Kostya Serebryany | 96eab65 | 2015-05-14 22:41:49 +0000 | [diff] [blame] | 1 | //===- FuzzerSHA1.h - Private copy of the SHA1 implementation ---*- C++ -* ===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // This code is taken from public domain |
| 10 | // (http://oauth.googlecode.com/svn/code/c/liboauth/src/sha1.c) |
| 11 | // and modified by adding anonymous namespace, adding an interface |
| 12 | // function fuzzer::ComputeSHA1() and removing unnecessary code. |
| 13 | // |
| 14 | // lib/Fuzzer can not use SHA1 implementation from openssl because |
| 15 | // openssl may not be available and because we may be fuzzing openssl itself. |
| 16 | // For the same reason we do not want to depend on SHA1 from LLVM tree. |
| 17 | //===----------------------------------------------------------------------===// |
| 18 | |
| 19 | #include "FuzzerInternal.h" |
| 20 | |
| 21 | /* This code is public-domain - it is based on libcrypt |
| 22 | * placed in the public domain by Wei Dai and other contributors. |
| 23 | */ |
| 24 | |
| 25 | #include <stdint.h> |
| 26 | #include <string.h> |
| 27 | |
| 28 | namespace { // Added for LibFuzzer |
| 29 | |
| 30 | #ifdef __BIG_ENDIAN__ |
| 31 | # define SHA_BIG_ENDIAN |
| 32 | #elif defined __LITTLE_ENDIAN__ |
| 33 | /* override */ |
| 34 | #elif defined __BYTE_ORDER |
| 35 | # if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
| 36 | # define SHA_BIG_ENDIAN |
| 37 | # endif |
| 38 | #else // ! defined __LITTLE_ENDIAN__ |
| 39 | # include <endian.h> // machine/endian.h |
| 40 | # if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
| 41 | # define SHA_BIG_ENDIAN |
| 42 | # endif |
| 43 | #endif |
| 44 | |
| 45 | |
| 46 | /* header */ |
| 47 | |
| 48 | #define HASH_LENGTH 20 |
| 49 | #define BLOCK_LENGTH 64 |
| 50 | |
| 51 | typedef struct sha1nfo { |
| 52 | uint32_t buffer[BLOCK_LENGTH/4]; |
| 53 | uint32_t state[HASH_LENGTH/4]; |
| 54 | uint32_t byteCount; |
| 55 | uint8_t bufferOffset; |
| 56 | uint8_t keyBuffer[BLOCK_LENGTH]; |
| 57 | uint8_t innerHash[HASH_LENGTH]; |
| 58 | } sha1nfo; |
| 59 | |
| 60 | /* public API - prototypes - TODO: doxygen*/ |
| 61 | |
| 62 | /** |
| 63 | */ |
| 64 | void sha1_init(sha1nfo *s); |
| 65 | /** |
| 66 | */ |
| 67 | void sha1_writebyte(sha1nfo *s, uint8_t data); |
| 68 | /** |
| 69 | */ |
| 70 | void sha1_write(sha1nfo *s, const char *data, size_t len); |
| 71 | /** |
| 72 | */ |
| 73 | uint8_t* sha1_result(sha1nfo *s); |
| 74 | |
| 75 | |
| 76 | /* code */ |
| 77 | #define SHA1_K0 0x5a827999 |
| 78 | #define SHA1_K20 0x6ed9eba1 |
| 79 | #define SHA1_K40 0x8f1bbcdc |
| 80 | #define SHA1_K60 0xca62c1d6 |
| 81 | |
| 82 | void sha1_init(sha1nfo *s) { |
| 83 | s->state[0] = 0x67452301; |
| 84 | s->state[1] = 0xefcdab89; |
| 85 | s->state[2] = 0x98badcfe; |
| 86 | s->state[3] = 0x10325476; |
| 87 | s->state[4] = 0xc3d2e1f0; |
| 88 | s->byteCount = 0; |
| 89 | s->bufferOffset = 0; |
| 90 | } |
| 91 | |
| 92 | uint32_t sha1_rol32(uint32_t number, uint8_t bits) { |
| 93 | return ((number << bits) | (number >> (32-bits))); |
| 94 | } |
| 95 | |
| 96 | void sha1_hashBlock(sha1nfo *s) { |
| 97 | uint8_t i; |
| 98 | uint32_t a,b,c,d,e,t; |
| 99 | |
| 100 | a=s->state[0]; |
| 101 | b=s->state[1]; |
| 102 | c=s->state[2]; |
| 103 | d=s->state[3]; |
| 104 | e=s->state[4]; |
| 105 | for (i=0; i<80; i++) { |
| 106 | if (i>=16) { |
