incubator-nuttx/include/nuttx/random.h

155 lines
5.1 KiB
C

/****************************************************************************
* include/nuttx/random.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_RANDOM_H
#define __INCLUDE_NUTTX_RANDOM_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stddef.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Size of entropy pool in 32-bit integers, must be power of two */
#define ENTROPY_POOL_SIZE 128
#define add_irq_randomness(x) up_rngaddint(RND_SRC_IRQ, (x))
#define add_sensor_randomness(x) up_rngaddint(RND_SRC_SENSOR, (x))
#define add_time_randomness(x) up_rngaddint(RND_SRC_TIME, (x))
#define add_hw_randomness(x) up_rngaddint(RND_SRC_HW, (x))
#define add_sw_randomness(x) up_rngaddint(RND_SRC_SW, (x))
#define add_ui_randomness(x) up_rngaddint(RND_SRC_UI, (x))
/* Allow above macros to always exist in source without ifdefs */
#ifndef CONFIG_CRYPTO_RANDOM_POOL
# define up_rngaddint(k, x) ((void)(k),(void)(x))
# define up_rngaddentropy(k, buf, x) ((void)(k),(void)(buf),(void)(x))
#endif
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/* Entropy pool structure */
struct entropy_pool_s
{
volatile uint32_t pool[ENTROPY_POOL_SIZE];
};
/* Randomness sources */
enum rnd_source_t
{
RND_SRC_TIME = 0,
RND_SRC_IRQ,
RND_SRC_SENSOR,
RND_SRC_HW, /* unique per HW UID or coming from factory line. */
RND_SRC_SW, /* unique per SW version. */
RND_SRC_UI /* buttons etc. user-visible interface elements. */
};
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef CONFIG_BOARD_ENTROPY_POOL
/* Entropy pool structure can be provided by board source. Use for this is,
* for example, allocate entropy pool from special area of RAM which content
* is kept over system reset.
*/
extern struct entropy_pool_s board_entropy_pool;
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef CONFIG_CRYPTO_RANDOM_POOL
/****************************************************************************
* Name: up_rngaddint
*
* Description:
* Add one integer to entropy pool, contributing a specific kind
* of entropy to pool.
*
* Input Parameters:
* kindof - Enumeration constant telling where val came from
* val - Integer to be added
*
* Returned Value:
* None
*
****************************************************************************/
void up_rngaddint(enum rnd_source_t kindof, int val);
/****************************************************************************
* Name: up_rngaddentropy
*
* Description:
* Add buffer of integers to entropy pool.
*
* Input Parameters:
* kindof - Enumeration constant telling where val came from
* buf - Buffer of integers to be added
* n - Number of elements in buf
*
* Returned Value:
* None
*
****************************************************************************/
void up_rngaddentropy(enum rnd_source_t kindof, FAR const uint32_t *buf,
size_t n);
/****************************************************************************
* Name: up_rngreseed
*
* Description:
* Force reseeding random number generator from entropy pool
*
****************************************************************************/
void up_rngreseed(void);
/****************************************************************************
* Name: up_randompool_initialize
*
* Description:
* Initialize entropy pool and random number generator
*
****************************************************************************/
void up_randompool_initialize(void);
#endif /* CONFIG_CRYPTO_RANDOM_POOL */
#endif /* __INCLUDE_NUTTX_RANDOM_H */