de.rub.nds.tlsattacker.attacks.padding.VeryShortPaddingGenerator Maven / Gradle / Ivy

/**
 * TLS-Attacker - A Modular Penetration Testing Framework for TLS
 *
 * Copyright 2014-2021 Ruhr University Bochum, Paderborn University, Hackmanit GmbH
 *
 * Licensed under Apache License, Version 2.0
 * http://www.apache.org/licenses/LICENSE-2.0.txt
 */

package de.rub.nds.tlsattacker.attacks.padding;

import de.rub.nds.modifiablevariable.bytearray.ByteArrayExplicitValueModification;
import de.rub.nds.modifiablevariable.bytearray.ByteArrayModificationFactory;
import de.rub.nds.modifiablevariable.bytearray.ByteArrayXorModification;
import de.rub.nds.tlsattacker.attacks.padding.vector.PaddingVector;
import de.rub.nds.tlsattacker.attacks.padding.vector.PlainPaddingVector;
import de.rub.nds.tlsattacker.attacks.padding.vector.TripleVector;
import de.rub.nds.tlsattacker.core.constants.AlgorithmResolver;
import de.rub.nds.tlsattacker.core.constants.CipherSuite;
import de.rub.nds.tlsattacker.core.constants.ProtocolVersion;
import java.util.LinkedList;
import java.util.List;

/**
 *
 *
 */
public class VeryShortPaddingGenerator extends PaddingVectorGenerator {

    /**
     * Default length of the encrypted data (app + mac + padding)
     */
    static final int DEFAULT_CIPHERTEXT_LENGTH = 80;
    /**
     * Default padding length for the construction of modified encrypted plaintexts
     */
    static final int DEFAULT_PADDING_LENGTH = 4;

    /**
     *
     * @param  suite
     * @param  version
     * @return
     */
    @Override
    public List getVectors(CipherSuite suite, ProtocolVersion version) {
        List vectorList = new LinkedList<>();
        vectorList.addAll(createOnlyPaddingVectors(suite, version));
        vectorList.addAll(createClassicModifiedPadding(suite, version));
        return vectorList;
    }

    List createOnlyPaddingVectors(CipherSuite suite, ProtocolVersion version) {
        List vectorList = new LinkedList<>();
        byte[] plain = createPaddingBytes(DEFAULT_CIPHERTEXT_LENGTH - 1);
        vectorList.add(createVectorWithPlainData("Plain XF (0xXF=#padding bytes)", "PlainOnlyPadding", plain));
        plain = new byte[] { (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255, (byte) 255,
            (byte) 255, };
        vectorList.add(createVectorWithPlainData("Plain FF", "PlainTooMuchPadding", plain));
        return vectorList;
    }

    List createClassicModifiedPadding(CipherSuite suite, ProtocolVersion version) {
        int macSize = AlgorithmResolver.getMacAlgorithm(version, suite).getSize();
        int paddingValue = DEFAULT_CIPHERTEXT_LENGTH - macSize - 1;
        int applicationLength = 0;
        List vectorList = createClassicModifiedPaddingWithValidMAC(applicationLength, paddingValue);
        vectorList.addAll(createClassicModifiedPaddingWithInvalidMAC(applicationLength, paddingValue));

        return vectorList;
    }

    private List createClassicModifiedPaddingWithValidMAC(int applicationLength, int paddingValue) {
        List vectorList = new LinkedList<>();
        // valid mac
        byte[] padding = createPaddingBytes(paddingValue);
        padding[0] ^= 0x80; // flip first padding byte highest bit
        vectorList.add(new TripleVector("InvPadValMac-[0]-" + applicationLength + "-" + paddingValue, "InvPadValMac",
            new ByteArrayExplicitValueModification(new byte[applicationLength]), null,
            new ByteArrayExplicitValueModification(padding)));
        return vectorList;
    }

    private List createClassicModifiedPaddingWithInvalidMAC(int applicationLength, int paddingValue) {
        List vectorList = new LinkedList<>();
        // invalid mac
        byte[] padding = createPaddingBytes(paddingValue);
        vectorList.add(new TripleVector("ValPadInvMac-[0]-" + applicationLength + "-" + paddingValue, "valPadInvMac",
            new ByteArrayExplicitValueModification(new byte[applicationLength]),
            new ByteArrayXorModification(new byte[] { 0x01 }, 0), new ByteArrayExplicitValueModification(padding)));
        return vectorList;
    }

    List createFlippedModifications(int byteLength) {
        List modificationList = new LinkedList<>();
        modificationList.add(new ByteArrayXorModification(new byte[] { 0x01 }, byteLength - 1)); // Last
        // Byte / lowest bit
        modificationList.add(new ByteArrayXorModification(new byte[] { 0x08 }, byteLength / 2)); // Some
        // Byte / middle bit
        modificationList.add(new ByteArrayXorModification(new byte[] { (byte) 0x80 }, 0)); // first
        // Byte / highest bit
        return modificationList;
    }

    private PaddingVector createVectorWithPlainData(String name, String identifier, byte[] plain) {
        return new PlainPaddingVector(name, identifier,
            (ByteArrayExplicitValueModification) ByteArrayModificationFactory.explicitValue(plain));
    }
}