Files
Linux_Drivers/fsbl/lib/BigDigits/bigdRand.h
forum_service 88cce7a8a2 fsbl: weekly update 2023-03-25
1. update release func

Change-Id: I221476630ce4f2f6a01e8f89fd96d9ac9701a270
2023-03-27 00:22:46 +08:00

70 lines
2.2 KiB
C

/* $Id: bigdRand.h $ */
/** @file
Interface for BigDigits "bd" random number functions using a "pretty-good" internal RNG
@par The internal random number generator (RNG)
The internal RNG uses a variant of the random number generation algorithm
in Appendix A of ANSI X9.31-1998, but using the Tiny Encryption Algorithm (TEAX)
instead of the Data Encryption Algorithm (DEA).
It uses the current time and process ID as a seed.
Although not strictly crypto secure, it is "pretty good", and certainly much better than
anything using the built-in rand() function in C. Look at the source code and make your own call.
@par
If you want proper cryptographic security, use the bdRandomSeeded() function with a call to a
secure RNG function that you trust.
*/
/***** BEGIN LICENSE BLOCK *****
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright (c) 2001-16 David Ireland, D.I. Management Services Pty Limited
* <http://www.di-mgt.com.au/bigdigits.html>. All rights reserved.
*
***** END LICENSE BLOCK *****/
/*
* Last updated:
* $Date: 2016-03-31 09:51:00 $
* $Revision: 2.6.1 $
* $Author: dai $
*/
#ifndef BIGDRAND_H_
#define BIGDRAND_H_ 1
#include "bigd.h"
#include "bigdRand.h"
#ifdef __cplusplus
extern "C" {
#endif
/** Generate a single random digit using internal RNG. */
bdigit_t bdRandDigit(void);
/** Generate a random BIGD number of bit length at most \c nbits using internal RNG
@param[out] a to receive generated random number
@param[in] nbits maximum number of bits
@returns Number of digits actually set
*/
size_t bdRandomBits(BIGD a, size_t nbits);
/* Added in [v2.4] */
/** Generate array of random octets (bytes) using internal RNG
* @remarks This function is in the correct form for BD_RANDFUNC.
*/
int bdRandomOctets(unsigned char *bytes, size_t nbytes, const unsigned char *seed, size_t seedlen);
/** Generate a number at random from a uniform distribution in [0, n-1] */
size_t bdRandomNumber(BIGD a, BIGD n);
#ifdef __cplusplus
}
#endif
#endif /* BIGDRAND_H_ */