1 /*
2 * Copyright (C) 2017 - This file is part of libecc project
3 *
4 * Authors:
5 * Ryad BENADJILA <ryadbenadjila@gmail.com>
6 * Arnaud EBALARD <arnaud.ebalard@ssi.gouv.fr>
7 * Jean-Pierre FLORI <jean-pierre.flori@ssi.gouv.fr>
8 *
9 * Contributors:
10 * Nicolas VIVET <nicolas.vivet@ssi.gouv.fr>
11 * Karim KHALFALLAH <karim.khalfallah@ssi.gouv.fr>
12 *
13 * This software is licensed under a dual BSD and GPL v2 license.
14 * See LICENSE file at the root folder of the project.
15 */
16 #include <libecc/lib_ecc_config.h>
17 #ifdef WITH_HASH_SHA256
18
19 #include <libecc/hash/sha256.h>
20
21 /* SHA-2 core processing */
sha256_process(sha256_context * ctx,const u8 data[SHA256_BLOCK_SIZE])22 ATTRIBUTE_WARN_UNUSED_RET static int sha256_process(sha256_context *ctx,
23 const u8 data[SHA256_BLOCK_SIZE])
24 {
25 u32 a, b, c, d, e, f, g, h;
26 u32 W[64];
27 unsigned int i;
28 int ret;
29
30 MUST_HAVE((data != NULL), ret, err);
31 SHA256_HASH_CHECK_INITIALIZED(ctx, ret, err);
32
33 /* Init our inner variables */
34 a = ctx->sha256_state[0];
35 b = ctx->sha256_state[1];
36 c = ctx->sha256_state[2];
37 d = ctx->sha256_state[3];
38 e = ctx->sha256_state[4];
39 f = ctx->sha256_state[5];
40 g = ctx->sha256_state[6];
41 h = ctx->sha256_state[7];
42
43 for (i = 0; i < 16; i++) {
44 GET_UINT32_BE(W[i], data, 4 * i);
45 SHA2CORE_SHA256(a, b, c, d, e, f, g, h, W[i], K_SHA256[i]);
46 }
47
48 for (i = 16; i < 64; i++) {
49 SHA2CORE_SHA256(a, b, c, d, e, f, g, h, UPDATEW_SHA256(W, i),
50 K_SHA256[i]);
51 }
52
53 /* Update state */
54 ctx->sha256_state[0] += a;
55 ctx->sha256_state[1] += b;
56 ctx->sha256_state[2] += c;
57 ctx->sha256_state[3] += d;
58 ctx->sha256_state[4] += e;
59 ctx->sha256_state[5] += f;
60 ctx->sha256_state[6] += g;
61 ctx->sha256_state[7] += h;
62
63 ret = 0;
64
65 err:
66 return ret;
67 }
68
69 /* Init hash function */
sha256_init(sha256_context * ctx)70 int sha256_init(sha256_context *ctx)
71 {
72 int ret;
73
74 MUST_HAVE((ctx != NULL), ret, err);
75
76 ctx->sha256_total = 0;
77 ctx->sha256_state[0] = 0x6A09E667;
78 ctx->sha256_state[1] = 0xBB67AE85;
79 ctx->sha256_state[2] = 0x3C6EF372;
80 ctx->sha256_state[3] = 0xA54FF53A;
81 ctx->sha256_state[4] = 0x510E527F;
82 ctx->sha256_state[5] = 0x9B05688C;
83 ctx->sha256_state[6] = 0x1F83D9AB;
84 ctx->sha256_state[7] = 0x5BE0CD19;
85
86 /* Tell that we are initialized */
87 ctx->magic = SHA256_HASH_MAGIC;
88
89 ret = 0;
90
91 err:
92 return ret;
93 }
94
95 /* Update hash function */
sha256_update(sha256_context * ctx,const u8 * input,u32 ilen)96 int sha256_update(sha256_context *ctx, const u8 *input, u32 ilen)
97 {
98 const u8 *data_ptr = input;
99 u32 remain_ilen = ilen;
100 u16 fill;
101 u8 left;
102 int ret;
103
104 MUST_HAVE((input != NULL) || (ilen == 0), ret, err);
105 SHA256_HASH_CHECK_INITIALIZED(ctx, ret, err);
106
107 /* Nothing to process, return */
108 if (ilen == 0) {
109 ret = 0;
110 goto err;
111 }
112
113 /* Get what's left in our local buffer */
114 left = (ctx->sha256_total & 0x3F);
115 fill = (u16)(SHA256_BLOCK_SIZE - left);
116
117 ctx->sha256_total += ilen;
118
119 if ((left > 0) && (remain_ilen >= fill)) {
120 /* Copy data at the end of the buffer */
121 ret = local_memcpy(ctx->sha256_buffer + left, data_ptr, fill); EG(ret, err);
122 ret = sha256_process(ctx, ctx->sha256_buffer); EG(ret, err);
123 data_ptr += fill;
124 remain_ilen -= fill;
125 left = 0;
126 }
127
128 while (remain_ilen >= SHA256_BLOCK_SIZE) {
129 ret = sha256_process(ctx, data_ptr); EG(ret, err);
