1 /*
2 * FIPS-180-2 compliant SHA-256 implementation
3 *
4 * Copyright (C) 2006-2021, ARM Limited, All Rights Reserved
5 * Copyright (C) 2019, STMicroelectronics, All Rights Reserved
6 * SPDX-License-Identifier: Apache-2.0
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License"); you may
9 * not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 *
20 * This file implements STMicroelectronics SHA256 with HW services based on mbed TLS API
21 */
22 /*
23 * The SHA-256 Secure Hash Standard was published by NIST in 2002.
24 *
25 * http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
26 */
27
28 /* Includes ------------------------------------------------------------------*/
29 #include "mbedtls/sha256.h"
30 #include "mbedtls/error.h"
31
32 #if defined(MBEDTLS_SHA256_C)
33 #if defined(MBEDTLS_SHA256_ALT)
34 #include <string.h>
35 #include "mbedtls/platform.h"
36 #include "mbedtls/platform_util.h"
37
38
39 /* Private typedef -----------------------------------------------------------*/
40 /* Private define ------------------------------------------------------------*/
41 #define ST_SHA256_TIMEOUT ((uint32_t) 3)
42
43 /* Parameter validation macros - mbedtls/platform_util.h has deprecated them */
44 #define SHA256_VALIDATE_RET( cond ) do { } while(0)
45 #define SHA256_VALIDATE( cond ) do { } while(0)
46
47 /* Private variables ---------------------------------------------------------*/
48 /* Private function prototypes -----------------------------------------------*/
49 /* Private functions ---------------------------------------------------------*/
50
51 /* Implementation that should never be optimized out by the compiler */
mbedtls_zeroize(void * v,size_t n)52 static void mbedtls_zeroize(void *v, size_t n)
53 {
54 volatile unsigned char *p = (unsigned char *)v;
55 while (n--)
56 {
57 *p++ = 0;
58 }
59 }
60
mbedtls_sha256_init(mbedtls_sha256_context * ctx)61 void mbedtls_sha256_init(mbedtls_sha256_context *ctx)
62 {
63 SHA256_VALIDATE( ctx != NULL );
64
65 mbedtls_zeroize(ctx, sizeof(mbedtls_sha256_context));
66
67 /* Enable HASH clock */
68 __HAL_RCC_HASH_CLK_ENABLE();
69 }
70
mbedtls_sha256_free(mbedtls_sha256_context * ctx)71 void mbedtls_sha256_free(mbedtls_sha256_context *ctx)
72 {
73 if (ctx == NULL)
74 {
75 return;
76 }
77 mbedtls_zeroize(ctx, sizeof(mbedtls_sha256_context));
78 }
79
mbedtls_sha256_clone(mbedtls_sha256_context * dst,const mbedtls_sha256_context * src)80 void mbedtls_sha256_clone(mbedtls_sha256_context *dst,
81 const mbedtls_sha256_context *src)
82 {
83 SHA256_VALIDATE( dst != NULL );
84 SHA256_VALIDATE( src != NULL );
85
86 *dst = *src;
87 }
88
mbedtls_sha256_starts(mbedtls_sha256_context * ctx,int is224)89 int mbedtls_sha256_starts(mbedtls_sha256_context *ctx, int is224)
90 {
91 SHA256_VALIDATE_RET( ctx != NULL );
92 SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
93
94 /* HASH Configuration */
95 if (HAL_HASH_DeInit(&ctx->hhash) != HAL_OK)
96 {
97 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
98 }
99 ctx->hhash.Init.DataType = HASH_DATATYPE_8B;
100 if (HAL_HASH_Init(&ctx->hhash) != HAL_OK)
101 {
102 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
103 }
104
105 ctx->MBEDTLS_PRIVATE(is224) = is224;
106
107 /* first block on 17 words */
108 ctx->first = ST_SHA256_EXTRA_BYTES;
109
110 ctx->sbuf_len = 0;
111
112 #ifdef ST_HW_CONTEXT_SAVING
113 /* save hw context */
114 HAL_HASH_ContextSaving(&ctx->hhash, ctx->ctx_save_regs);
115 #endif /* ST_HW_CONTEXT_SAVING */
116
117 return 0;
118 }
119
mbedtls_internal_sha256_process(mbedtls_sha256_context * ctx,const unsigned char data[ST_SHA256_BLOCK_SIZE])120 int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx, const unsigned char data[ST_SHA256_BLOCK_SIZE] )
121 {
122 SHA256_VALIDATE_RET( ctx != NULL );
123 SHA256_VALIDATE_RET( (const unsigned char *)data != NULL );
124
125 #ifdef ST_HW_CONTEXT_SAVING
126 /* restore hw context */
127 HAL_HASH_ContextRestoring(&ctx->hhash, ctx->ctx_save_regs);
128 #endif /* ST_HW_CONTEXT_SAVING */
129
130 if (ctx->MBEDTLS_PRIVATE(is224) == 0) {
131 if (HAL_HASHEx_SHA256_Accmlt(&ctx->hhash, (uint8_t *) data, ST_SHA256_BLOCK_SIZE) != 0) {
