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.pkcs.bc;

import java.io.InputStream;

import org.bouncycastle.asn1.pkcs.PKCS12PBEParams;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.ExtendedDigest;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.generators.PKCS12ParametersGenerator;
import org.bouncycastle.crypto.io.CipherInputStream;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.operator.GenericKey;
import org.bouncycastle.operator.InputDecryptor;
import org.bouncycastle.operator.InputDecryptorProvider;

public class BcPKCS12PBEInputDecryptorProviderBuilder
{
    private ExtendedDigest digest;

    public BcPKCS12PBEInputDecryptorProviderBuilder()
    {
         this(new SHA1Digest());
    }

    public BcPKCS12PBEInputDecryptorProviderBuilder(ExtendedDigest digest)
    {
         this.digest = digest;
    }

    public InputDecryptorProvider build(final char[] password)
    {
        return new InputDecryptorProvider()
        {
            public InputDecryptor get(final AlgorithmIdentifier algorithmIdentifier)
            {
                final PaddedBufferedBlockCipher engine = PKCS12PBEUtils.getEngine(algorithmIdentifier.getAlgorithm());

                PKCS12PBEParams           pbeParams = PKCS12PBEParams.getInstance(algorithmIdentifier.getParameters());

                CipherParameters params = PKCS12PBEUtils.createCipherParameters(algorithmIdentifier.getAlgorithm(), digest, engine.getBlockSize(), pbeParams, password);

                engine.init(false, params);

                return new InputDecryptor()
                {
                    public AlgorithmIdentifier getAlgorithmIdentifier()
                    {
                        return algorithmIdentifier;
                    }

                    public InputStream getInputStream(InputStream input)
                    {
                        return new CipherInputStream(input, engine);
                    }

                    public GenericKey getKey()
                    {
                        return new GenericKey(PKCS12ParametersGenerator.PKCS12PasswordToBytes(password));
                    }
                };
            }
        };

    }
}