From: Dominik Brodowski linux@dominikbrodowski.net
commit 96562f286884e2db89c74215b199a1084b5fb7f7 upstream.
Previously, the ChaCha constants for the primary pool were only initialized in crng_initialize_primary(), called by rand_initialize(). However, some randomness is actually extracted from the primary pool beforehand, e.g. by kmem_cache_create(). Therefore, statically initialize the ChaCha constants for the primary pool.
Cc: Herbert Xu herbert@gondor.apana.org.au Cc: "David S. Miller" davem@davemloft.net Cc: linux-crypto@vger.kernel.org Signed-off-by: Dominik Brodowski linux@dominikbrodowski.net Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/random.c | 5 ++++- include/crypto/chacha.h | 15 +++++++++++---- 2 files changed, 15 insertions(+), 5 deletions(-)
--- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -458,6 +458,10 @@ struct crng_state {
static struct crng_state primary_crng = { .lock = __SPIN_LOCK_UNLOCKED(primary_crng.lock), + .state[0] = CHACHA_CONSTANT_EXPA, + .state[1] = CHACHA_CONSTANT_ND_3, + .state[2] = CHACHA_CONSTANT_2_BY, + .state[3] = CHACHA_CONSTANT_TE_K, };
/* @@ -824,7 +828,6 @@ static void crng_initialize_secondary(st
static void __init crng_initialize_primary(struct crng_state *crng) { - chacha_init_consts(crng->state); _extract_entropy(&input_pool, &crng->state[4], sizeof(__u32) * 12, 0); if (crng_init_try_arch_early(crng) && trust_cpu && crng_init < 2) { invalidate_batched_entropy(); --- a/include/crypto/chacha.h +++ b/include/crypto/chacha.h @@ -51,12 +51,19 @@ int crypto_chacha12_setkey(struct crypto int crypto_chacha_crypt(struct skcipher_request *req); int crypto_xchacha_crypt(struct skcipher_request *req);
+enum chacha_constants { /* expand 32-byte k */ + CHACHA_CONSTANT_EXPA = 0x61707865U, + CHACHA_CONSTANT_ND_3 = 0x3320646eU, + CHACHA_CONSTANT_2_BY = 0x79622d32U, + CHACHA_CONSTANT_TE_K = 0x6b206574U +}; + static inline void chacha_init_consts(u32 *state) { - state[0] = 0x61707865; /* "expa" */ - state[1] = 0x3320646e; /* "nd 3" */ - state[2] = 0x79622d32; /* "2-by" */ - state[3] = 0x6b206574; /* "te k" */ + state[0] = CHACHA_CONSTANT_EXPA; + state[1] = CHACHA_CONSTANT_ND_3; + state[2] = CHACHA_CONSTANT_2_BY; + state[3] = CHACHA_CONSTANT_TE_K; }
#endif /* _CRYPTO_CHACHA_H */