[PATCH v2 07/14] AP: Rename SAE anti clogging variables and functions

Ilan Peer ilan.peer at intel.com
Wed Dec 16 06:00:58 EST 2020


PASN authentication mandates support for comeback flow, which
among others can be used for anti-clogging purposes.

As the SAE support for anti clogging can also be used for PASN,
start modifying the source code so the anti clogging support
can be used for both SAE and PASN.

As a start, rename some variables/functions etc. so that they
would not be SAE specific.

Signed-off-by: Ilan Peer <ilan.peer at intel.com>
---
 hostapd/config_file.c   |  4 +--
 src/ap/ap_config.c      |  2 +-
 src/ap/ap_config.h      |  2 +-
 src/ap/hostapd.h        |  8 ++---
 src/ap/ieee802_11.c     | 76 +++++++++++++++++++++++------------------
 tests/hwsim/test_sae.py | 12 +++----
 6 files changed, 56 insertions(+), 48 deletions(-)

diff --git a/hostapd/config_file.c b/hostapd/config_file.c
index 436a052aaf..ba7c348388 100644
--- a/hostapd/config_file.c
+++ b/hostapd/config_file.c
@@ -4203,8 +4203,8 @@ static int hostapd_config_fill(struct hostapd_config *conf,
 	} else if (os_strcmp(buf, "assocresp_elements") == 0) {
 		if (parse_wpabuf_hex(line, buf, &bss->assocresp_elements, pos))
 			return 1;
-	} else if (os_strcmp(buf, "sae_anti_clogging_threshold") == 0) {
-		bss->sae_anti_clogging_threshold = atoi(pos);
+	} else if (os_strcmp(buf, "anti_clogging_threshold") == 0) {
+		bss->anti_clogging_threshold = atoi(pos);
 	} else if (os_strcmp(buf, "sae_sync") == 0) {
 		bss->sae_sync = atoi(pos);
 	} else if (os_strcmp(buf, "sae_groups") == 0) {
diff --git a/src/ap/ap_config.c b/src/ap/ap_config.c
index 84d13512bd..502a68f743 100644
--- a/src/ap/ap_config.c
+++ b/src/ap/ap_config.c
@@ -121,7 +121,7 @@ void hostapd_config_defaults_bss(struct hostapd_bss_config *bss)
 
 	bss->radius_das_time_window = 300;
 
-	bss->sae_anti_clogging_threshold = 5;
+	bss->anti_clogging_threshold = 5;
 	bss->sae_sync = 5;
 
 	bss->gas_frag_limit = 1400;
diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index 7e7b6a8cc0..9652a1ced8 100644
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -655,7 +655,7 @@ struct hostapd_bss_config {
 	struct wpabuf *vendor_elements;
 	struct wpabuf *assocresp_elements;
 
-	unsigned int sae_anti_clogging_threshold;
+	unsigned int anti_clogging_threshold;
 	unsigned int sae_sync;
 	int sae_require_mfp;
 	int sae_confirm_immediate;
diff --git a/src/ap/hostapd.h b/src/ap/hostapd.h
index 80a34015e2..58feae17ac 100644
--- a/src/ap/hostapd.h
+++ b/src/ap/hostapd.h
@@ -327,10 +327,10 @@ struct hostapd_data {
 
 #ifdef CONFIG_SAE
 	/** 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];
+	u8 comeback_key[8];
+	struct os_reltime last_comeback_key_update;
+	u16 comeback_idx;
+	u16 comeback_pending_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 5c54da3cb9..0a24e297ff 100644
--- a/src/ap/ieee802_11.c
+++ b/src/ap/ieee802_11.c
@@ -685,12 +685,12 @@ static int auth_sae_send_confirm(struct hostapd_data *hapd,
 }
 
 
-static int use_sae_anti_clogging(struct hostapd_data *hapd)
+static int use_anti_clogging(struct hostapd_data *hapd)
 {
 	struct sta_info *sta;
 	unsigned int open = 0;
 
-	if (hapd->conf->sae_anti_clogging_threshold == 0)
+	if (hapd->conf->anti_clogging_threshold == 0)
 		return 1;
 
 	for (sta = hapd->sta_list; sta; sta = sta->next) {
@@ -700,7 +700,7 @@ static int use_sae_anti_clogging(struct hostapd_data *hapd)
 		    sta->sae->state != SAE_CONFIRMED)
 			continue;
 		open++;
-		if (open >= hapd->conf->sae_anti_clogging_threshold)
+		if (open >= hapd->conf->anti_clogging_threshold)
 			return 1;
 	}
 
