src/libcompiler_builtins/compiler-rt/lib/fuzzer/FuzzerSHA1.cpp

   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 "FuzzerSHA1.h"
  20 #include "FuzzerDefs.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
  31 namespace {  // Added for LibFuzzer
  32
  33 #ifdef __BIG_ENDIAN__
  34 # define SHA_BIG_ENDIAN
  35 #elif defined __LITTLE_ENDIAN__
  36 /* override */
  37 #elif defined __BYTE_ORDER
  38 # if __BYTE_ORDER__ ==  __ORDER_BIG_ENDIAN__
  39 # define SHA_BIG_ENDIAN
  40 # endif
  41 #else // ! defined __LITTLE_ENDIAN__
  42 # include <endian.h> // machine/endian.h
  43 # if __BYTE_ORDER__ ==  __ORDER_BIG_ENDIAN__
  44 #  define SHA_BIG_ENDIAN
  45 # endif
  46 #endif
  47
  48
  49 /* header */
  50
  51 #define HASH_LENGTH 20
  52 #define BLOCK_LENGTH 64
  53
  54 typedef struct sha1nfo {
  55         uint32_t buffer[BLOCK_LENGTH/4];
  56         uint32_t state[HASH_LENGTH/4];
  57         uint32_t byteCount;
  58         uint8_t bufferOffset;
  59         uint8_t keyBuffer[BLOCK_LENGTH];
  60         uint8_t innerHash[HASH_LENGTH];
  61 } sha1nfo;
  62
  63 /* public API - prototypes - TODO: doxygen*/
  64
  65 /**
  66  */
  67 void sha1_init(sha1nfo *s);
  68 /**
  69  */
  70 void sha1_writebyte(sha1nfo *s, uint8_t data);
  71 /**
  72  */
  73 void sha1_write(sha1nfo *s, const char *data, size_t len);
  74 /**
  75  */
  76 uint8_t* sha1_result(sha1nfo *s);
  77
  78
  79 /* code */
  80 #define SHA1_K0  0x5a827999
  81 #define SHA1_K20 0x6ed9eba1
  82 #define SHA1_K40 0x8f1bbcdc
  83 #define SHA1_K60 0xca62c1d6
  84
  85 void sha1_init(sha1nfo *s) {
  86         s->state[0] = 0x67452301;
  87         s->state[1] = 0xefcdab89;
  88         s->state[2] = 0x98badcfe;
  89         s->state[3] = 0x10325476;
  90         s->state[4] = 0xc3d2e1f0;
  91         s->byteCount = 0;
  92         s->bufferOffset = 0;
  93 }
  94
  95 uint32_t sha1_rol32(uint32_t number, uint8_t bits) {
  96         return ((number << bits) | (number >> (32-bits)));
  97 }
  98
  99 void sha1_hashBlock(sha1nfo *s) {
 100         uint8_t i;
 101         uint32_t a,b,c,d,e,t;
 102
 103         a=s->state[0];
 104         b=s->state[1];
 105         c=s->state[2];
 106         d=s->state[3];
 107         e=s->state[4];
 108         for (i=0; i<80; i++) {
 109                 if (i>=16) {
 110                         t = s->buffer[(i+13)&15] ^ s->buffer[(i+8)&15] ^ s->buffer[(i+2)&15] ^ s->buffer[i&15];
 111                         s->buffer[i&15] = sha1_rol32(t,1);
 112                 }
 113                 if (i<20) {
 114                         t = (d ^ (b & (c ^ d))) + SHA1_K0;
 115                 } else if (i<40) {
 116                         t = (b ^ c ^ d) + SHA1_K20;
 117                 } else if (i<60) {
 118                         t = ((b & c) | (d & (b | c))) + SHA1_K40;
 119                 } else {
 120                         t = (b ^ c ^ d) + SHA1_K60;
 121                 }
 122                 t+=sha1_rol32(a,5) + e + s->buffer[i&15];
 123                 e=d;
 124                 d=c;
 125                 c=sha1_rol32(b,30);
 126                 b=a;
 127                 a=t;
 128         }
 129         s->state[0] += a;
