================ @@ -1,185 +1,149 @@ -/* - SipHash reference C implementation - - Copyright (c) 2012-2022 Jean-Philippe Aumasson - <jeanphilippe.aumas...@gmail.com> - Copyright (c) 2012-2014 Daniel J. Bernstein <d...@cr.yp.to> - - To the extent possible under law, the author(s) have dedicated all copyright - and related and neighboring rights to this software to the public domain - worldwide. This software is distributed without any warranty. - - You should have received a copy of the CC0 Public Domain Dedication along - with - this software. If not, see - <http://creativecommons.org/publicdomain/zero/1.0/>. - */ - -#include "siphash.h" -#include <assert.h> -#include <stddef.h> -#include <stdint.h> - -/* default: SipHash-2-4 */ -#ifndef cROUNDS -#define cROUNDS 2 -#endif -#ifndef dROUNDS -#define dROUNDS 4 -#endif +//===--- 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 +// +//===----------------------------------------------------------------------===// -#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b)))) +#include "llvm/Support/Compiler.h" +#include <cstdint> -#define U32TO8_LE(p, v) \ - (p)[0] = (uint8_t)((v)); \ - (p)[1] = (uint8_t)((v) >> 8); \ - (p)[2] = (uint8_t)((v) >> 16); \ - (p)[3] = (uint8_t)((v) >> 24); +// Lightly adapted from the SipHash reference C implementation: +// https://github.com/veorq/SipHash +// by Jean-Philippe Aumasson and Daniel J. Bernstein -#define U64TO8_LE(p, v) \ - U32TO8_LE((p), (uint32_t)((v))); \ - U32TO8_LE((p) + 4, (uint32_t)((v) >> 32)); +#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b)))) #define U8TO64_LE(p) \ - (((uint64_t)((p)[0])) | ((uint64_t)((p)[1]) << 8) | \ - ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) | \ - ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) | \ - ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56)) + (((uint64_t)((p)[0])) | ((uint64_t)((p)[1]) << 8) | \ + ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) | \ + ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) | \ + ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56)) #define SIPROUND \ - do { \ - v0 += v1; \ - v1 = ROTL(v1, 13); \ - v1 ^= v0; \ - v0 = ROTL(v0, 32); \ - v2 += v3; \ - v3 = ROTL(v3, 16); \ - v3 ^= v2; \ - v0 += v3; \ - v3 = ROTL(v3, 21); \ - v3 ^= v0; \ - v2 += v1; \ - v1 = ROTL(v1, 17); \ - v1 ^= v2; \ - v2 = ROTL(v2, 32); \ - } while (0) - -#ifdef DEBUG_SIPHASH -#include <stdio.h> - -#define TRACE \ - do { \ - printf("(%3zu) v0 %016" PRIx64 "\n", inlen, v0); \ - printf("(%3zu) v1 %016" PRIx64 "\n", inlen, v1); \ - printf("(%3zu) v2 %016" PRIx64 "\n", inlen, v2); \ - printf("(%3zu) v3 %016" PRIx64 "\n", inlen, v3); \ - } while (0) -#else -#define TRACE -#endif - -/* - Computes a SipHash value - *in: pointer to input data (read-only) - inlen: input data length in bytes (any size_t value) - *k: pointer to the key data (read-only), must be 16 bytes - *out: pointer to output data (write-only), outlen bytes must be allocated - outlen: length of the output in bytes, must be 8 or 16 -*/ -int siphash(const void *in, const size_t inlen, const void *k, uint8_t *out, - const size_t outlen) { - - const unsigned char *ni = (const unsigned char *)in; - const unsigned char *kk = (const unsigned char *)k; - - assert((outlen == 8) || (outlen == 16)); - uint64_t v0 = UINT64_C(0x736f6d6570736575); - uint64_t v1 = UINT64_C(0x646f72616e646f6d); - uint64_t v2 = UINT64_C(0x6c7967656e657261); - uint64_t v3 = UINT64_C(0x7465646279746573); - uint64_t k0 = U8TO64_LE(kk); - uint64_t k1 = U8TO64_LE(kk + 8); - uint64_t m; - int i; - const unsigned char *end = ni + inlen - (inlen % sizeof(uint64_t)); - const int left = inlen & 7; - uint64_t b = ((uint64_t)inlen) << 56; - v3 ^= k1; - v2 ^= k0; - v1 ^= k1; - v0 ^= k0; - - if (outlen == 16) - v1 ^= 0xee; - - for (; ni != end; ni += 8) { - m = U8TO64_LE(ni); - v3 ^= m; - - TRACE; - for (i = 0; i < cROUNDS; ++i) - SIPROUND; - - v0 ^= m; - } - - switch (left) { - case 7: - b |= ((uint64_t)ni[6]) << 48; - /* FALLTHRU */ - case 6: - b |= ((uint64_t)ni[5]) << 40; - /* FALLTHRU */ - case 5: - b |= ((uint64_t)ni[4]) << 32; - /* FALLTHRU */ - case 4: - b |= ((uint64_t)ni[3]) << 24; - /* FALLTHRU */ - case 3: - b |= ((uint64_t)ni[2]) << 16; - /* FALLTHRU */ - case 2: - b |= ((uint64_t)ni[1]) << 8; - /* FALLTHRU */ - case 1: - b |= ((uint64_t)ni[0]); - break; - case 0: - break; - } - - v3 ^= b; - - TRACE; - for (i = 0; i < cROUNDS; ++i) - SIPROUND; - - v0 ^= b; - - if (outlen == 16) - v2 ^= 0xee; - else - v2 ^= 0xff; - - TRACE; - for (i = 0; i < dROUNDS; ++i) - SIPROUND; - - b = v0 ^ v1 ^ v2 ^ v3; - U64TO8_LE(out, b); + do { \ + v0 += v1; \ + v1 = ROTL(v1, 13); \ + v1 ^= v0; \ + v0 = ROTL(v0, 32); \ + v2 += v3; \ + v3 = ROTL(v3, 16); \ + v3 ^= v2; \ + v0 += v3; \ + v3 = ROTL(v3, 21); \ + v3 ^= v0; \ + v2 += v1; \ + v1 = ROTL(v1, 17); \ + v1 ^= v2; \ + v2 = ROTL(v2, 32); \ + } while (0) + +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, class ResultTy> +ResultTy siphash(const unsigned char *in, uint64_t inlen, + const unsigned char (&k)[16]) { + + const unsigned char *ni = (const unsigned char *)in; + const unsigned char *kk = (const unsigned char *)k; + + constexpr size_t outlen = sizeof(ResultTy); + static_assert(outlen == 8 || outlen == 16, + "result type should be uint64_t or uint128_t"); + + uint64_t v0 = UINT64_C(0x736f6d6570736575); + uint64_t v1 = UINT64_C(0x646f72616e646f6d); + uint64_t v2 = UINT64_C(0x6c7967656e657261); + uint64_t v3 = UINT64_C(0x7465646279746573); + uint64_t k0 = U8TO64_LE(kk); + uint64_t k1 = U8TO64_LE(kk + 8); + uint64_t m; + int i; + const unsigned char *end = ni + inlen - (inlen % sizeof(uint64_t)); + const int left = inlen & 7; + uint64_t b = ((uint64_t)inlen) << 56; + v3 ^= k1; + v2 ^= k0; + v1 ^= k1; + v0 ^= k0; + + if (outlen == 16) + v1 ^= 0xee; + + for (; ni != end; ni += 8) { + m = U8TO64_LE(ni); + v3 ^= m; - if (outlen == 8) - return 0; - - v1 ^= 0xdd; - - TRACE; - for (i = 0; i < dROUNDS; ++i) - SIPROUND; - - b = v0 ^ v1 ^ v2 ^ v3; - U64TO8_LE(out + 8, b); - - return 0; + for (i = 0; i < cROUNDS; ++i) + SIPROUND; + + v0 ^= m; + } + + switch (left) { + case 7: + b |= ((uint64_t)ni[6]) << 48; + LLVM_FALLTHROUGH; + case 6: + b |= ((uint64_t)ni[5]) << 40; + LLVM_FALLTHROUGH; + case 5: + b |= ((uint64_t)ni[4]) << 32; + LLVM_FALLTHROUGH; + case 4: + b |= ((uint64_t)ni[3]) << 24; + LLVM_FALLTHROUGH; + case 3: + b |= ((uint64_t)ni[2]) << 16; + LLVM_FALLTHROUGH; + case 2: + b |= ((uint64_t)ni[1]) << 8; + LLVM_FALLTHROUGH; + case 1: + b |= ((uint64_t)ni[0]); + break; + case 0: + break; + } + + v3 ^= b; + + for (i = 0; i < cROUNDS; ++i) + SIPROUND; + + v0 ^= b; + + if (outlen == 16) + v2 ^= 0xee; + else + v2 ^= 0xff; + + for (i = 0; i < dROUNDS; ++i) + SIPROUND; + + b = v0 ^ v1 ^ v2 ^ v3; + uint64_t firstHalf = b; + + if (outlen == 8) + return firstHalf; + + v1 ^= 0xdd; + + for (i = 0; i < dROUNDS; ++i) + SIPROUND; + + b = v0 ^ v1 ^ v2 ^ v3; + uint64_t secondHalf = b; + + return firstHalf | (ResultTy(secondHalf) << 64); ---------------- ahmedbougacha wrote:
In the 128-bit result case we'd be exposed to the big-endian host ABI's treatment of uint128_t results, and from what I can find that seems to be quite messy! [644b473](https://github.com/llvm/llvm-project/pull/94394/commits/644b473fa7d0382b035d4dfd2ea4ed88fcd97233) describes it a little bit more, and brings back the original's returning via an i8 array. The caller can figure out what it wants to do with the result bytes. For ptrauth in #93902 I made it `read64le` the result again (and we do define the truncation as based on the little-endian interpretation of the raw hash bytes already.) https://github.com/llvm/llvm-project/pull/94394 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
