lib/Support/SHA1.cpp

   1 //====- SHA1.cpp - 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 //
   9 // This code is taken from public domain
  10 // (http://oauth.googlecode.com/svn/code/c/liboauth/src/sha1.c and
  11 // http://cvsweb.netbsd.org/bsdweb.cgi/src/common/lib/libc/hash/sha1/sha1.c?rev=1.6)
  12 // and modified by wrapping it in a C++ interface for LLVM,
  13 // and removing unnecessary code.
  14 //
  15 //===----------------------------------------------------------------------===//
  16
  17 #include "llvm/Support/SHA1.h"
  18 #include "llvm/ADT/ArrayRef.h"
  19 #include "llvm/Support/Host.h"
  20 using namespace llvm;
  21
  22 #include <stdint.h>
  23 #include <string.h>
  24
  25 #if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
  26 #define SHA_BIG_ENDIAN
  27 #endif
  28
  29 static uint32_t rol(uint32_t Number, int Bits) {
  30   return (Number << Bits) | (Number >> (32 - Bits));
  31 }
  32
  33 static uint32_t blk0(uint32_t *Buf, int I) { return Buf[I]; }
  34
  35 static uint32_t blk(uint32_t *Buf, int I) {
  36   Buf[I & 15] = rol(Buf[(I + 13) & 15] ^ Buf[(I + 8) & 15] ^ Buf[(I + 2) & 15] ^
  37                         Buf[I & 15],
  38                     1);
  39   return Buf[I & 15];
  40 }
  41
  42 static void r0(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D, uint32_t &E,
  43                int I, uint32_t *Buf) {
  44   E += ((B & (C ^ D)) ^ D) + blk0(Buf, I) + 0x5A827999 + rol(A, 5);
  45   B = rol(B, 30);
  46 }
  47
  48 static void r1(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D, uint32_t &E,
  49                int I, uint32_t *Buf) {
  50   E += ((B & (C ^ D)) ^ D) + blk(Buf, I) + 0x5A827999 + rol(A, 5);
  51   B = rol(B, 30);
  52 }
  53
  54 static void r2(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D, uint32_t &E,
  55                int I, uint32_t *Buf) {
  56   E += (B ^ C ^ D) + blk(Buf, I) + 0x6ED9EBA1 + rol(A, 5);
  57   B = rol(B, 30);
  58 }
  59
  60 static void r3(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D, uint32_t &E,
  61                int I, uint32_t *Buf) {
  62   E += (((B | C) & D) | (B & C)) + blk(Buf, I) + 0x8F1BBCDC + rol(A, 5);
  63   B = rol(B, 30);
  64 }
  65
  66 static void r4(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D, uint32_t &E,
  67                int I, uint32_t *Buf) {
  68   E += (B ^ C ^ D) + blk(Buf, I) + 0xCA62C1D6 + rol(A, 5);
  69   B = rol(B, 30);
  70 }
  71
  72 /* code */
  73 #define SHA1_K0 0x5a827999
  74 #define SHA1_K20 0x6ed9eba1
  75 #define SHA1_K40 0x8f1bbcdc
  76 #define SHA1_K60 0xca62c1d6
  77
  78 #define SEED_0 0x67452301
  79 #define SEED_1 0xefcdab89
  80 #define SEED_2 0x98badcfe
  81 #define SEED_3 0x10325476
  82 #define SEED_4 0xc3d2e1f0
  83
  84 void SHA1::init() {
  85   InternalState.State[0] = SEED_0;
  86   InternalState.State[1] = SEED_1;
  87   InternalState.State[2] = SEED_2;
  88   InternalState.State[3] = SEED_3;
  89   InternalState.State[4] = SEED_4;
  90   InternalState.ByteCount = 0;
  91   InternalState.BufferOffset = 0;
  92 }
  93
  94 void SHA1::hashBlock() {
  95   uint32_t A = InternalState.State[0];
  96   uint32_t B = InternalState.State[1];
  97   uint32_t C = InternalState.State[2];
  98   uint32_t D = InternalState.State[3];
  99   uint32_t E = InternalState.State[4];
 100
 101   // 4 rounds of 20 operations each. Loop unrolled.
