+++ /dev/null
-/**
- * \file
- * <!--
- * This file is part of BeRTOS.
- *
- * Bertos 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.
- *
- * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * As a special exception, you may use this file as part of a free software
- * library without restriction. Specifically, if other files instantiate
- * templates or use macros or inline functions from this file, or you compile
- * this file and link it with other files to produce an executable, this
- * file does not by itself cause the resulting executable to be covered by
- * the GNU General Public License. This exception does not however
- * invalidate any other reasons why the executable file might be covered by
- * the GNU General Public License.
- *
- * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
- *
- * -->
- *
- * \brief API function for to manage entropy pool.
- *
- * \version $Id$
- * \author Daniele Basile <asterix@develer.com>
- */
-
-/*#*
- *#* $Log$
- *#* Revision 1.20 2007/06/07 16:06:39 batt
- *#* Fix some doxygen errors.
- *#*
- *#* Revision 1.19 2007/02/15 13:54:26 asterix
- *#* Rename randpool_getN in randpool_get. Fix bug in randpool_get.
- *#*
- *#* Revision 1.17 2007/02/15 13:40:42 asterix
- *#* Fix bug in randpool_add and randpool_strir.
- *#*
- *#* Revision 1.16 2007/02/13 15:11:37 asterix
- *#* Typo.
- *#*
- *#* Revision 1.14 2007/02/13 09:57:12 asterix
- *#* Add directive #if in struct EntropyPool, and remove #else in randpool_add.
- *#*
- *#* Revision 1.13 2007/02/12 18:25:34 asterix
- *#* Fix bug in randpool_getN.
- *#*
- *#* Revision 1.12 2007/02/12 09:47:39 asterix
- *#* Remove randpool_save. Add randpool_pool.
- *#*
- *#* Revision 1.10 2007/02/12 09:03:32 asterix
- *#* Add CONFIG_RANDPOOL_TIMER macro to swich on or off timer support
- *#*
- *#* Revision 1.9 2007/02/09 17:58:09 asterix
- *#* Add macro CONFIG_RANDPOOL_TIMER.
- *#*
- *#* Revision 1.6 2007/02/09 09:24:38 asterix
- *#* Typos. Add data_len in randpool_add and n_byte in randpool_push pototypes.
- *#*
- *#* Revision 1.3 2007/02/08 14:25:29 asterix
- *#* Write static funcion push_byte.
- *#*
- *#*/
-
-#include "randpool.h"
-#include "md2.h"
-
-#include <stdio.h> //sprintf();
-#include <string.h> //memset(), memcpy();
-
-#include <cfg/compiler.h>
-#include <cfg/debug.h> //ASSERT()
-#include <cfg/macros.h> //MIN(), ROUND_UP();
-
-#if CONFIG_RANDPOOL_TIMER
- #include <drv/timer.h> //timer_clock();
-#endif
-
-
-
-/*
- * Insert bytes in entropy pool, making a XOR of bytes present
- * in entropy pool.
- */
-static void randpool_push(EntropyPool *pool, void *_byte, size_t n_byte)
-{
- size_t i = pool->pos_add; // Current number of byte insert in entropy pool.
- uint8_t *byte;
-
- byte = (uint8_t *)_byte;
-
- /*
- * Insert a bytes in entropy pool.
- */
- for(int j = 0; j < n_byte; j++)
- {
- pool->pool_entropy[i] = pool->pool_entropy[i] ^ byte[j];
- i = (++i) % CONFIG_SIZE_ENTROPY_POOL;
- }
-
- pool->pos_add = i; // Update a insert bytes.
-}
-
-
-/*
- * This function stir entropy pool with MD2 function hash.
- *
- */
-static void randpool_stir(EntropyPool *pool)
-{
- size_t entropy = pool->entropy; //Save current calue of entropy.
- Md2Context context;
- uint8_t tmp_buf[((sizeof(size_t) * 2) + sizeof(int)) * 2 + 1]; //Temporary buffer.
-
- md2_init(&context); //Init MD2 algorithm.
-
- randpool_add(pool, NULL, 0);
-
- for (int i = 0; i < (CONFIG_SIZE_ENTROPY_POOL / MD2_DIGEST_LEN); i++)
- {
- sprintf(tmp_buf, "%0x%0x%0x",pool->counter, i, pool->pos_add);
-
- /*
- * Hash with MD2 algorithm the entropy pool.
