diff options
| -rw-r--r-- | crypto/ansi_cprng.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c index 72db0fd763c..486aa93646f 100644 --- a/crypto/ansi_cprng.c +++ b/crypto/ansi_cprng.c @@ -349,15 +349,25 @@ static int cprng_get_random(struct crypto_rng *tfm, u8 *rdata, return get_prng_bytes(rdata, dlen, prng); } +/* + * This is the cprng_registered reset method the seed value is + * interpreted as the tuple { V KEY DT} + * V and KEY are required during reset, and DT is optional, detected + * as being present by testing the length of the seed + */ static int cprng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen) { struct prng_context *prng = crypto_rng_ctx(tfm); - u8 *key = seed + DEFAULT_PRNG_KSZ; + u8 *key = seed + DEFAULT_BLK_SZ; + u8 *dt = NULL; if (slen < DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ) return -EINVAL; - reset_prng_context(prng, key, DEFAULT_PRNG_KSZ, seed, NULL); + if (slen >= (2 * DEFAULT_BLK_SZ + DEFAULT_PRNG_KSZ)) + dt = key + DEFAULT_PRNG_KSZ; + + reset_prng_context(prng, key, DEFAULT_PRNG_KSZ, seed, dt); if (prng->flags & PRNG_NEED_RESET) return -EINVAL; @@ -379,7 +389,7 @@ static struct crypto_alg rng_alg = { .rng = { .rng_make_random = cprng_get_random, .rng_reset = cprng_reset, - .seedsize = DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ, + .seedsize = DEFAULT_PRNG_KSZ + 2*DEFAULT_BLK_SZ, } } }; |