74 行
2.7 KiB
PHP
74 行
2.7 KiB
PHP
|
#include <stddef.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include "params.h"
|
||
|
|
#include "symmetric.h"
|
||
|
|
#include "fips202.h"
|
||
|
|
|
||
|
|
/*************************************************
|
||
|
|
* Name: kyber_shake128_absorb
|
||
|
|
*
|
||
|
|
* Description: Absorb step of the SHAKE128 specialized for the Kyber context.
|
||
|
|
*
|
||
|
|
* Arguments: - keccak_state *state: pointer to (uninitialized) output Keccak state
|
||
|
|
* - const uint8_t *seed: pointer to KYBER_SYMBYTES input to be absorbed into state
|
||
|
|
* - uint8_t i: additional byte of input
|
||
|
|
* - uint8_t j: additional byte of input
|
||
|
|
**************************************************/
|
||
|
|
void kyber_shake128_absorb(keccak_state *state,
|
||
|
|
const uint8_t seed[KYBER_SYMBYTES],
|
||
|
|
uint8_t x,
|
||
|
|
uint8_t y)
|
||
|
|
{
|
||
|
|
uint8_t extseed[KYBER_SYMBYTES+2];
|
||
|
|
|
||
|
|
memcpy(extseed, seed, KYBER_SYMBYTES);
|
||
|
|
extseed[KYBER_SYMBYTES+0] = x;
|
||
|
|
extseed[KYBER_SYMBYTES+1] = y;
|
||
|
|
|
||
|
|
shake128_absorb_once(state, extseed, sizeof(extseed));
|
||
|
|
}
|
||
|
|
|
||
|
|
/*************************************************
|
||
|
|
* Name: kyber_shake256_prf
|
||
|
|
*
|
||
|
|
* Description: Usage of SHAKE256 as a PRF, concatenates secret and public input
|
||
|
|
* and then generates outlen bytes of SHAKE256 output
|
||
|
|
*
|
||
|
|
* Arguments: - uint8_t *out: pointer to output
|
||
|
|
* - size_t outlen: number of requested output bytes
|
||
|
|
* - const uint8_t *key: pointer to the key (of length KYBER_SYMBYTES)
|
||
|
|
* - uint8_t nonce: single-byte nonce (public PRF input)
|
||
|
|
**************************************************/
|
||
|
|
void kyber_shake256_prf(uint8_t *out, size_t outlen, const uint8_t key[KYBER_SYMBYTES], uint8_t nonce)
|
||
|
|
{
|
||
|
|
uint8_t extkey[KYBER_SYMBYTES+1];
|
||
|
|
|
||
|
|
memcpy(extkey, key, KYBER_SYMBYTES);
|
||
|
|
extkey[KYBER_SYMBYTES] = nonce;
|
||
|
|
|
||
|
|
shake256(out, outlen, extkey, sizeof(extkey));
|
||
|
|
}
|
||
|
|
|
||
|
|
/*************************************************
|
||
|
|
* Name: kyber_shake256_prf
|
||
|
|
*
|
||
|
|
* Description: Usage of SHAKE256 as a PRF, concatenates secret and public input
|
||
|
|
* and then generates outlen bytes of SHAKE256 output
|
||
|
|
*
|
||
|
|
* Arguments: - uint8_t *out: pointer to output
|
||
|
|
* - size_t outlen: number of requested output bytes
|
||
|
|
* - const uint8_t *key: pointer to the key (of length KYBER_SYMBYTES)
|
||
|
|
* - uint8_t nonce: single-byte nonce (public PRF input)
|
||
|
|
**************************************************/
|
||
|
|
void kyber_shake256_rkprf(uint8_t out[KYBER_SSBYTES], const uint8_t key[KYBER_SYMBYTES], const uint8_t input[KYBER_CIPHERTEXTBYTES])
|
||
|
|
{
|
||
|
|
keccak_state s;
|
||
|
|
|
||
|
|
shake256_init(&s);
|
||
|
|
shake256_absorb(&s, key, KYBER_SYMBYTES);
|
||
|
|
shake256_absorb(&s, input, KYBER_CIPHERTEXTBYTES);
|
||
|
|
shake256_finalize(&s);
|
||
|
|
shake256_squeeze(out, KYBER_SSBYTES, &s);
|
||
|
|
}
|
