| /* aes.h - TinyCrypt interface to an AES-128 implementation */ |
| |
| /* |
| * Copyright (C) 2017 by Intel Corporation, All Rights Reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * - Neither the name of Intel Corporation nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * @brief -- Interface to an AES-128 implementation. |
| * |
| * Overview: AES-128 is a NIST approved block cipher specified in |
| * FIPS 197. Block ciphers are deterministic algorithms that |
| * perform a transformation specified by a symmetric key in fixed- |
| * length data sets, also called blocks. |
| * |
| * Security: AES-128 provides approximately 128 bits of security. |
| * |
| * Usage: 1) call tc_aes128_set_encrypt/decrypt_key to set the key. |
| * |
| * 2) call tc_aes_encrypt/decrypt to process the data. |
| */ |
| |
| #ifndef __TC_AES_H__ |
| #define __TC_AES_H__ |
| |
| #include <stdint.h> |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #define Nb (4) /* number of columns (32-bit words) comprising the state */ |
| #define Nk (4) /* number of 32-bit words comprising the key */ |
| #define Nr (10) /* number of rounds */ |
| #define TC_AES_BLOCK_SIZE (Nb*Nk) |
| #define TC_AES_KEY_SIZE (Nb*Nk) |
| |
| typedef struct tc_aes_key_sched_struct { |
| unsigned int words[Nb*(Nr+1)]; |
| } *TCAesKeySched_t; |
| |
| /** |
| * @brief Set AES-128 encryption key |
| * Uses key k to initialize s |
| * @return returns TC_CRYPTO_SUCCESS (1) |
| * returns TC_CRYPTO_FAIL (0) if: s == NULL or k == NULL |
| * @note This implementation skips the additional steps required for keys |
| * larger than 128 bits, and must not be used for AES-192 or |
| * AES-256 key schedule -- see FIPS 197 for details |
| * @param s IN/OUT -- initialized struct tc_aes_key_sched_struct |
| * @param k IN -- points to the AES key |
| */ |
| int tc_aes128_set_encrypt_key(TCAesKeySched_t s, const uint8_t *k); |
| |
| /** |
| * @brief AES-128 Encryption procedure |
| * Encrypts contents of in buffer into out buffer under key; |
| * schedule s |
| * @note Assumes s was initialized by aes_set_encrypt_key; |
| * out and in point to 16 byte buffers |
| * @return returns TC_CRYPTO_SUCCESS (1) |
| * returns TC_CRYPTO_FAIL (0) if: out == NULL or in == NULL or s == NULL |
| * @param out IN/OUT -- buffer to receive ciphertext block |
| * @param in IN -- a plaintext block to encrypt |
| * @param s IN -- initialized AES key schedule |
| */ |
| int tc_aes_encrypt(uint8_t *out, const uint8_t *in, |
| const TCAesKeySched_t s); |
| |
| /** |
| * @brief Set the AES-128 decryption key |
| * Uses key k to initialize s |
| * @return returns TC_CRYPTO_SUCCESS (1) |
| * returns TC_CRYPTO_FAIL (0) if: s == NULL or k == NULL |
| * @note This is the implementation of the straightforward inverse cipher |
| * using the cipher documented in FIPS-197 figure 12, not the |
| * equivalent inverse cipher presented in Figure 15 |
| * @warning This routine skips the additional steps required for keys larger |
| * than 128, and must not be used for AES-192 or AES-256 key |
| * schedule -- see FIPS 197 for details |
| * @param s IN/OUT -- initialized struct tc_aes_key_sched_struct |
| * @param k IN -- points to the AES key |
| */ |
| int tc_aes128_set_decrypt_key(TCAesKeySched_t s, const uint8_t *k); |
| |
| /** |
| * @brief AES-128 Encryption procedure |
| * Decrypts in buffer into out buffer under key schedule s |
| * @return returns TC_CRYPTO_SUCCESS (1) |
| * returns TC_CRYPTO_FAIL (0) if: out is NULL or in is NULL or s is NULL |
| * @note Assumes s was initialized by aes_set_encrypt_key |
| * out and in point to 16 byte buffers |
| * @param out IN/OUT -- buffer to receive ciphertext block |
| * @param in IN -- a plaintext block to encrypt |
| * @param s IN -- initialized AES key schedule |
| */ |
| int tc_aes_decrypt(uint8_t *out, const uint8_t *in, |
| const TCAesKeySched_t s); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* __TC_AES_H__ */ |
