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Commit | Line | Data |
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d7c208a9 | 1 | /* |
30ae47b4 | 2 | * SHA1 routine optimized to do word accesses rather than byte accesses, |
d7c208a9 | 3 | * and to avoid unnecessary copies into the context array. |
30ae47b4 NP |
4 | * |
5 | * This was initially based on the Mozilla SHA1 implementation, although | |
6 | * none of the original Mozilla code remains. | |
d7c208a9 LT |
7 | */ |
8 | ||
51ea5519 NP |
9 | /* this is only to get definitions for memcpy(), ntohl() and htonl() */ |
10 | #include "../git-compat-util.h" | |
d7c208a9 LT |
11 | |
12 | #include "sha1.h" | |
13 | ||
e9c5dcd1 | 14 | #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) |
b8e48a89 | 15 | |
dc52fd29 NP |
16 | /* |
17 | * Force usage of rol or ror by selecting the one with the smaller constant. | |
18 | * It _can_ generate slightly smaller code (a constant of 1 is special), but | |
19 | * perhaps more importantly it's possibly faster on any uarch that does a | |
20 | * rotate with a loop. | |
21 | */ | |
22 | ||
fd536d34 | 23 | #define SHA_ASM(op, x, n) ({ unsigned int __res; __asm__(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; }) |
b8e48a89 LT |
24 | #define SHA_ROL(x,n) SHA_ASM("rol", x, n) |
25 | #define SHA_ROR(x,n) SHA_ASM("ror", x, n) | |
26 | ||
27 | #else | |
28 | ||
fd536d34 | 29 | #define SHA_ROT(X,l,r) (((X) << (l)) | ((X) >> (r))) |
b8e48a89 LT |
30 | #define SHA_ROL(X,n) SHA_ROT(X,n,32-(n)) |
31 | #define SHA_ROR(X,n) SHA_ROT(X,32-(n),n) | |
32 | ||
33 | #endif | |
d7c208a9 | 34 | |
926172c5 LT |
35 | /* |
36 | * If you have 32 registers or more, the compiler can (and should) | |
37 | * try to change the array[] accesses into registers. However, on | |
38 | * machines with less than ~25 registers, that won't really work, | |
39 | * and at least gcc will make an unholy mess of it. | |
40 | * | |
41 | * So to avoid that mess which just slows things down, we force | |
42 | * the stores to memory to actually happen (we might be better off | |
43 | * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as | |
44 | * suggested by Artur Skawina - that will also make gcc unable to | |
45 | * try to do the silly "optimize away loads" part because it won't | |
46 | * see what the value will be). | |
47 | * | |
48 | * Ben Herrenschmidt reports that on PPC, the C version comes close | |
49 | * to the optimized asm with this (ie on PPC you don't want that | |
50 | * 'volatile', since there are lots of registers). | |
dc52fd29 NP |
51 | * |
52 | * On ARM we get the best code generation by forcing a full memory barrier | |
53 | * between each SHA_ROUND, otherwise gcc happily get wild with spilling and | |
54 | * the stack frame size simply explode and performance goes down the drain. | |
926172c5 | 55 | */ |
dc52fd29 NP |
56 | |
57 | #if defined(__i386__) || defined(__x86_64__) | |
926172c5 | 58 | #define setW(x, val) (*(volatile unsigned int *)&W(x) = (val)) |
e9c5dcd1 | 59 | #elif defined(__GNUC__) && defined(__arm__) |
dc52fd29 | 60 | #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0) |
926172c5 LT |
61 | #else |
62 | #define setW(x, val) (W(x) = (val)) | |
63 | #endif | |
ab14c823 | 64 | |
dc52fd29 NP |
65 | /* This "rolls" over the 512-bit array */ |
66 | #define W(x) (array[(x)&15]) | |
67 | ||
ab14c823 LT |
68 | /* |
69 | * Where do we get the source from? The first 16 iterations get it from | |
