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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 | ||
fd536d34 | 14 | #define SHA_ROT(X,l,r) (((X) << (l)) | ((X) >> (r))) |
b8e48a89 LT |
15 | #define SHA_ROL(X,n) SHA_ROT(X,n,32-(n)) |
16 | #define SHA_ROR(X,n) SHA_ROT(X,32-(n),n) | |
17 | ||
926172c5 LT |
18 | /* |
19 | * If you have 32 registers or more, the compiler can (and should) | |
20 | * try to change the array[] accesses into registers. However, on | |
21 | * machines with less than ~25 registers, that won't really work, | |
22 | * and at least gcc will make an unholy mess of it. | |
23 | * | |
24 | * So to avoid that mess which just slows things down, we force | |
25 | * the stores to memory to actually happen (we might be better off | |
26 | * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as | |
27 | * suggested by Artur Skawina - that will also make gcc unable to | |
28 | * try to do the silly "optimize away loads" part because it won't | |
29 | * see what the value will be). | |
30 | * | |
31 | * Ben Herrenschmidt reports that on PPC, the C version comes close | |
32 | * to the optimized asm with this (ie on PPC you don't want that | |
33 | * 'volatile', since there are lots of registers). | |
dc52fd29 NP |
34 | * |
35 | * On ARM we get the best code generation by forcing a full memory barrier | |
36 | * between each SHA_ROUND, otherwise gcc happily get wild with spilling and | |
37 | * the stack frame size simply explode and performance goes down the drain. | |
926172c5 | 38 | */ |
dc52fd29 NP |
39 | |
40 | #if defined(__i386__) || defined(__x86_64__) | |
926172c5 | 41 | #define setW(x, val) (*(volatile unsigned int *)&W(x) = (val)) |
e9c5dcd1 | 42 | #elif defined(__GNUC__) && defined(__arm__) |
dc52fd29 | 43 | #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0) |
926172c5 LT |
44 | #else |
45 | #define setW(x, val) (W(x) = (val)) | |
46 | #endif | |
ab14c823 | 47 | |
dc52fd29 NP |
48 | /* This "rolls" over the 512-bit array */ |
49 | #define W(x) (array[(x)&15]) | |
50 | ||
ab14c823 LT |
51 | /* |
52 | * Where do we get the source from? The first 16 iterations get it from | |
53 | * the input data, the next mix it from the 512-bit array. | |
54 | */ | |
23119ffb | 55 | #define SHA_SRC(t) get_be32((unsigned char *) block + (t)*4) |
3d8cbbf2 | 56 | #define SHA_MIX(t) SHA_ROL(W((t)+13) ^ W((t)+8) ^ W((t)+2) ^ W(t), 1) |
ab14c823 | 57 | |
30d12d4c | 58 | #define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \ |
66c9c6c0 LT |
59 | unsigned int TEMP = input(t); setW(t, TEMP); \ |
60 | E += TEMP + SHA_ROL(A,5) + (fn) + (constant); \ | |
61 | B = SHA_ROR(B, 2); } while (0) | |
ab14c823 | 62 | |
30d12d4c LT |
63 | #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 ) |
64 | #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 ) | |
65 | #define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E ) | |
66 | #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 ) | |
