com.h3xstream.findsecbugs.injection.InjectionDetector Maven / Gradle / Ivy

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Core module of the project. It include all the FindBugs detectors. The resulting jar is the published plugin.
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/**
 * Find Security Bugs
 * Copyright (c) 2013, Philippe Arteau, All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3.0 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.
 */
package com.h3xstream.findsecbugs.injection;

import com.h3xstream.findsecbugs.common.ByteCode;
import com.h3xstream.findsecbugs.injection.sql.HibernateInjectionSource;
import com.h3xstream.findsecbugs.injection.sql.JdoInjectionSource;
import com.h3xstream.findsecbugs.injection.sql.JpaInjectionSource;

import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.Detector;
import edu.umd.cs.findbugs.Priorities;
import edu.umd.cs.findbugs.ba.*;
import edu.umd.cs.findbugs.ba.constant.Constant;
import edu.umd.cs.findbugs.ba.constant.ConstantDataflow;
import edu.umd.cs.findbugs.ba.constant.ConstantFrame;

import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.*;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * Class inspired by the detector FindSqlInjection
 */
public abstract class InjectionDetector implements Detector {


    private ClassContext classContext;
    private BugReporter bugReporter;

    protected InjectionDetector(BugReporter bugReporter) {
        this.bugReporter = bugReporter;
    }

    @Override
    public void visitClassContext(ClassContext classContext) {
        JavaClass javaClass = classContext.getJavaClass();
        Method[] methodList = javaClass.getMethods();

        ConstantPoolGen cpg = classContext.getConstantPoolGen();

        List selectedSources = new ArrayList();

        for (InjectionSource source : getInjectionSource()) {
            if (source.isCandidate(cpg)) {
                selectedSources.add(source);
            }
        }

        if (selectedSources.size() > 0) {
            for (Method method : methodList) {
                MethodGen methodGen = classContext.getMethodGen(method);
                if (methodGen == null)
                    continue;

                try {
                    analyzeMethod(classContext, method, selectedSources);
                } catch (DataflowAnalysisException e) {
                } catch (CFGBuilderException e) {
                }
            }
        }
    }

    private void analyzeMethod(ClassContext classContext, Method method, List selectedSources) throws DataflowAnalysisException, CFGBuilderException {

        JavaClass javaClass = classContext.getJavaClass();
        this.classContext = classContext;
        MethodGen methodGen = classContext.getMethodGen(method);
        if (methodGen == null)
            return;

        ConstantPoolGen cpg = methodGen.getConstantPool();
        CFG cfg = classContext.getCFG(method);


        ConstantDataflow dataflow = classContext.getConstantDataflow(method);
        for (Iterator i = cfg.locationIterator(); i.hasNext(); ) {
            Location location = i.next();

            InstructionHandle insHandle = location.getHandle();
            Instruction ins = insHandle.getInstruction();
            if (!(ins instanceof InvokeInstruction))
                continue;
            InvokeInstruction invoke = (InvokeInstruction) ins;

            //ByteCode.printOpCode( ins, cpg );

            int[] injectableArguments = new int[0];
            for (InjectionSource source : selectedSources) {
                injectableArguments = source.getInjectableParameters(invoke, cpg, insHandle);
                //System.out.println("Get param from = " + source.getClass().getSimpleName());
                if (injectableArguments.length > 0) break;
            }

            if (injectableArguments.length > 0) {

                ConstantFrame frame = dataflow.getFactAtLocation(location);
                int numArguments = frame.getNumArguments(invoke, cpg);

                arguments : for (int arg : injectableArguments) {
                    Constant value = frame.getStackValue(arg);
//                    System.out.println(arg + ". " + frame.getStackValue(arg).getConstantString());
//
//                    System.out.println(numArguments);

                    if (value == null || !value.isConstantString()) {

                        Location prev = getPreviousLocation(cfg, location, true);
                        for (int a = 0; a < arg; a++) {
                            prev = getPreviousLocation(cfg, prev, true);
                        }
                        if (prev != null && !isSafeValue(prev, cpg, cfg)) {

                            bugReporter.reportBug(new BugInstance(this, getBugType(), Priorities.NORMAL_PRIORITY) //
                                    .addClass(javaClass) //
                                    .addMethod(javaClass, method) //
                                    .addSourceLine(classContext, method, location));
                            break arguments;
                            //System.out.println("!!!");
                        }
                    }
                }
            }

        }

    }

    private InstructionHandle getPreviousInstruction(InstructionHandle handle, boolean skipNops) {
        while (handle.getPrev() != null) {
            handle = handle.getPrev();
            Instruction prevIns = handle.getInstruction();
            if (!(prevIns instanceof NOP && skipNops)) {
                return handle;
            }
        }
        return null;
    }

    private Location getPreviousLocation(CFG cfg, Location startLocation, boolean skipNops) {
        Location loc = startLocation;
        InstructionHandle prev = getPreviousInstruction(loc.getHandle(), skipNops);
        if (prev != null)
            return new Location(prev, loc.getBasicBlock());
        BasicBlock block = loc.getBasicBlock();
        while (true) {
            block = cfg.getPredecessorWithEdgeType(block, EdgeTypes.FALL_THROUGH_EDGE);
            if (block == null)
                return null;
            InstructionHandle lastInstruction = block.getLastInstruction();
            if (lastInstruction != null)
                return new Location(lastInstruction, block);
        }
    }

    private boolean isSafeValue(Location location, ConstantPoolGen cpg, CFG cfg) throws CFGBuilderException {
        Instruction prevIns = location.getHandle().getInstruction();
        if (prevIns instanceof LDC || prevIns instanceof GETSTATIC)
            return true;
        if (prevIns instanceof InvokeInstruction) {
            String methodName = ((InvokeInstruction) prevIns).getMethodName(cpg);
            if (methodName.startsWith("to") && methodName.endsWith("String") && methodName.length() > 8) {
                return true;
            }
        }
        if (prevIns instanceof AALOAD) {

            Location prev = getPreviousLocation(cfg, location, true);
            if (prev != null) {
                Location prev2 = getPreviousLocation(cfg, prev, true);
                if (prev2 != null && prev2.getHandle().getInstruction() instanceof GETSTATIC) {
                    GETSTATIC getStatic = (GETSTATIC) prev2.getHandle().getInstruction();
                    if (getStatic.getSignature(cpg).equals("[Ljava/lang/String;")) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    @Override
    public void report() {
    }


    public abstract InjectionSource[] getInjectionSource();

    public abstract String getBugType();
}