random.h

BestCrypt开源加密原代码

// $Id: random.h,v 1.2 2002/10/29 07:11:46 crypt Rel-1.6-5 $
#ifndef __RANDOM_H__
#define __RANDOM_H__

#include <stddef.h>
#include "sha1.h"

typedef struct
{
	byte state [ SHA1_DIGEST_SIZE ];	/* Current state buffer */
	byte data  [ SHA1_DIGEST_SIZE ];	/* Stored random data   */

	unsigned int  residue;				/* Quantity of unused bytes */

} sSHA1Random;


#define RNGRESULT unsigned int

enum  { 
	RNG_OK = 0,
	RNG_MALLOC_ERROR,
	RNG_INIT_ERROR
};


/*************************************************************************************\
*
* Function:  SHA1RandomAllocate
*	sSHA1Random **sRandom				- pointer to sSHA1Random structure pointer;
*
* Return value:
*  If successfull return RNG_OK.
*
\*************************************************************************************/
RNGRESULT SHA1RandomAllocate( sSHA1Random **sRandom );


/*************************************************************************************\
*
* Function:  SHA1RandomInit - zeroes random structure.
*	sSHA1Random *sRandom				- pointer to sSHA1Random structure;
*
\*************************************************************************************/
void SHA1RandomInit( sSHA1Random *sRandom );


/*************************************************************************************\
*
* Function:  SHA1RandomUpdate
*	sSHA1Random *sRandom	- pointer to sSHA1Random structure;
*	const byte *seedBuffer	- pointer to initialisation buffer;
*	int seedBufferSize		- size of the initialization buffer;
*
* Description:
*  SHA1RandomInit initializes the sRandom struct by zero.
*  Use this function to initialize current random state by seedBuffer.
*  The seedBufferSize does not limited. State will always padded by SHA1 digest
*  algorithm.
*
\*************************************************************************************/
void SHA1RandomUpdate(
	sSHA1Random *sRandom ,
	const byte *seedBuffer ,
	int seedBufferSize );


/*************************************************************************************\
*
* Function: SHA1RandomGenerateBytes (
*	sSHA1Random *sRandom		- pointer to sSHA1Random structure;
*	unsigned char *buffer	- pointer to buffer for new generated random data
*	unsigned int bufferSize	- size in bytes of required random data
*
* Description:
*  sRandom structure must be initialized by SHA1RandomInit.
*  SHA1RandomGenerate function can by called numerous times.
\*************************************************************************************/
void SHA1RandomGenerateBytes(
	sSHA1Random *sRandom,
	unsigned char *buffer ,
	unsigned int bufferSize);


/*************************************************************************************\
*
* Function: SHA1RandomFinal - deallocate random structure.
* Parameter:
*	sSHA1Random **sRandom		- double pointer to sSHA1Random structure;
*
* Description:
*  secure zeroizes sRandom structure and deallocate it.
\*************************************************************************************/
void SHA1RandomFinal ( sSHA1Random **sRandom );


/*************************************************************************************\
*	Function : SHA1RandomGenerate
*		High level function.
*		Allocate and initialize SHA1 random generator;
*		Set seed by seedBuffer;
*		Generate random sequence of bytes to buffer;
*		Free SHA1 random generator.
*	Params:
*		byte	*byteBuffer ,	- destination buffer for random generation.
*		size_t	byteBufferSize,	- size of destnation buffer in bytes.
*		byte	*seedBuffer ,	- seed byte stream to initaialize prime random generator.
*		size_t	seedBufferSize	- size of seedBuffer in bytes.
*  Return value :
*		Return RNG_OK if successful.
\*************************************************************************************/
extern "C" RNGRESULT SHA1RandomGenerate(
	byte *byteBuffer ,
	size_t byteBufferSize ,
	byte *seedBuffer ,
	size_t seedBufferSize );


//
//	Main difference in random generation is,
//	SHA1RandomGenerateBytesEx does not use 
//		the SHA1RandomReGenerate ( the function simple increments sRandom->state ),
//		SHA1RandomGenerateBytesEx processes current state first and 
//		then processes all seed again.
extern "C" RNGRESULT SHA1RandomGenerateKey(
	byte *byteBuffer ,
	size_t byteBufferSize ,
	byte *seedBuffer ,
	size_t seedBufferSize );

#endif /* __RANDOM_H__ */