/* Copyright 2003-2006, Voltage Security, all rights reserved.
 */

#include "vibecrypto.h"
#include "environment.h"
#include "base.h"
#include "libctx.h"
#include "algobj.h"
#include "random.h"
#include "mpint.h"

#ifndef _FIPS_186_2_PRNG_H
#define _FIPS_186_2_PRNG_H

#ifdef __cplusplus
extern "C" {
#endif

/* Implements VSeedRandom.
 */
int VOLT_CALLING_CONV FIPS186SeedRandom VOLT_PROTO_LIST ((
   VoltRandomObject *obj,
   unsigned char *seedData,
   unsigned int seedLen
));

/* Implements VGenerateRandomBytes.
 */
int VOLT_CALLING_CONV FIPS186GenerateRandomBytes VOLT_PROTO_LIST ((
   VoltRandomObject *obj,
   unsigned char *randomBytes,
   unsigned int randomLen
));

/* What are the allowed XKEY sizes? These are the amounts the app can
 * pass in to avoid the INVALID_SET_INFO error.
 */
#define FIPS_186_PRNG_MIN_XKEY_SIZE  32
#define FIPS_186_PRNG_MAX_XKEY_SIZE  32

/* What is the sufficient seed length? This is the amount the app needs
 * to pass in to avoid the INSUFFICIENT_SEED error.
 */
#define FIPS_186_PRNG_MIN_SEED_LEN   32

/* How big is the buffer that holds output bytes? This buffer will be
 * the place where the bytes produced are first stored. Then as many
 * as necessary will go to the output buffer. The number produced may
 * be more than needed, so the rest will stick around in case another
 * call to Generate is made.
 */
#define FIPS_186_PRNG_OUTPUT_BLOCK_SIZE  20

/* Use these values to determine what to compare and what to output.
 */
#define VOLT_FIPS_186_INIT             0
#define VOLT_FIPS_186_NO_BUFFER        1
#define VOLT_FIPS_186_PREVIOUS_BUFFER  2
#define VOLT_FIPS_186_CURRENT_BUFFER   3

/* The localCtx for FIPS 186 PRNG looks like this.
 */
typedef struct
{
  unsigned int variation;
  unsigned int blockSizeBits;
  unsigned int byteSize;
  VoltMpIntCtx *mpCtx;
  VoltMpInt *primeQ;
  VoltMpInt *base;
  VoltMpInt *reduction;
  unsigned char *xseed;
  unsigned char *xkey;
  unsigned char *seedBuffer;
  unsigned int seedLen;
  unsigned int seedCount;
  VtAlgorithmObject digestObj;
  unsigned int currentBytesLen;
  unsigned int currentBytesOffset;
  unsigned int previousBytesFlag;
  unsigned char currentBytes[2 * FIPS_186_PRNG_OUTPUT_BLOCK_SIZE];
  unsigned char previousBytes[2 * FIPS_186_PRNG_OUTPUT_BLOCK_SIZE];
} VoltFips186PrngCtx;

/* Implements VCtxDestroy.
 */
void VOLT_CALLING_CONV FIPS186CtxDestroy VOLT_PROTO_LIST ((
   Pointer obj,
   Pointer ctx
));

#ifdef __cplusplus
}
#endif

#endif /* _FIPS_186_2_PRNG_H */