//generate 6 different functions and store in memory
void generateRoundFunctions(unsigned char * seed, unsigned int * bufint, int blocks)
{
int err;
int i=0;
int j=0;
unsigned char buf[4];
//bufint = malloc(blocks*sizeof(unsigned int));
int index = 0;
prng_state prng;
if ((err = fortuna_start(&prng)) != CRYPT_OK) {
printf("start error: %s\n", error_to_string(err));
}
if ((err = fortuna_add_entropy(seed, strlen(seed), &prng))!= CRYPT_OK) {
printf("Add entropy error: %s\n", error_to_string(err));
}
if ((err = fortuna_ready(&prng)) != CRYPT_OK) {
printf("Ready error: %s\n", error_to_string(err));
}
for(i=0;i<blocks;i++){
fortuna_read(buf,sizeof(buf),&prng);
bufint[i] = *(unsigned int *)buf;
}
}
static int sqlcipher_ltc_activate(void *ctx) {
ltc_ctx *ltc = (ltc_ctx*)ctx;
int random_buffer_sz = 32;
unsigned char random_buffer[random_buffer_sz];
if(ltc_init == 0) {
if(register_prng(&fortuna_desc) != CRYPT_OK) return SQLITE_ERROR;
if(register_cipher(&rijndael_desc) != CRYPT_OK) return SQLITE_ERROR;
if(register_hash(&sha1_desc) != CRYPT_OK) return SQLITE_ERROR;
ltc_init = 1;
}
if(fortuna_start(&(ltc->prng)) != CRYPT_OK) {
return SQLITE_ERROR;
}
sqlite3_randomness(random_buffer_sz, &random_buffer);
if(sqlcipher_ltc_add_random(ctx, random_buffer, random_buffer_sz) != SQLITE_OK) {
return SQLITE_ERROR;
}
if(sqlcipher_ltc_add_random(ctx, <c, sizeof(ltc_ctx*)) != SQLITE_OK) {
return SQLITE_ERROR;
}
if(fortuna_ready(&(ltc->prng)) != CRYPT_OK) {
return SQLITE_ERROR;
}
return SQLITE_OK;
}
static int sqlcipher_ltc_random(void *ctx, void *buffer, int length) {
ltc_ctx *ltc = (ltc_ctx*)ctx;
int rc;
if((rc = fortuna_ready(&(ltc->prng))) != CRYPT_OK) {
return SQLITE_ERROR;
}
fortuna_read(buffer, length, &(ltc->prng));
return SQLITE_OK;
}
static int sqlcipher_ltc_add_random(void *ctx, void *buffer, int length) {
int rc = 0;
int data_to_read = length;
int block_sz = data_to_read < FORTUNA_MAX_SZ ? data_to_read : FORTUNA_MAX_SZ;
const unsigned char * data = (const unsigned char *)buffer;
#ifndef SQLCIPHER_LTC_NO_MUTEX_RAND
sqlite3_mutex_enter(ltc_rand_mutex);
#endif
while(data_to_read > 0){
rc = fortuna_add_entropy(data, block_sz, &prng);
rc = rc != CRYPT_OK ? SQLITE_ERROR : SQLITE_OK;
if(rc != SQLITE_OK){
break;
}
data_to_read -= block_sz;
data += block_sz;
block_sz = data_to_read < FORTUNA_MAX_SZ ? data_to_read : FORTUNA_MAX_SZ;
}
fortuna_ready(&prng);
#ifndef SQLCIPHER_LTC_NO_MUTEX_RAND
sqlite3_mutex_leave(ltc_rand_mutex);
#endif
return rc;
}
