llvm/llvm/lib/Support/SipHash.cpp

//===--- SipHash.cpp - An ABI-stable string hash --------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//  This file implements an ABI-stable string hash based on SipHash, used to
//  compute ptrauth discriminators.
//
//===----------------------------------------------------------------------===//

#include "llvm/Support/SipHash.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Endian.h"
#include <cstdint>

usingnamespacellvm;
usingnamespacesupport;

#define DEBUG_TYPE …

// Lightly adapted from the SipHash reference C implementation:
//   https://github.com/veorq/SipHash
// by Jean-Philippe Aumasson and Daniel J. Bernstein

#define ROTL(x, b) …

#define SIPROUND …

namespace {

/// Computes a SipHash value
///
/// \param in: pointer to input data (read-only)
/// \param inlen: input data length in bytes (any size_t value)
/// \param k: reference to the key data 16-byte array (read-only)
/// \returns output data, must be 8 or 16 bytes
///
template <int cROUNDS, int dROUNDS, size_t outlen>
void siphash(const unsigned char *in, uint64_t inlen,
             const unsigned char (&k)[16], unsigned char (&out)[outlen]) { … }

} // end anonymous namespace

void llvm::getSipHash_2_4_64(ArrayRef<uint8_t> In, const uint8_t (&K)[16],
                             uint8_t (&Out)[8]) { … }

void llvm::getSipHash_2_4_128(ArrayRef<uint8_t> In, const uint8_t (&K)[16],
                              uint8_t (&Out)[16]) { … }

/// Compute an ABI-stable 16-bit hash of the given string.
uint16_t llvm::getPointerAuthStableSipHash(StringRef Str) { … }