130 data_ptr += SHA256_BLOCK_SIZE;
131 remain_ilen -= SHA256_BLOCK_SIZE;
132 }
133
134 if (remain_ilen > 0) {
135 ret = local_memcpy(ctx->sha256_buffer + left, data_ptr, remain_ilen); EG(ret, err);
136 }
137
138 ret = 0;
139
140 err:
141 return ret;
142 }
143
144 /* Finalize */
sha256_final(sha256_context * ctx,u8 output[SHA256_DIGEST_SIZE])145 int sha256_final(sha256_context *ctx, u8 output[SHA256_DIGEST_SIZE])
146 {
147 unsigned int block_present = 0;
148 u8 last_padded_block[2 * SHA256_BLOCK_SIZE];
149 int ret;
150
151 MUST_HAVE((output != NULL), ret, err);
152 SHA256_HASH_CHECK_INITIALIZED(ctx, ret, err);
153
154 /* Fill in our last block with zeroes */
155 ret = local_memset(last_padded_block, 0, sizeof(last_padded_block)); EG(ret, err);
156
157 /* This is our final step, so we proceed with the padding */
158 block_present = (ctx->sha256_total % SHA256_BLOCK_SIZE);
159 if (block_present != 0) {
160 /* Copy what's left in our temporary context buffer */
161 ret = local_memcpy(last_padded_block, ctx->sha256_buffer,
162 block_present); EG(ret, err);
163 }
164
165 /* Put the 0x80 byte, beginning of padding */
166 last_padded_block[block_present] = 0x80;
167
168 /* Handle possible additional block */
169 if (block_present > (SHA256_BLOCK_SIZE - 1 - sizeof(u64))) {
170 /* We need an additional block */
171 PUT_UINT64_BE(8 * ctx->sha256_total, last_padded_block,
172 (2 * SHA256_BLOCK_SIZE) - sizeof(u64));
173 ret = sha256_process(ctx, last_padded_block); EG(ret, err);
174 ret = sha256_process(ctx, last_padded_block + SHA256_BLOCK_SIZE); EG(ret, err);
175 } else {
176 /* We do not need an additional block */
177 PUT_UINT64_BE(8 * ctx->sha256_total, last_padded_block,
178 SHA256_BLOCK_SIZE - sizeof(u64));
179 ret = sha256_process(ctx, last_padded_block); EG(ret, err);
180 }
181
182 /* Output the hash result */
183 PUT_UINT32_BE(ctx->sha256_state[0], output, 0);
184 PUT_UINT32_BE(ctx->sha256_state[1], output, 4);
185 PUT_UINT32_BE(ctx->sha256_state[2], output, 8);
186 PUT_UINT32_BE(ctx->sha256_state[3], output, 12);
187 PUT_UINT32_BE(ctx->sha256_state[4], output, 16);
188 PUT_UINT32_BE(ctx->sha256_state[5], output, 20);
189 PUT_UINT32_BE(ctx->sha256_state[6], output, 24);
190 PUT_UINT32_BE(ctx->sha256_state[7], output, 28);
191
192 /* Tell that we are uninitialized */
193 ctx->magic = WORD(0);
194
195 ret = 0;
196
197 err:
198 return ret;
199 }
200
sha256_scattered(const u8 ** inputs,const u32 * ilens,u8 output[SHA256_DIGEST_SIZE])201 int sha256_scattered(const u8 **inputs, const u32 *ilens,
202 u8 output[SHA256_DIGEST_SIZE])
203 {
204 sha256_context ctx;
205 int ret, pos = 0;
206
207 MUST_HAVE((inputs != NULL) && (ilens != NULL) && (output != NULL), ret, err);
208
209 ret = sha256_init(&ctx); EG(ret, err);
210
211 while (inputs[pos] != NULL) {
212 ret = sha256_update(&ctx, inputs[pos], ilens[pos]); EG(ret, err);
213 pos += 1;
214 }
215
216 ret = sha256_final(&ctx, output);
217
218 err:
219 return ret;
220 }
221
sha256(const u8 * input,u32 ilen,u8 output[SHA256_DIGEST_SIZE])222 int sha256(const u8 *input, u32 ilen, u8 output[SHA256_DIGEST_SIZE])
223 {
224 sha256_context ctx;
225 int ret;
226
227 ret = sha256_init(&ctx); EG(ret, err);
228 ret = sha256_update(&ctx, input, ilen); EG(ret, err);
229 ret = sha256_final(&ctx, output);
230
231 err:
232 return ret;
233 }
234
235 #else /* WITH_HASH_SHA256 */
236
237 /*
238 * Dummy definition to avoid the empty translation unit ISO C warning
239 */
240 typedef int dummy;
241 #endif /* WITH_HASH_SHA256 */
242