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SAE: Maintain bignum of group order and prime in context data

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This simplifies operations by not having to create bignum instances
multiple times during SAE exchange.

Signed-hostap: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2013-01-05 21:12:29 +02:00
parent 305fe835d4
commit 388f535461
2 changed files with 14 additions and 10 deletions
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22
src/common/sae.c
View file

@ -25,6 +25,8 @@ int sae_set_group(struct sae_data *sae, int group)
sae->group = group; sae->group = group;
sae->prime_len = crypto_ec_prime_len(sae->ec); sae->prime_len = crypto_ec_prime_len(sae->ec);
sae->prime = crypto_ec_get_prime(sae->ec);
sae->order = crypto_ec_get_order(sae->ec);
return 0; return 0;
} }
@ -97,8 +99,8 @@ static struct crypto_bignum * sae_get_rand_and_mask(struct sae_data *sae)
struct crypto_bignum *bn; struct crypto_bignum *bn;
size_t prime_len_bits = crypto_ec_prime_len_bits(sae->ec); size_t prime_len_bits = crypto_ec_prime_len_bits(sae->ec);
if (crypto_bignum_to_bin(crypto_ec_get_order(sae->ec), if (crypto_bignum_to_bin(sae->order, order, sizeof(order),
order, sizeof(order), sae->prime_len) < 0) sae->prime_len) < 0)
return NULL; return NULL;
if (sae_get_rand(order, prime_len_bits, sae->sae_rand) < 0 || if (sae_get_rand(order, prime_len_bits, sae->sae_rand) < 0 ||
@ -135,8 +137,8 @@ static int sae_test_pwd_seed(struct sae_data *sae, const u8 *pwd_seed,
int y_bit; int y_bit;
size_t bits; size_t bits;
if (crypto_bignum_to_bin(crypto_ec_get_prime(sae->ec), if (crypto_bignum_to_bin(sae->prime, prime, sizeof(prime),
prime, sizeof(prime), sae->prime_len) < 0) sae->prime_len) < 0)
return -1; return -1;
wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-seed", pwd_seed, SHA256_MAC_LEN); wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-seed", pwd_seed, SHA256_MAC_LEN);
@ -271,7 +273,7 @@ static int sae_derive_commit(struct sae_data *sae, struct crypto_ec_point *pwe)
/* commit-scalar = (rand + mask) modulo r */ /* commit-scalar = (rand + mask) modulo r */
crypto_bignum_add(bn_rand, mask, x); crypto_bignum_add(bn_rand, mask, x);
crypto_bignum_mod(x, crypto_ec_get_order(sae->ec), x); crypto_bignum_mod(x, sae->order, x);
crypto_bignum_to_bin(x, sae->own_commit_scalar, crypto_bignum_to_bin(x, sae->own_commit_scalar,
sizeof(sae->own_commit_scalar), sae->prime_len); sizeof(sae->own_commit_scalar), sae->prime_len);
wpa_hexdump(MSG_DEBUG, "SAE: commit-scalar", wpa_hexdump(MSG_DEBUG, "SAE: commit-scalar",
@ -326,10 +328,10 @@ static int sae_check_peer_commit(struct sae_data *sae)
{ {
u8 order[SAE_MAX_PRIME_LEN], prime[SAE_MAX_PRIME_LEN]; u8 order[SAE_MAX_PRIME_LEN], prime[SAE_MAX_PRIME_LEN];
if (crypto_bignum_to_bin(crypto_ec_get_order(sae->ec), if (crypto_bignum_to_bin(sae->order, order, sizeof(order),
order, sizeof(order), sae->prime_len) < 0 || sae->prime_len) < 0 ||
crypto_bignum_to_bin(crypto_ec_get_prime(sae->ec), crypto_bignum_to_bin(sae->prime, prime, sizeof(prime),
prime, sizeof(prime), sae->prime_len) < 0) sae->prime_len) < 0)
return -1; return -1;
/* 0 < scalar < r */ /* 0 < scalar < r */
@ -428,7 +430,7 @@ static int sae_derive_keys(struct sae_data *sae, const u8 *k)
wpa_hexdump_key(MSG_DEBUG, "SAE: keyseed", keyseed, sizeof(keyseed)); wpa_hexdump_key(MSG_DEBUG, "SAE: keyseed", keyseed, sizeof(keyseed));
crypto_bignum_add(own_scalar, peer_scalar, tmp); crypto_bignum_add(own_scalar, peer_scalar, tmp);
crypto_bignum_mod(tmp, crypto_ec_get_order(sae->ec), tmp); crypto_bignum_mod(tmp, sae->order, tmp);
crypto_bignum_to_bin(tmp, val, sizeof(val), sae->prime_len); crypto_bignum_to_bin(tmp, val, sizeof(val), sae->prime_len);
wpa_hexdump(MSG_DEBUG, "SAE: PMKID", val, SAE_PMKID_LEN); wpa_hexdump(MSG_DEBUG, "SAE: PMKID", val, SAE_PMKID_LEN);
sha256_prf(keyseed, sizeof(keyseed), "SAE KCK and PMK", sha256_prf(keyseed, sizeof(keyseed), "SAE KCK and PMK",

2
src/common/sae.h
View file

@ -31,6 +31,8 @@ struct sae_data {
int group; int group;
struct crypto_ec *ec; struct crypto_ec *ec;
int prime_len; int prime_len;
const struct crypto_bignum *prime;
const struct crypto_bignum *order;
}; };
int sae_set_group(struct sae_data *sae, int group); int sae_set_group(struct sae_data *sae, int group);