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SAE: Split sae_parse_commit() into helper functions

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Signed-hostap: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2013-01-06 17:03:09 +02:00
parent b0f6124c1c
commit 24dc1e2a2c
1 changed files with 70 additions and 26 deletions
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96
src/common/sae.c
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@ -758,23 +758,9 @@ void sae_write_commit(struct sae_data *sae, struct wpabuf *buf,
}
u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
const u8 **token, size_t *token_len, int *allowed_groups)
static u16 sae_group_allowed(struct sae_data *sae, int *allowed_groups,
u16 group)
{
const u8 *pos = data, *end = data + len;
u16 group;
struct crypto_bignum *peer_scalar;
wpa_hexdump(MSG_DEBUG, "SAE: Commit fields", data, len);
if (token)
*token = NULL;
if (token_len)
*token_len = 0;
/* Check Finite Cyclic Group */
if (pos + 2 > end)
return WLAN_STATUS_UNSPECIFIED_FAILURE;
group = WPA_GET_LE16(pos);
if (allowed_groups) {
int i;
for (i = 0; allowed_groups[i] >= 0; i++) {
@ -788,38 +774,60 @@ u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
}
}
if (sae->state == SAE_COMMITTED && group != sae->group) {
wpa_printf(MSG_DEBUG, "SAE: Do not allow group to be changed");
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
}
if (group != sae->group && sae_set_group(sae, group) < 0) {
wpa_printf(MSG_DEBUG, "SAE: Unsupported Finite Cyclic Group %u",
group);
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
}
if (sae->dh && !allowed_groups) {
wpa_printf(MSG_DEBUG, "SAE: Do not allow FFC group %u without "
"explicit configuration enabling it", group);
return WLAN_STATUS_FINITE_CYCLIC_GROUP_NOT_SUPPORTED;
}
pos += 2;
if (pos + (sae->ec ? 3 : 2) * sae->prime_len < end) {
size_t tlen = end - (pos + (sae->ec ? 3 : 2) * sae->prime_len);
wpa_hexdump(MSG_DEBUG, "SAE: Anti-Clogging Token", pos, tlen);
return WLAN_STATUS_SUCCESS;
}
static void sae_parse_commit_token(struct sae_data *sae, const u8 **pos,
const u8 *end, const u8 **token,
size_t *token_len)
{
if (*pos + (sae->ec ? 3 : 2) * sae->prime_len < end) {
size_t tlen = end - (*pos + (sae->ec ? 3 : 2) * sae->prime_len);
wpa_hexdump(MSG_DEBUG, "SAE: Anti-Clogging Token", *pos, tlen);
if (token)
*token = pos;
*token = *pos;
if (token_len)
*token_len = tlen;
pos += tlen;
*pos += tlen;
} else {
if (token)
*token = NULL;
if (token_len)
*token_len = 0;
}
}
if (pos + sae->prime_len > end) {
static u16 sae_parse_commit_scalar(struct sae_data *sae, const u8 **pos,
const u8 *end)
{
struct crypto_bignum *peer_scalar;
if (*pos + sae->prime_len > end) {
wpa_printf(MSG_DEBUG, "SAE: Not enough data for scalar");
return WLAN_STATUS_UNSPECIFIED_FAILURE;
}
peer_scalar = crypto_bignum_init_set(pos, sae->prime_len);
peer_scalar = crypto_bignum_init_set(*pos, sae->prime_len);
if (peer_scalar == NULL)
return WLAN_STATUS_UNSPECIFIED_FAILURE;
@ -839,9 +847,16 @@ u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
crypto_bignum_deinit(sae->peer_commit_scalar, 0);
sae->peer_commit_scalar = peer_scalar;
wpa_hexdump(MSG_DEBUG, "SAE: Peer commit-scalar", pos, sae->prime_len);
pos += sae->prime_len;
wpa_hexdump(MSG_DEBUG, "SAE: Peer commit-scalar", *pos, sae->prime_len);
*pos += sae->prime_len;
return WLAN_STATUS_SUCCESS;
}
static u16 sae_parse_commit_element(struct sae_data *sae, const u8 *pos,
const u8 *end)
{
if (sae->dh) {
if (pos + sae->prime_len > end) {
wpa_printf(MSG_DEBUG, "SAE: Not enough data for "
@ -870,6 +885,35 @@ u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
}
u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
const u8 **token, size_t *token_len, int *allowed_groups)
{
const u8 *pos = data, *end = data + len;
u16 res;
wpa_hexdump(MSG_DEBUG, "SAE: Commit fields", data, len);
/* Check Finite Cyclic Group */
if (pos + 2 > end)
return WLAN_STATUS_UNSPECIFIED_FAILURE;
res = sae_group_allowed(sae, allowed_groups, WPA_GET_LE16(pos));
if (res != WLAN_STATUS_SUCCESS)
return res;
pos += 2;
/* Optional Anti-Clogging Token */
sae_parse_commit_token(sae, &pos, end, token, token_len);
/* commit-scalar */
res = sae_parse_commit_scalar(sae, &pos, end);
if (res != WLAN_STATUS_SUCCESS)
return res;
/* commit-element */
return sae_parse_commit_element(sae, pos, end);
}
static void sae_cn_confirm(struct sae_data *sae, const u8 *sc,
const struct crypto_bignum *scalar1,
const u8 *element1,