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			61 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * SPDX-FileCopyrightText: 2010-2021 Espressif Systems (Shanghai) CO LTD
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 *
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 * SPDX-License-Identifier: Apache-2.0
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 */
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#pragma once
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#include <stddef.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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 * @brief Enable an entropy source for RNG if RF subsystem is disabled
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 *
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 * @warning This function is not safe to use if any other subsystem is accessing the RF subsystem or
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 *          the ADC at the same time!
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 *
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 * The exact internal entropy source mechanism depends on the chip in use but
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 * all SoCs use the SAR ADC to continuously mix random bits (an internal
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 * noise reading) into the HWRNG. Consult the SoC Technical Reference
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 * Manual for more information.
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 *
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 * Can also be called from app code, if true random numbers are required without initialized RF subsystem.
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 * This might be the case in early startup code of the application when the RF subsystem has not
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 * started yet or if the RF subsystem should not be enabled for power saving.
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 *
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 * Consult ESP-IDF Programming Guide "Random Number Generation" section for
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 * details.
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 */
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void bootloader_random_enable(void);
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/**
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 * @brief Disable entropy source for RNG
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 *
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 * Disables internal entropy source. Must be called after
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 * bootloader_random_enable() and before RF subsystem features, ADC, or
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 * I2S (ESP32 only) are initialized.
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 *
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 * Consult the ESP-IDF Programming Guide "Random Number Generation"
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 * section for details.
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 */
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void bootloader_random_disable(void);
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/**
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 * @brief Fill buffer with 'length' random bytes
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 *
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 * @note If this function is being called from app code only, and never
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 * from the bootloader, then it's better to call esp_fill_random().
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 *
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 * @param buffer Pointer to buffer
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 * @param length This many bytes of random data will be copied to buffer
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 */
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void bootloader_fill_random(void *buffer, size_t length);
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#ifdef __cplusplus
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}
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#endif
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