 102   r0(A, B, C, D, E, 0, InternalState.Buffer.L);
 103   r0(E, A, B, C, D, 1, InternalState.Buffer.L);
 104   r0(D, E, A, B, C, 2, InternalState.Buffer.L);
 105   r0(C, D, E, A, B, 3, InternalState.Buffer.L);
 106   r0(B, C, D, E, A, 4, InternalState.Buffer.L);
 107   r0(A, B, C, D, E, 5, InternalState.Buffer.L);
 108   r0(E, A, B, C, D, 6, InternalState.Buffer.L);
 109   r0(D, E, A, B, C, 7, InternalState.Buffer.L);
 110   r0(C, D, E, A, B, 8, InternalState.Buffer.L);
 111   r0(B, C, D, E, A, 9, InternalState.Buffer.L);
 112   r0(A, B, C, D, E, 10, InternalState.Buffer.L);
 113   r0(E, A, B, C, D, 11, InternalState.Buffer.L);
 114   r0(D, E, A, B, C, 12, InternalState.Buffer.L);
 115   r0(C, D, E, A, B, 13, InternalState.Buffer.L);
 116   r0(B, C, D, E, A, 14, InternalState.Buffer.L);
 117   r0(A, B, C, D, E, 15, InternalState.Buffer.L);
 118   r1(E, A, B, C, D, 16, InternalState.Buffer.L);
 119   r1(D, E, A, B, C, 17, InternalState.Buffer.L);
 120   r1(C, D, E, A, B, 18, InternalState.Buffer.L);
 121   r1(B, C, D, E, A, 19, InternalState.Buffer.L);
 122
 123   r2(A, B, C, D, E, 20, InternalState.Buffer.L);
 124   r2(E, A, B, C, D, 21, InternalState.Buffer.L);
 125   r2(D, E, A, B, C, 22, InternalState.Buffer.L);
 126   r2(C, D, E, A, B, 23, InternalState.Buffer.L);
 127   r2(B, C, D, E, A, 24, InternalState.Buffer.L);
 128   r2(A, B, C, D, E, 25, InternalState.Buffer.L);
 129   r2(E, A, B, C, D, 26, InternalState.Buffer.L);
 130   r2(D, E, A, B, C, 27, InternalState.Buffer.L);
 131   r2(C, D, E, A, B, 28, InternalState.Buffer.L);
 132   r2(B, C, D, E, A, 29, InternalState.Buffer.L);
 133   r2(A, B, C, D, E, 30, InternalState.Buffer.L);
 134   r2(E, A, B, C, D, 31, InternalState.Buffer.L);
 135   r2(D, E, A, B, C, 32, InternalState.Buffer.L);
 136   r2(C, D, E, A, B, 33, InternalState.Buffer.L);
 137   r2(B, C, D, E, A, 34, InternalState.Buffer.L);
 138   r2(A, B, C, D, E, 35, InternalState.Buffer.L);
 139   r2(E, A, B, C, D, 36, InternalState.Buffer.L);
 140   r2(D, E, A, B, C, 37, InternalState.Buffer.L);
 141   r2(C, D, E, A, B, 38, InternalState.Buffer.L);
 142   r2(B, C, D, E, A, 39, InternalState.Buffer.L);
 143
 144   r3(A, B, C, D, E, 40, InternalState.Buffer.L);
 145   r3(E, A, B, C, D, 41, InternalState.Buffer.L);
 146   r3(D, E, A, B, C, 42, InternalState.Buffer.L);
 147   r3(C, D, E, A, B, 43, InternalState.Buffer.L);
 148   r3(B, C, D, E, A, 44, InternalState.Buffer.L);
 149   r3(A, B, C, D, E, 45, InternalState.Buffer.L);
 150   r3(E, A, B, C, D, 46, InternalState.Buffer.L);
 151   r3(D, E, A, B, C, 47, InternalState.Buffer.L);
 152   r3(C, D, E, A, B, 48, InternalState.Buffer.L);
 153   r3(B, C, D, E, A, 49, InternalState.Buffer.L);
 154   r3(A, B, C, D, E, 50, InternalState.Buffer.L);
 155   r3(E, A, B, C, D, 51, InternalState.Buffer.L);
 156   r3(D, E, A, B, C, 52, InternalState.Buffer.L);
 157   r3(C, D, E, A, B, 53, InternalState.Buffer.L);
 158   r3(B, C, D, E, A, 54, InternalState.Buffer.L);
 159   r3(A, B, C, D, E, 55, InternalState.Buffer.L);
 160   r3(E, A, B, C, D, 56, InternalState.Buffer.L);
 161   r3(D, E, A, B, C, 57, InternalState.Buffer.L);
 162   r3(C, D, E, A, B, 58, InternalState.Buffer.L);
 163   r3(B, C, D, E, A, 59, InternalState.Buffer.L);
 164
 165   r4(A, B, C, D, E, 60, InternalState.Buffer.L);
 166   r4(E, A, B, C, D, 61, InternalState.Buffer.L);
 167   r4(D, E, A, B, C, 62, InternalState.Buffer.L);
 168   r4(C, D, E, A, B, 63, InternalState.Buffer.L);
 169   r4(B, C, D, E, A, 64, InternalState.Buffer.L);
 170   r4(A, B, C, D, E, 65, InternalState.Buffer.L);
 171   r4(E, A, B, C, D, 66, InternalState.Buffer.L);
 172   r4(D, E, A, B, C, 67, InternalState.Buffer.L);
