http://www.bouncycastle.org/java.html: The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 to JDK 1.8. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.operator;

import org.bouncycastle.asn1.x509.AlgorithmIdentifier;

public abstract class SymmetricKeyUnwrapper
    implements KeyUnwrapper
{
    private AlgorithmIdentifier algorithmId;

    protected SymmetricKeyUnwrapper(AlgorithmIdentifier algorithmId)
    {
        this.algorithmId = algorithmId;
    }

    public AlgorithmIdentifier getAlgorithmIdentifier()
    {
        return algorithmId;
    }
}