[PATCH v3 1/2] Add hostapd options wpa_group_update_count and wpa_pairwise_update_count
Günther Kelleter
guenther.kelleter at devolo.de
Thu Jan 5 08:00:33 PST 2017
wpa_group_update_count and wpa_pairwise_update_count can now be used to
set the GTK and PTK rekey retries.
Defaults set to current hardcoded value (4).
Some stations may suffer from frequent deauthentications due to GTK rekey
failures: EAPOL 1/2 frame is not answered during the total timeout period
of currently ~3.5 seconds.
E.g. a Galaxy S6 with Android 6.0.1 appears to go into power save mode
for up to 5 seconds. Increasing wpa_group_update_count to 6 fixed this issue.
Signed-off-by: Günther Kelleter <guenther.kelleter at devolo.de>
---
hostapd/config_file.c | 18 ++++++++++++++++++
hostapd/hostapd.conf | 12 ++++++++++++
src/ap/ap_config.c | 2 ++
src/ap/ap_config.h | 2 ++
src/ap/wpa_auth.c | 33 +++++++++++++++++----------------
src/ap/wpa_auth.h | 2 ++
src/ap/wpa_auth_glue.c | 2 ++
src/ap/wpa_auth_i.h | 4 ++--
8 files changed, 57 insertions(+), 18 deletions(-)
diff --git a/hostapd/config_file.c b/hostapd/config_file.c
index b397034..85e8a00 100644
--- a/hostapd/config_file.c
+++ b/hostapd/config_file.c
@@ -2489,6 +2489,24 @@ static int hostapd_config_fill(struct hostapd_config *conf,
bss->wpa_gmk_rekey = atoi(pos);
} else if (os_strcmp(buf, "wpa_ptk_rekey") == 0) {
bss->wpa_ptk_rekey = atoi(pos);
+ } else if (os_strcmp(buf, "wpa_group_update_count") == 0) {
+ char *endp;
+ unsigned long val = strtoul(pos, &endp, 0);
+ if (*endp || val < 1 || val > (u32) -1) {
+ wpa_printf(MSG_ERROR, "Line %d: Invalid wpa_group_update_count=%lu; allowed range 1..4294967295",
+ line, val);
+ return 1;
+ }
+ bss->wpa_group_update_count = (u32) val;
+ } else if (os_strcmp(buf, "wpa_pairwise_update_count") == 0) {
+ char *endp;
+ unsigned long val = strtoul(pos, &endp, 0);
+ if (*endp || val < 1 || val > (u32) -1) {
+ wpa_printf(MSG_ERROR, "Line %d: Invalid wpa_pairwise_update_count=%lu; allowed range 1..4294967295",
+ line, val);
+ return 1;
+ }
+ bss->wpa_pairwise_update_count = (u32) val;
} else if (os_strcmp(buf, "wpa_passphrase") == 0) {
int len = os_strlen(pos);
if (len < 8 || len > 63) {
diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
index c9b105a..3abbb2b 100644
--- a/hostapd/hostapd.conf
+++ b/hostapd/hostapd.conf
@@ -1221,6 +1221,12 @@ own_ip_addr=127.0.0.1
# (dot11RSNAConfigGroupRekeyStrict)
#wpa_strict_rekey=1
+# The number of times Message 1 in the RSNA Group Key Handshake is retried
+# per GTK Handshake attempt.
+# (dot11RSNAConfigGroupUpdateCount)
+# range 1..4294967295; default: 4
+#wpa_group_update_count=4
+
# Time interval for rekeying GMK (master key used internally to generate GTKs
# (in seconds).
#wpa_gmk_rekey=86400
@@ -1229,6 +1235,12 @@ own_ip_addr=127.0.0.1
# PTK to mitigate some attacks against TKIP deficiencies.
#wpa_ptk_rekey=600
+# The number of times Message 1 and Message 3 in the RSNA 4-Way Handshake is
+# retried per 4-Way Handshake attempt.
+# (dot11RSNAConfigPairwiseUpdateCount)
