dk.alexandra.fresco.suite.bgw.configuration.BgwConfiguration.java Source code

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Here is the source code for dk.alexandra.fresco.suite.bgw.configuration.BgwConfiguration.java

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/*******************************************************************************
 * Copyright (c) 2015 FRESCO (http://github.com/aicis/fresco).
 *
 * This file is part of the FRESCO project.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * FRESCO uses SCAPI - http://crypto.biu.ac.il/SCAPI, Crypto++, Miracl, NTL,
 * and Bouncy Castle. Please see these projects for any further licensing issues.
 *******************************************************************************/
package dk.alexandra.fresco.suite.bgw.configuration;

import java.math.BigInteger;
import java.util.Properties;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.ParseException;

import dk.alexandra.fresco.framework.sce.configuration.ProtocolSuiteConfiguration;
import dk.alexandra.fresco.framework.sce.configuration.SCEConfiguration;

public interface BgwConfiguration extends ProtocolSuiteConfiguration {

    /**
     * @return The number of parties that can be corrupted without the protocol
     *         security breaking down.
     * 
     */
    int getThreshold();

    /**
     * 
     * @return The modulus used in BGW
     */
    BigInteger getModulus();

    // Here comes methods for BGW specific parameters and their validation.
    public static BgwConfiguration fromCmdLine(SCEConfiguration sceConf, CommandLine cmd) throws ParseException {
        // Validate BGW specific arguments.
        Properties p = cmd.getOptionProperties("D");
        if (!p.containsKey("bgw.threshold")) {
            throw new ParseException("BGW requires setting -Dbgw.threshold=[int]");
        }

        try {
            final int threshold = Integer.parseInt(p.getProperty("bgw.threshold"));
            if (threshold < 1)
                throw new ParseException("bgw.threshold must be > 0");
            if (threshold > sceConf.getParties().size() / 2)
                throw new ParseException("bgw.threshold must be < n/2");

            final BigInteger modulus = new BigInteger(p.getProperty("bgw.modulus", "618970019642690137449562111"));
            if (!modulus.isProbablePrime(40)) {
                throw new ParseException("BGW Modulus must be a prime number");
            }

            return new BgwConfiguration() {

                @Override
                public int getThreshold() {
                    return threshold;
                }

                @Override
                public BigInteger getModulus() {
                    return modulus;
                }

            };
        } catch (NumberFormatException e) {
            throw new ParseException("Invalid bgw.threshold value: '" + p.getProperty("bgw.threshold") + "'");
        }
    }

}