31 linhas
894 B
C
31 linhas
894 B
C
#include "chacha.h"
|
|
//#include "params.h"
|
|
#include "prg.h"
|
|
|
|
const unsigned char zero_nonce[12] = {0};
|
|
|
|
/**
|
|
* Generates rlen output bytes using ChaCha20 with a zero nonce and counter = 0
|
|
*/
|
|
void prg(unsigned char *r, unsigned long long rlen, const unsigned char *key, uint key_len)
|
|
{
|
|
CRYPTO_chacha_20_keystream(r, rlen, key, zero_nonce, 0);
|
|
}
|
|
|
|
/**
|
|
* Generates rlen output bytes using ChaCha20.
|
|
* Nonce and counter are set depending on the address addr.
|
|
*/
|
|
void prg_with_counter(unsigned char *r, unsigned long long rlen, const unsigned char *key, uint key_len, const unsigned char addr[16])
|
|
{
|
|
int i;
|
|
unsigned char nonce[12];
|
|
for(i = 0; i < 12; i++)
|
|
{
|
|
nonce[i] = addr[i];
|
|
}
|
|
uint32_t counter;
|
|
counter = (addr[12] << 24)|(addr[13] << 16)|(addr[14] << 8)|addr[15];
|
|
// TODO: Check address handling. Endianess?
|
|
CRYPTO_chacha_20_keystream(r, rlen, key, nonce, counter);
|
|
} |