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| 1 | +/** |
| 2 | + * \brief AES block cipher, ESP32 hardware accelerated version |
| 3 | + * Based on mbedTLS FIPS-197 compliant version. |
| 4 | + * |
| 5 | + * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved |
| 6 | + * Additions Copyright (C) 2016, Espressif Systems (Shanghai) PTE Ltd |
| 7 | + * SPDX-License-Identifier: Apache-2.0 |
| 8 | + * |
| 9 | + * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 10 | + * not use this file except in compliance with the License. |
| 11 | + * You may obtain a copy of the License at |
| 12 | + * |
| 13 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 14 | + * |
| 15 | + * Unless required by applicable law or agreed to in writing, software |
| 16 | + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 17 | + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 18 | + * See the License for the specific language governing permissions and |
| 19 | + * limitations under the License. |
| 20 | + * |
| 21 | + * |
| 22 | + */ |
| 23 | + |
| 24 | +#ifndef ESP_AES_H |
| 25 | +#define ESP_AES_H |
| 26 | + |
| 27 | +#include "esp_types.h" |
| 28 | +#include "esp32/rom/aes.h" |
| 29 | + |
| 30 | +#ifdef __cplusplus |
| 31 | +extern "C" { |
| 32 | +#endif |
| 33 | + |
| 34 | +/* padlock.c and aesni.c rely on these values! */ |
| 35 | +#define ESP_AES_ENCRYPT 1 |
| 36 | +#define ESP_AES_DECRYPT 0 |
| 37 | + |
| 38 | +#define ERR_ESP_AES_INVALID_KEY_LENGTH -0x0020 /**< Invalid key length. */ |
| 39 | +#define ERR_ESP_AES_INVALID_INPUT_LENGTH -0x0022 /**< Invalid data input length. */ |
| 40 | + |
| 41 | +/** |
| 42 | + * \brief AES context structure |
| 43 | + * |
| 44 | + */ |
| 45 | +typedef struct { |
| 46 | + uint8_t key_bytes; |
| 47 | + volatile uint8_t key_in_hardware; /* This variable is used for fault injection checks, so marked volatile to avoid optimisation */ |
| 48 | + uint8_t key[32]; |
| 49 | +} esp_aes_context; |
| 50 | + |
| 51 | +/** |
| 52 | + * \brief The AES XTS context-type definition. |
| 53 | + */ |
| 54 | +typedef struct |
| 55 | +{ |
| 56 | + esp_aes_context crypt; /*!< The AES context to use for AES block |
| 57 | + encryption or decryption. */ |
| 58 | + esp_aes_context tweak; /*!< The AES context used for tweak |
| 59 | + computation. */ |
| 60 | +} esp_aes_xts_context; |
| 61 | + |
| 62 | + |
| 63 | +/** |
| 64 | + * \brief Lock access to AES hardware unit |
| 65 | + * |
| 66 | + * AES hardware unit can only be used by one |
| 67 | + * consumer at a time. |
| 68 | + * |
| 69 | + * esp_aes_xxx API calls automatically manage locking & unlocking of |
| 70 | + * hardware, this function is only needed if you want to call |
| 71 | + * ets_aes_xxx functions directly. |
| 72 | + */ |
| 73 | +void esp_aes_acquire_hardware( void ); |
| 74 | + |
| 75 | +/** |
| 76 | + * \brief Unlock access to AES hardware unit |
| 77 | + * |
| 78 | + * esp_aes_xxx API calls automatically manage locking & unlocking of |
| 79 | + * hardware, this function is only needed if you want to call |
| 80 | + * ets_aes_xxx functions directly. |
| 81 | + */ |
| 82 | +void esp_aes_release_hardware( void ); |
| 83 | + |
| 84 | +/** |
| 85 | + * \brief Initialize AES context |
| 86 | + * |
| 87 | + * \param ctx AES context to be initialized |
| 88 | + */ |
| 89 | +void esp_aes_init( esp_aes_context *ctx ); |
| 90 | + |
| 91 | +/** |
| 92 | + * \brief Clear AES context |
| 93 | + * |
| 94 | + * \param ctx AES context to be cleared |
| 95 | + */ |
| 96 | +void esp_aes_free( esp_aes_context *ctx ); |
| 97 | + |
| 98 | +/** |
| 99 | + * \brief This function initializes the specified AES XTS context. |
| 100 | + * |
| 101 | + * It must be the first API called before using |
| 102 | + * the context. |
