http://www.bouncycastle.org/java.html: The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5 to JDK 1.8.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.jcajce.provider.digest;

import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.jcajce.provider.config.ConfigurableProvider;
import org.bouncycastle.jcajce.provider.util.AlgorithmProvider;

abstract class DigestAlgorithmProvider
    extends AlgorithmProvider
{
    protected void addHMACAlgorithm(
        ConfigurableProvider provider,
        String algorithm,
        String algorithmClassName,
        String keyGeneratorClassName)
    {
        String mainName = "HMAC" + algorithm;

        provider.addAlgorithm("Mac." + mainName, algorithmClassName);
        provider.addAlgorithm("Alg.Alias.Mac.HMAC-" + algorithm, mainName);
        provider.addAlgorithm("Alg.Alias.Mac.HMAC/" + algorithm, mainName);
        provider.addAlgorithm("KeyGenerator." + mainName, keyGeneratorClassName);
        provider.addAlgorithm("Alg.Alias.KeyGenerator.HMAC-" + algorithm, mainName);
        provider.addAlgorithm("Alg.Alias.KeyGenerator.HMAC/" + algorithm, mainName);
    }

    protected void addHMACAlias(
        ConfigurableProvider provider,
        String algorithm,
        ASN1ObjectIdentifier oid)
    {
        String mainName = "HMAC" + algorithm;

        provider.addAlgorithm("Alg.Alias.Mac." + oid, mainName);
        provider.addAlgorithm("Alg.Alias.KeyGenerator." + oid, mainName);
    }
}