225 lines · cpp
1//===- FuzzerSHA1.h - Private copy of the SHA1 implementation ---*- C++ -* ===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8// This code is taken from public domain9// (http://oauth.googlecode.com/svn/code/c/liboauth/src/sha1.c)10// and modified by adding anonymous namespace, adding an interface11// function fuzzer::ComputeSHA1() and removing unnecessary code.12//13// lib/Fuzzer can not use SHA1 implementation from openssl because14// openssl may not be available and because we may be fuzzing openssl itself.15// For the same reason we do not want to depend on SHA1 from LLVM tree.16//===----------------------------------------------------------------------===//17 18#include "FuzzerSHA1.h"19#include "FuzzerDefs.h"20#include "FuzzerPlatform.h"21 22/* This code is public-domain - it is based on libcrypt23 * placed in the public domain by Wei Dai and other contributors.24 */25 26#include <iomanip>27#include <sstream>28#include <stdint.h>29#include <string.h>30 31namespace { // Added for LibFuzzer32 33#ifdef __BIG_ENDIAN__34# define SHA_BIG_ENDIAN35// Windows is always little endian and MSVC doesn't have <endian.h>36#elif defined __LITTLE_ENDIAN__ || LIBFUZZER_WINDOWS37/* override */38#elif defined __BYTE_ORDER39# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__40# define SHA_BIG_ENDIAN41# endif42#else // ! defined __LITTLE_ENDIAN__43# include <endian.h> // machine/endian.h44# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__45# define SHA_BIG_ENDIAN46# endif47#endif48 49 50/* header */51 52#define HASH_LENGTH 2053#define BLOCK_LENGTH 6454 55typedef struct sha1nfo {56 uint32_t buffer[BLOCK_LENGTH/4];57 uint32_t state[HASH_LENGTH/4];58 uint32_t byteCount;59 uint8_t bufferOffset;60 uint8_t keyBuffer[BLOCK_LENGTH];61 uint8_t innerHash[HASH_LENGTH];62} sha1nfo;63 64/* public API - prototypes - TODO: doxygen*/65 66/**67 */68void sha1_init(sha1nfo *s);69/**70 */71void sha1_writebyte(sha1nfo *s, uint8_t data);72/**73 */74void sha1_write(sha1nfo *s, const char *data, size_t len);75/**76 */77uint8_t* sha1_result(sha1nfo *s);78 79 80/* code */81#define SHA1_K0 0x5a82799982#define SHA1_K20 0x6ed9eba183#define SHA1_K40 0x8f1bbcdc84#define SHA1_K60 0xca62c1d685 86void sha1_init(sha1nfo *s) {87 s->state[0] = 0x67452301;88 s->state[1] = 0xefcdab89;89 s->state[2] = 0x98badcfe;90 s->state[3] = 0x10325476;91 s->state[4] = 0xc3d2e1f0;92 s->byteCount = 0;93 s->bufferOffset = 0;94}95 96uint32_t sha1_rol32(uint32_t number, uint8_t bits) {97 return ((number << bits) | (number >> (32-bits)));98}99 100void sha1_hashBlock(sha1nfo *s) {101 uint8_t i;102 uint32_t a,b,c,d,e,t;103 104 a=s->state[0];105 b=s->state[1];106 c=s->state[2];107 d=s->state[3];108 e=s->state[4];109 for (i=0; i<80; i++) {110 if (i>=16) {111 t = s->buffer[(i+13)&15] ^ s->buffer[(i+8)&15] ^ s->buffer[(i+2)&15] ^ s->buffer[i&15];112 s->buffer[i&15] = sha1_rol32(t,1);113 }114 if (i<20) {115 t = (d ^ (b & (c ^ d))) + SHA1_K0;116 } else