| 103 | + * |
| 104 | + * \param ctx The AES XTS context to initialize. |
| 105 | + */ |
| 106 | +void esp_aes_xts_init( esp_aes_xts_context *ctx ); |
| 107 | + |
| 108 | +/** |
| 109 | + * \brief This function releases and clears the specified AES XTS context. |
| 110 | + * |
| 111 | + * \param ctx The AES XTS context to clear. |
| 112 | + */ |
| 113 | +void esp_aes_xts_free( esp_aes_xts_context *ctx ); |
| 114 | + |
| 115 | +/** |
| 116 | + * \brief AES set key schedule (encryption or decryption) |
| 117 | + * |
| 118 | + * \param ctx AES context to be initialized |
| 119 | + * \param key encryption key |
| 120 | + * \param keybits must be 128, 192 or 256 |
| 121 | + * |
| 122 | + * \return 0 if successful, or ERR_AES_INVALID_KEY_LENGTH |
| 123 | + */ |
| 124 | +int esp_aes_setkey( esp_aes_context *ctx, const unsigned char *key, unsigned int keybits ); |
| 125 | + |
| 126 | +/** |
| 127 | + * \brief AES-ECB block encryption/decryption |
| 128 | + * |
| 129 | + * \param ctx AES context |
| 130 | + * \param mode AES_ENCRYPT or AES_DECRYPT |
| 131 | + * \param input 16-byte input block |
| 132 | + * \param output 16-byte output block |
| 133 | + * |
| 134 | + * \return 0 if successful |
| 135 | + */ |
| 136 | +int esp_aes_crypt_ecb( esp_aes_context *ctx, int mode, const unsigned char input[16], unsigned char output[16] ); |
| 137 | + |
| 138 | +/** |
| 139 | + * \brief AES-CBC buffer encryption/decryption |
| 140 | + * Length should be a multiple of the block |
| 141 | + * size (16 bytes) |
| 142 | + * |
| 143 | + * \note Upon exit, the content of the IV is updated so that you can |
| 144 | + * call the function same function again on the following |
| 145 | + * block(s) of data and get the same result as if it was |
| 146 | + * encrypted in one call. This allows a "streaming" usage. |
| 147 | + * If on the other hand you need to retain the contents of the |
| 148 | + * IV, you should either save it manually or use the cipher |
| 149 | + * module instead. |
| 150 | + * |
| 151 | + * \param ctx AES context |
| 152 | + * \param mode AES_ENCRYPT or AES_DECRYPT |
| 153 | + * \param length length of the input data |
| 154 | + * \param iv initialization vector (updated after use) |
| 155 | + * \param input buffer holding the input data |
| 156 | + * \param output buffer holding the output data |
| 157 | + * |
| 158 | + * \return 0 if successful, or ERR_AES_INVALID_INPUT_LENGTH |
| 159 | + */ |
| 160 | +int esp_aes_crypt_cbc( esp_aes_context *ctx, |
| 161 | + int mode, |
| 162 | + size_t length, |
| 163 | + unsigned char iv[16], |
| 164 | + const unsigned char *input, |
| 165 | + unsigned char *output ); |
| 166 | + |
| 167 | + |
| 168 | +/** |
| 169 | + * \brief AES-CFB128 buffer encryption/decryption. |
| 170 | + * |
| 171 | + * Note: Due to the nature of CFB you should use the same key schedule for |
| 172 | + * both encryption and decryption. So a context initialized with |
| 173 | + * esp_aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT. |
| 174 | + * |
| 175 | + * \note Upon exit, the content of the IV is updated so that you can |
| 176 | + * call the function same function again on the following |
| 177 | + * block(s) of data and get the same result as if it was |
| 178 | + * encrypted in one call. This allows a "streaming" usage. |
| 179 | + * If on the other hand you need to retain the contents of the |
| 180 | + * IV, you should either save it manually or use the cipher |
| 181 | + * module instead. |
| 182 | + * |
| 183 | + * \param ctx AES context |
| 184 | + * \param mode AES_ENCRYPT or AES_DECRYPT |
| 185 | + * \param length length of the input data |
| 186 | + * \param iv_off offset in IV (updated after use) |
| 187 | + * \param iv initialization vector (updated after use) |
