1 /*
2 * Local implement of sha256.
3 *
4 * Copyright (C) 2013 Allwinner.
5 *
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
9 */
10 #include <linux/kernel.h>
11 #include <linux/string.h>
12
13 /****************************** MACROS ******************************/
14 #define ROTRIGHT(a, b) (((a) >> (b)) | ((a) << (32 - (b))))
15 #define CH(x, y, z) (((x) & (y)) ^ (~(x) & (z)))
16 #define MAJ(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
17 #define EP0(x) (ROTRIGHT(x, 2) ^ ROTRIGHT(x, 13) ^ ROTRIGHT(x, 22))
18 #define EP1(x) (ROTRIGHT(x, 6) ^ ROTRIGHT(x, 11) ^ ROTRIGHT(x, 25))
19 #define SIG0(x) (ROTRIGHT(x, 7) ^ ROTRIGHT(x, 18) ^ ((x) >> 3))
20 #define SIG1(x) (ROTRIGHT(x, 17) ^ ROTRIGHT(x, 19) ^ ((x) >> 10))
21
22 /**************************** VARIABLES *****************************/
23 static const uint32_t k[64] = {
24 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
25 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
26 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
27 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
28 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
29 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
30 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
31 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
32 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
33 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
34 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
35 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
36 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
37 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
38 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
39 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
40 };
41
42 struct sha256_ctx {
43 uint8_t data[64]; /* current 512-bit chunk of message data, just like a buffer */
44 uint32_t datalen; /* sign the data length of current chunk */
45 uint64_t bitlen; /* the bit length of the total message */
46 uint32_t state[8]; /* store the middle state of hash abstract */
47 };
48
49 /*********************** FUNCTION DEFINITIONS ***********************/
sha256_transform(struct sha256_ctx * ctx,const uint8_t * data)50 static void sha256_transform(struct sha256_ctx *ctx, const uint8_t *data)
51 {
52 uint32_t a, b, c, d, e, f, g, h, i, j, t1, t2, m[64];
53
54 /* initialization */
55 for (i = 0, j = 0; i < 16; ++i, j += 4)
56 m[i] = (data[j] << 24) | (data[j + 1] << 16) |
57 (data[j + 2] << 8) | (data[j + 3]);
58 for ( ; i < 64; ++i)
59 m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
60
61 a = ctx->state[0];
62 b = ctx->state[1];
63 c = ctx->state[2];
64 d = ctx->state[3];
65 e = ctx->state[4];
66 f = ctx->state[5];
67 g = ctx->state[6];
68 h = ctx->state[7];
69
70 for (i = 0; i < 64; ++i) {
71 t1 = h + EP1(e) + CH(e, f, g) + k[i] + m[i];
72 t2 = EP0(a) + MAJ(a, b, c);
73 h = g;
74 g = f;
75 f = e;
76 e = d + t1;
77 d = c;
78 c = b;
79 b = a;
80 a = t1 + t2;
81 }
82
83 ctx->state[0] += a;
84 ctx->state[1] += b;
85 ctx->state[2] += c;
86 ctx->state[3] += d;
87 ctx->state[4] += e;
88 ctx->state[5] += f;
89 ctx->state[6] += g;
90 ctx->state[7] += h;
91 }
92
sha256_init(struct sha256_ctx * ctx)93 static void sha256_init(struct sha256_ctx *ctx)
94 {
95 ctx->datalen = 0;
96 ctx->bitlen = 0;
97 ctx->state[0] = 0x6a09e667;
98 ctx->state[1] = 0xbb67ae85;
99 ctx->state[2] = 0x3c6ef372;
100 ctx->state[3] = 0xa54ff53a;
101 ctx->state[4] = 0x510e527f;
102 ctx->state[5] = 0x9b05688c;
103 ctx->state[6] = 0x1f83d9ab;
104 ctx->state[7] = 0x5be0cd19;
105 }
106
sha256_update(struct sha256_ctx * ctx,const uint8_t * data,size_t len)107 static void sha256_update(struct sha256_ctx *ctx, const uint8_t *data, size_t len)
108 {
109 uint32_t i;
110
111 for (i = 0; i < len; ++i) {
112 ctx->data[ctx->datalen] = data[i];
113 ctx->datalen++;
114 if (ctx->datalen == 64) {
115 /* 64 byte = 512 bit means the buffer ctx->data has
116 * fully stored one chunk of message,
117 * so do the sha256 hash map for the current chunk.
118 */
119 sha256_transform(ctx, ctx->data);
120 ctx->bitlen += 512;
121 ctx->datalen = 0;
122 }
123 }
124 }
125
sha256_final(struct sha256_ctx * ctx,uint8_t * hash)126 static void sha256_final(struct sha256_ctx *ctx, uint8_t *hash)
127 {
128 uint32_t i;
129
130 i = ctx->datalen;
131
132 /* Pad whatever data is left in the buffer. */
133 if (ctx->datalen < 56) {
134 ctx->data[i++] = 0x80; /* pad 10000000 = 0x80 */
135 while (i < 56)
136 ctx->data[i++] = 0x00;
137 } else {
138 ctx->data[i++] = 0x80;
139 while (i < 64)
140 ctx->data[i++] = 0x00;
141 sha256_transform(ctx, ctx->data);
142 memset(ctx->data, 0, 56);
143 }
144
145 /* Append to the padding the total message's length in bits and transform. */
146 ctx->bitlen += ctx->datalen * 8;
147 ctx->data[63] = ctx->bitlen;
148 ctx->data[62] = ctx->bitlen >> 8;
149 ctx->data[61] = ctx->bitlen >> 16;
150 ctx->data[60] = ctx->bitlen >> 24;
151 ctx->data[59] = ctx->bitlen >> 32;
152 ctx->data[58] = ctx->bitlen >> 40;
153 ctx->data[57] = ctx->bitlen >> 48;
154 ctx->data[56] = ctx->bitlen >> 56;
155 sha256_transform(ctx, ctx->data);
156
157 /* copying the final state to the output hash(use big endian). */
158 for (i = 0; i < 4; ++i) {
159 hash[i] = (ctx->state[0] >> (24 - i * 8)) & 0x000000ff;
160 hash[i + 4] = (ctx->state[1] >> (24 - i * 8)) & 0x000000ff;
161 hash[i + 8] = (ctx->state[2] >> (24 - i * 8)) & 0x000000ff;
162 hash[i + 12] = (ctx->state[3] >> (24 - i * 8)) & 0x000000ff;
163 hash[i + 16] = (ctx->state[4] >> (24 - i * 8)) & 0x000000ff;
164 hash[i + 20] = (ctx->state[5] >> (24 - i * 8)) & 0x000000ff;
165 hash[i + 24] = (ctx->state[6] >> (24 - i * 8)) & 0x000000ff;
166 hash[i + 28] = (ctx->state[7] >> (24 - i * 8)) & 0x000000ff;
167 }
168 }
169
hmac_sha256(const uint8_t * plaintext,ssize_t psize,uint8_t * output)170 int hmac_sha256(const uint8_t *plaintext, ssize_t psize, uint8_t *output)
171 {
172 struct sha256_ctx ctx;
173
174 sha256_init(&ctx);
175 sha256_update(&ctx, plaintext, psize);
176 sha256_final(&ctx, output);
177 return 0;
178 }
179