org.bouncycastle.cms.jcajce.JceKeyTransAuthenticatedRecipient Maven / Gradle / Ivy

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The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. The APIs are designed primarily to be used in conjunction with the BC FIPS provider. The APIs may also be used with other providers although if being used in a FIPS context it is the responsibility of the user to ensure that any other providers used are FIPS certified.

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package org.bouncycastle.cms.jcajce;

import java.io.OutputStream;
import java.security.Key;
import java.security.PrivateKey;

import javax.crypto.Mac;

import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.cms.CMSException;
import org.bouncycastle.cms.RecipientOperator;
import org.bouncycastle.jcajce.io.MacOutputStream;
import org.bouncycastle.operator.GenericKey;
import org.bouncycastle.operator.MacCalculator;
import org.bouncycastle.operator.jcajce.JceGenericKey;


/**
 * the KeyTransRecipientInformation class for a recipient who has been sent a secret
 * key encrypted using their public key that needs to be used to
 * extract the message.
 */
public class JceKeyTransAuthenticatedRecipient
    extends JceKeyTransRecipient
{
    public JceKeyTransAuthenticatedRecipient(PrivateKey recipientKey)
    {
        super(recipientKey);
    }

    public RecipientOperator getRecipientOperator(AlgorithmIdentifier keyEncryptionAlgorithm, final AlgorithmIdentifier contentMacAlgorithm, byte[] encryptedContentEncryptionKey)
        throws CMSException
    {
        final Key secretKey = extractSecretKey(keyEncryptionAlgorithm, contentMacAlgorithm, encryptedContentEncryptionKey);

        final Mac dataMac = contentHelper.createContentMac(secretKey, contentMacAlgorithm);

        return new RecipientOperator(new MacCalculator()
        {
            public AlgorithmIdentifier getAlgorithmIdentifier()
            {
                return contentMacAlgorithm;
            }

            public GenericKey getKey()
            {
                return new JceGenericKey(contentMacAlgorithm, secretKey);
            }

            public OutputStream getOutputStream()
            {
                return new MacOutputStream(dataMac);
            }

            public byte[] getMac()
            {
                return dataMac.doFinal();
            }
        });
    }
}