llvm/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/ADT/StringRef.h"
  20 #include "llvm/Support/Endian.h"
  21 #include "llvm/Support/Host.h"
  22 #include <string.h>
  23
  24 using namespace llvm;
  25
  26 #if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
  27 #define SHA_BIG_ENDIAN
  28 #endif
  29
  30 static inline uint32_t rol(uint32_t Number, int Bits) {
  31   return (Number << Bits) | (Number >> (32 - Bits));
  32 }
  33
  34 static inline uint32_t blk0(uint32_t *Buf, int I) { return Buf[I]; }
  35
  36 static inline uint32_t blk(uint32_t *Buf, int I) {
  37   Buf[I & 15] = rol(Buf[(I + 13) & 15] ^ Buf[(I + 8) & 15] ^ Buf[(I + 2) & 15] ^
  38                         Buf[I & 15],
  39                     1);
  40   return Buf[I & 15];
  41 }
  42
  43 static inline void r0(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D,
  44                       uint32_t &E, int I, uint32_t *Buf) {
  45   E += ((B & (C ^ D)) ^ D) + blk0(Buf, I) + 0x5A827999 + rol(A, 5);
  46   B = rol(B, 30);
  47 }
  48
  49 static inline void r1(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D,
  50                       uint32_t &E, int I, uint32_t *Buf) {
  51   E += ((B & (C ^ D)) ^ D) + blk(Buf, I) + 0x5A827999 + rol(A, 5);
  52   B = rol(B, 30);
  53 }
  54
  55 static inline void r2(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D,
  56                       uint32_t &E, int I, uint32_t *Buf) {
  57   E += (B ^ C ^ D) + blk(Buf, I) + 0x6ED9EBA1 + rol(A, 5);
  58   B = rol(B, 30);
  59 }
  60
  61 static inline void r3(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D,
  62                       uint32_t &E, int I, uint32_t *Buf) {
  63   E += (((B | C) & D) | (B & C)) + blk(Buf, I) + 0x8F1BBCDC + rol(A, 5);
  64   B = rol(B, 30);
  65 }
  66
  67 static inline void r4(uint32_t &A, uint32_t &B, uint32_t &C, uint32_t &D,
  68                       uint32_t &E, int I, uint32_t *Buf) {
  69   E += (B ^ C ^ D) + blk(Buf, I) + 0xCA62C1D6 + rol(A, 5);
  70   B = rol(B, 30);
  71 }
  72
  73 /* code */
  74 #define SHA1_K0 0x5a827999
  75 #define SHA1_K20 0x6ed9eba1
  76 #define SHA1_K40 0x8f1bbcdc
  77 #define SHA1_K60 0xca62c1d6
  78
  79 #define SEED_0 0x67452301
  80 #define SEED_1 0xefcdab89
  81 #define SEED_2 0x98badcfe
  82 #define SEED_3 0x10325476
  83 #define SEED_4 0xc3d2e1f0
  84
  85 void SHA1::init() {
  86   InternalState.State[0] = SEED_0;
  87   InternalState.State[1] = SEED_1;
  88   InternalState.State[2] = SEED_2;
  89   InternalState.State[3] = SEED_3;
  90   InternalState.State[4] = SEED_4;
  91   InternalState.ByteCount = 0;
  92   InternalState.BufferOffset = 0;
  93 }
  94
  95 void SHA1::hashBlock() {
  96   uint32_t A = InternalState.State[0];
  97   uint32_t B = InternalState.State[1];
  98   uint32_t C = InternalState.State[2];
  99   uint32_t D = InternalState.State[3];
 100   uint32_t E = InternalState.State[4];
 101
 102   // 4 rounds of 20 operations each. Loop unrolled.
