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/Endian.h"
20#include "llvm/Support/Host.h"
21using namespace llvm;
22
23#include <stdint.h>
24#include <string.h>
25
26#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
27#define SHA_BIG_ENDIAN
28#endif
29
30static inline uint32_t rol(uint32_t Number, int Bits) {
31  return (Number << Bits) | (Number >> (32 - Bits));
32}
33
34static inline uint32_t blk0(uint32_t *Buf, int I) { return Buf[I]; }
35
36static 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
43static 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
49static 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
55static 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
61static 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
67static 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
85void 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
95void 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
194void 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
208void SHA1::writebyte(uint8_t Data) {
209  ++InternalState.ByteCount;
210  addUncounted(Data);
211}
212
213void 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    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
241void SHA1::pad() {
242  // Implement SHA-1 padding (fips180-2 5.1.1)
243
244  // Pad with 0x80 followed by 0x00 until the end of the block
245  addUncounted(0x80);
246  while (InternalState.BufferOffset != 56)
247    addUncounted(0x00);
248
249  // Append length in the last 8 bytes
250  addUncounted(0); // We're only using 32 bit lengths
251  addUncounted(0); // But SHA-1 supports 64 bit lengths
252  addUncounted(0); // So zero pad the top bits
253  addUncounted(InternalState.ByteCount >> 29); // Shifting to multiply by 8
254  addUncounted(InternalState.ByteCount >>
255               21); // as SHA-1 supports bitstreams as well as
256  addUncounted(InternalState.ByteCount >> 13); // byte.
257  addUncounted(InternalState.ByteCount >> 5);
258  addUncounted(InternalState.ByteCount << 3);
259}
260
261StringRef SHA1::final() {
262  // Pad to complete the last block
263  pad();
264
265#ifdef SHA_BIG_ENDIAN
266  // Just copy the current state
267  for (int i = 0; i < 5; i++) {
268    HashResult[i] = InternalState.State[i];
269  }
270#else
271  // Swap byte order back
272  for (int i = 0; i < 5; i++) {
273    HashResult[i] = (((InternalState.State[i]) << 24) & 0xff000000) |
274                    (((InternalState.State[i]) << 8) & 0x00ff0000) |
275                    (((InternalState.State[i]) >> 8) & 0x0000ff00) |
276                    (((InternalState.State[i]) >> 24) & 0x000000ff);
277  }
278#endif
279
280  // Return pointer to hash (20 characters)
281  return StringRef((char *)HashResult, HASH_LENGTH);
282}
283
284StringRef SHA1::result() {
285  auto StateToRestore = InternalState;
286
287  auto Hash = final();
288
289  // Restore the state
290  InternalState = StateToRestore;
291
292  // Return pointer to hash (20 characters)
293  return Hash;
294}
295
296std::array<uint8_t, 20> SHA1::hash(ArrayRef<uint8_t> Data) {
297  SHA1 Hash;
298  Hash.update(Data);
299  StringRef S = Hash.final();
300
301  std::array<uint8_t, 20> Arr;
302  memcpy(Arr.data(), S.data(), S.size());
303  return Arr;
304}
305