if (i<40) {117 t = (b ^ c ^ d) + SHA1_K20;118 } else if (i<60) {119 t = ((b & c) | (d & (b | c))) + SHA1_K40;120 } else {121 t = (b ^ c ^ d) + SHA1_K60;122 }123 t+=sha1_rol32(a,5) + e + s->buffer[i&15];124 e=d;125 d=c;126 c=sha1_rol32(b,30);127 b=a;128 a=t;129 }130 s->state[0] += a;131 s->state[1] += b;132 s->state[2] += c;133 s->state[3] += d;134 s->state[4] += e;135}136 137// Adds the least significant byte of |data|.138void sha1_addUncounted(sha1nfo *s, uint32_t data) {139 uint8_t *const b = (uint8_t *)s->buffer;140#ifdef SHA_BIG_ENDIAN141 b[s->bufferOffset] = static_cast<uint8_t>(data);142#else143 b[s->bufferOffset ^ 3] = static_cast<uint8_t>(data);144#endif145 s->bufferOffset++;146 if (s->bufferOffset == BLOCK_LENGTH) {147 sha1_hashBlock(s);148 s->bufferOffset = 0;149 }150}151 152void sha1_writebyte(sha1nfo *s, uint8_t data) {153 ++s->byteCount;154 sha1_addUncounted(s, data);155}156 157void sha1_write(sha1nfo *s, const char *data, size_t len) {158 for (;len--;) sha1_writebyte(s, (uint8_t) *data++);159}160 161void sha1_pad(sha1nfo *s) {162 // Implement SHA-1 padding (fips180-2 §5.1.1)163 164 // Pad with 0x80 followed by 0x00 until the end of the block165 sha1_addUncounted(s, 0x80);166 while (s->bufferOffset != 56) sha1_addUncounted(s, 0x00);167 168 // Append length in the last 8 bytes169 sha1_addUncounted(s, 0); // We're only using 32 bit lengths170 sha1_addUncounted(s, 0); // But SHA-1 supports 64 bit lengths171 sha1_addUncounted(s, 0); // So zero pad the top bits172 sha1_addUncounted(s, s->byteCount >> 29); // Shifting to multiply by 8173 sha1_addUncounted(s, s->byteCount >> 21); // as SHA-1 supports bitstreams as well as174 sha1_addUncounted(s, s->byteCount >> 13); // byte.175 sha1_addUncounted(s, s->byteCount >> 5);176 sha1_addUncounted(s, s->byteCount << 3);177}178 179uint8_t* sha1_result(sha1nfo *s) {180 // Pad to complete the last block181 sha1_pad(s);182 183#ifndef SHA_BIG_ENDIAN184 // Swap byte order back185 int i;186 for (i=0; i<5; i++) {187 s->state[i]=188 (((s->state[i])<<24)& 0xff000000)189 | (((s->state[i])<<8) & 0x00ff0000)190 | (((s->state[i])>>8) & 0x0000ff00)191 | (((s->state[i])>>24)& 0x000000ff);192 }193#endif194 195 // Return pointer to hash (20 characters)196 return (uint8_t*) s->state;197}198 199} // namespace; Added for LibFuzzer200 201namespace fuzzer {202 203// The rest is added for LibFuzzer204void ComputeSHA1(const uint8_t *Data, size_t Len, uint8_t *Out) {205 sha1nfo s;206 sha1_init(&s);207 sha1_write(&s, (const char*)Data, Len);208 memcpy(Out, sha1_result(&s), HASH_LENGTH);209}210 211std::string Sha1ToString(const uint8_t Sha1[kSHA1NumBytes]) {212 std::stringstream SS;213 for (int i = 0; i < kSHA1NumBytes; i++)214 SS << std::hex << std::setfill('0') << std::setw(2) << (unsigned)Sha1[i];215 return SS.str();216}217 218std::string Hash(const Unit &U) {219 uint8_t Hash[kSHA1NumBytes];220 ComputeSHA1(U.data(), U.size(), Hash);221 return Sha1ToString(Hash);222}223 224}225