132 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
133 }
134 } else {
135 if (HAL_HASHEx_SHA224_Accmlt(&ctx->hhash, (uint8_t *) data, ST_SHA256_BLOCK_SIZE) != 0) {
136 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
137 }
138 }
139
140 #ifdef ST_HW_CONTEXT_SAVING
141 /* save hw context */
142 HAL_HASH_ContextSaving(&ctx->hhash, ctx->ctx_save_regs);
143 #endif /* ST_HW_CONTEXT_SAVING */
144
145 return 0;
146 }
147
mbedtls_sha256_update(mbedtls_sha256_context * ctx,const unsigned char * input,size_t ilen)148 int mbedtls_sha256_update(mbedtls_sha256_context *ctx, const unsigned char *input, size_t ilen)
149 {
150 size_t currentlen = ilen;
151
152 SHA256_VALIDATE_RET( ctx != NULL );
153 SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
154
155 #ifdef ST_HW_CONTEXT_SAVING
156 /* restore hw context */
157 HAL_HASH_ContextRestoring(&ctx->hhash, ctx->ctx_save_regs);
158 #endif /* ST_HW_CONTEXT_SAVING */
159
160 if (currentlen < (ST_SHA256_BLOCK_SIZE + ctx->first - ctx->sbuf_len))
161 {
162 /* only store input data in context buffer */
163 memcpy(ctx->sbuf + ctx->sbuf_len, input, currentlen);
164 ctx->sbuf_len += currentlen;
165 }
166 else
167 {
168 /* fill context buffer until ST_SHA256_BLOCK_SIZE bytes, and process it */
169 memcpy(ctx->sbuf + ctx->sbuf_len, input, (ST_SHA256_BLOCK_SIZE + ctx->first - ctx->sbuf_len));
170 currentlen -= (ST_SHA256_BLOCK_SIZE + ctx->first - ctx->sbuf_len);
171
172 if (ctx->MBEDTLS_PRIVATE(is224) == 0)
173 {
174 if (HAL_HASHEx_SHA256_Accmlt(&ctx->hhash, (uint8_t *)(ctx->sbuf), ST_SHA256_BLOCK_SIZE + ctx->first) != 0)
175 {
176 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
177 }
178 }
179 else
180 {
181 if (HAL_HASHEx_SHA224_Accmlt(&ctx->hhash, (uint8_t *)(ctx->sbuf), ST_SHA256_BLOCK_SIZE + ctx->first) != 0)
182 {
183 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
184 }
185 }
186
187 /* Process following input data with size multiple of ST_SHA256_BLOCK_SIZE bytes */
188 size_t iter = currentlen / ST_SHA256_BLOCK_SIZE;
189 if (iter != 0)
190 {
191 if (ctx->MBEDTLS_PRIVATE(is224) == 0)
192 {
193 if (HAL_HASHEx_SHA256_Accmlt(&ctx->hhash, (uint8_t *)(input + ST_SHA256_BLOCK_SIZE + ctx->first - ctx->sbuf_len), (iter * ST_SHA256_BLOCK_SIZE)) != 0)
194 {
195 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
196 }
197 }
198 else
199 {
200 if (HAL_HASHEx_SHA224_Accmlt(&ctx->hhash, (uint8_t *)(input + ST_SHA256_BLOCK_SIZE + ctx->first - ctx->sbuf_len), (iter * ST_SHA256_BLOCK_SIZE)) != 0)
201 {
202 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
203 }
204 }
205 }
206
207 /* following blocks on 16 words */
208 ctx->first = 0;
209
210 /* Store only the remaining input data up to (ST_SHA256_BLOCK_SIZE - 1) bytes */
211 ctx->sbuf_len = currentlen % ST_SHA256_BLOCK_SIZE;
212 if (ctx->sbuf_len != 0)
213 {
214 memcpy(ctx->sbuf, input + ilen - ctx->sbuf_len, ctx->sbuf_len);
215 }
216 }
217
218 #ifdef ST_HW_CONTEXT_SAVING
219 /* save hw context */
220 HAL_HASH_ContextSaving(&ctx->hhash, ctx->ctx_save_regs);
221 #endif /* ST_HW_CONTEXT_SAVING */
222 return 0;
223 }
224
mbedtls_sha256_finish(mbedtls_sha256_context * ctx,unsigned char output[32])225 int mbedtls_sha256_finish(mbedtls_sha256_context *ctx, unsigned char output[32])
226 {
227 SHA256_VALIDATE_RET( ctx != NULL );
228 SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
229
230 #ifdef ST_HW_CONTEXT_SAVING
231 /* restore hw context */
232 HAL_HASH_ContextRestoring(&ctx->hhash, ctx->ctx_save_regs);
233 #endif /* ST_HW_CONTEXT_SAVING */
234
235 /* Last accumulation for pending bytes in sbuf_len, then trig processing and get digest */
236 if (ctx->MBEDTLS_PRIVATE(is224) == 0)
237 {
238 if (HAL_HASHEx_SHA256_Accmlt_End(&ctx->hhash, ctx->sbuf, ctx->sbuf_len, output, ST_SHA256_TIMEOUT) != 0)
239 {
240 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
241 }
242 }
243 else
244 {
245 if (HAL_HASHEx_SHA224_Accmlt_End(&ctx->hhash, ctx->sbuf, ctx->sbuf_len, output, ST_SHA256_TIMEOUT) != 0)
246 {
247 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
248 }
249 }
250
251 ctx->sbuf_len = 0;
252
253 return 0;
254 }
255
256 #endif /* MBEDTLS_SHA256_ALT*/
257 #endif /* MBEDTLS_SHA256_C */
258
