1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * SHA-256, as specified in
4 * http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf
5 *
6 * SHA-256 code by Jean-Luc Cooke <jlcooke@certainkey.com>.
7 *
8 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
9 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
10 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
11 * Copyright (c) 2014 Red Hat Inc.
12 */
13
14 #include <asm/unaligned.h>
15 #include <crypto/sha256_base.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/string.h>
19
20 static const u32 SHA256_K[] = {
21 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
22 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
23 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
24 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
25 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
26 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
27 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
28 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
29 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
30 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
31 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
32 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
33 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
34 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
35 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
36 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
37 };
38
39 static inline u32 Ch(u32 x, u32 y, u32 z)
40 {
41 return z ^ (x & (y ^ z));
42 }
43
44 static inline u32 Maj(u32 x, u32 y, u32 z)
45 {
46 return (x & y) | (z & (x | y));
47 }
48
49 #define e0(x) (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22))
50 #define e1(x) (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25))
51 #define s0(x) (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3))
52 #define s1(x) (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10))
53
54 static inline void LOAD_OP(int I, u32 *W, const u8 *input)
55 {
56 W[I] = get_unaligned_be32((__u32 *)input + I);
57 }
58
59 static inline void BLEND_OP(int I, u32 *W)
60 {
61 W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
62 }
63
64 #define SHA256_ROUND(i, a, b, c, d, e, f, g, h) do { \
65 u32 t1, t2; \
66 t1 = h + e1(e) + Ch(e, f, g) + SHA256_K[i] + W[i]; \
67 t2 = e0(a) + Maj(a, b, c); \
68 d += t1; \
69 h = t1 + t2; \
70 } while (0)
71
72 static void sha256_transform(u32 *state, const u8 *input, u32 *W)
73 {
74 u32 a, b, c, d, e, f, g, h;
75 int i;
76
77 /* load the input */
78 for (i = 0; i < 16; i += 8) {
79 LOAD_OP(i + 0, W, input);
80 LOAD_OP(i + 1, W, input);
81 LOAD_OP(i + 2, W, input);
82 LOAD_OP(i + 3, W, input);
83 LOAD_OP(i + 4, W, input);
84 LOAD_OP(i + 5, W, input);
85 LOAD_OP(i + 6, W, input);
86 LOAD_OP(i + 7, W, input);
87 }
88
89 /* now blend */
90 for (i = 16; i < 64; i += 8) {
91 BLEND_OP(i + 0, W);
92 BLEND_OP(i + 1, W);
93 BLEND_OP(i + 2, W);
94 BLEND_OP(i + 3, W);
95 BLEND_OP(i + 4, W);
96 BLEND_OP(i + 5, W);
97 BLEND_OP(i + 6, W);
98 BLEND_OP(i + 7, W);
99 }
100
101 /* load the state into our registers */
102 a = state[0]; b = state[1]; c = state[2]; d = state[3];
103 e = state[4]; f = state[5]; g = state[6]; h = state[7];
104
105 /* now iterate */
106 for (i = 0; i < 64; i += 8) {
107 SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h);
108 SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g);
109 SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f);
110 SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e);
111 SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d);
112 SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c);
113 SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b);
114 SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a);
115 }
116
117 state[0] += a; state[1] += b; state[2] += c; state[3] += d;
118 state[4] += e; state[5] += f; state[6] += g; state[7] += h;
119 }
120
121 static void sha256_transform_blocks(struct sha256_state *sctx,
122 const u8 *input, int blocks)
123 {
124 u32 W[64];
125
126 do {
127 sha256_transform(sctx->state, input, W);
128 input += SHA256_BLOCK_SIZE;
129 } while (--blocks);
130
131 memzero_explicit(W, sizeof(W));
132 }
133
134 void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
135 {
136 lib_sha256_base_do_update(sctx, data, len, sha256_transform_blocks);
137 }
138 EXPORT_SYMBOL(sha256_update);
139
140 static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_size)
141 {
142 lib_sha256_base_do_finalize(sctx, sha256_transform_blocks);
143 lib_sha256_base_finish(sctx, out, digest_size);
144 }
145
146 void sha256_final(struct sha256_state *sctx, u8 *out)
147 {
148 __sha256_final(sctx, out, 32);
149 }
150 EXPORT_SYMBOL(sha256_final);
151
152 void sha224_final(struct sha256_state *sctx, u8 *out)
153 {
154 __sha256_final(sctx, out, 28);
155 }
156 EXPORT_SYMBOL(sha224_final);
157
158 void sha256(const u8 *data, unsigned int len, u8 *out)
159 {
160 struct sha256_state sctx;
161
162 sha256_init(&sctx);
163 sha256_update(&sctx, data, len);
164 sha256_final(&sctx, out);
165 }
166 EXPORT_SYMBOL(sha256);
167
168 MODULE_DESCRIPTION("SHA-256 Algorithm");
169 MODULE_LICENSE("GPL");
170
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