70 | * the input data, the next mix it from the 512-bit array. | |
71 | */ | |
23119ffb JN |
72 | #define SHA_SRC(t) get_be32((unsigned char *) block + (t)*4) |
73 | #define SHA_MIX(t) SHA_ROL(W((t)+13) ^ W((t)+8) ^ W((t)+2) ^ W(t), 1); | |
ab14c823 | 74 | |
30d12d4c | 75 | #define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \ |
66c9c6c0 LT |
76 | unsigned int TEMP = input(t); setW(t, TEMP); \ |
77 | E += TEMP + SHA_ROL(A,5) + (fn) + (constant); \ | |
78 | B = SHA_ROR(B, 2); } while (0) | |
ab14c823 | 79 | |
30d12d4c LT |
80 | #define T_0_15(t, A, B, C, D, E) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) |
81 | #define T_16_19(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) | |
82 | #define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E ) | |
83 | #define T_40_59(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc, A, B, C, D, E ) | |
84 | #define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E ) | |
ab14c823 | 85 | |
5f6a1125 | 86 | static void blk_SHA1_Block(blk_SHA_CTX *ctx, const void *block) |
d7c208a9 | 87 | { |
30d12d4c | 88 | unsigned int A,B,C,D,E; |
7b5075fc | 89 | unsigned int array[16]; |
d7c208a9 | 90 | |
d7c208a9 LT |
91 | A = ctx->H[0]; |
92 | B = ctx->H[1]; | |
93 | C = ctx->H[2]; | |
94 | D = ctx->H[3]; | |
95 | E = ctx->H[4]; | |
96 | ||
5f6a1125 | 97 | /* Round 1 - iterations 0-16 take their input from 'block' */ |
30d12d4c LT |
98 | T_0_15( 0, A, B, C, D, E); |
99 | T_0_15( 1, E, A, B, C, D); | |
100 | T_0_15( 2, D, E, A, B, C); | |
101 | T_0_15( 3, C, D, E, A, B); | |
102 | T_0_15( 4, B, C, D, E, A); | |
103 | T_0_15( 5, A, B, C, D, E); | |
104 | T_0_15( 6, E, A, B, C, D); | |
105 | T_0_15( 7, D, E, A, B, C); | |
106 | T_0_15( 8, C, D, E, A, B); | |
107 | T_0_15( 9, B, C, D, E, A); | |
108 | T_0_15(10, A, B, C, D, E); | |
109 | T_0_15(11, E, A, B, C, D); | |
110 | T_0_15(12, D, E, A, B, C); | |
111 | T_0_15(13, C, D, E, A, B); | |
112 | T_0_15(14, B, C, D, E, A); | |
113 | T_0_15(15, A, B, C, D, E); | |
139e3456 | 114 | |
ab14c823 | 115 | /* Round 1 - tail. Input from 512-bit mixing array */ |
30d12d4c LT |
116 | T_16_19(16, E, A, B, C, D); |
117 | T_16_19(17, D, E, A, B, C); | |
118 | T_16_19(18, C, D, E, A, B); | |
119 | T_16_19(19, B, C, D, E, A); | |
d7c208a9 | 120 | |
ab14c823 | 121 | /* Round 2 */ |
30d12d4c LT |
122 | T_20_39(20, A, B, C, D, E); |
123 | T_20_39(21, E, A, B, C, D); | |
124 | T_20_39(22, D, E, A, B, C); | |
125 | T_20_39(23, C, D, E, A, B); | |
126 | T_20_39(24, B, C, D, E, A); | |
127 | T_20_39(25, A, B, C, D, E); | |
128 | T_20_39(26, E, A, B, C, D); | |
129 | T_20_39(27, D, E, A, B, C); | |
130 | T_20_39(28, C, D, E, A, B); | |
131 | T_20_39(29, B, C, D, E, A); | |
132 | T_20_39(30, A, B, C, D, E); | |
133 | T_20_39(31, E, A, B, C, D); | |
134 | T_20_39(32, D, E, A, B, C); | |
135 | T_20_39(33, C, D, E, A, B); | |
136 | T_20_39(34, B, C, D, E, A); | |
137 | T_20_39(35, A, B, C, D, E); | |
138 | T_20_39(36, E, A, B, C, D); | |
139 | T_20_39(37, D, E, A, B, C); | |
140 | T_20_39(38, C, D, E, A, B); | |
141 | T_20_39(39, B, C, D, E, A); | |
d7c208a9 | 142 | |
ab14c823 | 143 | /* Round 3 */ |
30d12d4c LT |
144 | T_40_59(40, A, B, C, D, E); |
145 | T_40_59(41, E, A, B, C, D); | |
146 | T_40_59(42, D, E, A, B, C); | |
147 | T_40_59(43, C, D, E, A, B); | |
148 | T_40_59(44, B, C, D, E, A); | |
149 | T_40_59(45, A, B, C, D, E); | |
150 | T_40_59(46, E, A, B, C, D); | |
151 | T_40_59(47, D, E, A, B, C); | |
