org.bouncycastle.cms.CMSEnvelopedData.java Source code

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Here is the source code for org.bouncycastle.cms.CMSEnvelopedData.java

Source

package org.bouncycastle.cms;

import java.io.IOException;
import java.io.InputStream;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1Set;
import org.bouncycastle.asn1.cms.AttributeTable;
import org.bouncycastle.asn1.cms.ContentInfo;
import org.bouncycastle.asn1.cms.EncryptedContentInfo;
import org.bouncycastle.asn1.cms.EnvelopedData;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.util.Encodable;

/**
 * containing class for an CMS Enveloped Data object
 * <p>
 * Example of use - assuming the first recipient matches the private key we have.
 * <pre>
 *      CMSEnvelopedData     ed = new CMSEnvelopedData(inputStream);
 *
 *      RecipientInformationStore  recipients = ed.getRecipientInfos();
 *
 *      Collection  c = recipients.getRecipients();
 *      Iterator    it = c.iterator();
 *
 *      if (it.hasNext())
 *      {
 *          RecipientInformation   recipient = (RecipientInformation)it.next();
 *
 *          byte[] recData = recipient.getContent(new JceKeyTransEnvelopedRecipient(privateKey).setProvider("BC"));
 *
 *          processData(recData);
 *      }
 *  </pre>
 */
public class CMSEnvelopedData implements Encodable {
    RecipientInformationStore recipientInfoStore;
    ContentInfo contentInfo;

    private AlgorithmIdentifier encAlg;
    private ASN1Set unprotectedAttributes;
    private OriginatorInformation originatorInfo;

    public CMSEnvelopedData(byte[] envelopedData) throws CMSException {
        this(CMSUtils.readContentInfo(envelopedData));
    }

    public CMSEnvelopedData(InputStream envelopedData) throws CMSException {
        this(CMSUtils.readContentInfo(envelopedData));
    }

    /**
     * Construct a CMSEnvelopedData object from a content info object.
     *
     * @param contentInfo the contentInfo containing the CMS EnvelopedData object.
     * @throws CMSException in the case where malformed content is encountered.
     */
    public CMSEnvelopedData(ContentInfo contentInfo) throws CMSException {
        this.contentInfo = contentInfo;

        try {
            EnvelopedData envData = EnvelopedData.getInstance(contentInfo.getContent());

            if (envData.getOriginatorInfo() != null) {
                originatorInfo = new OriginatorInformation(envData.getOriginatorInfo());
            }

            //
            // read the recipients
            //
            ASN1Set recipientInfos = envData.getRecipientInfos();

            //
            // read the encrypted content info
            //
            EncryptedContentInfo encInfo = envData.getEncryptedContentInfo();
            this.encAlg = encInfo.getContentEncryptionAlgorithm();
            CMSReadable readable = new CMSProcessableByteArray(encInfo.getEncryptedContent().getOctets());
            CMSSecureReadable secureReadable = new CMSEnvelopedHelper.CMSEnvelopedSecureReadable(this.encAlg,
                    readable);

            //
            // build the RecipientInformationStore
            //
            this.recipientInfoStore = CMSEnvelopedHelper.buildRecipientInformationStore(recipientInfos, this.encAlg,
                    secureReadable);

            this.unprotectedAttributes = envData.getUnprotectedAttrs();
        } catch (ClassCastException e) {
            throw new CMSException("Malformed content.", e);
        } catch (IllegalArgumentException e) {
            throw new CMSException("Malformed content.", e);
        }
    }

    private byte[] encodeObj(ASN1Encodable obj) throws IOException {
        if (obj != null) {
            return obj.toASN1Primitive().getEncoded();
        }

        return null;
    }

    /**
     * Return the originator information associated with this message if present.
     *
     * @return OriginatorInformation, null if not present.
     */
    public OriginatorInformation getOriginatorInfo() {
        return originatorInfo;
    }

    /**
     * Return the content encryption algorithm details for the data in this object.
     *
     * @return AlgorithmIdentifier representing the content encryption algorithm.
     */
    public AlgorithmIdentifier getContentEncryptionAlgorithm() {
        return encAlg;
    }

    /**
     * return the object identifier for the content encryption algorithm.
     */
    public String getEncryptionAlgOID() {
        return encAlg.getAlgorithm().getId();
    }

    /**
     * return the ASN.1 encoded encryption algorithm parameters, or null if
     * there aren't any.
     */
    public byte[] getEncryptionAlgParams() {
        try {
            return encodeObj(encAlg.getParameters());
        } catch (Exception e) {
            throw new RuntimeException("exception getting encryption parameters " + e);
        }
    }

    /**
     * return a store of the intended recipients for this message
     */
    public RecipientInformationStore getRecipientInfos() {
        return recipientInfoStore;
    }

    /**
     * return the ContentInfo
     */
    public ContentInfo toASN1Structure() {
        return contentInfo;
    }

    /**
     * return a table of the unprotected attributes indexed by
     * the OID of the attribute.
     */
    public AttributeTable getUnprotectedAttributes() {
        if (unprotectedAttributes == null) {
            return null;
        }

        return new AttributeTable(unprotectedAttributes);
    }

    /**
     * return the ASN.1 encoded representation of this object.
     */
    public byte[] getEncoded() throws IOException {
        return contentInfo.getEncoded();
    }
}