67 | #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 | 68 | |
5f6a1125 | 69 | static void blk_SHA1_Block(blk_SHA_CTX *ctx, const void *block) |
d7c208a9 | 70 | { |
30d12d4c | 71 | unsigned int A,B,C,D,E; |
7b5075fc | 72 | unsigned int array[16]; |
d7c208a9 | 73 | |
d7c208a9 LT |
74 | A = ctx->H[0]; |
75 | B = ctx->H[1]; | |
76 | C = ctx->H[2]; | |
77 | D = ctx->H[3]; | |
78 | E = ctx->H[4]; | |
79 | ||
5f6a1125 | 80 | /* Round 1 - iterations 0-16 take their input from 'block' */ |
30d12d4c LT |
81 | T_0_15( 0, A, B, C, D, E); |
82 | T_0_15( 1, E, A, B, C, D); | |
83 | T_0_15( 2, D, E, A, B, C); | |
84 | T_0_15( 3, C, D, E, A, B); | |
85 | T_0_15( 4, B, C, D, E, A); | |
86 | T_0_15( 5, A, B, C, D, E); | |
87 | T_0_15( 6, E, A, B, C, D); | |
88 | T_0_15( 7, D, E, A, B, C); | |
89 | T_0_15( 8, C, D, E, A, B); | |
90 | T_0_15( 9, B, C, D, E, A); | |
91 | T_0_15(10, A, B, C, D, E); | |
92 | T_0_15(11, E, A, B, C, D); | |
93 | T_0_15(12, D, E, A, B, C); | |
94 | T_0_15(13, C, D, E, A, B); | |
95 | T_0_15(14, B, C, D, E, A); | |
96 | T_0_15(15, A, B, C, D, E); | |
139e3456 | 97 | |
ab14c823 | 98 | /* Round 1 - tail. Input from 512-bit mixing array */ |
30d12d4c LT |
99 | T_16_19(16, E, A, B, C, D); |
100 | T_16_19(17, D, E, A, B, C); | |
101 | T_16_19(18, C, D, E, A, B); | |
102 | T_16_19(19, B, C, D, E, A); | |
d7c208a9 | 103 | |
ab14c823 | 104 | /* Round 2 */ |
30d12d4c LT |
105 | T_20_39(20, A, B, C, D, E); |
106 | T_20_39(21, E, A, B, C, D); | |
107 | T_20_39(22, D, E, A, B, C); | |
108 | T_20_39(23, C, D, E, A, B); | |
109 | T_20_39(24, B, C, D, E, A); | |
110 | T_20_39(25, A, B, C, D, E); | |
111 | T_20_39(26, E, A, B, C, D); | |
112 | T_20_39(27, D, E, A, B, C); | |
113 | T_20_39(28, C, D, E, A, B); | |
114 | T_20_39(29, B, C, D, E, A); | |
115 | T_20_39(30, A, B, C, D, E); | |
116 | T_20_39(31, E, A, B, C, D); | |
117 | T_20_39(32, D, E, A, B, C); | |
118 | T_20_39(33, C, D, E, A, B); | |
119 | T_20_39(34, B, C, D, E, A); | |
120 | T_20_39(35, A, B, C, D, E); | |
121 | T_20_39(36, E, A, B, C, D); | |
122 | T_20_39(37, D, E, A, B, C); | |
123 | T_20_39(38, C, D, E, A, B); | |
124 | T_20_39(39, B, C, D, E, A); | |
d7c208a9 | 125 | |
ab14c823 | 126 | /* Round 3 */ |
30d12d4c LT |
127 | T_40_59(40, A, B, C, D, E); |
128 | T_40_59(41, E, A, B, C, D); | |
129 | T_40_59(42, D, E, A, B, C); | |
130 | T_40_59(43, C, D, E, A, B); | |
131 | T_40_59(44, B, C, D, E, A); | |
132 | T_40_59(45, A, B, C, D, E); | |
133 | T_40_59(46, E, A, B, C, D); | |
134 | T_40_59(47, D, E, A, B, C); | |
135 | T_40_59(48, C, D, E, A, B); | |
136 | T_40_59(49, B, C, D, E, A); | |
137 | T_40_59(50, A, B, C, D, E); | |
138 | T_40_59(51, E, A, B, C, D); | |
139 | T_40_59(52, D, E, A, B, C); | |
140 | T_40_59(53, C, D, E, A, B); | |
141 | T_40_59(54, B, C, D, E, A); | |
142 | T_40_59(55, A, B, C, D, E); | |
143 | T_40_59(56, E, A, B, C, D); | |
144 | T_40_59(57, D, E, A, B, C); | |
145 | T_40_59(58, C, D, E, A, B); | |
146 | T_40_59(59, B, C, D, E, A); | |
d7c208a9 | 147 | |
ab14c823 | 148 | /* Round 4 */ |