 173   r4(C, D, E, A, B, 68, InternalState.Buffer.L);
 174   r4(B, C, D, E, A, 69, InternalState.Buffer.L);
 175   r4(A, B, C, D, E, 70, InternalState.Buffer.L);
 176   r4(E, A, B, C, D, 71, InternalState.Buffer.L);
 177   r4(D, E, A, B, C, 72, InternalState.Buffer.L);
 178   r4(C, D, E, A, B, 73, InternalState.Buffer.L);
 179   r4(B, C, D, E, A, 74, InternalState.Buffer.L);
 180   r4(A, B, C, D, E, 75, InternalState.Buffer.L);
 181   r4(E, A, B, C, D, 76, InternalState.Buffer.L);
 182   r4(D, E, A, B, C, 77, InternalState.Buffer.L);
 183   r4(C, D, E, A, B, 78, InternalState.Buffer.L);
 184   r4(B, C, D, E, A, 79, InternalState.Buffer.L);
 185
 186   InternalState.State[0] += A;
 187   InternalState.State[1] += B;
 188   InternalState.State[2] += C;
 189   InternalState.State[3] += D;
 190   InternalState.State[4] += E;
 191 }
 192
 193 void SHA1::addUncounted(uint8_t Data) {
 194 #ifdef SHA_BIG_ENDIAN
 195   InternalState.Buffer.C[InternalState.BufferOffset] = Data;
 196 #else
 197   InternalState.Buffer.C[InternalState.BufferOffset ^ 3] = Data;
 198 #endif
 199
 200   InternalState.BufferOffset++;
 201   if (InternalState.BufferOffset == BLOCK_LENGTH) {
 202     hashBlock();
 203     InternalState.BufferOffset = 0;
 204   }
 205 }
 206
 207 void SHA1::writebyte(uint8_t Data) {
 208   ++InternalState.ByteCount;
 209   addUncounted(Data);
 210 }
 211
 212 void SHA1::update(ArrayRef<uint8_t> Data) {
 213   for (auto &C : Data)
 214     writebyte(C);
 215 }
 216
 217 void SHA1::pad() {
 218   // Implement SHA-1 padding (fips180-2 5.1.1)
 219
 220   // Pad with 0x80 followed by 0x00 until the end of the block
 221   addUncounted(0x80);
 222   while (InternalState.BufferOffset != 56)
 223     addUncounted(0x00);
 224
 225   // Append length in the last 8 bytes
 226   addUncounted(0); // We're only using 32 bit lengths
 227   addUncounted(0); // But SHA-1 supports 64 bit lengths
 228   addUncounted(0); // So zero pad the top bits
 229   addUncounted(InternalState.ByteCount >> 29); // Shifting to multiply by 8
 230   addUncounted(InternalState.ByteCount >>
 231                21); // as SHA-1 supports bitstreams as well as
 232   addUncounted(InternalState.ByteCount >> 13); // byte.
 233   addUncounted(InternalState.ByteCount >> 5);
 234   addUncounted(InternalState.ByteCount << 3);
 235 }
 236
 237 StringRef SHA1::final() {
 238   // Pad to complete the last block
 239   pad();
 240
 241 #ifdef SHA_BIG_ENDIAN
 242   // Just copy the current state
 243   for (int i = 0; i < 5; i++) {
 244     HashResult[i] = InternalState.State[i];
 245   }
 246 #else
 247   // Swap byte order back
 248   for (int i = 0; i < 5; i++) {
 249     HashResult[i] = (((InternalState.State[i]) << 24) & 0xff000000) |
 250                     (((InternalState.State[i]) << 8) & 0x00ff0000) |
 251                     (((InternalState.State[i]) >> 8) & 0x0000ff00) |
 252                     (((InternalState.State[i]) >> 24) & 0x000000ff);
 253   }
 254 #endif
 255
 256   // Return pointer to hash (20 characters)
 257   return StringRef((char *)HashResult, HASH_LENGTH);
 258 }
 259
 260 StringRef SHA1::result() {
 261   auto StateToRestore = InternalState;
 262
 263   auto Hash = final();
 264
 265   // Restore the state
 266   InternalState = StateToRestore;
 267
 268   // Return pointer to hash (20 characters)
 269   return Hash;
 270 }
 271
 272 std::array<uint8_t, 20> SHA1::hash(ArrayRef<uint8_t> Data) {
 273   SHA1 Hash;
 274   Hash.update(Data);
 275   StringRef S = Hash.final();
 276
 277   std::array<uint8_t, 20> Arr;
 278   memcpy(Arr.data(), S.data(), S.size());
 279   return Arr;
 280 }