static String getClassName(String algType,
    String algName,
    Provider p) 
{
            String class_name =
                p.getProperty("Alg.Alias." + algType + "." + algName);
            if(class_name==null)
                class_name = p.getProperty(algType + "." + algName);
            else
                class_name = p.getProperty(algType + "." + class_name);
            return class_name;
}

 static Object[] getImplementation(String type,
    String algorithm) throws NoSuchAlgorithmException 
{
        Provider[] providers = Security.getProviders();
        if( (providers==null) || (providers.length==0) )
            throw new NoSuchAlgorithmException("No providers installed");
        for(int i=0; i< providers.length; i++)
        {
            Object[] res = getImplementation(type, algorithm, providers[i]);
            if(res != null)
                return res;
        }
        throw new NoSuchAlgorithmException(
            "Algorithm not found. [" + type + "." + algorithm + "]");
}

 static Object[] getImplementation(String type,
    String algorithm,
    String provider) throws NoSuchAlgorithmException, NoSuchProviderException 
{
        Provider p = Security.getProvider(provider);
        if(p==null)
            throw new NoSuchProviderException(
                "Provider not found. [" + provider + "]");
        Object[] res = getImplementation(type, algorithm, p);
        if(res != null)
            return res;
        throw new NoSuchAlgorithmException(
            "Algorithm not found. [" + type + "." + algorithm + "]");
}

 static Object[] getImplementation(String algType,
    String algName,
    Provider p) 
{
        try
        {
            String class_name =
                p.getProperty("Alg.Alias." + algType + "." + algName);
            if(class_name==null)
                class_name = p.getProperty(algType + "." + algName);
            else
                class_name = p.getProperty(algType + "." + class_name);
            if(class_name == null)
                return null;
            Object[] res = new Object[2];
            res[0] = Class.forName(class_name).newInstance();
            res[1] = p;
            return res;
        }
        catch(LinkageError e)
        {
            e.printStackTrace();
            // FIXME: Throw a RuntimeException with a sensible message????
        }
        catch(ClassNotFoundException e)
        {
            e.printStackTrace();
            // FIXME: Throw a RuntimeException with a sensible message????
        }
        catch(InstantiationException e)
        {
            e.printStackTrace();
            // FIXME: Throw a RuntimeException with a sensible message????
        }
        catch(IllegalAccessException e)
        {
            e.printStackTrace();
            // FIXME: Throw a RuntimeException with a sensible message????
        }
        return null;
}