X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=algos%2Frandpool.c;h=6881bc4896fb5943f59604ab416e138655e90330;hb=45fb90739a9806843719dc9f64b11518e0278ac0;hp=81aa0eab789501c0a50c77895dc99bf54e7630b6;hpb=77b88716dcd82d0910512567d4849befdbe34405;p=bertos.git diff --git a/algos/randpool.c b/algos/randpool.c index 81aa0eab..6881bc48 100755 --- a/algos/randpool.c +++ b/algos/randpool.c @@ -13,38 +13,255 @@ /*#* *#* $Log$ - *#* Revision 1.1 2007/02/08 11:13:40 asterix - *#* Add function prototypes. + *#* 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 //sprintf(); +#include //memset(), memcpy(); #include -#include //ASSERT() +#include //ASSERT() +#include //MIN() + +#if CONFIG_RANDPOOL_TIMER + #include //timer_clock(); +#endif + -void add_entropy(void *data, size_t n_bit) +/* + * 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]; //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(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(void) +/** + * 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(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(void *data, size_t n_bit) +void randpool_get(EntropyPool *pool, void *data, size_t n_byte) { + } -bool save_pool(void) +/** + * 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); + uint8_t *data; + + data = (uint8_t *)_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 load_pool(void) +/** + * Return a pointer to entropy pool. + */ +uint8_t *randpool_pool(EntropyPool *pool) { + return pool->pool_entropy; }