30d12d4c LT |
149 | T_60_79(60, A, B, C, D, E); |
150 | T_60_79(61, E, A, B, C, D); | |
151 | T_60_79(62, D, E, A, B, C); | |
152 | T_60_79(63, C, D, E, A, B); | |
153 | T_60_79(64, B, C, D, E, A); | |
154 | T_60_79(65, A, B, C, D, E); | |
155 | T_60_79(66, E, A, B, C, D); | |
156 | T_60_79(67, D, E, A, B, C); | |
157 | T_60_79(68, C, D, E, A, B); | |
158 | T_60_79(69, B, C, D, E, A); | |
159 | T_60_79(70, A, B, C, D, E); | |
160 | T_60_79(71, E, A, B, C, D); | |
161 | T_60_79(72, D, E, A, B, C); | |
162 | T_60_79(73, C, D, E, A, B); | |
163 | T_60_79(74, B, C, D, E, A); | |
164 | T_60_79(75, A, B, C, D, E); | |
165 | T_60_79(76, E, A, B, C, D); | |
166 | T_60_79(77, D, E, A, B, C); | |
167 | T_60_79(78, C, D, E, A, B); | |
168 | T_60_79(79, B, C, D, E, A); | |
d7c208a9 LT |
169 | |
170 | ctx->H[0] += A; | |
171 | ctx->H[1] += B; | |
172 | ctx->H[2] += C; | |
173 | ctx->H[3] += D; | |
174 | ctx->H[4] += E; | |
175 | } | |
30ba0de7 NP |
176 | |
177 | void blk_SHA1_Init(blk_SHA_CTX *ctx) | |
178 | { | |
179 | ctx->size = 0; | |
180 | ||
181 | /* Initialize H with the magic constants (see FIPS180 for constants) */ | |
182 | ctx->H[0] = 0x67452301; | |
183 | ctx->H[1] = 0xefcdab89; | |
184 | ctx->H[2] = 0x98badcfe; | |
185 | ctx->H[3] = 0x10325476; | |
186 | ctx->H[4] = 0xc3d2e1f0; | |
187 | } | |
188 | ||
9bb4542b | 189 | void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, size_t len) |
30ba0de7 | 190 | { |
9eafa120 | 191 | unsigned int lenW = ctx->size & 63; |
30ba0de7 NP |
192 | |
193 | ctx->size += len; | |
194 | ||
195 | /* Read the data into W and process blocks as they get full */ | |
196 | if (lenW) { | |
9eafa120 | 197 | unsigned int left = 64 - lenW; |
30ba0de7 NP |
198 | if (len < left) |
199 | left = len; | |
200 | memcpy(lenW + (char *)ctx->W, data, left); | |
201 | lenW = (lenW + left) & 63; | |
202 | len -= left; | |
a1221857 | 203 | data = ((const char *)data + left); |
30ba0de7 NP |
204 | if (lenW) |
205 | return; | |
206 | blk_SHA1_Block(ctx, ctx->W); | |
207 | } | |
208 | while (len >= 64) { | |
209 | blk_SHA1_Block(ctx, data); | |
a1221857 | 210 | data = ((const char *)data + 64); |
30ba0de7 NP |
211 | len -= 64; |
212 | } | |
213 | if (len) | |
214 | memcpy(ctx->W, data, len); | |
215 | } | |
216 | ||
217 | void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx) | |
218 | { | |
219 | static const unsigned char pad[64] = { 0x80 }; | |
220 | unsigned int padlen[2]; | |
221 | int i; | |
222 | ||
223 | /* Pad with a binary 1 (ie 0x80), then zeroes, then length */ | |
9eafa120 RJ |
224 | padlen[0] = htonl((uint32_t)(ctx->size >> 29)); |
225 | padlen[1] = htonl((uint32_t)(ctx->size << 3)); | |
30ba0de7 NP |
226 | |
227 | i = ctx->size & 63; | |
6b2dd0e5 | 228 | blk_SHA1_Update(ctx, pad, 1 + (63 & (55 - i))); |
30ba0de7 NP |
229 | blk_SHA1_Update(ctx, padlen, 8); |
230 | ||
231 | /* Output hash */ | |
232 | for (i = 0; i < 5; i++) | |
6b2dd0e5 | 233 | put_be32(hashout + i * 4, ctx->H[i]); |
30ba0de7 | 234 | } |