/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ #ifndef __fsprgh__ #define __fsprgh__ /* * fsprg v0.1 - (seekable) forward-secure pseudorandom generator * Copyright (C) 2012 B. Poettering * Contact: fsprg@point-at-infinity.org * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301 USA * */ #include <sys/types.h> #include <inttypes.h> #include "macro.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. */ void 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. */ void FSPRG_GenState0(void *state, const void *mpk, const void *seed, size_t seedlen); void 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). */ void FSPRG_Seek(void *state, uint64_t epoch, const void *msk, const void *seed, size_t seedlen); void FSPRG_GetKey(const void *state, void *key, size_t keylen, uint32_t idx); #ifdef __cplusplus } #endif #endif