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SAE: Use EC group context to get the group prime

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Do not use the hardcoded group19_prime buffer for this to allow group
negotiation.

Signed-hostap: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2013-01-01 12:27:00 +02:00
parent 09200a1166
commit a55f2eef71
3 changed files with 36 additions and 23 deletions
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32
src/common/sae.c
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@ -16,14 +16,6 @@
#include "sae.h"
static const u8 group19_prime[] = {
0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
};
int sae_set_group(struct sae_data *sae, int group)
{
crypto_ec_deinit(sae->ec);
@ -125,20 +117,23 @@ static void sae_pwd_seed_key(const u8 *addr1, const u8 *addr2, u8 *key)
static int sae_test_pwd_seed(struct sae_data *sae, const u8 *pwd_seed,
struct crypto_ec_point *pwe, u8 *pwe_bin)
{
u8 pwd_value[SAE_MAX_PRIME_LEN];
u8 pwd_value[SAE_MAX_PRIME_LEN], prime[SAE_MAX_PRIME_LEN];
struct crypto_bignum *x;
int y_bit;
if (crypto_bignum_to_bin(crypto_ec_get_prime(sae->ec),
prime, sizeof(prime), sae->prime_len) < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-seed", pwd_seed, SHA256_MAC_LEN);
/* pwd-value = KDF-z(pwd-seed, "SAE Hunting and Pecking", p) */
sha256_prf(pwd_seed, SHA256_MAC_LEN, "SAE Hunting and Pecking",
group19_prime, sizeof(group19_prime),
pwd_value, sizeof(pwd_value));
prime, sae->prime_len, pwd_value, sizeof(pwd_value));
wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-value",
pwd_value, sizeof(pwd_value));
if (os_memcmp(pwd_value, group19_prime, sizeof(group19_prime)) >= 0)
if (os_memcmp(pwd_value, prime, sae->prime_len) >= 0)
return 0;
y_bit = pwd_seed[SHA256_MAC_LEN - 1] & 0x01;
@ -308,10 +303,12 @@ int sae_prepare_commit(const u8 *addr1, const u8 *addr2,
static int sae_check_peer_commit(struct sae_data *sae)
{
u8 order[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),
order, sizeof(order), sae->prime_len) < 0)
order, sizeof(order), sae->prime_len) < 0 ||
crypto_bignum_to_bin(crypto_ec_get_prime(sae->ec),
prime, sizeof(prime), sae->prime_len) < 0)
return -1;
/* 0 < scalar < r */
@ -322,10 +319,9 @@ static int sae_check_peer_commit(struct sae_data *sae)
}
/* element x and y coordinates < p */
if (os_memcmp(sae->peer_commit_element, group19_prime,
sizeof(group19_prime)) >= 0 ||
os_memcmp(sae->peer_commit_element + sae->prime_len, group19_prime,
sizeof(group19_prime)) >= 0) {
if (os_memcmp(sae->peer_commit_element, prime, sae->prime_len) >= 0 ||
os_memcmp(sae->peer_commit_element + sae->prime_len, prime,
sae->prime_len) >= 0) {
wpa_printf(MSG_DEBUG, "SAE: Invalid coordinates in peer "
"element");
return -1;