CreateLargeEncryptedMail.javaAPI DocBouncy Castle Crypto API 1.41 (Java 1.5)3548Wed Oct 01 10:55:30 BST 2008org.bouncycastle.mail.smime.examples

package org.bouncycastle.mail.smime.examples;

import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.Address;
import javax.mail.Message;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;

import org.bouncycastle.mail.smime.SMIMEEnvelopedGenerator;

 * a simple example that creates a single encrypted mail message.
 * <p>
 * The key store can be created using the class in
 * org.bouncycastle.jce.examples.PKCS12Example - the program expects only one
 * key to be present in the key file.
 * <p>
 * Note: while this means that both the private key is available to
 * the program, the private key is retrieved from the keystore only for
 * the purposes of locating the corresponding public key, in normal circumstances
 * you would only be doing this with a certificate available.
public class CreateLargeEncryptedMail
    public static void main(
        String args[])
        throws Exception
        if (args.length != 3)
            System.err.println("usage: CreateLargeEncryptedMail pkcs12Keystore password inputFile");

        // Open the key store
        KeyStore    ks = KeyStore.getInstance("PKCS12", "BC");
        String      keyAlias = ExampleUtils.findKeyAlias(ks, args[0], args[1].toCharArray());

        Certificate[]   chain = ks.getCertificateChain(keyAlias);

        // create the generator for creating an smime/encrypted message
        SMIMEEnvelopedGenerator  gen = new SMIMEEnvelopedGenerator();

        // create a subject key id - this has to be done the same way as
        // it is done in the certificate associated with the private key
        // version 3 only.
        MessageDigest           dig = MessageDigest.getInstance("SHA1", "BC");

        gen.addKeyTransRecipient(cert.getPublicKey(), dig.digest());
        // create the base for our message
        MimeBodyPart    msg = new MimeBodyPart();

        msg.setDataHandler(new DataHandler(new FileDataSource(new File(args[2]))));
        msg.setHeader("Content-Type", "application/octet-stream");
        msg.setHeader("Content-Transfer-Encoding", "binary");

        MimeBodyPart mp = gen.generate(msg, SMIMEEnvelopedGenerator.RC2_CBC, "BC");
        // Get a Session object and create the mail message
        Properties props = System.getProperties();
        Session session = Session.getDefaultInstance(props, null);

        Address fromUser = new InternetAddress("\"Eric H. Echidna\"<>");
        Address toUser = new InternetAddress("");

        MimeMessage body = new MimeMessage(session);
        body.setRecipient(Message.RecipientType.TO, toUser);
        body.setSubject("example encrypted message");
        body.setContent(mp.getContent(), mp.getContentType());

        body.writeTo(new FileOutputStream("encrypted.message"));