[thirdparty/systemd.git] / src / libsystemd / sd-journal / fsprg.h

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once

/*
 * fsprg v0.1  -  (seekable) forward-secure pseudorandom generator
 * Copyright © 2012 B. Poettering
 * Contact: fsprg@point-at-infinity.org
 */

#include "forward.h"

#ifdef __cplusplus
extern "C" {
#endif

#define FSPRG_RECOMMENDED_SECPAR 1536
#define FSPRG_RECOMMENDED_SEEDLEN (96/8)

size_t FSPRG_mskinbytes(unsigned secpar) _const_;
size_t FSPRG_mpkinbytes(unsigned secpar) _const_;
size_t FSPRG_stateinbytes(unsigned secpar) _const_;

/* Setup msk and mpk. Providing seed != NULL makes this algorithm deterministic. */
int FSPRG_GenMK(void *msk, void *mpk, const void *seed, size_t seedlen, unsigned secpar);

/* Initialize state deterministically in dependence on seed. */
/* Note: in case one wants to run only one GenState0 per GenMK it is safe to use
   the same seed for both GenMK and GenState0.
*/
int FSPRG_GenState0(void *state, const void *mpk, const void *seed, size_t seedlen);

int FSPRG_Evolve(void *state);

uint64_t FSPRG_GetEpoch(const void *state) _pure_;

/* Seek to any arbitrary state (by providing msk together with seed from GenState0). */
int FSPRG_Seek(void *state, uint64_t epoch, const void *msk, const void *seed, size_t seedlen);

int FSPRG_GetKey(const void *state, void *key, size_t keylen, uint32_t idx);

#ifdef __cplusplus
}
#endif
Commit	Line	Data
	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
	2	#pragma once
	3
	4	/*
	5	* fsprg v0.1 - (seekable) forward-secure pseudorandom generator
	6	* Copyright © 2012 B. Poettering
	7	* Contact: fsprg@point-at-infinity.org
	8	*/
	9
	10	#include "forward.h"
	11
	12	#ifdef __cplusplus
	13	extern "C" {
	14	#endif
	15
	16	#define FSPRG_RECOMMENDED_SECPAR 1536
	17	#define FSPRG_RECOMMENDED_SEEDLEN (96/8)
	18
	19	size_t FSPRG_mskinbytes(unsigned secpar) _const_;
	20	size_t FSPRG_mpkinbytes(unsigned secpar) _const_;
	21	size_t FSPRG_stateinbytes(unsigned secpar) _const_;
	22
	23	/* Setup msk and mpk. Providing seed != NULL makes this algorithm deterministic. */
	24	int FSPRG_GenMK(void msk, void mpk, const void *seed, size_t seedlen, unsigned secpar);
	25
	26	/* Initialize state deterministically in dependence on seed. */
	27	/* Note: in case one wants to run only one GenState0 per GenMK it is safe to use
	28	the same seed for both GenMK and GenState0.
	29	*/
	30	int FSPRG_GenState0(void state, const void mpk, const void *seed, size_t seedlen);
	31
	32	int FSPRG_Evolve(void *state);
	33
	34	uint64_t FSPRG_GetEpoch(const void *state) _pure_;
	35
	36	/* Seek to any arbitrary state (by providing msk together with seed from GenState0). */
	37	int FSPRG_Seek(void state, uint64_t epoch, const void msk, const void *seed, size_t seedlen);
	38
	39	int FSPRG_GetKey(const void state, void key, size_t keylen, uint32_t idx);
	40
	41	#ifdef __cplusplus
	42	}
	43	#endif