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-exception
6//
7//===----------------------------------------------------------------------===//
8// This code is taken from public domain
9// (http://oauth.googlecode.com/svn/code/c/liboauth/src/sha1.c)
10// and modified by adding anonymous namespace, adding an interface
11// function fuzzer::ComputeSHA1() and removing unnecessary code.
12//
13// lib/Fuzzer can not use SHA1 implementation from openssl because
14// 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 libcrypt
23 * 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 LibFuzzer
32
33#ifdef __BIG_ENDIAN__
34# define SHA_BIG_ENDIAN
35// Windows is always little endian and MSVC doesn't have <endian.h>
36#elif defined __LITTLE_ENDIAN__ || LIBFUZZER_WINDOWS
37/* override */
38#elif defined __BYTE_ORDER
39# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
40# define SHA_BIG_ENDIAN
41# endif
42#else // ! defined __LITTLE_ENDIAN__
43# include <endian.h> // machine/endian.h
44# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
45# define SHA_BIG_ENDIAN
46# endif
47#endif
48
49
50/* header */
51
52#define HASH_LENGTH 20
53#define BLOCK_LENGTH 64
54
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 0x5a827999
82#define SHA1_K20 0x6ed9eba1
83#define SHA1_K40 0x8f1bbcdc
84#define SHA1_K60 0xca62c1d6
85
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(number: t,bits: 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(number: a,bits: 5) + e + s->buffer[i&15];
124 e=d;
125 d=c;
126 c=sha1_rol32(number: b,bits: 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_ENDIAN
141 b[s->bufferOffset] = static_cast<uint8_t>(data);
142#else
143 b[s->bufferOffset ^ 3] = static_cast<uint8_t>(data);
144#endif
145 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, data: (uint8_t) *data++);
159}
160
161void sha1_pad(sha1nfo *s) {
162 // Implement SHA-1 padding (fips180-2 ยง5.1.1)
163
164 // Pad with 0x80 followed by 0x00 until the end of the block
165 sha1_addUncounted(s, data: 0x80);
166 while (s->bufferOffset != 56) sha1_addUncounted(s, data: 0x00);
167
168 // Append length in the last 8 bytes
169 sha1_addUncounted(s, data: 0); // We're only using 32 bit lengths
170 sha1_addUncounted(s, data: 0); // But SHA-1 supports 64 bit lengths
171 sha1_addUncounted(s, data: 0); // So zero pad the top bits
172 sha1_addUncounted(s, data: s->byteCount >> 29); // Shifting to multiply by 8
173 sha1_addUncounted(s, data: s->byteCount >> 21); // as SHA-1 supports bitstreams as well as
174 sha1_addUncounted(s, data: s->byteCount >> 13); // byte.
175 sha1_addUncounted(s, data: s->byteCount >> 5);
176 sha1_addUncounted(s, data: s->byteCount << 3);
177}
178
179uint8_t* sha1_result(sha1nfo *s) {
180 // Pad to complete the last block
181 sha1_pad(s);
182
183#ifndef SHA_BIG_ENDIAN
184 // Swap byte order back
185 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#endif
194
195 // Return pointer to hash (20 characters)
196 return (uint8_t*) s->state;
197}
198
199} // namespace; Added for LibFuzzer
200
201namespace fuzzer {
202
203// The rest is added for LibFuzzer
204void ComputeSHA1(const uint8_t *Data, size_t Len, uint8_t *Out) {
205 sha1nfo s;
206 sha1_init(s: &s);
207 sha1_write(s: &s, data: (const char*)Data, len: Len);
208 memcpy(dest: Out, src: sha1_result(s: &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(Data: U.data(), Len: U.size(), Out: Hash);
221 return Sha1ToString(Sha1: Hash);
222}
223
224}
225

source code of compiler-rt/lib/fuzzer/FuzzerSHA1.cpp