/*#*
*#* $Log$
+ *#* Revision 1.11 2007/02/12 09:40:43 asterix
+ *#* Remove randpool_load function. Add *data in randpool_init prototype.
+ *#*
+ *#* 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 <string.h> //memset(), memcpy();
+#include <stdio.h> //sprintf();
+#include <string.h> //memset(), memcpy();
+
#include <cfg/compiler.h>
-#include <cfg/debug.h> //ASSERT()
+#include <cfg/debug.h> //ASSERT()
+#include <cfg/macros.h> //MIN()
+
+#if CONFIG_RANDPOOL_TIMER
+ #include <drv/timer.h> //timer_clock();
+#endif
+
-static void stir(EntrPool *pool)
-{
-
-}
/*
* Insert bytes in entropy pool, making a XOR of bytes present
* in entropy pool.
*/
-static void push_byte(EntrPool *pool, void *_byte)
+static void randpool_push(EntropyPool *pool, void *_byte, size_t n_byte)
{
- size_t i = pool->pool_pos_add; // Current number of byte insert in entropy pool.
- size_t len_byte;
+ size_t i = pool->pos_add; // Current number of byte insert in entropy pool.
uint8_t *byte;
-
byte = (uint8_t *)_byte;
- len_byte = strlen(byte);
/*
* Insert a bytes in entropy pool.
*/
- for(int j = 0; j < len_byte; j++)
+ 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->pool_pos_add = i; // Update a insert bytes.
+ pool->pos_add = i; // Update a insert bytes.
}
-void init_pool(EntrPool *pool)
+
+/*
+ * This function stir entropy pool with MD2 function hash.
+ *
+ */
+static void randpool_stir(EntropyPool *pool)
{
-
- memset(pool, 0, sizeof(EntrPool));
+ size_t entropy = pool->entropy; //Save current calue of entropy.
+ Md2Context context;
+ uint8_t tmp_buf[((sizeof(size_t) * 2) + sizeof(int)) * 2]; //Temporary buffer.
+
+ md2_init(&context); //Init MD2 algorithm.
+
+ randpool_add(pool, "", 0, 0);
+
+ for (int i = 0; i < NUM_STIR_LOOP; 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, strlen(tmp_buf));
+
+ /*Insert a message digest in entropy pool.*/
+ randpool_push(pool, md2_end(&context), CONFIG_MD2_BLOCK_LEN);
+
+ pool->counter = (pool->counter + 1) & 0xFFFFFFFF; //Clamp a counter to 4 byte.
+
+ }
+
+ /*Insert in pool the difference between a two call of this function (see above).*/
+ randpool_add(pool, "", 0, 0);
+
+ pool->entropy = entropy; //Restore old value of entropy. We haven't add entropy.
}
-void add_data(EntrPool *pool, void *data, size_t n_bit)
+/**
+ * Add n_bit of entropy in entropy pool.
+ */
+void randpool_add(EntropyPool *pool, void *data, size_t data_len, size_t entropy)
{
+ uint8_t sep[] = "\xaa\xaa\xaa\xaa"; // ??
+
+ randpool_push(pool, data, data_len); //Insert data to entropy pool.
+
+ randpool_push(pool, sep, strlen(sep)); // ??
+
+#if CONFIG_RANDPOOL_TIMER
+
+ ticks_t event = timer_clock();
+ uint32_t delta;
+
+ /*Difference of time between a two accese to entropy pool.*/
+ delta = event - pool->last_counter;
+
+
+ randpool_push(pool, &delta, sizeof(delta));
+
+ delta = delta & 0xff;
+
+ randpool_push(pool, &delta, sizeof(delta));
+ /*
+ * Count of number entropy bit add with delta.
+ */
+ while(delta)
+ {
+ delta >>= 1;
+ entropy++;
+ }
+
+#else
+ size_t event = 0;
+
+ /*Difference of time between a two accese to entropy pool.*/
+ event = pool->last_counter++;
+
+#endif
+
+ pool->entropy += entropy; //Update a entropy of the pool.
+ pool->last_counter = event;
}
-size_t pool_size(EntrPool *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 = CONFIG_MD2_BLOCK_LEN;
+
+#if CONFIG_RANDPOOL_TIMER
+ pool->last_counter = timer_clock();
+#endif
+
+ ASSERT(len < CONFIG_SIZE_ENTROPY_POOL);
+
+ if(len > 0)
+ {
+ /*
+ * Initialize a entropy pool with a
+ * previous pool, and assume all pool as
+ * entropy.
+ */
+ memcpy(pool->pool_entropy, data, len);
+ pool->entropy = len;
+ }
+
}
-void get_bit(EntrPool *pool, void *data, size_t n_bit)
+/**
+ * Get the actual value of entropy.
+ */
+size_t randpool_size(EntropyPool *pool)
{
+ return pool->entropy;
}
-void get_bit_n(EntrPool *pool, void *data, size_t n_bit)
+void randpool_get(EntropyPool *pool, void *data, size_t n_byte)
{
+
}
-bool save_pool(void *data)
+/**
+ * Get n_byte from entropy pool. If n_byte is larger than number
+ * byte of entropy in entropy pool, rand_pool_getN continue
+ * to generate pseudocasual value from previous state of
+ * pool.
+ */
+void randpool_getN(EntropyPool *pool, void *data, size_t n_byte)
{
+ Md2Context context;
+ size_t i = pool->pos_get;
+ int n = n_byte;
+ size_t len = MIN((size_t)CONFIG_MD2_BLOCK_LEN, n_byte);
+
+ /* Test if i + CONFIG_MD2_BLOCK_LEN is inside of entropy pool.*/
+ ASSERT((CONFIG_MD2_BLOCK_LEN + i) < CONFIG_SIZE_ENTROPY_POOL);
+
+ md2_init(&context);
+
+ while(n < 0)
+ {
+ /*Hash previous state of pool*/
+ md2_update(&context, &pool->pool_entropy[i], CONFIG_MD2_BLOCK_LEN);
+
+ memcpy(data, md2_end(&context), len);
+
+ n -= len; //Number of byte copied in data.
+
+ len = MIN(n, CONFIG_MD2_BLOCK_LEN);
+
+ i = (i + CONFIG_MD2_BLOCK_LEN) % CONFIG_SIZE_ENTROPY_POOL;
+
+ /* If we haven't more entropy pool to hash, we stir it.*/
+ if(i < CONFIG_MD2_BLOCK_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;
}
-uint8_t *load_pool(void)
+bool randpool_save(void *data)
{
}
projects / bertos.git / blobdiff