 103   r0(A, B, C, D, E, 0, InternalState.Buffer.L);
 104   r0(E, A, B, C, D, 1, InternalState.Buffer.L);
 105   r0(D, E, A, B, C, 2, InternalState.Buffer.L);
 106   r0(C, D, E, A, B, 3, InternalState.Buffer.L);
 107   r0(B, C, D, E, A, 4, InternalState.Buffer.L);
 108   r0(A, B, C, D, E, 5, InternalState.Buffer.L);
 109   r0(E, A, B, C, D, 6, InternalState.Buffer.L);
 110   r0(D, E, A, B, C, 7, InternalState.Buffer.L);
 111   r0(C, D, E, A, B, 8, InternalState.Buffer.L);
 112   r0(B, C, D, E, A, 9, InternalState.Buffer.L);
 113   r0(A, B, C, D, E, 10, InternalState.Buffer.L);
 114   r0(E, A, B, C, D, 11, InternalState.Buffer.L);
 115   r0(D, E, A, B, C, 12, InternalState.Buffer.L);
 116   r0(C, D, E, A, B, 13, InternalState.Buffer.L);
 117   r0(B, C, D, E, A, 14, InternalState.Buffer.L);
 118   r0(A, B, C, D, E, 15, InternalState.Buffer.L);
 119   r1(E, A, B, C, D, 16, InternalState.Buffer.L);
 120   r1(D, E, A, B, C, 17, InternalState.Buffer.L);
 121   r1(C, D, E, A, B, 18, InternalState.Buffer.L);
 122   r1(B, C, D, E, A, 19, InternalState.Buffer.L);
 123
 124   r2(A, B, C, D, E, 20, InternalState.Buffer.L);
 125   r2(E, A, B, C, D, 21, InternalState.Buffer.L);
 126   r2(D, E, A, B, C, 22, InternalState.Buffer.L);
 127   r2(C, D, E, A, B, 23, InternalState.Buffer.L);
 128   r2(B, C, D, E, A, 24, InternalState.Buffer.L);
 129   r2(A, B, C, D, E, 25, InternalState.Buffer.L);
 130   r2(E, A, B, C, D, 26, InternalState.Buffer.L);
 131   r2(D, E, A, B, C, 27, InternalState.Buffer.L);
 132   r2(C, D, E, A, B, 28, InternalState.Buffer.L);
 133   r2(B, C, D, E, A, 29, InternalState.Buffer.L);
 134   r2(A, B, C, D, E, 30, InternalState.Buffer.L);
 135   r2(E, A, B, C, D, 31, InternalState.Buffer.L);
 136   r2(D, E, A, B, C, 32, InternalState.Buffer.L);
 137   r2(C, D, E, A, B, 33, InternalState.Buffer.L);
 138   r2(B, C, D, E, A, 34, InternalState.Buffer.L);
 139   r2(A, B, C, D, E, 35, InternalState.Buffer.L);
 140   r2(E, A, B, C, D, 36, InternalState.Buffer.L);
 141   r2(D, E, A, B, C, 37, InternalState.Buffer.L);
 142   r2(C, D, E, A, B, 38, InternalState.Buffer.L);
 143   r2(B, C, D, E, A, 39, InternalState.Buffer.L);
 144
 145   r3(A, B, C, D, E, 40, InternalState.Buffer.L);
 146   r3(E, A, B, C, D, 41, InternalState.Buffer.L);
 147   r3(D, E, A, B, C, 42, InternalState.Buffer.L);
 148   r3(C, D, E, A, B, 43, InternalState.Buffer.L);
 149   r3(B, C, D, E, A, 44, InternalState.Buffer.L);
 150   r3(A, B, C, D, E, 45, InternalState.Buffer.L);
 151   r3(E, A, B, C, D, 46, InternalState.Buffer.L);
 152   r3(D, E, A, B, C, 47, InternalState.Buffer.L);
 153   r3(C, D, E, A, B, 48, InternalState.Buffer.L);
 154   r3(B, C, D, E, A, 49, InternalState.Buffer.L);
 155   r3(A, B, C, D, E, 50, InternalState.Buffer.L);
 156   r3(E, A, B, C, D, 51, InternalState.Buffer.L);
 157   r3(D, E, A, B, C, 52, InternalState.Buffer.L);
 158   r3(C, D, E, A, B, 53, InternalState.Buffer.L);
 159   r3(B, C, D, E, A, 54, InternalState.Buffer.L);
 160   r3(A, B, C, D, E, 55, InternalState.Buffer.L);
 161   r3(E, A, B, C, D, 56, InternalState.Buffer.L);
 162   r3(D, E, A, B, C, 57, InternalState.Buffer.L);
 163   r3(C, D, E, A, B, 58, InternalState.Buffer.L);
 164   r3(B, C, D, E, A, 59, InternalState.Buffer.L);
 165
 166   r4(A, B, C, D, E, 60, InternalState.Buffer.L);
 167   r4(E, A, B, C, D, 61, InternalState.Buffer.L);
 168   r4(D, E, A, B, C, 62, InternalState.Buffer.L);
 169   r4(C, D, E, A, B, 63, InternalState.Buffer.L);
 170   r4(B, C, D, E, A, 64, InternalState.Buffer.L);
 171   r4(A, B, C, D, E, 65, InternalState.Buffer.L);
 172   r4(E, A, B, C, D, 66, InternalState.Buffer.L);
 173   r4(D, E, A, B, C, 67, InternalState.Buffer.L);
 174   r4(C, D, E, A, B, 68, InternalState.Buffer.L);
 175   r4(B, C, D, E, A, 69, InternalState.Buffer.L);
 176   r4(A, B, C, D, E, 70, InternalState.Buffer.L);
 177   r4(E, A, B, C, D, 71, InternalState.Buffer.L);
 178   r4(D, E, A, B, C, 72, InternalState.Buffer.L);
 179   r4(C, D, E, A, B, 73, InternalState.Buffer.L);
 180   r4(B, C, D, E, A, 74, InternalState.Buffer.L);
 181   r4(A, B, C, D, E, 75, InternalState.Buffer.L);
 182   r4(E, A, B, C, D, 76, InternalState.Buffer.L);
 183   r4(D, E, A, B, C, 77, InternalState.Buffer.L);
 184   r4(C, D, E, A, B, 78, InternalState.Buffer.L);
 185   r4(B, C, D, E, A, 79, InternalState.Buffer.L);
 186
 187   InternalState.State[0] += A;
 188   InternalState.State[1] += B;
 189   InternalState.State[2] += C;
 190   InternalState.State[3] += D;
 191   InternalState.State[4] += E;
 192 }
 193
 194 void SHA1::addUncounted(uint8_t Data) {
 195 #ifdef SHA_BIG_ENDIAN
 196   InternalState.Buffer.C[InternalState.BufferOffset] = Data;
 197 #else
 198   InternalState.Buffer.C[InternalState.BufferOffset ^ 3] = Data;
 199 #endif
 200
 201   InternalState.BufferOffset++;
 202   if (InternalState.BufferOffset == BLOCK_LENGTH) {
 203     hashBlock();
 204     InternalState.BufferOffset = 0;
 205   }
 206 }
 207
 208 void SHA1::writebyte(uint8_t Data) {
 209   ++InternalState.ByteCount;
 210   addUncounted(Data);
 211 }
 212
 213 void SHA1::update(ArrayRef<uint8_t> Data) {
 214   InternalState.ByteCount += Data.size();
 215
 216   // Finish the current block.
