org.bouncycastle.cms.jcajce.JceKEKRecipient Maven / Gradle / Ivy
package org.bouncycastle.cms.jcajce;
import java.security.Key;
import java.security.Provider;
import javax.crypto.SecretKey;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.cms.CMSException;
import org.bouncycastle.cms.KEKRecipient;
import org.bouncycastle.operator.OperatorException;
import org.bouncycastle.operator.SymmetricKeyUnwrapper;
public abstract class JceKEKRecipient
implements KEKRecipient
{
private SecretKey recipientKey;
protected EnvelopedDataHelper helper = new EnvelopedDataHelper(new DefaultJcaJceExtHelper());
protected EnvelopedDataHelper contentHelper = helper;
protected boolean validateKeySize = false;
public JceKEKRecipient(SecretKey recipientKey)
{
this.recipientKey = recipientKey;
}
/**
* Set the provider to use for key recovery and content processing.
*
* @param provider provider to use.
* @return this recipient.
*/
public JceKEKRecipient 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 JceKEKRecipient setProvider(String providerName)
{
this.helper = new EnvelopedDataHelper(new NamedJcaJceExtHelper(providerName));
this.contentHelper = helper;
return this;
}
/**
* Set the provider to use for content processing.
*
* @param provider the provider to use.
* @return this recipient.
*/
public JceKEKRecipient setContentProvider(Provider provider)
{
this.contentHelper = new EnvelopedDataHelper(new ProviderJcaJceExtHelper(provider));
return this;
}
/**
* Set the provider to use for content processing.
*
* @param providerName the name of the provider to use.
* @return this recipient.
*/
public JceKEKRecipient setContentProvider(String providerName)
{
this.contentHelper = new EnvelopedDataHelper(new NamedJcaJceExtHelper(providerName));
return this;
}
/**
* Set validation of retrieved key sizes against the algorithm parameters for the encrypted key where possible - default is off.
*
* This setting will not have any affect if the encryption algorithm in the recipient does not specify a particular key size, or
* if the unwrapper is a HSM and the byte encoding of the unwrapped secret key is not available.
*
* @param doValidate true if unwrapped key's should be validated against the content encryption algorithm, false otherwise.
* @return this recipient.
*/
public JceKEKRecipient setKeySizeValidation(boolean doValidate)
{
this.validateKeySize = doValidate;
return this;
}
protected Key extractSecretKey(AlgorithmIdentifier keyEncryptionAlgorithm, AlgorithmIdentifier encryptedKeyAlgorithm, byte[] encryptedContentEncryptionKey)
throws CMSException
{
SymmetricKeyUnwrapper unwrapper = helper.createSymmetricUnwrapper(keyEncryptionAlgorithm, recipientKey);
try
{
Key key = helper.getJceKey(encryptedKeyAlgorithm.getAlgorithm(), unwrapper.generateUnwrappedKey(encryptedKeyAlgorithm, encryptedContentEncryptionKey));
if (validateKeySize)
{
helper.keySizeCheck(encryptedKeyAlgorithm, key);
}
return key;
}
catch (OperatorException e)
{
throw new CMSException("exception unwrapping key: " + e.getMessage(), e);
}
}
}