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.
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package org.bouncycastle.jcajce.provider.digest;

import org.bouncycastle.asn1.gm.GMObjectIdentifiers;
import org.bouncycastle.crypto.digests.SM3Digest;
import org.bouncycastle.jcajce.provider.config.ConfigurableProvider;

public class SM3
{
    private SM3()
    {
    }

    static public class Digest
        extends BCMessageDigest
        implements Cloneable
    {
        public Digest()
        {
            super(new SM3Digest());
        }

        public Object clone()
            throws CloneNotSupportedException
        {
            Digest d = (Digest)super.clone();
            d.digest = new SM3Digest((SM3Digest)digest);

            return d;
        }
    }

    public static class Mappings
        extends DigestAlgorithmProvider
    {
        private static final String PREFIX = SM3.class.getName();

        public Mappings()
        {
        }

        public void configure(ConfigurableProvider provider)
        {
            provider.addAlgorithm("MessageDigest.SM3", PREFIX + "$Digest");
            provider.addAlgorithm("Alg.Alias.MessageDigest.SM3", "SM3");
            provider.addAlgorithm("Alg.Alias.MessageDigest.1.2.156.197.1.401", "SM3");  // old draft OID - deprecated
            provider.addAlgorithm("Alg.Alias.MessageDigest." + GMObjectIdentifiers.sm3, "SM3");
        }
    }
}