X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=algos%2Frandpool.c;h=63a2716a6fa8a9b89145e1aef5b34eed1f1c0984;hb=bd5a6de1603564daa55869e9dc524bb20be79556;hp=b2d91727c6bb7162fe008edf0966a04af24e52c4;hpb=96b027ed7b226e3f269b0f01b6bfe8957a8f2741;p=bertos.git diff --git a/algos/randpool.c b/algos/randpool.c index b2d91727..63a2716a 100755 --- a/algos/randpool.c +++ b/algos/randpool.c @@ -13,6 +13,15 @@ /*#* *#* $Log$ + *#* 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. *#* @@ -24,12 +33,16 @@ #include "randpool.h" #include "md2.h" -#include //memset(), memcpy(); +#include //sprintf(); +#include //memset(), memcpy(); + #include -#include //ASSERT() -#include //timer_clock(); +#include //ASSERT() +#include //MIN() -#include //sprintf(); +#if CONFIG_RANDPOOL_TIMER + #include //timer_clock(); +#endif @@ -37,7 +50,7 @@ * Insert bytes in entropy pool, making a XOR of bytes present * in entropy pool. */ -static void randpool_push(EntrPool *pool, void *_byte, size_t n_byte) +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; @@ -57,22 +70,64 @@ static void randpool_push(EntrPool *pool, void *_byte, size_t n_byte) } +/* + * 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]; //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. +} + /** * Add n_bit of entropy in entropy pool. */ -void randpool_add(EntrPool *pool, void *data, size_t data_len, size_t entropy) +void randpool_add(EntropyPool *pool, void *data, size_t data_len, size_t entropy) { - uint32_t event = timer_clock(); - uint32_t delta; 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; @@ -88,82 +143,113 @@ void randpool_add(EntrPool *pool, void *data, size_t data_len, size_t entropy) entropy++; } - pool->entropy = entropy; //Update a entropy of the pool. +#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; } -/* \ - * This function stir entropy pool with MD2 function hash. - * +/** + * Randpool function initialization. + * The entropy pool can be initialize also with + * a previous entropy pool. */ -static void randpool_stir(EntrPool *pool) +void randpool_init(EntropyPool *pool, void *_data, size_t len) { - size_t entropy = pool->entropy; //Save current calue of entropy. - Md2Context context; - uint8_t tmp_buf[(sizeof(size_t) * 2) + sizeof(int)]; //Temporary buffer. + uint8_t *data; - md2_init(&context); + data = (uint8_t *)_data; - randpool_add(pool, "", 0, 0); + memset(pool, 0, sizeof(EntropyPool)); + pool->pos_get = CONFIG_MD2_BLOCK_LEN; - for (int i = 0; i < (CONFIG_SIZE_ENTROPY_POOL / CONFIG_MD2_BLOCK_LEN); i++) - { - sprintf(tmp_buf, "%x%x%x",pool->counter, i, pool->pos_add); +#if CONFIG_RANDPOOL_TIMER + pool->last_counter = timer_clock(); +#endif + + ASSERT(len < CONFIG_SIZE_ENTROPY_POOL); + if(len > 0) + { /* - * Hash with MD2 algorithm the entropy pool. + * Initialize a entropy pool with a + * previous pool, and assume all pool as + * entropy. */ - md2_update(&context, pool->pool_entropy, CONFIG_SIZE_ENTROPY_POOL); - - md2_update(&context, tmp_buf, CONFIG_SIZE_ENTROPY_POOL); - - /*Insert a message digest in entropy pool.*/ - randpool_push(pool, md2_end(&context), CONFIG_MD2_BLOCK_LEN); - - pool->counter = (pool->counter + 1) & 0xFFFFFFFF; //Update a counter modulo 4. - + memcpy(pool->pool_entropy, data, len); + pool->entropy = len; } - /*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 randpool_init(EntrPool *pool) -{ - - memset(pool, 0, sizeof(EntrPool)); - pool->pos_get = CONFIG_MD2_BLOCK_LEN; - pool->last_counter = timer_clock(); - - //TODO: inizializzazione del timer di sistema. - } /** * Get the actual value of entropy. */ -size_t randpool_size(EntrPool *pool) +size_t randpool_size(EntropyPool *pool) { return pool->entropy; } -void randpool_get(EntrPool *pool, void *data, size_t n_byte) +void randpool_get(EntropyPool *pool, void *data, size_t n_byte) { } -void randpool_getN(EntrPool *pool, void *data, size_t n_byte) +/** + * 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); -bool randpool_save(void *data) -{ + /* 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 *randpool_load(void) +bool randpool_save(void *data) { }