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package org.bouncycastle.cert.crmf.jcajce;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.PrivateKey;
import java.security.Provider;
import java.security.ProviderException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.cert.crmf.CRMFException;
import org.bouncycastle.cert.crmf.ValueDecryptorGenerator;
import org.bouncycastle.jcajce.util.DefaultJcaJceHelper;
import org.bouncycastle.jcajce.util.NamedJcaJceHelper;
import org.bouncycastle.jcajce.util.ProviderJcaJceHelper;
import org.bouncycastle.operator.InputDecryptor;
public class JceAsymmetricValueDecryptorGenerator
implements ValueDecryptorGenerator
{
private PrivateKey recipientKey;
private CRMFHelper helper = new CRMFHelper(new DefaultJcaJceHelper());
public JceAsymmetricValueDecryptorGenerator(PrivateKey recipientKey)
{
this.recipientKey = recipientKey;
}
public JceAsymmetricValueDecryptorGenerator setProvider(Provider provider)
{
this.helper = new CRMFHelper(new ProviderJcaJceHelper(provider));
return this;
}
public JceAsymmetricValueDecryptorGenerator setProvider(String providerName)
{
this.helper = new CRMFHelper(new NamedJcaJceHelper(providerName));
return this;
}
private Key extractSecretKey(AlgorithmIdentifier keyEncryptionAlgorithm, AlgorithmIdentifier contentEncryptionAlgorithm, byte[] encryptedContentEncryptionKey)
throws CRMFException
{
try
{
Key sKey = null;
Cipher keyCipher = helper.createCipher(keyEncryptionAlgorithm.getAlgorithm());
try
{
keyCipher.init(Cipher.UNWRAP_MODE, recipientKey);
sKey = keyCipher.unwrap(encryptedContentEncryptionKey, contentEncryptionAlgorithm.getAlgorithm().getId(), Cipher.SECRET_KEY);
}
catch (GeneralSecurityException e)
{
}
catch (IllegalStateException e)
{
}
catch (UnsupportedOperationException e)
{
}
catch (ProviderException e)
{
}
// some providers do not support UNWRAP (this appears to be only for asymmetric algorithms)
if (sKey == null)
{
keyCipher.init(Cipher.DECRYPT_MODE, recipientKey);
sKey = new SecretKeySpec(keyCipher.doFinal(encryptedContentEncryptionKey), contentEncryptionAlgorithm.getAlgorithm().getId());
}
return sKey;
}
catch (InvalidKeyException e)
{
throw new CRMFException("key invalid in message.", e);
}
catch (IllegalBlockSizeException e)
{
throw new CRMFException("illegal blocksize in message.", e);
}
catch (BadPaddingException e)
{
throw new CRMFException("bad padding in message.", e);
}
}
public InputDecryptor getValueDecryptor(AlgorithmIdentifier keyEncryptionAlgorithm, final AlgorithmIdentifier contentEncryptionAlgorithm, byte[] encryptedContentEncryptionKey)
throws CRMFException
{
Key secretKey = extractSecretKey(keyEncryptionAlgorithm, contentEncryptionAlgorithm, encryptedContentEncryptionKey);
final Cipher dataCipher = helper.createContentCipher(secretKey, contentEncryptionAlgorithm);
return new InputDecryptor()
{
public AlgorithmIdentifier getAlgorithmIdentifier()
{
return contentEncryptionAlgorithm;
}
public InputStream getInputStream(InputStream dataIn)
{
return new CipherInputStream(dataIn, dataCipher);
}
};
}
}
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