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-rw-r--r--src/ap/hostapd.h2
-rw-r--r--src/ap/ieee802_11.c66
2 files changed, 62 insertions, 6 deletions
diff --git a/src/ap/hostapd.h b/src/ap/hostapd.h
index 733f3f2..b8637c4 100644
--- a/src/ap/hostapd.h
+++ b/src/ap/hostapd.h
@@ -314,6 +314,8 @@ struct hostapd_data {
/** Key used for generating SAE anti-clogging tokens */
u8 sae_token_key[8];
struct os_reltime last_sae_token_key_update;
+ u16 sae_token_idx;
+ u16 sae_pending_token_idx[256];
int dot11RSNASAERetransPeriod; /* msec */
struct dl_list sae_commit_queue; /* struct hostapd_sae_commit_queue */
#endif /* CONFIG_SAE */
diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c
index 0da1d42..afa17db 100644
--- a/src/ap/ieee802_11.c
+++ b/src/ap/ieee802_11.c
@@ -532,18 +532,47 @@ static int use_sae_anti_clogging(struct hostapd_data *hapd)
}
+static u8 sae_token_hash(struct hostapd_data *hapd, const u8 *addr)
+{
+ u8 hash[SHA256_MAC_LEN];
+
+ hmac_sha256(hapd->sae_token_key, sizeof(hapd->sae_token_key),
+ addr, ETH_ALEN, hash);
+ return hash[0];
+}
+
+
static int check_sae_token(struct hostapd_data *hapd, const u8 *addr,
const u8 *token, size_t token_len)
{
u8 mac[SHA256_MAC_LEN];
+ const u8 *addrs[2];
+ size_t len[2];
+ u16 token_idx;
+ u8 idx;
if (token_len != SHA256_MAC_LEN)
return -1;
- if (hmac_sha256(hapd->sae_token_key, sizeof(hapd->sae_token_key),
- addr, ETH_ALEN, mac) < 0 ||
- os_memcmp_const(token, mac, SHA256_MAC_LEN) != 0)
+ idx = sae_token_hash(hapd, addr);
+ token_idx = hapd->sae_pending_token_idx[idx];
+ if (token_idx == 0 || token_idx != WPA_GET_BE16(token)) {
+ wpa_printf(MSG_DEBUG, "SAE: Invalid anti-clogging token from "
+ MACSTR " - token_idx 0x%04x, expected 0x%04x",
+ MAC2STR(addr), WPA_GET_BE16(token), token_idx);
+ return -1;
+ }
+
+ addrs[0] = addr;
+ len[0] = ETH_ALEN;
+ addrs[1] = token;
+ len[1] = 2;
+ if (hmac_sha256_vector(hapd->sae_token_key, sizeof(hapd->sae_token_key),
+ 2, addrs, len, mac) < 0 ||
+ os_memcmp_const(token + 2, &mac[2], SHA256_MAC_LEN - 2) != 0)
return -1;
+ hapd->sae_pending_token_idx[idx] = 0; /* invalidate used token */
+
return 0;
}
@@ -554,16 +583,25 @@ static struct wpabuf * auth_build_token_req(struct hostapd_data *hapd,
struct wpabuf *buf;
u8 *token;
struct os_reltime now;
+ u8 idx[2];
+ const u8 *addrs[2];
+ size_t len[2];
+ u8 p_idx;
+ u16 token_idx;
os_get_reltime(&now);
if (!os_reltime_initialized(&hapd->last_sae_token_key_update) ||
- os_reltime_expired(&now, &hapd->last_sae_token_key_update, 60)) {
+ os_reltime_expired(&now, &hapd->last_sae_token_key_update, 60) ||
+ hapd->sae_token_idx == 0xffff) {
if (random_get_bytes(hapd->sae_token_key,
sizeof(hapd->sae_token_key)) < 0)
return NULL;
wpa_hexdump(MSG_DEBUG, "SAE: Updated token key",
hapd->sae_token_key, sizeof(hapd->sae_token_key));
hapd->last_sae_token_key_update = now;
+ hapd->sae_token_idx = 0;
+ os_memset(hapd->sae_pending_token_idx, 0,
+ sizeof(hapd->sae_pending_token_idx));
}
buf = wpabuf_alloc(sizeof(le16) + SHA256_MAC_LEN);
@@ -572,9 +610,25 @@ static struct wpabuf * auth_build_token_req(struct hostapd_data *hapd,
wpabuf_put_le16(buf, group); /* Finite Cyclic Group */
+ p_idx = sae_token_hash(hapd, addr);
+ token_idx = hapd->sae_pending_token_idx[p_idx];
+ if (!token_idx) {
+ hapd->sae_token_idx++;
+ token_idx = hapd->sae_token_idx;
+ hapd->sae_pending_token_idx[p_idx] = token_idx;
+ }
+ WPA_PUT_BE16(idx, token_idx);
token = wpabuf_put(buf, SHA256_MAC_LEN);
- hmac_sha256(hapd->sae_token_key, sizeof(hapd->sae_token_key),
- addr, ETH_ALEN, token);
+ addrs[0] = addr;
+ len[0] = ETH_ALEN;
+ addrs[1] = idx;
+ len[1] = sizeof(idx);
+ if (hmac_sha256_vector(hapd->sae_token_key, sizeof(hapd->sae_token_key),
+ 2, addrs, len, token) < 0) {
+ wpabuf_free(buf);
+ return NULL;
+ }
+ WPA_PUT_BE16(token, token_idx);
return buf;
}