152 | T_40_59(48, C, D, E, A, B); | |
153 | T_40_59(49, B, C, D, E, A); | |
154 | T_40_59(50, A, B, C, D, E); | |
155 | T_40_59(51, E, A, B, C, D); | |
156 | T_40_59(52, D, E, A, B, C); | |
157 | T_40_59(53, C, D, E, A, B); | |
158 | T_40_59(54, B, C, D, E, A); | |
159 | T_40_59(55, A, B, C, D, E); | |
160 | T_40_59(56, E, A, B, C, D); | |
161 | T_40_59(57, D, E, A, B, C); | |
162 | T_40_59(58, C, D, E, A, B); | |
163 | T_40_59(59, B, C, D, E, A); | |
d7c208a9 | 164 | |
ab14c823 | 165 | /* Round 4 */ |
30d12d4c LT |
166 | T_60_79(60, A, B, C, D, E); |
167 | T_60_79(61, E, A, B, C, D); | |
168 | T_60_79(62, D, E, A, B, C); | |
169 | T_60_79(63, C, D, E, A, B); | |
170 | T_60_79(64, B, C, D, E, A); | |
171 | T_60_79(65, A, B, C, D, E); | |
172 | T_60_79(66, E, A, B, C, D); | |
173 | T_60_79(67, D, E, A, B, C); | |
174 | T_60_79(68, C, D, E, A, B); | |
175 | T_60_79(69, B, C, D, E, A); | |
176 | T_60_79(70, A, B, C, D, E); | |
177 | T_60_79(71, E, A, B, C, D); | |
178 | T_60_79(72, D, E, A, B, C); | |
179 | T_60_79(73, C, D, E, A, B); | |
180 | T_60_79(74, B, C, D, E, A); | |
181 | T_60_79(75, A, B, C, D, E); | |
182 | T_60_79(76, E, A, B, C, D); | |
183 | T_60_79(77, D, E, A, B, C); | |
184 | T_60_79(78, C, D, E, A, B); | |
185 | T_60_79(79, B, C, D, E, A); | |
d7c208a9 LT |
186 | |
187 | ctx->H[0] += A; | |
188 | ctx->H[1] += B; | |
189 | ctx->H[2] += C; | |
190 | ctx->H[3] += D; | |
191 | ctx->H[4] += E; | |
192 | } | |
30ba0de7 NP |
193 | |
194 | void blk_SHA1_Init(blk_SHA_CTX *ctx) | |
195 | { | |
196 | ctx->size = 0; | |
197 | ||
198 | /* Initialize H with the magic constants (see FIPS180 for constants) */ | |
199 | ctx->H[0] = 0x67452301; | |
200 | ctx->H[1] = 0xefcdab89; | |
201 | ctx->H[2] = 0x98badcfe; | |
202 | ctx->H[3] = 0x10325476; | |
203 | ctx->H[4] = 0xc3d2e1f0; | |
204 | } | |
205 | ||
206 | void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len) | |
207 | { | |
9eafa120 | 208 | unsigned int lenW = ctx->size & 63; |
30ba0de7 NP |
209 | |
210 | ctx->size += len; | |
211 | ||
212 | /* Read the data into W and process blocks as they get full */ | |
213 | if (lenW) { | |
9eafa120 | 214 | unsigned int left = 64 - lenW; |
30ba0de7 NP |
215 | if (len < left) |
216 | left = len; | |
217 | memcpy(lenW + (char *)ctx->W, data, left); | |
218 | lenW = (lenW + left) & 63; | |
219 | len -= left; | |
a1221857 | 220 | data = ((const char *)data + left); |
30ba0de7 NP |
221 | if (lenW) |
222 | return; | |
223 | blk_SHA1_Block(ctx, ctx->W); | |
224 | } | |
225 | while (len >= 64) { | |
226 | blk_SHA1_Block(ctx, data); | |
a1221857 | 227 | data = ((const char *)data + 64); |
30ba0de7 NP |
228 | len -= 64; |
229 | } | |
230 | if (len) | |
231 | memcpy(ctx->W, data, len); | |
232 | } | |
233 | ||
234 | void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx) | |
235 | { | |
236 | static const unsigned char pad[64] = { 0x80 }; | |
237 | unsigned int padlen[2]; | |
238 | int i; | |
239 | ||
240 | /* Pad with a binary 1 (ie 0x80), then zeroes, then length */ | |
9eafa120 RJ |
241 | padlen[0] = htonl((uint32_t)(ctx->size >> 29)); |
242 | padlen[1] = htonl((uint32_t)(ctx->size << 3)); | |
30ba0de7 NP |
243 | |
244 | i = ctx->size & 63; | |
6b2dd0e5 | 245 | blk_SHA1_Update(ctx, pad, 1 + (63 & (55 - i))); |
30ba0de7 NP |
246 | blk_SHA1_Update(ctx, padlen, 8); |
247 | ||
248 | /* Output hash */ | |
249 | for (i = 0; i < 5; i++) | |
6b2dd0e5 | 250 | put_be32(hashout + i * 4, ctx->H[i]); |
30ba0de7 | 251 | } |