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targets/TARGET_Maxim/TARGET_MAX32625/mxc/aes.c
- Committer:
- amithy
- Date:
- 2017-11-09
- Revision:
- 178:c26431f84b0d
- Parent:
- 150:02e0a0aed4ec
File content as of revision 178:c26431f84b0d:
/** * @file aes.c * @brief This file contains the function implementations for the Advanced * Encryption Standard (AES) peripheral module. */ /* **************************************************************************** * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. * * Except as contained in this notice, the name of Maxim Integrated * Products, Inc. shall not be used except as stated in the Maxim Integrated * Products, Inc. Branding Policy. * * The mere transfer of this software does not imply any licenses * of trade secrets, proprietary technology, copyrights, patents, * trademarks, maskwork rights, or any other form of intellectual * property whatsoever. Maxim Integrated Products, Inc. retains all * ownership rights. * * $Date: 2016-08-02 13:39:05 -0500 (Tue, 02 Aug 2016) $ * $Revision: 23894 $ * *************************************************************************** */ /* **** Includes **** */ #include <string.h> /* Included for memcpy() & #includes stddef for NULL */ #include "mxc_config.h" #include "aes.h" /** * @ingroup aes * @{ */ /* **** Definitions **** */ /* **** Globals **** */ /* **** Local Function Prototypes **** */ static int aes_memcpy32(uint32_t *out, uint32_t *in, unsigned int count); /* **** Functions **** */ /* ************************************************************************* */ int AES_SetKey(const uint8_t *key, mxc_aes_mode_t mode) { unsigned int len; /* Erase any existing key */ MXC_AES_MEM->key[7] = MXC_AES_MEM->key[6] = MXC_AES_MEM->key[5] = MXC_AES_MEM->key[4] \ = MXC_AES_MEM->key[3] = MXC_AES_MEM->key[2] = MXC_AES_MEM->key[1] = MXC_AES_MEM->key[0] \ = 0x00000000; /* Determine length of key */ if (mode == MXC_E_AES_MODE_256) { len = MXC_AES_KEY_256_LEN; } else if (mode == MXC_E_AES_MODE_192) { len = MXC_AES_KEY_192_LEN; } else if (mode == MXC_E_AES_MODE_128) { len = MXC_AES_KEY_128_LEN; } else { return E_BAD_PARAM; } /* Load new key, based on key mode */ if (aes_memcpy32((uint32_t *)MXC_AES_MEM->key, (uint32_t *)key, len / sizeof(uint32_t)) < 0) { return E_NULL_PTR; } return E_SUCCESS; } /* ************************************************************************* */ int AES_ECBOp(const uint8_t *in, uint8_t *out, mxc_aes_mode_t mode, mxc_aes_dir_t dir) { /* Output array can't be a NULL, unless we are in _ASYNC mode */ if ((out == NULL) && ((dir != MXC_E_AES_ENCRYPT_ASYNC) && (dir != MXC_E_AES_DECRYPT_ASYNC))) { return E_NULL_PTR; } /* Another encryption is already in progress */ if (MXC_AES->ctrl & MXC_F_AES_CTRL_START) { return E_BUSY; } /* Clear interrupt flag and any existing configuration*/ MXC_AES->ctrl = MXC_F_AES_CTRL_INTFL; /* Select key size & direction * * Note: This is done first to detect argument errors, before sensitive data * is loaded into AES_MEM block * */ switch (mode) { case MXC_E_AES_MODE_128: MXC_AES->ctrl |= MXC_S_AES_CTRL_KEY_SIZE_128; break; case MXC_E_AES_MODE_192: MXC_AES->ctrl |= MXC_S_AES_CTRL_KEY_SIZE_192; break; case MXC_E_AES_MODE_256: MXC_AES->ctrl |= MXC_S_AES_CTRL_KEY_SIZE_256; break; default: return E_BAD_PARAM; } switch (dir) { case MXC_E_AES_ENCRYPT: case MXC_E_AES_ENCRYPT_ASYNC: MXC_AES->ctrl |= MXC_S_AES_CTRL_ENCRYPT_MODE; break; case MXC_E_AES_DECRYPT: case MXC_E_AES_DECRYPT_ASYNC: MXC_AES->ctrl |= MXC_S_AES_CTRL_DECRYPT_MODE; break; default: return E_BAD_PARAM; } /* If non-blocking mode has been selected, interrupts are automatically enabled */ if ((dir == MXC_E_AES_ENCRYPT_ASYNC) || (dir == MXC_E_AES_DECRYPT_ASYNC)) { MXC_AES->ctrl |= MXC_F_AES_CTRL_INTEN; } /* Load input into engine */ if (aes_memcpy32((uint32_t *)MXC_AES_MEM->inp, (uint32_t *)in, MXC_AES_DATA_LEN / sizeof(uint32_t)) < 0) { return E_NULL_PTR; } /* Start operation */ MXC_AES->ctrl |= MXC_F_AES_CTRL_START; /* Block, waiting on engine to complete, or fall through if non-blocking */ if ((dir != MXC_E_AES_ENCRYPT_ASYNC) && (dir != MXC_E_AES_DECRYPT_ASYNC)) { while (MXC_AES->ctrl & MXC_F_AES_CTRL_START) { /* Ensure that this wait loop is not optimized out */ __NOP(); } /* Get output from engine */ return AES_GetOutput(out); } return E_SUCCESS; } /* ************************************************************************* */ int AES_GetOutput(uint8_t *out) { /* Don't read it out of the AES memory unless engine is idle */ if (MXC_AES->ctrl & MXC_F_AES_CTRL_START) { return E_BUSY; } /* Pull out result */ if (aes_memcpy32((uint32_t *)out, (uint32_t *)MXC_AES_MEM->out, MXC_AES_DATA_LEN / sizeof(uint32_t)) < 0) { return E_NULL_PTR; } /* Clear interrupt flag, write 1 to clear */ MXC_AES->ctrl |= MXC_F_AES_CTRL_INTFL; return E_SUCCESS; } /** * @internal This memory copy is used only by the AES module to avoid data leakage by the standard C library. * Copy count number of 32-bit locations from in to out */ static int aes_memcpy32(uint32_t *out, uint32_t *in, unsigned int count) { if ((out == NULL) || (in == NULL)) { /* Invalid arguments, but is internal-only so don't use error codes */ return -1; } while (count--) { *out++ = *in++; } return 0; } /**@} end of group aes */