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Data Structures | Functions
xoodyak-prng.h File Reference

Pseudorandom number generator (PRNG) built around Xoodoo. More...

#include <stddef.h>

Go to the source code of this file.

Data Structures

union  xoodyak_prng_state_t
 State information for a Xoodoo-based PRNG. More...
 

Functions

void xoodyak_prng_add_ident (const unsigned char *data, size_t size)
 Adds unique identification information for this device to the global pool. More...
 
int xoodyak_prng_init (xoodyak_prng_state_t *state)
 Initializes a Xoodoo-based PRNG. More...
 
void xoodyak_prng_free (xoodyak_prng_state_t *state)
 Frees a Xoodoo-based PRNG and destroys all sensitive information. More...
 
int xoodyak_prng_reseed (xoodyak_prng_state_t *state)
 Forces a Xoodoo-based PRNG to re-seed from the system TRNG. More...
 
void xoodyak_prng_feed (xoodyak_prng_state_t *state, const unsigned char *data, size_t size)
 Feeds data into a Xoodoo-based PRNG state to seed it from other sources besides the system TRNG. More...
 
int xoodyak_prng_fetch (xoodyak_prng_state_t *state, unsigned char *data, size_t size)
 Fetches data from a Xoodoo-based PRNG state. More...
 
int xoodyak_prng_generate (unsigned char *data, size_t size)
 Fetches random data using a Xoodoo-based PRNG. More...
 

Detailed Description

Pseudorandom number generator (PRNG) built around Xoodoo.

This PRNG implementation uses the SpongePRNG construction with Xoodoo as the sponge permutation.

Reference: "Sponge-based pseudo-random number generators", Guido Bertoni et al, https://keccak.team/files/SpongePRNG.pdf

Function Documentation

void xoodyak_prng_add_ident ( const unsigned char *  data,
size_t  size 
)

Adds unique identification information for this device to the global pool.

Parameters
dataPoints to the identification information.
sizeNumber of bytes of identification information.

The application should use this function at startup to add serial numbers and other unique identification information to the global pool for the PRNG. This data does not need to be secret but can help make the generated output unique for each device.

Note
This function is not thread-safe so it should be called at startup before threads start using the PRNG to generate random data.
void xoodyak_prng_feed ( xoodyak_prng_state_t state,
const unsigned char *  data,
size_t  size 
)

Feeds data into a Xoodoo-based PRNG state to seed it from other sources besides the system TRNG.

Parameters
statePRNG state to be feed new seed data.
dataPoints to the data to be fed into the PRNG state.
sizeNumber of bytes of data to be fed into the PRNG state.
int xoodyak_prng_fetch ( xoodyak_prng_state_t state,
unsigned char *  data,
size_t  size 
)

Fetches data from a Xoodoo-based PRNG state.

Parameters
statePRNG state to fetch data from.
dataPoints to a buffer to receive the generated random data.
sizeNumber of bytes of random data to be generated.
Returns
Zero if the PRNG was re-seeded from the system TRNG during the fetch but there is no system TRNG or it has failed.
void xoodyak_prng_free ( xoodyak_prng_state_t state)

Frees a Xoodoo-based PRNG and destroys all sensitive information.

Parameters
statePRNG state to be freed.
int xoodyak_prng_generate ( unsigned char *  data,
size_t  size 
)

Fetches random data using a Xoodoo-based PRNG.

Parameters
dataPoints to a buffer to receive the generated random data.
sizeNumber of bytes of random data to be generated.
Returns
Non-zero if the PRNG was initialized from system TRNG data, or zero if there is no system TRNG or it has failed.

This function will create a temporary PRNG state object, seed it from the system TRNG, and then generate size bytes of random data. It is intended for quick one-off generation of random material.

int xoodyak_prng_init ( xoodyak_prng_state_t state)

Initializes a Xoodoo-based PRNG.

Parameters
statePRNG state to be initialized.
Returns
Non-zero if the PRNG was initialized from system TRNG data, or zero if there is no system TRNG or it has failed.

This function will fetch fresh data from the system TRNG to prepare the PRNG state to generate random data.

int xoodyak_prng_reseed ( xoodyak_prng_state_t state)

Forces a Xoodoo-based PRNG to re-seed from the system TRNG.

Parameters
statePRNG state to be re-seeded.
Returns
Non-zero if the PRNG was re-seeded from system TRNG data, or zero if there is no system TRNG or it has failed.