http://www.bouncycastle.org/java.html: The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 to JDK 1.8. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.cms;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;

import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Set;
import org.bouncycastle.asn1.BEROctetString;
import org.bouncycastle.asn1.BERSet;
import org.bouncycastle.asn1.cms.AttributeTable;
import org.bouncycastle.asn1.cms.CMSObjectIdentifiers;
import org.bouncycastle.asn1.cms.ContentInfo;
import org.bouncycastle.asn1.cms.EncryptedContentInfo;
import org.bouncycastle.asn1.cms.EncryptedData;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.operator.OutputEncryptor;


General class for generating a CMS encrypted-data message.
A simple example of usage.

      CMSTypedData msg     = new CMSProcessableByteArray("Hello World!".getBytes());
      CMSEncryptedDataGenerator edGen = new CMSEncryptedDataGenerator();
      CMSEncryptedData ed = edGen.generate(
                                      msg,
                                      new JceCMSContentEncryptorBuilder(CMSAlgorithm.DES_EDE3_CBC)
                                             .setProvider("BC").build());



/**
 * General class for generating a CMS encrypted-data message.
 *
 * A simple example of usage.
 *
 * <pre>
 *       CMSTypedData msg     = new CMSProcessableByteArray("Hello World!".getBytes());
 *
 *       CMSEncryptedDataGenerator edGen = new CMSEncryptedDataGenerator();
 *
 *       CMSEncryptedData ed = edGen.generate(
 *                                       msg,
 *                                       new JceCMSContentEncryptorBuilder(CMSAlgorithm.DES_EDE3_CBC)
 *                                              .setProvider("BC").build());
 *
 * </pre>
 */
public class CMSEncryptedDataGenerator
    extends CMSEncryptedGenerator
{
    
base constructor

/**
     * base constructor
     */
    public CMSEncryptedDataGenerator()
    {
    }

    private CMSEncryptedData doGenerate(
        CMSTypedData content,
        OutputEncryptor contentEncryptor)
        throws CMSException
    {
        AlgorithmIdentifier     encAlgId;
        ASN1OctetString         encContent;

        ByteArrayOutputStream bOut = new ByteArrayOutputStream();

        try
        {
            OutputStream cOut = contentEncryptor.getOutputStream(bOut);

            content.write(cOut);

            cOut.close();
        }
        catch (IOException e)
        {
            throw new CMSException("");
        }

        byte[] encryptedContent = bOut.toByteArray();

        encAlgId = contentEncryptor.getAlgorithmIdentifier();

        encContent = new BEROctetString(encryptedContent);

        EncryptedContentInfo  eci = new EncryptedContentInfo(
                        content.getContentType(),
                        encAlgId,
                        encContent);

        ASN1Set unprotectedAttrSet = null;
        if (unprotectedAttributeGenerator != null)
        {
            AttributeTable attrTable = unprotectedAttributeGenerator.getAttributes(new HashMap());

            unprotectedAttrSet = new BERSet(attrTable.toASN1EncodableVector());
        }

        ContentInfo contentInfo = new ContentInfo(
                CMSObjectIdentifiers.encryptedData,
                new EncryptedData(eci, unprotectedAttrSet));

        return new CMSEncryptedData(contentInfo);
    }

    
generate an encrypted object that contains an CMS Encrypted Data structure.

Params:
  • content – the content to be encrypted
  • contentEncryptor – the symmetric key based encryptor to encrypt the content with.
/**
     * generate an encrypted object that contains an CMS Encrypted Data structure.
     *
     * @param content the content to be encrypted
     * @param contentEncryptor the symmetric key based encryptor to encrypt the content with.
     */
    public CMSEncryptedData generate(
        CMSTypedData content,
        OutputEncryptor contentEncryptor)
        throws CMSException
    {
        return doGenerate(content, contentEncryptor);
    }
}