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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
1eb19a12 MSB |
3 | * SHA1 routine optimized to do word accesses rather than byte accesses, |
4 | * and to avoid unnecessary copies into the context array. | |
5 | * | |
6 | * This was based on the git SHA1 implementation. | |
1da177e4 LT |
7 | */ |
8 | ||
9 | #include <linux/kernel.h> | |
8bc3bcc9 | 10 | #include <linux/export.h> |
1eb19a12 | 11 | #include <linux/bitops.h> |
a24d22b2 | 12 | #include <crypto/sha1.h> |
1eb19a12 | 13 | #include <asm/unaligned.h> |
1da177e4 | 14 | |
1eb19a12 MSB |
15 | /* |
16 | * If you have 32 registers or more, the compiler can (and should) | |
17 | * try to change the array[] accesses into registers. However, on | |
18 | * machines with less than ~25 registers, that won't really work, | |
19 | * and at least gcc will make an unholy mess of it. | |
20 | * | |
21 | * So to avoid that mess which just slows things down, we force | |
22 | * the stores to memory to actually happen (we might be better off | |
23 | * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as | |
24 | * suggested by Artur Skawina - that will also make gcc unable to | |
25 | * try to do the silly "optimize away loads" part because it won't | |
26 | * see what the value will be). | |
27 | * | |
28 | * Ben Herrenschmidt reports that on PPC, the C version comes close | |
29 | * to the optimized asm with this (ie on PPC you don't want that | |
30 | * 'volatile', since there are lots of registers). | |
31 | * | |
32 | * On ARM we get the best code generation by forcing a full memory barrier | |
33 | * between each SHA_ROUND, otherwise gcc happily get wild with spilling and | |
34 | * the stack frame size simply explode and performance goes down the drain. | |
35 | */ | |
1da177e4 | 36 | |
1eb19a12 MSB |
37 | #ifdef CONFIG_X86 |
38 | #define setW(x, val) (*(volatile __u32 *)&W(x) = (val)) | |
39 | #elif defined(CONFIG_ARM) | |
40 | #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0) | |
41 | #else | |
42 | #define setW(x, val) (W(x) = (val)) | |
43 | #endif | |
1da177e4 | 44 | |
1eb19a12 MSB |
45 | /* This "rolls" over the 512-bit array */ |
46 | #define W(x) (array[(x)&15]) | |
1da177e4 | 47 | |
1eb19a12 MSB |
48 | /* |
49 | * Where do we get the source from? The first 16 iterations get it from | |
50 | * the input data, the next mix it from the 512-bit array. | |
51 | */ | |
52 | #define SHA_SRC(t) get_unaligned_be32((__u32 *)data + t) | |
53 | #define SHA_MIX(t) rol32(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1) | |
54 | ||
55 | #define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \ | |
56 | __u32 TEMP = input(t); setW(t, TEMP); \ | |
57 | E += TEMP + rol32(A,5) + (fn) + (constant); \ | |
58 | B = ror32(B, 2); } while (0) | |
59 | ||
60 | #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 ) | |
61 | #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 ) | |
62 | #define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E ) | |
63 | #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 ) | |
64 | #define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E ) | |
1da177e4 | 65 | |
72fd4a35 | 66 | /** |
6b0b0fa2 | 67 | * sha1_transform - single block SHA1 transform (deprecated) |
1da177e4 LT |
68 | * |
69 | * @digest: 160 bit digest to update | |
70 | * @data: 512 bits of data to hash | |
1eb19a12 | 71 | * @array: 16 words of workspace (see note) |
1da177e4 | 72 | * |
6b0b0fa2 EB |
73 | * This function executes SHA-1's internal compression function. It updates the |
74 | * 160-bit internal state (@digest) with a single 512-bit data block (@data). | |
75 | * | |
76 | * Don't use this function. SHA-1 is no longer considered secure. And even if | |
77 | * you do have to use SHA-1, this isn't the correct way to hash something with | |
78 | * SHA-1 as this doesn't handle padding and finalization. | |
1da177e4 LT |
79 | * |
80 | * Note: If the hash is security sensitive, the caller should be sure | |
81 | * to clear the workspace. This is left to the caller to avoid | |
82 | * unnecessary clears between chained hashing operations. | |
83 | */ | |