 130         s->state[1] += b;
 131         s->state[2] += c;
 132         s->state[3] += d;
 133         s->state[4] += e;
 134 }
 135
 136 void sha1_addUncounted(sha1nfo *s, uint8_t data) {
 137         uint8_t * const b = (uint8_t*) s->buffer;
 138 #ifdef SHA_BIG_ENDIAN
 139         b[s->bufferOffset] = data;
 140 #else
 141         b[s->bufferOffset ^ 3] = data;
 142 #endif
 143         s->bufferOffset++;
 144         if (s->bufferOffset == BLOCK_LENGTH) {
 145                 sha1_hashBlock(s);
 146                 s->bufferOffset = 0;
 147         }
 148 }
 149
 150 void sha1_writebyte(sha1nfo *s, uint8_t data) {
 151         ++s->byteCount;
 152         sha1_addUncounted(s, data);
 153 }
 154
 155 void sha1_write(sha1nfo *s, const char *data, size_t len) {
 156         for (;len--;) sha1_writebyte(s, (uint8_t) *data++);
 157 }
 158
 159 void sha1_pad(sha1nfo *s) {
 160         // Implement SHA-1 padding (fips180-2 §5.1.1)
 161
 162         // Pad with 0x80 followed by 0x00 until the end of the block
 163         sha1_addUncounted(s, 0x80);
 164         while (s->bufferOffset != 56) sha1_addUncounted(s, 0x00);
 165
 166         // Append length in the last 8 bytes
 167         sha1_addUncounted(s, 0); // We're only using 32 bit lengths
 168         sha1_addUncounted(s, 0); // But SHA-1 supports 64 bit lengths
 169         sha1_addUncounted(s, 0); // So zero pad the top bits
 170         sha1_addUncounted(s, s->byteCount >> 29); // Shifting to multiply by 8
 171         sha1_addUncounted(s, s->byteCount >> 21); // as SHA-1 supports bitstreams as well as
 172         sha1_addUncounted(s, s->byteCount >> 13); // byte.
 173         sha1_addUncounted(s, s->byteCount >> 5);
 174         sha1_addUncounted(s, s->byteCount << 3);
 175 }
 176
 177 uint8_t* sha1_result(sha1nfo *s) {
 178         // Pad to complete the last block
 179         sha1_pad(s);
 180
 181 #ifndef SHA_BIG_ENDIAN
 182         // Swap byte order back
 183         int i;
 184         for (i=0; i<5; i++) {
 185                 s->state[i]=
 186                           (((s->state[i])<<24)& 0xff000000)
 187                         | (((s->state[i])<<8) & 0x00ff0000)
 188                         | (((s->state[i])>>8) & 0x0000ff00)
 189                         | (((s->state[i])>>24)& 0x000000ff);
 190         }
 191 #endif
 192
 193         // Return pointer to hash (20 characters)
 194         return (uint8_t*) s->state;
 195 }
 196
 197 }  // namespace; Added for LibFuzzer
 198
 199 namespace fuzzer {
 200
 201 // The rest is added for LibFuzzer
 202 void ComputeSHA1(const uint8_t *Data, size_t Len, uint8_t *Out) {
 203   sha1nfo s;
 204   sha1_init(&s);
 205   sha1_write(&s, (const char*)Data, Len);
 206   memcpy(Out, sha1_result(&s), HASH_LENGTH);
 207 }
 208
 209 std::string Sha1ToString(const uint8_t Sha1[kSHA1NumBytes]) {
 210   std::stringstream SS;
 211   for (int i = 0; i < kSHA1NumBytes; i++)
 212     SS << std::hex << std::setfill('0') << std::setw(2) << (unsigned)Sha1[i];
 213   return SS.str();
 214 }
 215
 216 std::string Hash(const Unit &U) {
 217   uint8_t Hash[kSHA1NumBytes];
 218   ComputeSHA1(U.data(), U.size(), Hash);
 219   return Sha1ToString(Hash);
 220 }
 221
 222 }