../svn-commit.tmp

Source/lib/utils/randomizer.c

@@ -0,0 +1,165 @@
+/**
+ * @file randomizer.c
+ * 
+ * @brief Implementation of randomizer_t.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "randomizer.h"
+
+#include <utils/allocator.h>
+
+typedef struct private_randomizer_t private_randomizer_t;
+
+/**
+ * Private data of an randomizer_t object.
+ */
+struct private_randomizer_t {
+
+	/**
+	 * Public randomizer_t interface.
+	 */
+	randomizer_t public;
+	
+	/**
+	 * @brief Reads a specific number of bytes from random or pseudo random device.
+	 * 
+	 * @param this					calling object
+	 * @param pseudo_random			TRUE, if from pseudo random bytes should be read,
+	 * 								FALSE for true random bytes
+	 * @param bytes					number of bytes to read
+	 * @param[out] buffer			pointer to buffer where to write the data in.
+	 * 								Size of buffer has to be at least bytes.
+	 */
+	status_t (*get_bytes_from_device) (private_randomizer_t *this,bool pseudo_random, size_t bytes, u_int8_t *buffer);
+};
+
+
+/**
+ * Implementation of private_randomizer_t.get_bytes_from_device.
+ */
+static status_t get_bytes_from_device(private_randomizer_t *this,bool pseudo_random, size_t bytes, u_int8_t *buffer)
+{
+	size_t ndone;
+	int device;
+	size_t got;
+	char * device_name;
+
+	device_name = pseudo_random ? RANDOM_DEVICE : PSEUDO_RANDOM_DEVICE;
+
+	device = open(device_name, 0);
+	if (device < 0) {
+		return FAILED;
+	}
+	ndone = 0;
+	
+	/* read until nbytes are read */
+	while (ndone < bytes)
+	{
+		got = read(device, buffer + ndone, bytes - ndone);
+		if (got <= 0) {
+			close(device);
+			return FAILED;
+		}
+		ndone += got;
+	}
+	close(device);
+	return SUCCESS;
+}
+
+/**
+ * Implementation of randomizer_t.get_random_bytes.
+ */
+static status_t get_random_bytes(private_randomizer_t *this,size_t bytes, u_int8_t *buffer)
+{
+	return this->get_bytes_from_device(this, FALSE, bytes, buffer);
+}
+
+/**
+ * Implementation of randomizer_t.allocate_random_bytes.
+ */
+static status_t allocate_random_bytes(private_randomizer_t *this, size_t bytes, chunk_t *chunk)
+{
+	status_t status;
+	chunk->len = bytes;
+	chunk->ptr = allocator_alloc(bytes);
+	status = this->get_bytes_from_device(this, FALSE, bytes, chunk->ptr);
+	if (status != SUCCESS)
+	{
+		allocator_free(chunk->ptr);
+	}
+	return status;
+}
+
+/**
+ * Implementation of randomizer_t.get_pseudo_random_bytes.
+ */
+static status_t get_pseudo_random_bytes(private_randomizer_t *this,size_t bytes, u_int8_t *buffer)
+{
+	return (this->get_bytes_from_device(this, TRUE, bytes, buffer));
+}
+
+/**
+ * Implementation of randomizer_t.allocate_pseudo_random_bytes.
+ */
+static status_t allocate_pseudo_random_bytes(private_randomizer_t *this, size_t bytes, chunk_t *chunk)
+{
+	status_t status;
+	chunk->len = bytes;
+	chunk->ptr = allocator_alloc(bytes);
+	status = this->get_bytes_from_device(this, TRUE, bytes, chunk->ptr);
+	if (status != SUCCESS)
+	{
+		allocator_free(chunk->ptr);
+	}
+	return status;
+}
+
+/**
+ * Implementation of randomizer_t.destroy.
+ */
+static void destroy(private_randomizer_t *this)
+{
+	allocator_free(this);
+}
+
+/*
+ * Described in header.
+ */
+randomizer_t *randomizer_create(void)
+{
+	private_randomizer_t *this = allocator_alloc_thing(private_randomizer_t);
+
+	/* public functions */
+	this->public.get_random_bytes = (status_t (*) (randomizer_t *,size_t, u_int8_t *)) get_random_bytes;
+	this->public.allocate_random_bytes = (status_t (*) (randomizer_t *,size_t, chunk_t *)) allocate_random_bytes;
+	this->public.get_pseudo_random_bytes = (status_t (*) (randomizer_t *,size_t, u_int8_t *)) get_pseudo_random_bytes;
+	this->public.allocate_pseudo_random_bytes = (status_t (*) (randomizer_t *,size_t, chunk_t *)) allocate_pseudo_random_bytes;
+	this->public.destroy = (void (*) (randomizer_t *))destroy;
+	
+	/* private functions */
+	this->get_bytes_from_device = get_bytes_from_device;
+	
+	return &(this->public);
+}