Imported Upstream version 2.6.1

[debian/amanda] / common-src / simpleprng.h

diff --git a/common-src/simpleprng.h b/common-src/simpleprng.h
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+/*
+ * Copyright (c) 2005-2008 Zmanda Inc.  All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program 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 General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ * Contact information: Zmanda Inc, 465 S Mathlida Ave, Suite 300
+ * Sunnyvale, CA 94086, USA, or: http://www.zmanda.com
+ */
+
+#ifndef SIMPLEPRNG_H
+#define        SIMPLEPRNG_H
+
+#include "amanda.h"
+
+/* A very simple, thread-safe PRNG.  This is intended for use in reproducable
+ * generating bytestreams for testing purposes.  It is *not* cryptographically
+ * secure! */
+
+typedef guint32 simpleprng_state_t;
+
+/* Initialize and seed the PRNG
+ *
+ * @param state: pointer to PRNG state
+ * @param seed: initial value
+ */
+void simpleprng_seed(
+    simpleprng_state_t *state,
+    guint32 seed);
+
+/* Get a random guint32
+ *
+ * @param state: pointer to PRNG state
+ * @returns: random integer
+ */
+guint32 simpleprng_rand(
+    simpleprng_state_t *state);
+
+/* Get a random byte
+ *
+ * @param state: pointer to PRNG state
+ * @returns: random integer
+ */
+/* use the high-order bytes, as they're "more random" */
+#define simpleprng_rand_byte(state) \
+    ((guint8)(simpleprng_rand((state)) >> 24))
+
+/* Fill the given buffer with a sequence of bytes
+ *
+ * @param state: pointer to PRNG state
+ * @param buf: buffer to fill
+ * @param len: number of bytes to write
+ */
+void simpleprng_fill_buffer(
+    simpleprng_state_t *state,
+    gpointer buf,
+    size_t len);
+
+/* Verify that a buffer matches the values from the PRNG.
+ *
+ * @param state: pointer to PRNG state
+ * @param buf: buffer to verify
+ * @param len: number of bytes to verify
+ * @returns: true if all bytes match
+ */
+gboolean simpleprng_verify_buffer(
+    simpleprng_state_t *state,
+    gpointer buf,
+    size_t len);
+
+#endif /* SIMPLEPRNG_H */