6b0b0fa2 | 84 | void sha1_transform(__u32 *digest, const char *data, __u32 *array) |
1da177e4 | 85 | { |
1eb19a12 MSB |
86 | __u32 A, B, C, D, E; |
87 | ||
88 | A = digest[0]; | |
89 | B = digest[1]; | |
90 | C = digest[2]; | |
91 | D = digest[3]; | |
92 | E = digest[4]; | |
93 | ||
94 | /* Round 1 - iterations 0-16 take their input from 'data' */ | |
95 | T_0_15( 0, A, B, C, D, E); | |
96 | T_0_15( 1, E, A, B, C, D); | |
97 | T_0_15( 2, D, E, A, B, C); | |
98 | T_0_15( 3, C, D, E, A, B); | |
99 | T_0_15( 4, B, C, D, E, A); | |
100 | T_0_15( 5, A, B, C, D, E); | |
101 | T_0_15( 6, E, A, B, C, D); | |
102 | T_0_15( 7, D, E, A, B, C); | |
103 | T_0_15( 8, C, D, E, A, B); | |
104 | T_0_15( 9, B, C, D, E, A); | |
105 | T_0_15(10, A, B, C, D, E); | |
106 | T_0_15(11, E, A, B, C, D); | |
107 | T_0_15(12, D, E, A, B, C); | |
108 | T_0_15(13, C, D, E, A, B); | |
109 | T_0_15(14, B, C, D, E, A); | |
110 | T_0_15(15, A, B, C, D, E); | |
111 | ||
112 | /* Round 1 - tail. Input from 512-bit mixing array */ | |
113 | T_16_19(16, E, A, B, C, D); | |
114 | T_16_19(17, D, E, A, B, C); | |
115 | T_16_19(18, C, D, E, A, B); | |
116 | T_16_19(19, B, C, D, E, A); | |
117 | ||
118 | /* Round 2 */ | |
119 | T_20_39(20, A, B, C, D, E); | |
120 | T_20_39(21, E, A, B, C, D); | |
121 | T_20_39(22, D, E, A, B, C); | |
122 | T_20_39(23, C, D, E, A, B); | |
123 | T_20_39(24, B, C, D, E, A); | |
124 | T_20_39(25, A, B, C, D, E); | |
125 | T_20_39(26, E, A, B, C, D); | |
126 | T_20_39(27, D, E, A, B, C); | |
127 | T_20_39(28, C, D, E, A, B); | |
128 | T_20_39(29, B, C, D, E, A); | |
129 | T_20_39(30, A, B, C, D, E); | |
130 | T_20_39(31, E, A, B, C, D); | |
131 | T_20_39(32, D, E, A, B, C); | |
132 | T_20_39(33, C, D, E, A, B); | |
133 | T_20_39(34, B, C, D, E, A); | |
134 | T_20_39(35, A, B, C, D, E); | |
135 | T_20_39(36, E, A, B, C, D); | |
136 | T_20_39(37, D, E, A, B, C); | |
137 | T_20_39(38, C, D, E, A, B); | |
138 | T_20_39(39, B, C, D, E, A); | |
139 | ||
140 | /* Round 3 */ | |
141 | T_40_59(40, A, B, C, D, E); | |
142 | T_40_59(41, E, A, B, C, D); | |
143 | T_40_59(42, D, E, A, B, C); | |
144 | T_40_59(43, C, D, E, A, B); | |
145 | T_40_59(44, B, C, D, E, A); | |
146 | T_40_59(45, A, B, C, D, E); | |
147 | T_40_59(46, E, A, B, C, D); | |
148 | T_40_59(47, D, E, A, B, C); | |
149 | T_40_59(48, C, D, E, A, B); | |
150 | T_40_59(49, B, C, D, E, A); | |
151 | T_40_59(50, A, B, C, D, E); | |
152 | T_40_59(51, E, A, B, C, D); | |
153 | T_40_59(52, D, E, A, B, C); | |
154 | T_40_59(53, C, D, E, A, B); | |
155 | T_40_59(54, B, C, D, E, A); | |
156 | T_40_59(55, A, B, C, D, E); | |
157 | T_40_59(56, E, A, B, C, D); | |
158 | T_40_59(57, D, E, A, B, C); | |
159 | T_40_59(58, C, D, E, A, B); | |
160 | T_40_59(59, B, C, D, E, A); | |
161 | ||
162 | /* Round 4 */ | |
163 | T_60_79(60, A, B, C, D, E); | |
164 | T_60_79(61, E, A, B, C, D); | |
165 | T_60_79(62, D, E, A, B, C); | |
166 | T_60_79(63, C, D, E, A, B); | |
167 | T_60_79(64, B, C, D, E, A); | |
168 | T_60_79(65, A, B, C, D, E); | |
169 | T_60_79(66, E, A, B, C, D); | |
170 | T_60_79(67, D, E, A, B, C); | |
171 | T_60_79(68, C, D, E, A, B); | |
172 | T_60_79(69, B, C, D, E, A); | |
173 | T_60_79(70, A, B, C, D, E); | |
174 | T_60_79(71, E, A, B, C, D); | |
175 | T_60_79(72, D, E, A, B, C); | |
176 | T_60_79(73, C, D, E, A, B); | |
177 | T_60_79(74, B, C, D, E, A); | |
178 | T_60_79(75, A, B, C, D, E); | |
179 | T_60_79(76, E, A, B, C, D); | |
180 | T_60_79(77, D, E, A, B, C); | |
181 | T_60_79(78, C, D, E, A, B); | |
182 | T_60_79(79, B, C, D, E, A); | |
183 | ||
184 | digest[0] += A; | |
185 | digest[1] += B; | |
186 | digest[2] += C; | |
187 | digest[3] += D; | |
188 | digest[4] += E; | |
1da177e4 | 189 | } |
6b0b0fa2 | 190 | EXPORT_SYMBOL(sha1_transform); |
1da177e4 | 191 | |
72fd4a35 | 192 | /** |
6b0b0fa2 | 193 | * sha1_init - initialize the vectors for a SHA1 digest |
1da177e4 LT |
194 | * @buf: vector to initialize |
195 | */ | |
6b0b0fa2 | 196 | void sha1_init(__u32 *buf) |
1da177e4 LT |
197 | { |
198 | buf[0] = 0x67452301; | |
199 | buf[1] = 0xefcdab89; | |
200 | buf[2] = 0x98badcfe; | |
201 | buf[3] = 0x10325476; | |
202 | buf[4] = 0xc3d2e1f0; | |
203 | } | |
6b0b0fa2 | 204 | EXPORT_SYMBOL(sha1_init); |