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
20static 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
39static inline u32 Ch(u32 x, u32 y, u32 z)
40{
41	return z ^ (x & (y ^ z));
42}
43
44static 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
54static inline void LOAD_OP(int I, u32 *W, const u8 *input)
55{
56	W[I] = get_unaligned_be32((__u32 *)input + I);
57}
58
59static 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
72static 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
121static 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
134void 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}
138EXPORT_SYMBOL(sha256_update);
139
140static 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
146void sha256_final(struct sha256_state *sctx, u8 *out)
147{
148	__sha256_final(sctx, out, 32);
149}
150EXPORT_SYMBOL(sha256_final);
151
152void sha224_final(struct sha256_state *sctx, u8 *out)
153{
154	__sha256_final(sctx, out, 28);
155}
156EXPORT_SYMBOL(sha224_final);
157
158void 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}
166EXPORT_SYMBOL(sha256);
167
168MODULE_LICENSE("GPL");
169