chapter9.KeyTransEnvelopedDataExample2.java Source code

Introduction

Here is the source code for chapter9.KeyTransEnvelopedDataExample2.java

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package chapter9;

import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.cert.CertStore;
import java.security.cert.Certificate;
import java.security.cert.CollectionCertStoreParameters;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import org.bouncycastle.cms.CMSEnvelopedData;
import org.bouncycastle.cms.CMSEnvelopedDataGenerator;
import org.bouncycastle.cms.CMSProcessable;
import org.bouncycastle.cms.CMSProcessableByteArray;
import org.bouncycastle.cms.KeyTransRecipientInformation;
import org.bouncycastle.cms.RecipientInformation;
import org.bouncycastle.cms.RecipientInformationStore;
import utils.CryptoDefs;

/**
 * Demostrate creation and processing a public key recipient
 * enveloped-message.
 * @author fran
 */
public class KeyTransEnvelopedDataExample2 implements java.io.Serializable {
    private static final long serialVersionUID = -1L;
    private static final String _NAME = KeyTransEnvelopedDataExample2.class.getName();

    /*------------------------------------------------------------------------*/
    /*                          Metodos Privados                              */
    /*------------------------------------------------------------------------*/

    /*------------------------------------------------------------------------*/
    /*                          Default Access                                */
    /*------------------------------------------------------------------------*/

    /*------------------------------------------------------------------------*/
    /*                          Metodos Protegidos                            */
    /*------------------------------------------------------------------------*/

    /*------------------------------------------------------------------------*/
    /*                            Constructores                               */
    /*------------------------------------------------------------------------*/
    /**
     * Constructor por defecto.
     */
    public KeyTransEnvelopedDataExample2() {
    }

    /*------------------------------------------------------------------------*/
    /*                          Metodos Publicos                              */
    /*------------------------------------------------------------------------*/
    /**
     *
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        KeyStore credentials = Utils.createCredentials();
        PrivateKey key = (PrivateKey) credentials.getKey(Utils.END_ENTITY_ALIAS, Utils.KEY_PASSWD);

        Certificate[] chain = credentials.getCertificateChain(Utils.END_ENTITY_ALIAS);

        X509Certificate cert = (X509Certificate) chain[0];

        //1.- Set up the generator
        CMSEnvelopedDataGenerator gen = new CMSEnvelopedDataGenerator();

        gen.addKeyTransRecipient(cert);

        //2.- Create the enveloped-data object
        CMSProcessable data = new CMSProcessableByteArray("Hello World!!".getBytes());
        CMSEnvelopedData enveloped = gen.generate(data, CMSEnvelopedDataGenerator.AES128_CBC,
                CryptoDefs.Provider.BC.getName());

        //3.- Re-create
        enveloped = new CMSEnvelopedData(enveloped.getEncoded());

        //4.- Look for our recipient identifier
        //    Set up to iterate through the recipients
        RecipientInformationStore recipients = enveloped.getRecipientInfos();
        CertStore certStore = CertStore.getInstance("Collection",
                new CollectionCertStoreParameters(Collections.singleton(cert)), CryptoDefs.Provider.BC.getName());

        RecipientInformation recipient = null;
        for (Object o : recipients.getRecipients()) {
            recipient = (RecipientInformation) o;

            if (recipient instanceof KeyTransRecipientInformation) {
                //5.- Match the recipient ID
                Collection<?> matches = certStore.getCertificates(recipient.getRID());

                if (matches.isEmpty() == false) {
                    //6.- Decrypt the data
                    byte[] recData = recipient.getContent(key, CryptoDefs.Provider.BC.getName());

                    //7.- Compare recovered data to the original data
                    if (Arrays.equals((byte[]) data.getContent(), recData) == true) {
                        System.out.println("\t data recovery succeeded!!");
                        break;
                    } else {
                        System.out.println("\t data recovery failed!!");
                        break;
                    }
                }
            }
        }

        if (recipient == null) {
            System.out.println("\t Could not find a matching recipient!!");
        }
    }
}