hash.c

#include "api.h"
#include "ascon.h"
#include "loadstore.h"
#include "permutations.h"
#include "printstate.h"

int crypto_hash(uint8_t* out, const uint8_t* in, uint64_t len) {
  state_t s;

  /* initialization */
  s.x0 = ASCON_HASH_IV;
  s.x1 = 0;
  s.x2 = 0;
  s.x3 = 0;
  s.x4 = 0;
  P12(&s);
  printstate("initialization", &s);

  /* absorb plaintext */
  while (len >= ASCON_128_RATE) {
    s.x0 ^= LOAD(in, 8);
    P12(&s);
    in += ASCON_128_RATE;
    len -= ASCON_128_RATE;
  }
  s.x0 ^= LOAD(in, len);
  s.x0 ^= PAD(len);
  P12(&s);
  printstate("absorb plaintext", &s);

  /* squeeze output */
  len = CRYPTO_BYTES;
  while (len > ASCON_128_RATE) {
    STORE(out, s.x0, 8);
    P12(&s);
    out += ASCON_128_RATE;
    len -= ASCON_128_RATE;
  }
  STORE(out, s.x0, 8);
  printstate("squeeze output", &s);

  return 0;
}