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Separate XorShift128 PRNG from /dev/urandom and make it generally available.

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This commit is contained in:
Gregory Nutt 2016-08-20 11:36:02 -06:00
parent a5440fff64
commit 6f833be9d5
5 changed files with 254 additions and 62 deletions
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77
drivers/dev_urandom.c
View File

@ -51,6 +51,7 @@
#include <errno.h>
#include <nuttx/lib/lib.h>
#include <nuttx/lib/xorshift128.h>
#include <nuttx/fs/fs.h>
#include <nuttx/drivers/drivers.h>
@ -75,17 +76,13 @@
* Private Types
****************************************************************************/
typedef union
struct xorshift128_state_s
{
struct
{
uint32_t x;
uint32_t y;
uint32_t z;
uint32_t w;
};
uint8_t u[16];
} xorshift128_state_t;
uint32_t x;
uint32_t y;
uint32_t z;
uint32_t w;
};
/****************************************************************************
* Private Function Prototypes
@ -106,7 +103,7 @@ static int devurand_poll(FAR struct file *filep, FAR struct pollfd *fds,
* Private Data
****************************************************************************/
static const struct file_operations devurand_fops =
static const struct file_operations g_urand_fops =
{
NULL, /* open */
NULL, /* close */
@ -122,37 +119,10 @@ static const struct file_operations devurand_fops =
#endif
};
#ifdef CONFIG_DEV_URANDOM_XORSHIFT128
static xorshift128_state_t prng;
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: xorshift128
****************************************************************************/
#ifdef CONFIG_DEV_URANDOM_XORSHIFT128
static uint32_t xorshift128(void)
{
uint32_t t = prng.x;
t ^= t << 11;
t ^= t >> 8;
prng.x = prng.y;
prng.y = prng.z;
prng.z = prng.w;
prng.w ^= prng.w >> 19;
prng.w ^= t;
return prng.w;
}
#endif
/****************************************************************************
* Name: congruential
****************************************************************************/
@ -241,14 +211,26 @@ static ssize_t devurand_write(FAR struct file *filep, FAR const char *buffer,
#ifdef CONFIG_DEV_URANDOM_CONGRUENTIAL
unsigned int seed = 0;
len = min(len, sizeof(unsigned int));
memcpy(&seed, buffer, len);
if (len < sizeof(unsigned int))
{
return -ERANGE;
}
memcpy(&seed, buffer, sizeof(unsigned int));
srand(seed);
return len;
return sizeof(unsigned int);
#else
len = min(len, sizeof(prng.u));
memcpy(&prng.u, buffer, len);
return len;
struct xorshift128_state_s seed;
if (len < sizeof(struct xorshift128_state_s))
{
return -ERANGE;
}
memcpy(&seed, buffer, sizeof(struct xorshift128_state_s));
xorshift128_seed(seed.w, seed.x, seed.y, seed.z);
return sizeof(struct xorshift128_state_s);
#endif
}
@ -292,13 +274,10 @@ void devurandom_register(void)
#else
/* Seed the PRNG */
prng.w = 97;
prng.x = 101;
prng.y = prng.w << 17;
prng.z = prng.x << 25;
xorshift128_seed(97, 101, 97 << 17, 101 << 25);
#endif
(void)register_driver("/dev/urandom", &devurand_fops, 0666, NULL);
(void)register_driver("/dev/urandom", &g_urand_fops, 0666, NULL);
}
#endif /* CONFIG_DEV_URANDOM && CONFIG_DEV_URANDOM_ARCH */

98
include/nuttx/lib/xorshift128.h Normal file
View File

@ -0,0 +1,98 @@
/****************************************************************************
* include/nuttx/lib/xorshift128.h
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: David S. Alessio
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/* This random number generator is simple, fast and portable.
* Ref: https://en.wikipedia.org/wiki/Xorshift
*/
#ifndef __INCLUDE_NUTTX_LIB_XORSHIFT128_H
#define __INCLUDE_NUTTX_LIB_XORSHIFT128_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: xorshift128_seed
*
* Description:
* Seed the XorShift128 PRNG
*
* Input Parameters:
* w, x, y, z: Values for XorShift128 generation state.
*
* Returned Value:
* No
*
****************************************************************************/
void xorshift128_seed(uint32_t w, uint32_t x, uint32_t y, uint32_t z);
/****************************************************************************
* Name: xorshift128
*
* Description:
* Generate one 32-bit pseudo-random number
*
* Input Parameters:
* None
*
* Returned Value:
* The generated pseudo-random number
*
****************************************************************************/
uint32_t xorshift128(void);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_LIB_XORSHIFT128_H */

2
libc/misc/Make.defs
View File

@ -36,7 +36,7 @@
# Add the internal C files to the build
CSRCS += lib_stream.c lib_filesem.c lib_utsname.c
CSRCS += lib_tea_encrypt.c lib_tea_decrypt.c
CSRCS += lib_xorshift128.c lib_tea_encrypt.c lib_tea_decrypt.c
# Support for platforms that do not have long long types

123
libc/misc/lib_xorshift128.c Normal file
View File

@ -0,0 +1,123 @@
/****************************************************************************
* libc/misc/lib_xorshift.c
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: David S. Alessio
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/* This random number generator is simple, fast and portable.
* Ref: https://en.wikipedia.org/wiki/Xorshift
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
/****************************************************************************
* Private Types
****************************************************************************/
struct xorshift128_state_s
{
uint32_t x;
uint32_t y;
uint32_t z;
uint32_t w;
};
/****************************************************************************
* Private Data
****************************************************************************/
static struct xorshift128_state_s g_prng;
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: xorshift128_seed
*
* Description:
* Seed the XorShift128 PRNG
*
* Input Parameters:
* w, x, y, z: Values for XorShift128 generation state.
*
* Returned Value:
* No
*
****************************************************************************/
void xorshift128_seed(uint32_t w, uint32_t x, uint32_t y, uint32_t z)
{
/* Seed the PRNG */
g_prng.w = w;
g_prng.x = x;
g_prng.y = y;
g_prng.z = z;
}
/****************************************************************************
* Name: xorshift128
*
* Description:
* Generate one 32-bit pseudo-random number
*
* Input Parameters:
* None
*
* Returned Value:
* The generated pseudo-random number
*
****************************************************************************/
uint32_t xorshift128(void)
{
uint32_t t;
t = g_prng.x;
t ^= t << 11;
t ^= t >> 8;
g_prng.x = g_prng.y;
g_prng.y = g_prng.z;
g_prng.z = g_prng.w;
g_prng.w ^= g_prng.w >> 19;
g_prng.w ^= t;
return g_prng.w;
}

16
sched/sched/sched_processtimer.c
View File

@ -50,14 +50,6 @@
#include "wdog/wdog.h"
#include "clock/clock.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_SCHED_CPULOAD_TIMECONSTANT
# define CONFIG_SCHED_CPULOAD_TIMECONSTANT 2
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
@ -69,10 +61,10 @@
* Check for operations specific to scheduling policy of the currently
* active task.
*
* Inputs:
* Input Parameters:
* None
*
* Return Value:
* Returned Value:
* None
*
****************************************************************************/
@ -134,10 +126,10 @@ static inline void sched_process_scheduler(void)
* function periodically -- the calling interval must be
* USEC_PER_TICK
*
* Inputs:
* Input Parameters:
* None
*
* Return Value:
* Returned Value:
* None
*
****************************************************************************/