diff options
Diffstat (limited to 'lib/include/tinycrypt/aes.h')
| -rw-r--r-- | lib/include/tinycrypt/aes.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/lib/include/tinycrypt/aes.h b/lib/include/tinycrypt/aes.h new file mode 100644 index 0000000..c6fcc96 --- /dev/null +++ b/lib/include/tinycrypt/aes.h @@ -0,0 +1,133 @@ +/* aes.h - TinyCrypt interface to an AES-128 implementation */ + +/* + * Copyright (C) 2015 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) + +struct tc_aes_key_sched_struct { + uint32_t words[Nb*(Nr+1)]; +}; +typedef struct tc_aes_key_sched_struct *TCAesKeySched_t; + +/** + * @brief Set AES-128 encryption key + * Uses key k to initialize s + * @return returns TC_SUCCESS (1) + * returns TC_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 + */ +int32_t 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_SUCCESS (1) + * returns TC_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 + */ +int32_t 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_SUCCESS (1) + * returns TC_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 + */ +int32_t 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_SUCCESS (1) + * returns TC_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 + */ +int32_t tc_aes_decrypt(uint8_t *out, + const uint8_t *in, + const TCAesKeySched_t s); + +#ifdef __cplusplus +} +#endif + +#endif |