@@ -708,27 +708,29 @@ static int use_sae_anti_clogging(struct hostapd_data *hapd)
 	 * there are enough pending commit messages in the processing queue to
 	 * potentially result in too many open sessions. */
 	if (open + dl_list_len(&hapd->sae_commit_queue) >=
-	    hapd->conf->sae_anti_clogging_threshold)
+	    hapd->conf->anti_clogging_threshold)
 		return 1;
 
 	return 0;
 }
 
 
-static int sae_token_hash(struct hostapd_data *hapd, const u8 *addr, u8 *idx)
+static int comeback_token_hash(struct hostapd_data *hapd, const u8 *addr,
+			       u8 *idx)
 {
 	u8 hash[SHA256_MAC_LEN];
 
-	if (hmac_sha256(hapd->sae_token_key, sizeof(hapd->sae_token_key),
-			addr, ETH_ALEN, hash) < 0)
+	if (hmac_sha256(hapd->comeback_key, sizeof(hapd->comeback_key),
+		    addr, ETH_ALEN, hash) < 0)
 		return -1;
+
 	*idx = hash[0];
 	return 0;
 }
 
 
-static int check_sae_token(struct hostapd_data *hapd, const u8 *addr,
-			   const u8 *token, size_t token_len)
+static int check_comeback_token(struct hostapd_data *hapd, const u8 *addr,
+				const u8 *token, size_t token_len)
 {
 	u8 mac[SHA256_MAC_LEN];
 	const u8 *addrs[2];
@@ -736,11 +738,14 @@ static int check_sae_token(struct hostapd_data *hapd, const u8 *addr,
 	u16 token_idx;
 	u8 idx;
 
-	if (token_len != SHA256_MAC_LEN || sae_token_hash(hapd, addr, &idx) < 0)
-		return -1;
-	token_idx = hapd->sae_pending_token_idx[idx];
+	if (token_len != SHA256_MAC_LEN ||
+	    comeback_token_hash(hapd, addr, &idx) < 0)
+	    return -1;
+
+	token_idx = hapd->comeback_pending_idx[idx];
 	if (token_idx == 0 || token_idx != WPA_GET_BE16(token)) {
-		wpa_printf(MSG_DEBUG, "SAE: Invalid anti-clogging token from "
+		wpa_printf(MSG_DEBUG,
+			   "Comeback: Invalid anti-clogging token from "
 			   MACSTR " - token_idx 0x%04x, expected 0x%04x",
 			   MAC2STR(addr), WPA_GET_BE16(token), token_idx);
 		return -1;
@@ -750,12 +755,12 @@ static int check_sae_token(struct hostapd_data *hapd, const u8 *addr,
 	len[0] = ETH_ALEN;
 	addrs[1] = token;
 	len[1] = 2;
-	if (hmac_sha256_vector(hapd->sae_token_key, sizeof(hapd->sae_token_key),
+	if (hmac_sha256_vector(hapd->comeback_key, sizeof(hapd->comeback_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 */
+	hapd->comeback_pending_idx[idx] = 0; /* invalidate used token */
 
 	return 0;
 }
@@ -774,18 +779,19 @@ static struct wpabuf * auth_build_token_req(struct hostapd_data *hapd,
 	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) ||
-	    hapd->sae_token_idx == 0xffff) {
-		if (random_get_bytes(hapd->sae_token_key,
-				     sizeof(hapd->sae_token_key)) < 0)
+	if (!os_reltime_initialized(&hapd->last_comeback_key_update) ||
+	    os_reltime_expired(&now, &hapd->last_comeback_key_update, 60) ||
+	    hapd->comeback_idx == 0xffff) {
+		if (random_get_bytes(hapd->comeback_key,
+				     sizeof(hapd->comeback_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));
+		wpa_hexdump(MSG_DEBUG,
+			    "Comeback: Updated token key",
+			    hapd->comeback_key, sizeof(hapd->comeback_key));
+		hapd->last_comeback_key_update = now;
+		hapd->comeback_idx = 0;
+		os_memset(hapd->comeback_pending_idx, 0,
+			  sizeof(hapd->comeback_pending_idx));
 	}
 
 	buf = wpabuf_alloc(sizeof(le16) + 3 + SHA256_MAC_LEN);
@@ -801,15 +807,16 @@ static struct wpabuf * auth_build_token_req(struct hostapd_data *hapd,
 		wpabuf_put_u8(buf, WLAN_EID_EXT_ANTI_CLOGGING_TOKEN);
 	}
 
-	if (sae_token_hash(hapd, addr, &p_idx) < 0) {
+	if (comeback_token_hash(hapd, addr, &p_idx) < 0) {
 		wpabuf_free(buf);
 		return NULL;
 	}
-	token_idx = hapd->sae_pending_token_idx[p_idx];
+
+	token_idx = hapd->comeback_pending_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;
+		hapd->comeback_idx++;
+		token_idx = hapd->comeback_idx;
+		hapd->comeback_pending_idx[p_idx] = token_idx;
 	}
 	WPA_PUT_BE16(idx, token_idx);
 	token = wpabuf_put(buf, SHA256_MAC_LEN);
@@ -817,7 +824,7 @@ static struct wpabuf * auth_build_token_req(struct hostapd_data *hapd,
 	len[0] = ETH_ALEN;
 	addrs[1] = idx;
 	len[1] = sizeof(idx);
-	if (hmac_sha256_vector(hapd->sae_token_key, sizeof(hapd->sae_token_key),
+	if (hmac_sha256_vector(hapd->comeback_key, sizeof(hapd->comeback_key),
 			       2, addrs, len, token) < 0) {
 		wpabuf_free(buf);
 		return NULL;
@@ -1448,7 +1455,8 @@ static void handle_auth_sae(struct hostapd_data *hapd, struct sta_info *sta,
 			goto remove_sta;
 		}
 
