/*
* Copyright (C) 2006-2016 DLR, Germany
*
* All rights reserved
*
* http://www.rcenvironment.de/
*/
package de.rcenvironment.core.communication.model.internal;
import java.util.Random;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import de.rcenvironment.core.utils.common.StringUtils;
/**
* Utility class to intentionally corrupt network request or response payloads for testing error handling and robustness.
*
* @author Robert Mischke
*/
public final class PayloadTestFuzzer {
/**
* Whether the fuzz testing feature(s) should be enabled.
*
* IMPORTANT: this setting must always be "false" on release!
*/
public static final boolean ENABLED = false;
// note: these values probably still need tweaking
private static final float MIN_P_TO_CORRUPT_PAYLOAD = 0.001f;
private static final float MAX_P_TO_CORRUPT_PAYLOAD = 0.01f;
private static final int PAYLOAD_SIZE_CEILING = 50000; // at this size, MAX_CHANCE is reached
private static final float P_INCREMENT_PER_BYTE = (MAX_P_TO_CORRUPT_PAYLOAD - MIN_P_TO_CORRUPT_PAYLOAD)
/ PAYLOAD_SIZE_CEILING;
private static final Random sharedRandom = new Random();
private static final Log sharedLog = LogFactory.getLog(PayloadTestFuzzer.class);
private PayloadTestFuzzer() {}
/**
* May apply one or more random corruptions (byte randomizations) to this byte array; the probability of this happening is based on te
* payload's length.
*
* @param payload the payload array to potentially modify/corrupt
*/
public static void apply(byte[] payload) {
int relevantSize = Math.min(payload.length, PAYLOAD_SIZE_CEILING);
float p = MIN_P_TO_CORRUPT_PAYLOAD + relevantSize * P_INCREMENT_PER_BYTE;
int n = 0;
while (sharedRandom.nextFloat() <= p) {
int pos = sharedRandom.nextInt(payload.length);
payload[pos] = (byte) sharedRandom.nextInt();
n++;
}
if (n > 0) {
sharedLog.debug(StringUtils.format("Corrupted %d bytes of a payload at p=%.4f", n, p));
}
}
}