esp-idf/components/esp_hw_support/include/esp_random.h
Sudeep Mohanty a9fda54d39 esp_hw_support/esp_system: Re-evaluate header inclusions and include directories
This commit updates the visibility of various header files and cleans up
some unnecessary inclusions. Also, this commit removes certain header
include paths which were maintained for backward compatibility.
2022-03-07 11:18:08 +05:30

48 lines
1.2 KiB
C

/*
* SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef __ESP_RANDOM_H__
#define __ESP_RANDOM_H__
#include <stddef.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Get one random 32-bit word from hardware RNG
*
* If Wi-Fi or Bluetooth are enabled, this function returns true random numbers. In other
* situations, if true random numbers are required then consult the ESP-IDF Programming
* Guide "Random Number Generation" section for necessary prerequisites.
*
* This function automatically busy-waits to ensure enough external entropy has been
* introduced into the hardware RNG state, before returning a new random number. This delay
* is very short (always less than 100 CPU cycles).
*
* @return Random value between 0 and UINT32_MAX
*/
uint32_t esp_random(void);
/**
* @brief Fill a buffer with random bytes from hardware RNG
*
* @note This function is implemented via calls to esp_random(), so the same
* constraints apply.
*
* @param buf Pointer to buffer to fill with random numbers.
* @param len Length of buffer in bytes
*/
void esp_fill_random(void *buf, size_t len);
#ifdef __cplusplus
}
#endif
#endif /* __ESP_RANDOM_H__ */