-		if (token && check_sae_token(hapd, sta->addr, token, token_len)
+		if (token && check_comeback_token(hapd, sta->addr, token,
+						  token_len)
 		    < 0) {
 			wpa_printf(MSG_DEBUG, "SAE: Drop commit message with "
 				   "incorrect token from " MACSTR,
@@ -1465,7 +1473,7 @@ static void handle_auth_sae(struct hostapd_data *hapd, struct sta_info *sta,
 			goto reply;
 		}
 
-		if (!token && use_sae_anti_clogging(hapd) && !allow_reuse) {
+		if (!token && use_anti_clogging(hapd) && !allow_reuse) {
 			int h2e = 0;
 
 			wpa_printf(MSG_DEBUG,
diff --git a/tests/hwsim/test_sae.py b/tests/hwsim/test_sae.py
index 9276e513ec..057ad5fe06 100644
--- a/tests/hwsim/test_sae.py
+++ b/tests/hwsim/test_sae.py
@@ -256,7 +256,7 @@ def test_sae_anti_clogging(dev, apdev):
     check_sae_capab(dev[1])
     params = hostapd.wpa2_params(ssid="test-sae", passphrase="12345678")
     params['wpa_key_mgmt'] = 'SAE'
-    params['sae_anti_clogging_threshold'] = '1'
+    params['anti_clogging_threshold'] = '1'
     hostapd.add_ap(apdev[0], params)
 
     dev[0].request("SET sae_groups ")
@@ -277,7 +277,7 @@ def test_sae_forced_anti_clogging(dev, apdev):
     check_sae_capab(dev[1])
     params = hostapd.wpa2_params(ssid="test-sae", passphrase="12345678")
     params['wpa_key_mgmt'] = 'SAE WPA-PSK'
-    params['sae_anti_clogging_threshold'] = '0'
+    params['anti_clogging_threshold'] = '0'
     hostapd.add_ap(apdev[0], params)
     dev[2].connect("test-sae", psk="12345678", scan_freq="2412")
     for i in range(0, 2):
@@ -291,7 +291,7 @@ def test_sae_mixed(dev, apdev):
     check_sae_capab(dev[1])
     params = hostapd.wpa2_params(ssid="test-sae", passphrase="12345678")
     params['wpa_key_mgmt'] = 'SAE WPA-PSK'
-    params['sae_anti_clogging_threshold'] = '0'
+    params['anti_clogging_threshold'] = '0'
     hapd = hostapd.add_ap(apdev[0], params)
 
     dev[2].connect("test-sae", psk="12345678", scan_freq="2412")
@@ -1771,7 +1771,7 @@ def test_sae_forced_anti_clogging_pw_id(dev, apdev):
     check_sae_capab(dev[0])
     params = hostapd.wpa2_params(ssid="test-sae")
     params['wpa_key_mgmt'] = 'SAE'
-    params['sae_anti_clogging_threshold'] = '0'
+    params['anti_clogging_threshold'] = '0'
     params['sae_password'] = 'secret|id=' + 29*'A'
     hostapd.add_ap(apdev[0], params)
     for i in range(0, 2):
@@ -2401,7 +2401,7 @@ def test_sae_forced_anti_clogging_h2e(dev, apdev):
     params = hostapd.wpa2_params(ssid="test-sae", passphrase="12345678")
     params['wpa_key_mgmt'] = 'SAE WPA-PSK'
     params['sae_pwe'] = "1"
-    params['sae_anti_clogging_threshold'] = '0'
+    params['anti_clogging_threshold'] = '0'
     hostapd.add_ap(apdev[0], params)
     dev[2].connect("test-sae", psk="12345678", scan_freq="2412")
     try:
@@ -2421,7 +2421,7 @@ def test_sae_forced_anti_clogging_h2e_loop(dev, apdev):
     params = hostapd.wpa2_params(ssid="test-sae", passphrase="12345678")
     params['wpa_key_mgmt'] = 'SAE WPA-PSK'
     params['sae_pwe'] = "2"
-    params['sae_anti_clogging_threshold'] = '0'
+    params['anti_clogging_threshold'] = '0'
     hostapd.add_ap(apdev[0], params)
     dev[2].connect("test-sae", psk="12345678", scan_freq="2412")
     try:
-- 
2.17.1




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