org.bouncycastle.jcajce.provider.symmetric.util.GcmSpecUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of bcprov-lts8on Show documentation
The Long Term Stable (LTS) Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains the JCA/JCE provider and low-level API for the BC LTS version 2.73.7 for Java 8 and later.
There is a newer version: 2.73.7
Show newest version
package org.bouncycastle.jcajce.provider.symmetric.util;

import java.security.AccessController;
import java.security.InvalidAlgorithmParameterException;
import java.security.PrivilegedExceptionAction;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;

import javax.crypto.spec.GCMParameterSpec;

import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.crypto.params.AEADParameters;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.internal.asn1.cms.GCMParameters;
import org.bouncycastle.util.Integers;

public class GcmSpecUtil
{
    static final Class gcmSpecClass = GCMParameterSpec.class;
//    private static final Constructor constructor;
//    private static final Method tLen;
//    private static final Method iv;

    static
    {
 //       gcmSpecClass = ClassUtil.loadClass(GcmSpecUtil.class, "javax.crypto.spec.GCMParameterSpec");

//        if (gcmSpecClass != null)
//        {
//            constructor = extractConstructor();
//            tLen = extractMethod("getTLen");
//            iv = extractMethod("getIV");
//        }
//        else
//        {
//            constructor = null;
//            tLen = null;
//            iv = null;
//        }
    }

//    private static Constructor extractConstructor()
//    {
//        try
//        {
//            return (Constructor)AccessController.doPrivileged(new PrivilegedExceptionAction()
//            {
//                public Object run()
//                    throws Exception
//                {
//                    return gcmSpecClass.getConstructor(new Class[]{ Integer.TYPE, byte[].class });
//                }
//            });
//        }
//        catch (PrivilegedActionException e)
//        {
//            return null;
//        }
//    }
//
//    private static Method extractMethod(final String name)
//    {
//        try
//        {
//            return (Method)AccessController.doPrivileged(new PrivilegedExceptionAction()
//            {
//                public Object run()
//                    throws Exception
//                {
//                    return gcmSpecClass.getDeclaredMethod(name, new Class[0]);
//                }
//            });
//        }
//        catch (PrivilegedActionException e)
//        {
//            return null;
//        }
//    }

    public static boolean gcmSpecExists()
    {
        return true;
    }

    public static boolean gcmSpecExtractable()
    {
        return true;
    }

    public static boolean isGcmSpec(AlgorithmParameterSpec paramSpec)
    {
        return gcmSpecClass != null && gcmSpecClass.isInstance(paramSpec);
    }

    public static boolean isGcmSpec(Class paramSpecClass)
    {
        return gcmSpecClass == paramSpecClass;
    }

    public static AlgorithmParameterSpec extractGcmSpec(ASN1Primitive spec)
        throws InvalidParameterSpecException
    {
        try
        {
            GCMParameters gcmParams = GCMParameters.getInstance(spec);

            return new GCMParameterSpec(Integers.valueOf(gcmParams.getIcvLen() * 8), gcmParams.getNonce());
        }
        catch (Exception e)
        {
            throw new InvalidParameterSpecException("Construction failed: " + e.getMessage());   // should never happen
        }
    }

    static AEADParameters extractAeadParameters(final KeyParameter keyParam, final AlgorithmParameterSpec params)
        throws InvalidAlgorithmParameterException
    {
        try
        {
            return (AEADParameters)AccessController.doPrivileged(new PrivilegedExceptionAction()
            {
                public Object run()
                    throws Exception
                {
                    GCMParameterSpec spec = (GCMParameterSpec)params;
                    return new AEADParameters(keyParam, spec.getTLen(), spec.getIV());
                }
            });
        }
        catch (Exception e)
        {
            throw new InvalidAlgorithmParameterException("Cannot process GCMParameterSpec.");
        }
    }

    public static GCMParameters extractGcmParameters(final AlgorithmParameterSpec paramSpec)
        throws InvalidParameterSpecException
    {
        try
        {
            return (GCMParameters)AccessController.doPrivileged(new PrivilegedExceptionAction()
            {
                public Object run()
                    throws Exception
                {
                    GCMParameterSpec spec = (GCMParameterSpec)paramSpec;
                    return new GCMParameters(spec.getIV(), spec.getTLen() / 8);
                }
            });
        }
        catch (Exception e)
        {
            throw new InvalidParameterSpecException("Cannot process GCMParameterSpec");
        }
    }
}