CFG createCFG(String className) throws ClassNotFoundException { CFG cfg = new CFG(); JavaClass jc = Repository.lookupClass(className); ClassGen cg = new ClassGen(jc); ConstantPoolGen cpg = cg.getConstantPool(); for (Method m : cg.getMethods()) { MethodGen mg = new MethodGen(m, cg.getClassName(), cpg); InstructionList il = mg.getInstructionList(); InstructionHandle[] handles = il.getInstructionHandles(); int prev = 0; for (InstructionHandle ih : handles) { int position = ih.getPosition(); cfg.addNode(position, m, jc); Instruction inst = ih.getInstruction(); boolean br = inst.getName().contains("if") || inst.getName().contains("goto"); boolean ret = inst.getName().contains("return"); boolean stat = inst.getName().contains("invokestatic"); int len = inst.getLength(); if (stat) { int index = inst.toString(true).indexOf(" "); String name = inst.toString(true).substring(index + 1); int tar = Integer.valueOf(name); INVOKESTATIC inv = new INVOKESTATIC(tar); name = inv.getMethodName(cpg); Method m2 = null; Method[] tm = cg.getMethods(); for (int i = 0; i < tm.length; i++) { if (tm[i].getName().equals(name)) { m2 = tm[i]; } } cfg.addEdge(position, m, jc, 0, m2, jc); cfg.addEdge(-1, m2, jc, position + len, m, jc); } if (!ret && !stat) { cfg.addEdge(position, position + len, m, jc); } if (br) { cfg.addEdge(position, position + len, m, jc); IF_ICMPGE comp = new IF_ICMPGE(ih); String name = comp.getTarget().toString(false); int index = name.indexOf(">"); name = name.substring(index + 2); int tar = Integer.valueOf(name); cfg.addEdge(position, tar, m, jc); } if (ret) { cfg.addEdge(position, -1, m, jc); } prev = position; } System.out.println(cfg.toString()); } return cfg; }
@Override public void visitClassContext(ClassContext classContext) { JavaClass javaClass = classContext.getJavaClass(); Method[] methodList = javaClass.getMethods(); for (Method m : methodList) { MethodGen methodGen = classContext.getMethodGen(m); if (DEBUG) { System.out.println(">>> Method: " + m.getName()); } // To suspect that an invalid String representation is being build, // we identify the construction of a MessageDigest and // the use of a function that trim leading 0. boolean invokeMessageDigest = false; boolean invokeToHexString = false; ConstantPoolGen cpg = classContext.getConstantPoolGen(); if (methodGen == null || methodGen.getInstructionList() == null) { continue; // No instruction .. nothing to do } for (Iterator itIns = methodGen.getInstructionList().iterator(); itIns.hasNext(); ) { Instruction inst = ((InstructionHandle) itIns.next()).getInstruction(); if (DEBUG) { ByteCode.printOpCode(inst, cpg); } if (inst instanceof INVOKEVIRTUAL) { // MessageDigest.digest is called INVOKEVIRTUAL invoke = (INVOKEVIRTUAL) inst; if ("java.security.MessageDigest".equals(invoke.getClassName(cpg)) && "digest".equals(invoke.getMethodName(cpg))) { invokeMessageDigest = true; } } else if (inst instanceof INVOKESTATIC && invokeMessageDigest) { // The conversion must occurs after the digest was created INVOKESTATIC invoke = (INVOKESTATIC) inst; if ("java.lang.Integer".equals(invoke.getClassName(cpg)) && "toHexString".equals(invoke.getMethodName(cpg))) { invokeToHexString = true; } } } if (invokeMessageDigest && invokeToHexString) { bugReporter.reportBug( new BugInstance(this, BAD_HEXA_CONVERSION_TYPE, Priorities.NORMAL_PRIORITY) // .addClassAndMethod(javaClass, m)); } } }
public static String getCallClassName(Instruction ins, ConstantPoolGen cp) { if (ins instanceof INVOKESTATIC) { INVOKESTATIC invst = (INVOKESTATIC) ins; return invst.getClassName(cp); } else if (ins instanceof INVOKEVIRTUAL) { INVOKEVIRTUAL invst = (INVOKEVIRTUAL) ins; return invst.getClassName(cp); } else if (ins instanceof INVOKEINTERFACE) { INVOKEINTERFACE invst = (INVOKEINTERFACE) ins; return invst.getClassName(cp); } else if (ins instanceof INVOKESPECIAL) { INVOKESPECIAL invst = (INVOKESPECIAL) ins; return invst.getClassName(cp); } else { return null; } }
