1 //====- SHA256.cpp - SHA256 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 * The SHA-256 Secure Hash Standard was published by NIST in 2002.
10 *
11 * http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
12 *
13 * The implementation is based on nacl's sha256 implementation [0] and LLVM's
14 * pre-exsiting SHA1 code [1].
15 *
16 * [0] https://hyperelliptic.org/nacl/nacl-20110221.tar.bz2 (public domain
17 * code)
18 * [1] llvm/lib/Support/SHA1.{h,cpp}
19 */
20 //===----------------------------------------------------------------------===//
21
22 #include "llvm/Support/SHA256.h"
23 #include "llvm/ADT/ArrayRef.h"
24 #include "llvm/ADT/StringRef.h"
25 #include "llvm/Support/Endian.h"
26 #include "llvm/Support/SwapByteOrder.h"
27 #include <string.h>
28
29 namespace llvm {
30
31 #define SHR(x, c) ((x) >> (c))
32 #define ROTR(x, n) (((x) >> n) | ((x) << (32 - (n))))
33
34 #define CH(x, y, z) (((x) & (y)) ^ (~(x) & (z)))
35 #define MAJ(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
36
37 #define SIGMA_0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
38 #define SIGMA_1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
39
40 #define SIGMA_2(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
41 #define SIGMA_3(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
42
43 #define F_EXPAND(A, B, C, D, E, F, G, H, M1, M2, M3, M4, k) \
44 do { \
45 H += SIGMA_1(E) + CH(E, F, G) + M1 + k; \
46 D += H; \
47 H += SIGMA_0(A) + MAJ(A, B, C); \
48 M1 += SIGMA_2(M2) + M3 + SIGMA_3(M4); \
49 } while (0);
50
init()51 void SHA256::init() {
52 InternalState.State[0] = 0x6A09E667;
53 InternalState.State[1] = 0xBB67AE85;
54 InternalState.State[2] = 0x3C6EF372;
55 InternalState.State[3] = 0xA54FF53A;
56 InternalState.State[4] = 0x510E527F;
57 InternalState.State[5] = 0x9B05688C;
58 InternalState.State[6] = 0x1F83D9AB;
59 InternalState.State[7] = 0x5BE0CD19;
60 InternalState.ByteCount = 0;
61 InternalState.BufferOffset = 0;
62 }
63
hashBlock()64 void SHA256::hashBlock() {
65 uint32_t A = InternalState.State[0];
66 uint32_t B = InternalState.State[1];
67 uint32_t C = InternalState.State[2];
68 uint32_t D = InternalState.State[3];
69 uint32_t E = InternalState.State[4];
70 uint32_t F = InternalState.State[5];
71 uint32_t G = InternalState.State[6];
72 uint32_t H = InternalState.State[7];
73
74 uint32_t W00 = InternalState.Buffer.L[0];
75 uint32_t W01 = InternalState.Buffer.L[1];
76 uint32_t W02 = InternalState.Buffer.L[2];
77 uint32_t W03 = InternalState.Buffer.L[3];
78 uint32_t W04 = InternalState.Buffer.L[4];
79 uint32_t W05 = InternalState.Buffer.L[5];
80 uint32_t W06 = InternalState.Buffer.L[6];
81 uint32_t W07 = InternalState.Buffer.L[7];
82 uint32_t W08 = InternalState.Buffer.L[8];
83 uint32_t W09 = InternalState.Buffer.L[9];
84 uint32_t W10 = InternalState.Buffer.L[10];
85 uint32_t W11 = InternalState.Buffer.L[11];
86 uint32_t W12 = InternalState.Buffer.L[12];
87 uint32_t W13 = InternalState.Buffer.L[13];
88 uint32_t W14 = InternalState.Buffer.L[14];
89 uint32_t W15 = InternalState.Buffer.L[15];
90
91 F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0x428A2F98);
92 F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0x71374491);
93 F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0xB5C0FBCF);
94 F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0xE9B5DBA5);
95 F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x3956C25B);
96 F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x59F111F1);
97 F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x923F82A4);
98 F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0xAB1C5ED5);
99 F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0xD807AA98);
100 F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0x12835B01);
101 F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0x243185BE);
102 F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0x550C7DC3);
103 F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0x72BE5D74);
104 F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0x80DEB1FE);
105 F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0x9BDC06A7);
106 F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0xC19BF174);
107
108 F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0xE49B69C1);
109 F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0xEFBE4786);
110 F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0x0FC19DC6);
111 F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0x240CA1CC);
112 F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x2DE92C6F);
113 F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x4A7484AA);
114 F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x5CB0A9DC);
115 F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0x76F988DA);
116 F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0x983E5152);
117 F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0xA831C66D);
118 F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0xB00327C8);
119 F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0xBF597FC7);
120 F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0xC6E00BF3);
121 F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0xD5A79147);
122 F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0x06CA6351);
123 F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0x14292967);
124
125 F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0x27B70A85);
126 F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0x2E1B2138);
127 F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0x4D2C6DFC);
128 F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0x53380D13);
129 F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x650A7354);
