Write add_data and stir function. Typos

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@770 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/algos/randpool.c b/algos/randpool.c
index b7f090b92daeabe6b805db3fcddcef84686a384f..92751dd7a49d947302199322a0b934f782bc74ca 100755 (executable)
--- a/algos/randpool.c
+++ b/algos/randpool.c
@@ -13,6 +13,9 @@
 
 /*#*
  *#* $Log$
+ *#* Revision 1.4  2007/02/08 17:18:00  asterix
+ *#* Write add_data and stir function. Typos
+ *#*
  *#* Revision 1.3  2007/02/08 14:25:29  asterix
  *#* Write static funcion push_byte.
  *#*
@@ -24,11 +27,11 @@
 #include <string.h>            //memset(), memcpy();
 #include <cfg/compiler.h>
 #include <cfg/debug.h>        //ASSERT()
+#include <drv/timer.h>        //timer_clock();
+
+#include <stdio.h>   //sprintf();
+
 
-static void stir(EntrPool *pool)
-{
-       
-}
 
 /*
  * Insert bytes in entropy pool, making a XOR of bytes present
@@ -56,16 +59,85 @@ static void push_byte(EntrPool *pool, void *_byte)
        pool->pool_pos_add  =  i; // Update a insert bytes.
 }
 
+/* 
+ * This function stir entropy pool with MD2 function hash.
+ *
+ */
+static void stir(EntrPool *pool)
+{
+       size_t entropy = pool->entropy; //Save current calue of entropy.
+       Md2Context context;
+       uint8_t tmp_buf[(sizeof(size_t) * 2) + sizeof(int)];  //Temporary buffer.
+
+       md2_init(&context);
+       
+       add_data(pool, "", 0);
+               
+       for (int i = 0; i < (CONFIG_SIZE_ENTROPY_POOL / CONFIG_MD2_BLOCK_LEN); i++)
+       {
+               sprintf(tmp_buf, "%x%x%x",pool->counter, i, pool->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, CONFIG_SIZE_ENTROPY_POOL);
+
+               push_byte(pool, md2_end(&context)); //Insert a message digest in entropy pool.
+
+               pool->counter = (pool->counter + 1) & 0xFFFFFFFF; //Update a counter modulo 4.
+       
+       }
+       
+       /*Insert in pool the difference between a two call of this function (see above).*/
+       add_data(pool, "", 0); 
+       
+       pool->entropy = entropy; //Restore old value of entropy. We haven't add entropy.
+}
+
+
 void init_pool(EntrPool *pool)
 {
        
        memset(pool, 0, sizeof(EntrPool));
 
+       //TODO: inizializzazione del timer di sistema.
+
 }
 
+/**
+ * Add n_bit of  entropy in entropy pool.
+ */
 void add_data(EntrPool *pool, void *data, size_t n_bit)
 {
+       uint32_t event = timer_clock();
+       uint32_t delta;
+
+       push_byte(pool, data); //Insert data to entropy pool. 
+       
+       push_byte(pool, "\xaa\xaa\xaa\xaa"); // ??
+
+       /*Difference of time between a two accese to entropy pool.*/
+       delta = event - pool->last_counter;
+       
+       push_byte(pool, &delta);
+       
+       delta = delta & 0xff;
+       
+       push_byte(pool, &delta);
 
+       /*
+        * Count of number entropy bit add with delta.
+        */
+       while(delta) 
+       {
+               delta >>= 1;
+               n_bit++;
+       }
+       
+       pool->entropy = n_bit;      //Update a entropy of the pool.
+       pool->last_counter = event;
 }
 
 size_t pool_size(EntrPool *pool)

diff --git a/algos/randpool.h b/algos/randpool.h
index 02daafa243aedbe762c9d7ebc725b310268cf72b..e996fa3cd93abc8d7f6561a6b95209d25a68f604 100755 (executable)
--- a/algos/randpool.h
+++ b/algos/randpool.h
@@ -14,6 +14,9 @@
 
 /*#*
  *#* $Log$
+ *#* Revision 1.4  2007/02/08 17:18:01  asterix
+ *#* Write add_data and stir function. Typos
+ *#*
  *#* Revision 1.3  2007/02/08 14:25:56  asterix
  *#* Typos.
  *#*
@@ -36,7 +39,7 @@
  */
 typedef struct EntrPool 
 {
-       size_t entropy;                                  ///< Actual value of entropy.
+       size_t entropy;                                  ///< Actual value of entropy (In bit).
        size_t pool_pos_add;                             ///< Size of byte insert in entropy pool.
        size_t pool_pos_get;                             ///< Size of byte take in entropy pool.
        size_t counter;                                  ///< Counter.