| 188 | + * \param input buffer holding the input data |
| 189 | + * \param output buffer holding the output data |
| 190 | + * |
| 191 | + * \return 0 if successful |
| 192 | + */ |
| 193 | +int esp_aes_crypt_cfb128( esp_aes_context *ctx, |
| 194 | + int mode, |
| 195 | + size_t length, |
| 196 | + size_t *iv_off, |
| 197 | + unsigned char iv[16], |
| 198 | + const unsigned char *input, |
| 199 | + unsigned char *output ); |
| 200 | + |
| 201 | +/** |
| 202 | + * \brief AES-CFB8 buffer encryption/decryption. |
| 203 | + * |
| 204 | + * Note: Due to the nature of CFB you should use the same key schedule for |
| 205 | + * both encryption and decryption. So a context initialized with |
| 206 | + * esp_aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT. |
| 207 | + * |
| 208 | + * \note Upon exit, the content of the IV is updated so that you can |
| 209 | + * call the function same function again on the following |
| 210 | + * block(s) of data and get the same result as if it was |
| 211 | + * encrypted in one call. This allows a "streaming" usage. |
| 212 | + * If on the other hand you need to retain the contents of the |
| 213 | + * IV, you should either save it manually or use the cipher |
| 214 | + * module instead. |
| 215 | + * |
| 216 | + * \param ctx AES context |
| 217 | + * \param mode AES_ENCRYPT or AES_DECRYPT |
| 218 | + * \param length length of the input data |
| 219 | + * \param iv initialization vector (updated after use) |
| 220 | + * \param input buffer holding the input data |
| 221 | + * \param output buffer holding the output data |
| 222 | + * |
| 223 | + * \return 0 if successful |
| 224 | + */ |
| 225 | +int esp_aes_crypt_cfb8( esp_aes_context *ctx, |
| 226 | + int mode, |
| 227 | + size_t length, |
| 228 | + unsigned char iv[16], |
| 229 | + const unsigned char *input, |
| 230 | + unsigned char *output ); |
| 231 | + |
| 232 | +/** |
| 233 | + * \brief AES-CTR buffer encryption/decryption |
| 234 | + * |
| 235 | + * Warning: You have to keep the maximum use of your counter in mind! |
| 236 | + * |
| 237 | + * Note: Due to the nature of CTR you should use the same key schedule for |
| 238 | + * both encryption and decryption. So a context initialized with |
| 239 | + * esp_aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT. |
| 240 | + * |
| 241 | + * \param ctx AES context |
| 242 | + * \param length The length of the data |
| 243 | + * \param nc_off The offset in the current stream_block (for resuming |
| 244 | + * within current cipher stream). The offset pointer to |
| 245 | + * should be 0 at the start of a stream. |
| 246 | + * \param nonce_counter The 128-bit nonce and counter. |
| 247 | + * \param stream_block The saved stream-block for resuming. Is overwritten |
| 248 | + * by the function. |
| 249 | + * \param input The input data stream |
| 250 | + * \param output The output data stream |
| 251 | + * |
| 252 | + * \return 0 if successful |
| 253 | + */ |
| 254 | +int esp_aes_crypt_ctr( esp_aes_context *ctx, |
| 255 | + size_t length, |
| 256 | + size_t *nc_off, |
| 257 | + unsigned char nonce_counter[16], |
| 258 | + unsigned char stream_block[16], |
| 259 | + const unsigned char *input, |
| 260 | + unsigned char *output ); |
| 261 | + |
| 262 | +/** |
| 263 | + * \brief This function prepares an XTS context for encryption and |
| 264 | + * sets the encryption key. |
| 265 | + * |
| 266 | + * \param ctx The AES XTS context to which the key should be bound. |
| 267 | + * \param key The encryption key. This is comprised of the XTS key1 |
| 268 | + * concatenated with the XTS key2. |
| 269 | + * \param keybits The size of \p key passed in bits. Valid options are: |
| 270 | + * <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li> |