 217   if (InternalState.BufferOffset > 0) {
 218     const size_t Remainder = std::min<size_t>(
 219         Data.size(), BLOCK_LENGTH - InternalState.BufferOffset);
 220     for (size_t I = 0; I < Remainder; ++I)
 221       addUncounted(Data[I]);
 222     Data = Data.drop_front(Remainder);
 223   }
 224
 225   // Fast buffer filling for large inputs.
 226   while (Data.size() >= BLOCK_LENGTH) {
 227     assert(InternalState.BufferOffset == 0);
 228     static_assert(BLOCK_LENGTH % 4 == 0, "");
 229     constexpr size_t BLOCK_LENGTH_32 = BLOCK_LENGTH / 4;
 230     for (size_t I = 0; I < BLOCK_LENGTH_32; ++I)
 231       InternalState.Buffer.L[I] = support::endian::read32be(&Data[I * 4]);
 232     hashBlock();
 233     Data = Data.drop_front(BLOCK_LENGTH);
 234   }
 235
 236   // Finish the remainder.
 237   for (uint8_t C : Data)
 238     addUncounted(C);
 239 }
 240
 241 void SHA1::update(StringRef Str) {
 242   update(
 243       ArrayRef<uint8_t>((uint8_t *)const_cast<char *>(Str.data()), Str.size()));
 244 }
 245
 246 void SHA1::pad() {
 247   // Implement SHA-1 padding (fips180-2 5.1.1)
 248
 249   // Pad with 0x80 followed by 0x00 until the end of the block
 250   addUncounted(0x80);
 251   while (InternalState.BufferOffset != 56)
 252     addUncounted(0x00);
 253
 254   // Append length in the last 8 bytes
 255   addUncounted(0); // We're only using 32 bit lengths
 256   addUncounted(0); // But SHA-1 supports 64 bit lengths
 257   addUncounted(0); // So zero pad the top bits
 258   addUncounted(InternalState.ByteCount >> 29); // Shifting to multiply by 8
 259   addUncounted(InternalState.ByteCount >>
 260                21); // as SHA-1 supports bitstreams as well as
 261   addUncounted(InternalState.ByteCount >> 13); // byte.
 262   addUncounted(InternalState.ByteCount >> 5);
 263   addUncounted(InternalState.ByteCount << 3);
 264 }
 265
 266 StringRef SHA1::final() {
 267   // Pad to complete the last block
 268   pad();
 269
 270 #ifdef SHA_BIG_ENDIAN
 271   // Just copy the current state
 272   for (int i = 0; i < 5; i++) {
 273     HashResult[i] = InternalState.State[i];
 274   }
 275 #else
 276   // Swap byte order back
 277   for (int i = 0; i < 5; i++) {
 278     HashResult[i] = (((InternalState.State[i]) << 24) & 0xff000000) |
 279                     (((InternalState.State[i]) << 8) & 0x00ff0000) |
 280                     (((InternalState.State[i]) >> 8) & 0x0000ff00) |
 281                     (((InternalState.State[i]) >> 24) & 0x000000ff);
 282   }
 283 #endif
 284
 285   // Return pointer to hash (20 characters)
 286   return StringRef((char *)HashResult, HASH_LENGTH);
 287 }
 288
 289 StringRef SHA1::result() {
 290   auto StateToRestore = InternalState;
 291
 292   auto Hash = final();
 293
 294   // Restore the state
 295   InternalState = StateToRestore;
 296
 297   // Return pointer to hash (20 characters)
 298   return Hash;
 299 }
 300
 301 std::array<uint8_t, 20> SHA1::hash(ArrayRef<uint8_t> Data) {
 302   SHA1 Hash;
 303   Hash.update(Data);
 304   StringRef S = Hash.final();
 305
 306   std::array<uint8_t, 20> Arr;
 307   memcpy(Arr.data(), S.data(), S.size());
 308   return Arr;
 309 }