- randomizer_t written and tested
authorJan Hutter <jhutter@hsr.ch>
Wed, 16 Nov 2005 08:36:31 +0000 (08:36 -0000)
committerJan Hutter <jhutter@hsr.ch>
Wed, 16 Nov 2005 08:36:31 +0000 (08:36 -0000)
Source/charon/utils/randomizer.c [new file with mode: 0644]
Source/charon/utils/randomizer.h [new file with mode: 0644]

diff --git a/Source/charon/utils/randomizer.c b/Source/charon/utils/randomizer.c
new file mode 100644 (file)
index 0000000..90ad95b
--- /dev/null
@@ -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);
+}
diff --git a/Source/charon/utils/randomizer.h b/Source/charon/utils/randomizer.h
new file mode 100644 (file)
index 0000000..ae2bb53
--- /dev/null
@@ -0,0 +1,94 @@
+/**
+ * @file randomizer.h
+ * 
+ * @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.
+ */
+
+#ifndef RANDOMIZER_H_
+#define RANDOMIZER_H_
+
+#include "../types.h"
+
+/**
+ * Object representing an randomizer
+ * 
+ * This class is thread save as file system read calls are thread save...
+ */
+typedef struct randomizer_s randomizer_t;
+
+struct randomizer_s {
+       
+       /**
+        * @brief Reads a specific number of bytes from random device.
+        * 
+        * @param this                                  calling randomizer_t object
+        * @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_random_bytes) (randomizer_t *this,size_t bytes, u_int8_t *buffer);
+       
+       /**
+        * @brief Reads a specific number of bytes from pseudo random device.
+        * 
+        * @param this                                  calling randomizer_t object
+        * @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_pseudo_random_bytes) (randomizer_t *this,size_t bytes, u_int8_t *buffer);
+
+
+       /**
+        * @brief Destroys a randomizer_t object.
+        *
+        * @param this  randomizer_t object to destroy
+        * @return              
+        *                              SUCCESS in any case
+        */
+       status_t (*destroy) (randomizer_t *this);
+};
+
+/**
+ * @brief Create an randomizer_t object
+ * 
+ * @return                     
+ *                                     - created randomizer_t, or
+ *                                     - NULL if failed
+ */
+randomizer_t *randomizer_create();
+
+/**
+ * @brief Create an randomizer_t object with specific random device names
+ * 
+ * @param random_dev_name      Device name for random values, etc /dev/random
+ * @param prandom_dev_name     Device name for pseudo random values, etc /dev/urandom
+ * @return                                     
+ *                                                     - created randomizer_t, or
+ *                                                     - NULL if failed
+ */
+randomizer_t *randomizer_create_on_devices(char * random_dev_name,char * prandom_dev_name);
+
+#endif /*RANDOMIZER_H_*/