- */
- md2_update(&context, pool->pool_entropy, CONFIG_SIZE_ENTROPY_POOL);
-
- md2_update(&context, tmp_buf, sizeof(tmp_buf) - 1);
-
- /*Insert a message digest in entropy pool.*/
- randpool_push(pool, md2_end(&context), MD2_DIGEST_LEN);
-
- pool->counter = pool->counter + 1;
-
- }
-
- /*Insert in pool the difference between a two call of this function (see above).*/
- randpool_add(pool, NULL, 0);
-
- pool->entropy = entropy; //Restore old value of entropy. We haven't add entropy.
-}
-
-/**
- * Add \param entropy bits from \param data buffer to the entropy \param pool
- */
-void randpool_add(EntropyPool *pool, void *data, size_t entropy)
-{
- uint8_t sep[] = "\xaa\xaa\xaa\xaa"; // ??
- size_t data_len = ROUND_UP(entropy, 8) / 8; //Number of entropy byte in input.
-
- randpool_push(pool, data, data_len); //Insert data to entropy pool.
-
-#if CONFIG_RANDPOOL_TIMER
-
- ticks_t event = timer_clock();
- ticks_t delta;
-
- /*Difference of time between a two accese to entropy pool.*/
- delta = event - pool->last_counter;
-
- randpool_push(pool, &event, sizeof(ticks_t));
- randpool_push(pool, sep, sizeof(sep) - 1); // ??
- randpool_push(pool, &delta, sizeof(delta));
-
- /*
- * Count of number entropy bit add with delta.
- */
- delta = delta & 0xff;
- while(delta)
- {
- delta >>= 1;
- entropy++;
- }
-
- pool->last_counter = event;
-
-#endif
-
- pool->entropy += entropy; //Update a entropy of the pool.
-}
-
-/**
- * Randpool function initialization.
- * The entropy pool can be initialize also with
- * a previous entropy pool.
- */
-void randpool_init(EntropyPool *pool, void *_data, size_t len)
-{
- uint8_t *data;
-
- data = (uint8_t *)_data;
-
- memset(pool, 0, sizeof(EntropyPool));
- pool->pos_get = MD2_DIGEST_LEN;
-
-#if CONFIG_RANDPOOL_TIMER
- pool->last_counter = timer_clock();
-#endif
-
- if(data)
- {
- /*
- * Initialize a entropy pool with a
- * previous pool, and assume all pool as
- * entropy.
- */
- len = MIN(len,(size_t)CONFIG_SIZE_ENTROPY_POOL);
- memcpy(pool->pool_entropy, data, len);
- pool->entropy = len;
- }
-
-}
-
-/**
- * Get the actual value of entropy.
- */
-size_t randpool_size(EntropyPool *pool)
-{
- return pool->entropy;
-}
-
-/**
- * Get \param n_byte from entropy pool. If n_byte is larger than number
- * byte of entropy in entropy pool, randpool_get continue
- * to generate pseudocasual value from previous state of
- * pool.
- * \param n_byte number fo bytes to read.
- * \param pool is the pool entropy context.
- * \param _data is the pointer to write the random data to.
- */
-void randpool_get(EntropyPool *pool, void *_data, size_t n_byte)
-{
- Md2Context context;
- size_t i = pool->pos_get;
- size_t n = n_byte;
- size_t pos_write = 0; //Number of block has been written in data.
- size_t len = MIN((size_t)MD2_DIGEST_LEN, n_byte);
- uint8_t *data;
-
- data = (uint8_t *)_data;
-
- /* Test if i + CONFIG_MD2_BLOCK_LEN is inside of entropy pool.*/
- ASSERT((MD2_DIGEST_LEN + i) < CONFIG_SIZE_ENTROPY_POOL);
-
- md2_init(&context);
-
- while(n > 0)
- {
-
- /*Hash previous state of pool*/
- md2_update(&context, &pool->pool_entropy[i], MD2_DIGEST_LEN);
-
- memcpy(&data[pos_write], md2_end(&context), len);
-
- pos_write += len; //Update number of block has been written in data.
- n -= len; //Number of byte copied in data.
-
- len = MIN(n,(size_t)MD2_DIGEST_LEN);
-
- i = (i + MD2_DIGEST_LEN) % CONFIG_SIZE_ENTROPY_POOL;
-
- /* If we haven't more entropy pool to hash, we stir it.*/
- if(i < MD2_DIGEST_LEN)
- {
- randpool_stir(pool);
- i = pool->pos_get;
- }
-
- }
-
- pool->pos_get = i; //Current number of byte we get from pool.
- pool->entropy -= n_byte; //Update a entropy.
-
- /*If we get all entropy entropy is 0*/
- if(pool->entropy < 0)
- pool->entropy = 0;
-
-}
-
-/**
- * Return a pointer to entropy pool.
- */
-uint8_t *randpool_pool(EntropyPool *pool)
-{
- return pool->pool_entropy;
-}
-
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