mirror of https://github.com/ARMmbed/mbed-os.git
124 lines
4.5 KiB
C
124 lines
4.5 KiB
C
/**
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* @file
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* @brief Pseudo-random number generator(PRNG) Peripheral Module.
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* @note The PRNG hardware does not produce true random numbers. The
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* output should be used as a seed to an approved random-number
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* algorithm, per a certifying authority such as NIST or PCI. The
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* approved algorithm will output random numbers which are cerfitied
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* for use in encryption and authentication algorithms.
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*/
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/* ****************************************************************************
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* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
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* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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* Except as contained in this notice, the name of Maxim Integrated
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* Products, Inc. shall not be used except as stated in the Maxim Integrated
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* Products, Inc. Branding Policy.
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*
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* The mere transfer of this software does not imply any licenses
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* of trade secrets, proprietary technology, copyrights, patents,
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* trademarks, maskwork rights, or any other form of intellectual
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* property whatsoever. Maxim Integrated Products, Inc. retains all
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* ownership rights.
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*
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* $Date: 2016-10-10 19:26:15 -0500 (Mon, 10 Oct 2016) $
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* $Revision: 24668 $
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*
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******************************************************************************/
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/* **** Includes **** */
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#include "prng_regs.h"
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/* Define to prevent redundant inclusion */
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#ifndef _PRNG_H_
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#define _PRNG_H_
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#ifdef __cplusplus
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extern "C" {
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#endif
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/**
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* @ingroup periphlibs
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* @defgroup prng Pseudo-Random Number Generator (PRNG)
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* @brief Pseudo-random number generator(PRNG) Peripheral Module.
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* @note The PRNG hardware does not produce true random numbers. The
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* output should be used as a seed to an approved random-number
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* algorithm, per a certifying authority such as NIST or PCI. The
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* approved algorithm will output random numbers which are cerfitied
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* for use in encryption and authentication algorithms.
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* @{
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*/
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/* **** Definitions **** */
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/* **** Globals **** */
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/* **** Function Prototypes **** */
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/**
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* @brief Initialize required clocks and enable PRNG module
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* @note This function will set the clock divisors to divide by 1 if they are disabled.
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* Otherwise, the clock divisors are left unchanged.
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*/
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void PRNG_Init(void);
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/**
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* @brief Returns ready bit to indicates that the PRNG_GetSeed can be
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* called without being held off. Only needs to be called one time after a POR event.
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*
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* @retval 0 PRNG not ready
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* @retval non-zero PRNG ready to read
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*/
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__STATIC_INLINE uint16_t PRNG_Ready(void)
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{
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return (MXC_PRNG->user_entropy & MXC_F_PRNG_USER_ENTROPY_RND_NUM_READY);
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}
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/**
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* @brief Retrieve a seed value from the PRNG.
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* @note The PRNG hardware does not produce true random numbers. The
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* output should be used as a seed to an approved random-number
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* algorithm, per a certifying authority such as NIST or PCI. The
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* approved algorithm will output random numbers which are cerfitied
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* for use in encryption and authentication algorithms.
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*
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* @return 16-bit seed value
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*/
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__STATIC_INLINE uint16_t PRNG_GetSeed(void)
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{
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return MXC_PRNG->rnd_num;
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}
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/**
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* @brief Add user entropy to the PRNG entropy source.
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*
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* @param entropy A value to be mixed into the PRNG entropy source.
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*/
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__STATIC_INLINE void PRNG_AddUserEntropy(uint8_t entropy)
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{
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MXC_PRNG->user_entropy = (uint32_t)entropy;
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}
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/**@}*/
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#ifdef __cplusplus
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}
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#endif
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#endif /* _PRNG_H_ */
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