- randomizer_t written and tested

1 files changed, 197 insertions, 0 deletions

diff --git a/Source/charon/utils/randomizer.c b/Source/charon/utils/randomizer.c
new file mode 100644
index 000000000..90ad95bcb
--- /dev/null
+++ b/Source/charon/utils/randomizer.c
@@ -0,0 +1,197 @@
+/**
+ * @file randomizer.c
+ * 
+ * @brief Class used to get random and pseudo random values
+ * 
+ */
+
+/*
+ * 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 "allocator.h"
+
+/**
+ * Default random device used when no device is given.
+ */
+#define DEFAULT_RANDOM_DEVICE "/dev/random"
+
+/**
+ * Pseudo random device used when no device is given.
+ */
+#define DEFAULT_PSEUDO_RANDOM_DEVICE "/dev/urandom"
+
+typedef struct private_randomizer_s private_randomizer_t;
+
+struct private_randomizer_s {
+	/**
+	 * public interface
+	 */
+	randomizer_t public;
+	
+	/**
+	 * @brief Reads a specific number of bytes from random or pseudo random device
+	 * 
+	 * @param pseudo_random			TRUE, if 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.
+	 * @return
+	 * 								- SUCCESS
+	 * 								- FAILED
+	 */
+	status_t (*get_bytes_from_device) (private_randomizer_t *this,bool pseudo_random, size_t bytes, u_int8_t *buffer);
+		
+	/**
+	 * Random device name
+	 */
+	char *random_dev_name;
+	
+	/**
+	 * Pseudo random device name
+	 */
+	char *pseudo_random_dev_name;
+};
+
+
+/**
+ * Implements private_randomizer_t's get_bytes_from_device function.
+ * See #private_randomizer_t.get_bytes_from_device for description.
+ */
+static status_t get_bytes_from_device(private_randomizer_t *this,bool pseudo_random, size_t bytes, u_int8_t *buffer)
+{
+	/* number of bytes already done */
+	size_t ndone;
+	/* device file descriptor */
+	int device;
+	size_t got;
+	char * device_name;
+
+	device_name = (pseudo_random) ? this->pseudo_random_dev_name : this->random_dev_name;
+
+	// open 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) {
+			return FAILED;
+		}
+		if (got == 0) {
+			return FAILED;
+		}
+		ndone += got;
+	}
+	// close device
+	close(device);
+	return SUCCESS;
+}
+
+/**
+ * Implements randomizer_t's get_random_bytes function.
+ * See #randomizer_t.get_random_bytes for description.
+ */
+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));
+}
+
+/**
+ * Implements randomizer_t's get_pseudo_random_bytes function.
+ * See #randomizer_t.get_pseudo_random_bytes for description.
+ */
+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));
+}
+
+/**
+ * Implements randomizer_t's destroy function.
+ * See #randomizer_t.destroy for description.
+ */
+static status_t destroy(private_randomizer_t *this)
+{
+	allocator_free(this->random_dev_name);
+	allocator_free(this->pseudo_random_dev_name);
+	allocator_free(this);
+	
+	return SUCCESS;
+}
+
+/*
+ * Described in header.
+ */
+randomizer_t *randomizer_create(void)
+{
+	return randomizer_create_on_devices(DEFAULT_RANDOM_DEVICE,DEFAULT_PSEUDO_RANDOM_DEVICE);
+}
+
+/*
+ * Described in header.
+ */
+randomizer_t *randomizer_create_on_devices(char * random_dev_name,char * prandom_dev_name)
+{
+	private_randomizer_t *this = allocator_alloc_thing(private_randomizer_t);
+	if (this == NULL)
+	{
+		return NULL;
+	}
+	if ((random_dev_name == NULL) || (prandom_dev_name == NULL))
+	{
+		return NULL;
+	}
+	
+	/* public functions */
+	this->public.get_random_bytes = (status_t (*) (randomizer_t *,size_t, u_int8_t *)) get_random_bytes;
+	this->public.get_pseudo_random_bytes = (status_t (*) (randomizer_t *,size_t, u_int8_t *)) get_pseudo_random_bytes;
+	this->public.destroy = (status_t (*) (randomizer_t *))destroy;
+	
+	/* private functions */
+	this->get_bytes_from_device = get_bytes_from_device;
+	
+	/* private fields */
+	this->random_dev_name = allocator_alloc(strlen(random_dev_name) + 1);
+	if (this->random_dev_name == NULL)
+	{
+		allocator_free(this);
+		return NULL;
+	}
+	strcpy(this->random_dev_name,random_dev_name);
+	
+	this->pseudo_random_dev_name = allocator_alloc(strlen(prandom_dev_name) + 1);
+	if (this->pseudo_random_dev_name == NULL)
+	{
+		allocator_free(this->random_dev_name);
+		allocator_free(this);
+		return NULL;
+	}
+	strcpy(this->pseudo_random_dev_name,prandom_dev_name);	
+	
+	return &(this->public);
+}