journald: initial version of FSPRG hookup

[elogind.git] / src / journal / fsprg.h

diff --git a/src/journal/fsprg.h b/src/journal/fsprg.h
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+++ b/src/journal/fsprg.h
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+/*-*- 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>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define FSPRG_RECOMMENDED_SECPAR 1536
+#define FSPRG_RECOMMENDED_SEEDLEN (96/8)
+
+size_t FSPRG_mskinbytes(unsigned secpar);
+size_t FSPRG_mpkinbytes(unsigned secpar);
+size_t FSPRG_stateinbytes(unsigned secpar);
+
+/* 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);
+
+/* 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