/*
* Hash_DRBG Instantiate NIST SP 800-80 10.1.1.2
*
* NOTE: bytes & len are entropy || nonce || personalization_string. In
* normal operation, NSS calculates them all together in a single call.
*/
static SECStatus
prng_instantiate(RNGContext *rng, const PRUint8 *bytes, unsigned int len)
{
if (len < PRNG_SEEDLEN) {
/* if the seedlen is to small, it's probably because we failed to get
* enough random data */
PORT_SetError(SEC_ERROR_NEED_RANDOM);
return SECFailure;
}
prng_Hash_df(V(rng), VSize(rng), bytes, len, NULL, 0);
rng->V_type = prngCGenerateType;
prng_Hash_df(rng->C,sizeof rng->C,rng->V_Data,sizeof rng->V_Data,NULL,0);
PRNG_RESET_RESEED_COUNT(rng)
return SECSuccess;
}
/*
* Hash_DRBG Instantiate NIST SP 800-90 10.1.1.2
*
* NOTE: bytes & len are entropy || nonce || personalization_string. In
* normal operation, NSS calculates them all together in a single call.
*/
static SECStatus
prng_instantiate(RNGContext *rng, const PRUint8 *bytes, unsigned int len)
{
if (!rng->isKatTest && len < PRNG_SEEDLEN) {
/* If the seedlen is too small, it's probably because we failed to get
* enough random data.
* This is stricter than NIST SP800-90A requires. Don't enforce it for
* tests. */
PORT_SetError(SEC_ERROR_NEED_RANDOM);
return SECFailure;
}
prng_Hash_df(V(rng), VSize(rng), bytes, len, NULL, 0);
rng->V_type = prngCGenerateType;
prng_Hash_df(rng->C, sizeof rng->C, rng->V_Data, sizeof rng->V_Data, NULL, 0);
PRNG_RESET_RESEED_COUNT(rng)
return SECSuccess;
}
/*
* Clean up the global RNG context
*/
static void
prng_freeRNGContext(RNGContext *rng)
{
PRUint8 inputhash[VSize(rng) + (sizeof rng->C)];
/* destroy context lock */
SKIP_AFTER_FORK(PZ_DestroyLock(globalrng->lock));
/* zero global RNG context except for C & V to preserve entropy */
prng_Hash_df(inputhash, sizeof rng->C, rng->C, sizeof rng->C, NULL, 0);
prng_Hash_df(&inputhash[sizeof rng->C], VSize(rng), V(rng), VSize(rng),
NULL, 0);
memset(rng, 0, sizeof *rng);
memcpy(rng->C, inputhash, sizeof rng->C);
memcpy(V(rng), &inputhash[sizeof rng->C], VSize(rng));
memset(inputhash, 0, sizeof inputhash);
}
/*
* Update the global random number generator with more seeding
* material. Use the Hash_DRBG reseed algorithm from NIST SP-800-90
* section 10.1.1.3
*
* If entropy is NULL, it is fetched from the noise generator.
*/
static SECStatus
prng_reseed(RNGContext *rng, const PRUint8 *entropy, unsigned int entropy_len,
const PRUint8 *additional_input, unsigned int additional_input_len)
{
PRUint8 noiseData[(sizeof rng->V_Data)+PRNG_SEEDLEN];
PRUint8 *noise = &noiseData[0];
/* if entropy wasn't supplied, fetch it. (normal operation case) */
if (entropy == NULL) {
entropy_len = (unsigned int) RNG_SystemRNG(
&noiseData[sizeof rng->V_Data], PRNG_SEEDLEN);
} else {
/* NOTE: this code is only available for testing, not to applications */
/* if entropy was too big for the stack variable, get it from malloc */
if (entropy_len > PRNG_SEEDLEN) {
noise = PORT_Alloc(entropy_len + (sizeof rng->V_Data));
if (noise == NULL) {
return SECFailure;
}
}
PORT_Memcpy(&noise[sizeof rng->V_Data],entropy, entropy_len);
}
if (entropy_len < 256/PR_BITS_PER_BYTE) {
/* noise == &noiseData[0] at this point, so nothing to free */
PORT_SetError(SEC_ERROR_NEED_RANDOM);
return SECFailure;
}
rng->V_type = prngReseedType;
PORT_Memcpy(noise, rng->V_Data, sizeof rng->V_Data);
prng_Hash_df(V(rng), VSize(rng), noise, (sizeof rng->V_Data) + entropy_len,
additional_input, additional_input_len);
/* clear potential CSP */
PORT_Memset(noise, 0, (sizeof rng->V_Data) + entropy_len);
rng->V_type = prngCGenerateType;
prng_Hash_df(rng->C,sizeof rng->C,rng->V_Data,sizeof rng->V_Data,NULL,0);
PRNG_RESET_RESEED_COUNT(rng)
if (noise != &noiseData[0]) {
PORT_Free(noise);
}
return SECSuccess;
}