| 107 | t = s->buffer[(i+13)&15] ^ s->buffer[(i+8)&15] ^ s->buffer[(i+2)&15] ^ s->buffer[i&15]; |
| 108 | s->buffer[i&15] = sha1_rol32(t,1); |
| 109 | } |
| 110 | if (i<20) { |
| 111 | t = (d ^ (b & (c ^ d))) + SHA1_K0; |
| 112 | } else if (i<40) { |
| 113 | t = (b ^ c ^ d) + SHA1_K20; |
| 114 | } else if (i<60) { |
| 115 | t = ((b & c) | (d & (b | c))) + SHA1_K40; |
| 116 | } else { |
| 117 | t = (b ^ c ^ d) + SHA1_K60; |
| 118 | } |
| 119 | t+=sha1_rol32(a,5) + e + s->buffer[i&15]; |
| 120 | e=d; |
| 121 | d=c; |
| 122 | c=sha1_rol32(b,30); |
| 123 | b=a; |
| 124 | a=t; |
| 125 | } |
| 126 | s->state[0] += a; |
| 127 | s->state[1] += b; |
| 128 | s->state[2] += c; |
| 129 | s->state[3] += d; |
| 130 | s->state[4] += e; |
| 131 | } |
| 132 | |
| 133 | void sha1_addUncounted(sha1nfo *s, uint8_t data) { |
| 134 | uint8_t * const b = (uint8_t*) s->buffer; |
| 135 | #ifdef SHA_BIG_ENDIAN |
| 136 | b[s->bufferOffset] = data; |
| 137 | #else |
| 138 | b[s->bufferOffset ^ 3] = data; |
| 139 | #endif |
| 140 | s->bufferOffset++; |
| 141 | if (s->bufferOffset == BLOCK_LENGTH) { |
| 142 | sha1_hashBlock(s); |
| 143 | s->bufferOffset = 0; |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | void sha1_writebyte(sha1nfo *s, uint8_t data) { |
| 148 | ++s->byteCount; |
| 149 | sha1_addUncounted(s, data); |
| 150 | } |
| 151 | |
| 152 | void sha1_write(sha1nfo *s, const char *data, size_t len) { |
| 153 | for (;len--;) sha1_writebyte(s, (uint8_t) *data++); |
| 154 | } |
| 155 | |
| 156 | void sha1_pad(sha1nfo *s) { |
| 157 | // Implement SHA-1 padding (fips180-2 ยง5.1.1) |
| 158 | |
| 159 | // Pad with 0x80 followed by 0x00 until the end of the block |
| 160 | sha1_addUncounted(s, 0x80); |
| 161 | while (s->bufferOffset != 56) sha1_addUncounted(s, 0x00); |
| 162 | |
| 163 | // Append length in the last 8 bytes |
| 164 | sha1_addUncounted(s, 0); // We're only using 32 bit lengths |
| 165 | sha1_addUncounted(s, 0); // But SHA-1 supports 64 bit lengths |
| 166 | sha1_addUncounted(s, 0); // So zero pad the top bits |
| 167 | sha1_addUncounted(s, s->byteCount >> 29); // Shifting to multiply by 8 |
| 168 | sha1_addUncounted(s, s->byteCount >> 21); // as SHA-1 supports bitstreams as well as |
| 169 | sha1_addUncounted(s, s->byteCount >> 13); // byte. |
| 170 | sha1_addUncounted(s, s->byteCount >> 5); |
| 171 | sha1_addUncounted(s, s->byteCount << 3); |
| 172 | } |
| 173 | |
| 174 | uint8_t* sha1_result(sha1nfo *s) { |
| 175 | // Pad to complete the last block |
| 176 | sha1_pad(s); |
| 177 | |
| 178 | #ifndef SHA_BIG_ENDIAN |
| 179 | // Swap byte order back |
| 180 | int i; |
| 181 | for (i=0; i<5; i++) { |
| 182 | s->state[i]= |
| 183 | (((s->state[i])<<24)& 0xff000000) |
| 184 | | (((s->state[i])<<8) & 0x00ff0000) |
| 185 | | (((s->state[i])>>8) & 0x0000ff00) |
| 186 | | (((s->state[i])>>24)& 0x000000ff); |
| 187 | } |
| 188 | #endif |
| 189 | |
| 190 | // Return pointer to hash (20 characters) |
| 191 | return (uint8_t*) s->state; |
| 192 | } |
| 193 | |
| 194 | } // namespace; Added for LibFuzzer |
| 195 | |
| 196 | // The rest is added for LibFuzzer |
| 197 | void fuzzer::ComputeSHA1(const uint8_t *Data, size_t Len, uint8_t *Out) { |
| 198 | sha1nfo s; |
| 199 | sha1_init(&s); |
| 200 | sha1_write(&s, (const char*)Data, Len); |
| 201 | memcpy(Out, sha1_result(&s), HASH_LENGTH); |
| 202 | } |