| 271 | + * <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul> |
| 272 | + * |
| 273 | + * \return \c 0 on success. |
| 274 | + * \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure. |
| 275 | + */ |
| 276 | +int esp_aes_xts_setkey_enc( esp_aes_xts_context *ctx, |
| 277 | + const unsigned char *key, |
| 278 | + unsigned int keybits ); |
| 279 | + |
| 280 | +/** |
| 281 | + * \brief This function performs an AES-OFB (Output Feedback Mode) |
| 282 | + * encryption or decryption operation. |
| 283 | + * |
| 284 | + * \param ctx The AES context to use for encryption or decryption. |
| 285 | + * It must be initialized and bound to a key. |
| 286 | + * \param length The length of the input data. |
| 287 | + * \param iv_off The offset in IV (updated after use). |
| 288 | + * It must point to a valid \c size_t. |
| 289 | + * \param iv The initialization vector (updated after use). |
| 290 | + * It must be a readable and writeable buffer of \c 16 Bytes. |
| 291 | + * \param input The buffer holding the input data. |
| 292 | + * It must be readable and of size \p length Bytes. |
| 293 | + * \param output The buffer holding the output data. |
| 294 | + * It must be writeable and of size \p length Bytes. |
| 295 | + * |
| 296 | + * \return \c 0 on success. |
| 297 | + */ |
| 298 | +int esp_aes_crypt_ofb( esp_aes_context *ctx, |
| 299 | + size_t length, |
| 300 | + size_t *iv_off, |
| 301 | + unsigned char iv[16], |
| 302 | + const unsigned char *input, |
| 303 | + unsigned char *output ); |
| 304 | + |
| 305 | +/** |
| 306 | + * \brief This function prepares an XTS context for decryption and |
| 307 | + * sets the decryption key. |
| 308 | + * |
| 309 | + * \param ctx The AES XTS context to which the key should be bound. |
| 310 | + * \param key The decryption key. This is comprised of the XTS key1 |
| 311 | + * concatenated with the XTS key2. |
| 312 | + * \param keybits The size of \p key passed in bits. Valid options are: |
| 313 | + * <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li> |
| 314 | + * <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul> |
| 315 | + * |
| 316 | + * \return \c 0 on success. |
| 317 | + * \return #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure. |
| 318 | + */ |
| 319 | +int esp_aes_xts_setkey_dec( esp_aes_xts_context *ctx, |
| 320 | + const unsigned char *key, |
| 321 | + unsigned int keybits ); |
| 322 | + |
| 323 | + |
| 324 | +/** |
| 325 | + * \brief Internal AES block encryption function |
| 326 | + * (Only exposed to allow overriding it, |
| 327 | + * see AES_ENCRYPT_ALT) |
| 328 | + * |
| 329 | + * \param ctx AES context |
| 330 | + * \param input Plaintext block |
| 331 | + * \param output Output (ciphertext) block |
| 332 | + */ |
| 333 | +int esp_internal_aes_encrypt( esp_aes_context *ctx, const unsigned char input[16], unsigned char output[16] ); |
| 334 | + |
| 335 | +/** |
| 336 | + * \brief Internal AES block decryption function |
| 337 | + * (Only exposed to allow overriding it, |
| 338 | + * see AES_DECRYPT_ALT) |
| 339 | + * |
| 340 | + * \param ctx AES context |
| 341 | + * \param input Ciphertext block |
| 342 | + * \param output Output (plaintext) block |
| 343 | + */ |
| 344 | +int esp_internal_aes_decrypt( esp_aes_context *ctx, const unsigned char input[16], unsigned char output[16] ); |
| 345 | + |
| 346 | +/** AES-XTS buffer encryption/decryption */ |
| 347 | +int esp_aes_crypt_xts( esp_aes_xts_context *ctx, int mode, size_t length, const unsigned char data_unit[16], const unsigned char *input, unsigned char *output ); |
| 348 | + |
| 349 | +#ifdef __cplusplus |
| 350 | +} |
| 351 | +#endif |
| 352 | + |
| 353 | +#endif /* aes.h */ |
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