1//======- SHA1.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 wrapping it in a C++ interface for LLVM,
12// and removing unnecessary code.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/Support/Host.h"
17#include "llvm/Support/SHA1.h"
18#include "llvm/ADT/ArrayRef.h"
19using namespace llvm;
20
21#include <stdint.h>
22#include <string.h>
23
24#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
25#define SHA_BIG_ENDIAN
26#endif
27
28/* code */
29#define SHA1_K0 0x5a827999
30#define SHA1_K20 0x6ed9eba1
31#define SHA1_K40 0x8f1bbcdc
32#define SHA1_K60 0xca62c1d6
33
34#define SEED_0 0x67452301
35#define SEED_1 0xefcdab89
36#define SEED_2 0x98badcfe
37#define SEED_3 0x10325476
38#define SEED_4 0xc3d2e1f0
39
40void SHA1::init() {
41  InternalState.State[0] = SEED_0;
42  InternalState.State[1] = SEED_1;
43  InternalState.State[2] = SEED_2;
44  InternalState.State[3] = SEED_3;
45  InternalState.State[4] = SEED_4;
46  InternalState.ByteCount = 0;
47  InternalState.BufferOffset = 0;
48}
49
50static uint32_t rol32(uint32_t number, uint8_t bits) {
51  return ((number << bits) | (number >> (32 - bits)));
52}
53
54void SHA1::hashBlock() {
55  uint8_t i;
56  uint32_t a, b, c, d, e, t;
57
58  a = InternalState.State[0];
59  b = InternalState.State[1];
60  c = InternalState.State[2];
61  d = InternalState.State[3];
62  e = InternalState.State[4];
63  for (i = 0; i < 80; i++) {
64    if (i >= 16) {
65      t = InternalState.Buffer[(i + 13) & 15] ^
66          InternalState.Buffer[(i + 8) & 15] ^
67          InternalState.Buffer[(i + 2) & 15] ^ InternalState.Buffer[i & 15];
68      InternalState.Buffer[i & 15] = rol32(t, 1);
69    }
70    if (i < 20) {
71      t = (d ^ (b & (c ^ d))) + SHA1_K0;
72    } else if (i < 40) {
73      t = (b ^ c ^ d) + SHA1_K20;
74    } else if (i < 60) {
75      t = ((b & c) | (d & (b | c))) + SHA1_K40;
76    } else {
77      t = (b ^ c ^ d) + SHA1_K60;
78    }
79    t += rol32(a, 5) + e + InternalState.Buffer[i & 15];
80    e = d;
81    d = c;
82    c = rol32(b, 30);
83    b = a;
84    a = t;
85  }
86  InternalState.State[0] += a;
87  InternalState.State[1] += b;
88  InternalState.State[2] += c;
89  InternalState.State[3] += d;
90  InternalState.State[4] += e;
91}
92
93void SHA1::addUncounted(uint8_t data) {
94  uint8_t *const b = (uint8_t *)InternalState.Buffer;
95#ifdef SHA_BIG_ENDIAN
96  b[InternalState.BufferOffset] = data;
97#else
98  b[InternalState.BufferOffset ^ 3] = data;
99#endif
100  InternalState.BufferOffset++;
101  if (InternalState.BufferOffset == BLOCK_LENGTH) {
102    hashBlock();
103    InternalState.BufferOffset = 0;
104  }
105}
106
107void SHA1::writebyte(uint8_t data) {
108  ++InternalState.ByteCount;
109  addUncounted(data);
110}
111
112void SHA1::update(ArrayRef<uint8_t> Data) {
113  for (auto &C : Data)
114    writebyte(C);
115}
116
117void SHA1::pad() {
118  // Implement SHA-1 padding (fips180-2 5.1.1)
119
120  // Pad with 0x80 followed by 0x00 until the end of the block
121  addUncounted(0x80);
122  while (InternalState.BufferOffset != 56)
123    addUncounted(0x00);
124
125  // Append length in the last 8 bytes
126  addUncounted(0); // We're only using 32 bit lengths
127  addUncounted(0); // But SHA-1 supports 64 bit lengths
128  addUncounted(0); // So zero pad the top bits
129  addUncounted(InternalState.ByteCount >> 29); // Shifting to multiply by 8
130  addUncounted(InternalState.ByteCount >>
131               21); // as SHA-1 supports bitstreams as well as
132  addUncounted(InternalState.ByteCount >> 13); // byte.
133  addUncounted(InternalState.ByteCount >> 5);
134  addUncounted(InternalState.ByteCount << 3);
135}
136
137StringRef SHA1::final() {
138  // Pad to complete the last block
139  pad();
140
141#ifdef SHA_BIG_ENDIAN
142  // Just copy the current state
143  for (int i = 0; i < 5; i++) {
144    HashResult[i] = InternalState.State[i];
145  }
146#else
147  // Swap byte order back
148  for (int i = 0; i < 5; i++) {
149    HashResult[i] = (((InternalState.State[i]) << 24) & 0xff000000) |
150                    (((InternalState.State[i]) << 8) & 0x00ff0000) |
151                    (((InternalState.State[i]) >> 8) & 0x0000ff00) |
152                    (((InternalState.State[i]) >> 24) & 0x000000ff);
153  }
154#endif
155
156  // Return pointer to hash (20 characters)
157  return StringRef((char *)HashResult, HASH_LENGTH);
158}
159
160StringRef SHA1::result() {
161  auto StateToRestore = InternalState;
162
163  auto Hash = final();
164
165  // Restore the state
166  InternalState = StateToRestore;
167
168  // Return pointer to hash (20 characters)
169  return Hash;
170}
171