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 <linux/bitops.h>
15 #include <linux/export.h>
16 #include <linux/module.h>
17 #include <linux/string.h>
18 #include <crypto/sha2.h>
19 #include <asm/unaligned.h>
20
21 static const u32 SHA256_K[] = {
22 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
23 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
24 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
25 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
26 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
27 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
28 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
29 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
30 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
31 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
32 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
33 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
34 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
35 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
36 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
37 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
38 };
39
Ch(u32 x,u32 y,u32 z)40 static inline u32 Ch(u32 x, u32 y, u32 z)
41 {
42 return z ^ (x & (y ^ z));
43 }
44
Maj(u32 x,u32 y,u32 z)45 static inline u32 Maj(u32 x, u32 y, u32 z)
46 {
47 return (x & y) | (z & (x | y));
48 }
49
50 #define e0(x) (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22))
51 #define e1(x) (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25))
52 #define s0(x) (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3))
53 #define s1(x) (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10))
54
LOAD_OP(int I,u32 * W,const u8 * input)55 static inline void LOAD_OP(int I, u32 *W, const u8 *input)
56 {
57 W[I] = get_unaligned_be32((__u32 *)input + I);
58 }
59
BLEND_OP(int I,u32 * W)60 static inline void BLEND_OP(int I, u32 *W)
61 {
62 W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
63 }
64
65 #define SHA256_ROUND(i, a, b, c, d, e, f, g, h) do { \
66 u32 t1, t2; \
67 t1 = h + e1(e) + Ch(e, f, g) + SHA256_K[i] + W[i]; \
68 t2 = e0(a) + Maj(a, b, c); \
69 d += t1; \
70 h = t1 + t2; \
71 } while (0)
72
sha256_transform(u32 * state,const u8 * input,u32 * W)73 static void sha256_transform(u32 *state, const u8 *input, u32 *W)
74 {
75 u32 a, b, c, d, e, f, g, h;
76 int i;
77
78 /* load the input */
79 for (i = 0; i < 16; i += 8) {
80 LOAD_OP(i + 0, W, input);
81 LOAD_OP(i + 1, W, input);
82 LOAD_OP(i + 2, W, input);
83 LOAD_OP(i + 3, W, input);
84 LOAD_OP(i + 4, W, input);
85 LOAD_OP(i + 5, W, input);
86 LOAD_OP(i + 6, W, input);
87 LOAD_OP(i + 7, W, input);
88 }
89
90 /* now blend */
91 for (i = 16; i < 64; i += 8) {
92 BLEND_OP(i + 0, W);
93 BLEND_OP(i + 1, W);
94 BLEND_OP(i + 2, W);
95 BLEND_OP(i + 3, W);
96 BLEND_OP(i + 4, W);
97 BLEND_OP(i + 5, W);
98 BLEND_OP(i + 6, W);
99 BLEND_OP(i + 7, W);
100 }
101
102 /* load the state into our registers */
103 a = state[0]; b = state[1]; c = state[2]; d = state[3];
104 e = state[4]; f = state[5]; g = state[6]; h = state[7];
105
106 /* now iterate */
107 for (i = 0; i < 64; i += 8) {
108 SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h);
109 SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g);
110 SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f);
111 SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e);
112 SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d);
113 SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c);
114 SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b);
115 SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a);
116 }
117
118 state[0] += a; state[1] += b; state[2] += c; state[3] += d;
119 state[4] += e; state[5] += f; state[6] += g; state[7] += h;
120 }
121
sha256_update(struct sha256_state * sctx,const u8 * data,unsigned int len)122 void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
123 {
124 unsigned int partial, done;
125 const u8 *src;
126 u32 W[64];
127
128 partial = sctx->count & 0x3f;
129 sctx->count += len;
130 done = 0;
131 src = data;
132
133 if ((partial + len) > 63) {
134 if (partial) {
135 done = -partial;
136 memcpy(sctx->buf + partial, data, done + 64);
137 src = sctx->buf;
138 }
139
140 do {
141 sha256_transform(sctx->state, src, W);
142 done += 64;
143 src = data + done;
144 } while (done + 63 < len);
145
146 memzero_explicit(W, sizeof(W));
147
148 partial = 0;
149 }
150 memcpy(sctx->buf + partial, src, len - done);
151 }
152 EXPORT_SYMBOL(sha256_update);
153
sha224_update(struct sha256_state * sctx,const u8 * data,unsigned int len)154 void sha224_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
155 {
156 sha256_update(sctx, data, len);
157 }
158 EXPORT_SYMBOL(sha224_update);
159
__sha256_final(struct sha256_state * sctx,u8 * out,int digest_words)160 static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_words)
161 {
162 __be32 *dst = (__be32 *)out;
163 __be64 bits;
164 unsigned int index, pad_len;
165 int i;
166 static const u8 padding[64] = { 0x80, };
167
168 /* Save number of bits */
169 bits = cpu_to_be64(sctx->count << 3);
170
171 /* Pad out to 56 mod 64. */
172 index = sctx->count & 0x3f;
173 pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
174 sha256_update(sctx, padding, pad_len);
175
176 /* Append length (before padding) */
177 sha256_update(sctx, (const u8 *)&bits, sizeof(bits));
178
179 /* Store state in digest */
180 for (i = 0; i < digest_words; i++)
181 put_unaligned_be32(sctx->state[i], &dst[i]);
182
183 /* Zeroize sensitive information. */
184 memzero_explicit(sctx, sizeof(*sctx));
185 }
186
sha256_final(struct sha256_state * sctx,u8 * out)187 void sha256_final(struct sha256_state *sctx, u8 *out)
188 {
189 __sha256_final(sctx, out, 8);
190 }
191 EXPORT_SYMBOL(sha256_final);
192
sha224_final(struct sha256_state * sctx,u8 * out)193 void sha224_final(struct sha256_state *sctx, u8 *out)
194 {
195 __sha256_final(sctx, out, 7);
196 }
197 EXPORT_SYMBOL(sha224_final);
198
sha256(const u8 * data,unsigned int len,u8 * out)199 void sha256(const u8 *data, unsigned int len, u8 *out)
200 {
201 struct sha256_state sctx;
202
203 sha256_init(&sctx);
204 sha256_update(&sctx, data, len);
205 sha256_final(&sctx, out);
206 }
207 EXPORT_SYMBOL(sha256);
208
209 MODULE_LICENSE("GPL");
210