X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=algos%2Frandpool.c;h=3bb64770f51856d74c4efae8459fd55e9d8dd047;hb=80c290f0451b6dffa973a14893e6b6b20d189662;hp=42d50d5565716cc10799f759296824ec95d0510a;hpb=775a4c184ac4b83d0a0a6d1cef015ad912c769bc;p=bertos.git diff --git a/algos/randpool.c b/algos/randpool.c index 42d50d55..3bb64770 100755 --- a/algos/randpool.c +++ b/algos/randpool.c @@ -13,46 +13,257 @@ /*#* *#* $Log$ - *#* Revision 1.2 2007/02/08 11:53:03 asterix - *#* Add EntrPool struct. Typos. + *#* 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 //sprintf(); +#include //memset(), memcpy(); + #include -#include //ASSERT() +#include //ASSERT() +#include //MIN(), ROUND_UP(); + +#if CONFIG_RANDPOOL_TIMER + #include //timer_clock(); +#endif + -static void stir(EntrPool *pool) -{ -} -void init_pool(EntrPool *pool); +/* + * 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. } -void add_data(EntrPool *pool, void *data, size_t n_bit); + +/* + * 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. } -size_t pool_size(EntrPool *pool); +/** + * 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. } -void get_bit(EntrPool *pool, void *data, size_t n_bit); +/** + * 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; + } + } -void get_bit_n(EntrPool *pool, void *data, size_t n_bit); +/** + * Get the actual value of entropy. + */ +size_t randpool_size(EntropyPool *pool) { + return pool->entropy; } -bool save_pool(void *data); +/** + * 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. + */ +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; + } -uint8_t *load_pool(void); +/** + * Return a pointer to entropy pool. + */ +uint8_t *randpool_pool(EntropyPool *pool) { + return pool->pool_entropy; }