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21befa7761
A pass that adds random noops to X86 binaries to introduce diversity with the goal of increasing security against most return-oriented programming attacks. Command line options: -noop-insertion // Enable noop insertion. -noop-insertion-percentage=X // X% of assembly instructions will have a noop prepended (default: 50%, requires -noop-insertion) -max-noops-per-instruction=X // Randomly generate X noops per instruction. ie. roll the dice X times with probability set above (default: 1). This doesn't guarantee X noop instructions. In addition, the following 'quick switch' in clang enables basic diversity using default settings (currently: noop insertion and schedule randomization; it is intended to be extended in the future). -fdiversify This is the llvm part of the patch. clang part: D3393 http://reviews.llvm.org/D3392 Patch by Stephen Crane (@rinon) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225908 91177308-0d34-0410-b5e6-96231b3b80d8
73 lines
2.3 KiB
C++
73 lines
2.3 KiB
C++
//==- llvm/Support/RandomNumberGenerator.h - RNG for diversity ---*- C++ -*-==//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines an abstraction for deterministic random number
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// generation (RNG). Note that the current implementation is not
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// cryptographically secure as it uses the C++11 <random> facilities.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_SUPPORT_RANDOMNUMBERGENERATOR_H_
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#define LLVM_SUPPORT_RANDOMNUMBERGENERATOR_H_
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/DataTypes.h" // Needed for uint64_t on Windows.
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#include <random>
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namespace llvm {
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/// A random number generator.
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///
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/// Instances of this class should not be shared across threads. The
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/// seed should be set by passing the -rng-seed=<uint64> option. Use
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/// Module::createRNG to create a new RNG instance for use with that
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/// module.
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class RandomNumberGenerator {
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public:
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typedef std::mt19937_64 RNG;
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typedef RNG::result_type result_type;
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/// Returns a random number in the range [0, Max).
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result_type operator()();
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// Must define min and max to be compatible with URNG as used by
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// std::uniform_*_distribution
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static LLVM_CONSTEXPR result_type min() {
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return RNG::min();
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}
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static LLVM_CONSTEXPR result_type max() {
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return RNG::max();
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}
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private:
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/// Seeds and salts the underlying RNG engine.
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///
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/// This constructor should not be used directly. Instead use
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/// Module::createRNG to create a new RNG salted with the Module ID.
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RandomNumberGenerator(StringRef Salt);
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// 64-bit Mersenne Twister by Matsumoto and Nishimura, 2000
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// http://en.cppreference.com/w/cpp/numeric/random/mersenne_twister_engine
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// This RNG is deterministically portable across C++11
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// implementations.
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RNG Generator;
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// Noncopyable.
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RandomNumberGenerator(const RandomNumberGenerator &other)
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LLVM_DELETED_FUNCTION;
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RandomNumberGenerator &
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operator=(const RandomNumberGenerator &other) LLVM_DELETED_FUNCTION;
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friend class Module;
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};
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}
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#endif
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