

import chapter4.Utils;

/**
 * Simple example showing use of X509EncodedKeySpec
 */
public class X509EncodedKeySpecExample
{
    public static void main(
        String[]    args)
        throws Exception
    {
        // create the keys
        KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA", "BC");
        
        generator.initialize(128, Utils.createFixedRandom());

        KeyPair               pair = generator.generateKeyPair();

        // dump public key
        ASN1InputStream	      aIn = new ASN1InputStream(pair.getPublic().getEncoded());
        SubjectPublicKeyInfo  info = SubjectPublicKeyInfo.getInstance(aIn.readObject());
        
        System.out.println(ASN1Dump.dumpAsString(info));        
        System.out.println(ASN1Dump.dumpAsString(info.getPublicKey()));

        // create from specification
        X509EncodedKeySpec  x509Spec = new X509EncodedKeySpec(pair.getPublic().getEncoded());
        KeyFactory          keyFact = KeyFactory.getInstance("RSA", "BC");
        PublicKey           pubKey = keyFact.generatePublic(x509Spec);
        
        if (pubKey.equals(pair.getPublic()))
        {
            System.out.println("key recovery successful");
        }
        else
        {
            System.out.println("key recovery failed");
        }
    }
}