public static Type[] getCallArgTypes(Instruction ins, ConstantPoolGen cp) { if (ins instanceof INVOKESTATIC) { INVOKESTATIC invst = (INVOKESTATIC) ins; return invst.getArgumentTypes(cp); } else if (ins instanceof INVOKEVIRTUAL) { INVOKEVIRTUAL invst = (INVOKEVIRTUAL) ins; return invst.getArgumentTypes(cp); } else if (ins instanceof INVOKEINTERFACE) { INVOKEINTERFACE invst = (INVOKEINTERFACE) ins; return invst.getArgumentTypes(cp); } else if (ins instanceof INVOKESPECIAL) { INVOKESPECIAL invst = (INVOKESPECIAL) ins; return invst.getArgumentTypes(cp); } else { return null; } }
/** Symbolically executes the corresponding Java Virtual Machine instruction. */ public void visitINVOKESTATIC(INVOKESTATIC o) { for (int i = 0; i < o.getArgumentTypes(cpg).length; i++) { stack().pop(); } // We are sure the invoked method will xRETURN eventually // We simulate xRETURNs functionality here because we // don't really "jump into" and simulate the invoked // method. if (o.getReturnType(cpg) != Type.VOID) { Type t = o.getReturnType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } }
public static Instruction getNewInvoke(Instruction ins, int index) { if (ins instanceof INVOKESTATIC) { INVOKESTATIC invst = (INVOKESTATIC) ins; invst.setIndex(index); return invst; } else if (ins instanceof INVOKEVIRTUAL) { INVOKEVIRTUAL invst = (INVOKEVIRTUAL) ins; invst.setIndex(index); return invst; } else if (ins instanceof INVOKEINTERFACE) { INVOKEINTERFACE invst = (INVOKEINTERFACE) ins; invst.setIndex(index); return invst; } else if (ins instanceof INVOKESPECIAL) { INVOKESPECIAL invst = (INVOKESPECIAL) ins; invst.setIndex(index); return invst; } else { return null; } }
/** * Transforms invoke instructions that match the specified list for this class to call the * specified static call instead. */ private InstructionList xform_inst(MethodGen mg, Instruction inst) { switch (inst.getOpcode()) { case Constants.INVOKESTATIC: { InstructionList il = new InstructionList(); INVOKESTATIC is = (INVOKESTATIC) inst; String cname = is.getClassName(pgen); String mname = is.getMethodName(pgen); Type[] args = is.getArgumentTypes(pgen); MethodDef orig = new MethodDef(cname + "." + mname, args); MethodInfo call = method_map.get(orig); if (call != null) { call.cnt++; String classname = call.method_class; String methodname = mname; debug_map.log( "%s.%s: Replacing method %s.%s (%s) with %s.%s%n", mg.getClassName(), mg.getName(), cname, mname, UtilMDE.join(args, ", "), classname, methodname); il.append( ifact.createInvoke( classname, methodname, is.getReturnType(pgen), args, Constants.INVOKESTATIC)); } return (il); } case Constants.INVOKEVIRTUAL: { InstructionList il = new InstructionList(); INVOKEVIRTUAL iv = (INVOKEVIRTUAL) inst; String cname = iv.getClassName(pgen); String mname = iv.getMethodName(pgen); Type[] args = iv.getArgumentTypes(pgen); Type instance_type = iv.getReferenceType(pgen); Type[] new_args = BCELUtil.insert_type(instance_type, args); MethodDef orig = new MethodDef(cname + "." + mname, args); if (debug_class) System.out.printf("looking for %s in map %s%n", orig, method_map); MethodInfo call = method_map.get(orig); if (call != null) { call.cnt++; String classname = call.method_class; String methodname = mname; debug_map.log( "Replacing method %s.%s (%s) with %s.%s%n", cname, mname, ArraysMDE.toString(args), classname, methodname); il.append( ifact.createInvoke( classname, methodname, iv.getReturnType(pgen), new_args, Constants.INVOKESTATIC)); } return (il); } default: return (null); } }