130 F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x766A0ABB);
131 F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x81C2C92E);
132 F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0x92722C85);
133 F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0xA2BFE8A1);
134 F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0xA81A664B);
135 F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0xC24B8B70);
136 F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0xC76C51A3);
137 F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0xD192E819);
138 F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0xD6990624);
139 F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0xF40E3585);
140 F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0x106AA070);
141
142 F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0x19A4C116);
143 F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0x1E376C08);
144 F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0x2748774C);
145 F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0x34B0BCB5);
146 F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x391C0CB3);
147 F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x4ED8AA4A);
148 F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x5B9CCA4F);
149 F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0x682E6FF3);
150 F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0x748F82EE);
151 F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0x78A5636F);
152 F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0x84C87814);
153 F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0x8CC70208);
154 F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0x90BEFFFA);
155 F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0xA4506CEB);
156 F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0xBEF9A3F7);
157 F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0xC67178F2);
158
159 InternalState.State[0] += A;
160 InternalState.State[1] += B;
161 InternalState.State[2] += C;
162 InternalState.State[3] += D;
163 InternalState.State[4] += E;
164 InternalState.State[5] += F;
165 InternalState.State[6] += G;
166 InternalState.State[7] += H;
167 }
168
addUncounted(uint8_t Data)169 void SHA256::addUncounted(uint8_t Data) {
170 if constexpr (sys::IsBigEndianHost)
171 InternalState.Buffer.C[InternalState.BufferOffset] = Data;
172 else
173 InternalState.Buffer.C[InternalState.BufferOffset ^ 3] = Data;
174
175 InternalState.BufferOffset++;
176 if (InternalState.BufferOffset == BLOCK_LENGTH) {
177 hashBlock();
178 InternalState.BufferOffset = 0;
179 }
180 }
181
writebyte(uint8_t Data)182 void SHA256::writebyte(uint8_t Data) {
183 ++InternalState.ByteCount;
184 addUncounted(Data);
185 }
186
update(ArrayRef<uint8_t> Data)187 void SHA256::update(ArrayRef<uint8_t> Data) {
188 InternalState.ByteCount += Data.size();
189
190 // Finish the current block.
191 if (InternalState.BufferOffset > 0) {
192 const size_t Remainder = std::min<size_t>(
193 Data.size(), BLOCK_LENGTH - InternalState.BufferOffset);
194 for (size_t I = 0; I < Remainder; ++I)
195 addUncounted(Data[I]);
196 Data = Data.drop_front(Remainder);
197 }
198
199 // Fast buffer filling for large inputs.
200 while (Data.size() >= BLOCK_LENGTH) {
201 assert(InternalState.BufferOffset == 0);
202 static_assert(BLOCK_LENGTH % 4 == 0);
203 constexpr size_t BLOCK_LENGTH_32 = BLOCK_LENGTH / 4;
204 for (size_t I = 0; I < BLOCK_LENGTH_32; ++I)
205 InternalState.Buffer.L[I] = support::endian::read32be(&Data[I * 4]);
206 hashBlock();
207 Data = Data.drop_front(BLOCK_LENGTH);
208 }
209
210 // Finish the remainder.
211 for (uint8_t C : Data)
212 addUncounted(C);
213 }
214
update(StringRef Str)215 void SHA256::update(StringRef Str) {
216 update(
217 ArrayRef<uint8_t>((uint8_t *)const_cast<char *>(Str.data()), Str.size()));
218 }
219
pad()220 void SHA256::pad() {
221 // Implement SHA-2 padding (fips180-2 5.1.1)
222
223 // Pad with 0x80 followed by 0x00 until the end of the block
224 addUncounted(0x80);
225 while (InternalState.BufferOffset != 56)
226 addUncounted(0x00);
227
228 uint64_t len = InternalState.ByteCount << 3; // bit size
229
230 // Append length in the last 8 bytes big edian encoded
231 addUncounted(len >> 56);
232 addUncounted(len >> 48);
233 addUncounted(len >> 40);
234 addUncounted(len >> 32);
235 addUncounted(len >> 24);
236 addUncounted(len >> 16);
237 addUncounted(len >> 8);
238 addUncounted(len);
239 }
240
final(std::array<uint32_t,HASH_LENGTH/4> & HashResult)241 void SHA256::final(std::array<uint32_t, HASH_LENGTH / 4> &HashResult) {
242 // Pad to complete the last block
243 pad();
244
245 if constexpr (sys::IsBigEndianHost) {
246 // Just copy the current state
247 for (int i = 0; i < 8; i++) {
248 HashResult[i] = InternalState.State[i];
249 }
250 } else {
251 // Swap byte order back
252 for (int i = 0; i < 8; i++) {
253 HashResult[i] = llvm::byteswap(InternalState.State[i]);
254 }
255 }
256 }
257
final()258 std::array<uint8_t, 32> SHA256::final() {
259 union {
260 std::array<uint32_t, HASH_LENGTH / 4> HashResult;
261 std::array<uint8_t, HASH_LENGTH> ReturnResult;
262 };
263 static_assert(sizeof(HashResult) == sizeof(ReturnResult));
264 final(HashResult);
265 return ReturnResult;
266 }
267
result()268 std::array<uint8_t, 32> SHA256::result() {
269 auto StateToRestore = InternalState;
270
271 auto Hash = final();
272
273 // Restore the state
274 InternalState = StateToRestore;
275
276 // Return pointer to hash (32 characters)
277 return Hash;
278 }
279
hash(ArrayRef<uint8_t> Data)280 std::array<uint8_t, 32> SHA256::hash(ArrayRef<uint8_t> Data) {
281 SHA256 Hash;
282 Hash.update(Data);
283 return Hash.final();
284 }
285
286 } // namespace llvm
287