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 void SHA1::final(std::array<uint32_t, HASH_LENGTH / 4> &HashResult) {
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 
286 std::array<uint8_t, 20> SHA1::final() {
287   union {
288     std::array<uint32_t, HASH_LENGTH / 4> HashResult;
289     std::array<uint8_t, HASH_LENGTH> ReturnResult;
290   };
291   static_assert(sizeof(HashResult) == sizeof(ReturnResult), "");
292   final(HashResult);
293   return ReturnResult;
294 }
295 
296 std::array<uint8_t, 20> SHA1::result() {
297   auto StateToRestore = InternalState;
298 
299   auto Hash = final();
300 
301   // Restore the state
302   InternalState = StateToRestore;
303 
304   // Return pointer to hash (20 characters)
305   return Hash;
306 }
307 
308 std::array<uint8_t, 20> SHA1::hash(ArrayRef<uint8_t> Data) {
309   SHA1 Hash;
310   Hash.update(Data);
311   return Hash.final();
312 }
313