package org.spongycastle.cms.jcajce;
import java.security.Key;
import java.security.PrivateKey;
import java.security.Provider;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.spongycastle.asn1.ASN1ObjectIdentifier;
import org.spongycastle.asn1.x509.AlgorithmIdentifier;
import org.spongycastle.cms.CMSException;
import org.spongycastle.cms.KeyTransRecipient;
import org.spongycastle.operator.OperatorException;
import org.spongycastle.operator.jcajce.JceAsymmetricKeyUnwrapper;
public abstract class JceKeyTransRecipient
implements KeyTransRecipient
{
private PrivateKey recipientKey;
protected EnvelopedDataHelper helper = new EnvelopedDataHelper(new DefaultJcaJceExtHelper());
protected EnvelopedDataHelper contentHelper = helper;
protected Map extraMappings = new HashMap();
public JceKeyTransRecipient(PrivateKey recipientKey)
{
this.recipientKey = recipientKey;
}
/**
* Set the provider to use for key recovery and content processing.
*
* @param provider provider to use.
* @return this recipient.
*/
public JceKeyTransRecipient setProvider(Provider provider)
{
this.helper = new EnvelopedDataHelper(new ProviderJcaJceExtHelper(provider));
this.contentHelper = helper;
return this;
}
/**
* Set the provider to use for key recovery and content processing.
*
* @param providerName the name of the provider to use.
* @return this recipient.
*/
public JceKeyTransRecipient setProvider(String providerName)
{
this.helper = new EnvelopedDataHelper(new NamedJcaJceExtHelper(providerName));
this.contentHelper = helper;
return this;
}
/**
* Internally algorithm ids are converted into cipher names using a lookup table. For some providers
* the standard lookup table won't work. Use this method to establish a specific mapping from an
* algorithm identifier to a specific algorithm.
* <p>
* For example:
* <pre>
* unwrapper.setAlgorithmMapping(PKCSObjectIdentifiers.rsaEncryption, "RSA");
* </pre>
* </p>
* @param algorithm OID of algorithm in recipient.
* @param algorithmName JCE algorithm name to use.
* @return the current Recipient.
*/
public JceKeyTransRecipient setAlgorithmMapping(ASN1ObjectIdentifier algorithm, String algorithmName)
{
extraMappings.put(algorithm, algorithmName);
return this;
}
/**
* Set the provider to use for content processing. If providerName is null a "no provider" search will be
* used to satisfy getInstance calls.
*
* @param provider the provider to use.
* @return this recipient.
*/
public JceKeyTransRecipient setContentProvider(Provider provider)
{
this.contentHelper = CMSUtils.createContentHelper(provider);
return this;
}
/**
* Set the provider to use for content processing. If providerName is null a "no provider" search will be
* used to satisfy getInstance calls.
*
* @param providerName the name of the provider to use.
* @return this recipient.
*/
public JceKeyTransRecipient setContentProvider(String providerName)
{
this.contentHelper = CMSUtils.createContentHelper(providerName);
return this;
}
protected Key extractSecretKey(AlgorithmIdentifier keyEncryptionAlgorithm, AlgorithmIdentifier encryptedKeyAlgorithm, byte[] encryptedEncryptionKey)
throws CMSException
{
JceAsymmetricKeyUnwrapper unwrapper = helper.createAsymmetricUnwrapper(keyEncryptionAlgorithm, recipientKey);
if (!extraMappings.isEmpty())
{
for (Iterator it = extraMappings.keySet().iterator(); it.hasNext();)
{
ASN1ObjectIdentifier algorithm = (ASN1ObjectIdentifier)it.next();
unwrapper.setAlgorithmMapping(algorithm, (String)extraMappings.get(algorithm));
}
}
try
{
return helper.getJceKey(encryptedKeyAlgorithm.getAlgorithm(), unwrapper.generateUnwrappedKey(encryptedKeyAlgorithm, encryptedEncryptionKey));
}
catch (OperatorException e)
{
throw new CMSException("exception unwrapping key: " + e.getMessage(), e);
}
}
}