+# range 1..4294967295; default: 4
+#wpa_pairwise_update_count=4
+
# Enable IEEE 802.11i/RSN/WPA2 pre-authentication. This is used to speed up
# roaming be pre-authenticating IEEE 802.1X/EAP part of the full RSN
# authentication and key handshake before actually associating with a new AP.
diff --git a/src/ap/ap_config.c b/src/ap/ap_config.c
index e417a12..6438a2f 100644
--- a/src/ap/ap_config.c
+++ b/src/ap/ap_config.c
@@ -55,6 +55,8 @@ void hostapd_config_defaults_bss(struct hostapd_bss_config *bss)
bss->wpa_group_rekey = 600;
bss->wpa_gmk_rekey = 86400;
+ bss->wpa_group_update_count = 4;
+ bss->wpa_pairwise_update_count = 4;
bss->wpa_key_mgmt = WPA_KEY_MGMT_PSK;
bss->wpa_pairwise = WPA_CIPHER_TKIP;
bss->wpa_group = WPA_CIPHER_TKIP;
diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index 075261c..9e599e0 100644
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -330,6 +330,8 @@ struct hostapd_bss_config {
int wpa_strict_rekey;
int wpa_gmk_rekey;
int wpa_ptk_rekey;
+ u32 wpa_group_update_count;
+ u32 wpa_pairwise_update_count;
int rsn_pairwise;
int rsn_preauth;
char *rsn_preauth_interfaces;
diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
index 43e3558..be11621 100644
--- a/src/ap/wpa_auth.c
+++ b/src/ap/wpa_auth.c
@@ -60,8 +60,6 @@ static void wpa_group_put(struct wpa_authenticator *wpa_auth,
struct wpa_group *group);
static u8 * ieee80211w_kde_add(struct wpa_state_machine *sm, u8 *pos);
-static const u32 dot11RSNAConfigGroupUpdateCount = 4;
-static const u32 dot11RSNAConfigPairwiseUpdateCount = 4;
static const u32 eapol_key_timeout_first = 100; /* ms */
static const u32 eapol_key_timeout_subseq = 1000; /* ms */
static const u32 eapol_key_timeout_first_group = 500; /* ms */
@@ -1617,7 +1615,7 @@ static void wpa_send_eapol(struct wpa_authenticator *wpa_auth,
{
int timeout_ms;
int pairwise = key_info & WPA_KEY_INFO_KEY_TYPE;
- int ctr;
+ u32 ctr;
if (sm == NULL)
return;
@@ -1634,7 +1632,7 @@ static void wpa_send_eapol(struct wpa_authenticator *wpa_auth,
if (pairwise && ctr == 1 && !(key_info & WPA_KEY_INFO_MIC))
sm->pending_1_of_4_timeout = 1;
wpa_printf(MSG_DEBUG, "WPA: Use EAPOL-Key timeout of %u ms (retry "
- "counter %d)", timeout_ms, ctr);
+ "counter %u)", timeout_ms, ctr);
eloop_register_timeout(timeout_ms / 1000, (timeout_ms % 1000) * 1000,
wpa_send_eapol_timeout, wpa_auth, sm);
}
@@ -1996,7 +1994,8 @@ SM_STATE(WPA_PTK, PTKSTART)
sm->alt_snonce_valid = FALSE;
sm->TimeoutCtr++;
- if (sm->TimeoutCtr > (int) dot11RSNAConfigPairwiseUpdateCount) {
+ if (sm->TimeoutCtr >
+ (u64) sm->wpa_auth->conf.wpa_pairwise_update_count) {
/* No point in sending the EAPOL-Key - we will disconnect
* immediately following this. */
return;
@@ -2684,7 +2683,8 @@ SM_STATE(WPA_PTK, PTKINITNEGOTIATING)
sm->TimeoutEvt = FALSE;
sm->TimeoutCtr++;
- if (sm->TimeoutCtr > (int) dot11RSNAConfigPairwiseUpdateCount) {
+ if (sm->TimeoutCtr >
+ (u64) sm->wpa_auth->conf.wpa_pairwise_update_count) {
/* No point in sending the EAPOL-Key - we will disconnect
* immediately following this. */
return;
@@ -2979,11 +2979,11 @@ SM_STEP(WPA_PTK)
sm->EAPOLKeyPairwise)
SM_ENTER(WPA_PTK, PTKCALCNEGOTIATING);
else if (sm->TimeoutCtr >
- (int) dot11RSNAConfigPairwiseUpdateCount) {
+ (u64) sm->wpa_auth->conf.wpa_pairwise_update_count) {
wpa_auth->dot11RSNA4WayHandshakeFailures++;
wpa_auth_vlogger(sm->wpa_auth, sm->addr, LOGGER_DEBUG,
- "PTKSTART: Retry limit %d reached",
- dot11RSNAConfigPairwiseUpdateCount);
+ "PTKSTART: Retry limit %u reached",
+ sm->wpa_auth->conf.wpa_pairwise_update_count);
SM_ENTER(WPA_PTK, DISCONNECT);
} else if (sm->TimeoutEvt)
SM_ENTER(WPA_PTK, PTKSTART);
@@ -3007,12 +3007,12 @@ SM_STEP(WPA_PTK)
sm->EAPOLKeyPairwise && sm->MICVerified)
SM_ENTER(WPA_PTK, PTKINITDONE);
else if (sm->TimeoutCtr >
- (int) dot11RSNAConfigPairwiseUpdateCount) {
+ (u64) sm->wpa_auth->conf.wpa_pairwise_update_count) {
wpa_auth->dot11RSNA4WayHandshakeFailures++;
wpa_auth_vlogger(sm->wpa_auth, sm->addr, LOGGER_DEBUG,
- "PTKINITNEGOTIATING: Retry limit %d "
+ "PTKINITNEGOTIATING: Retry limit %u "
"reached",
- dot11RSNAConfigPairwiseUpdateCount);
+ sm->wpa_auth->conf.wpa_pairwise_update_count);
SM_ENTER(WPA_PTK, DISCONNECT);
} else if (sm->TimeoutEvt)
SM_ENTER(WPA_PTK, PTKINITNEGOTIATING);
@@ -3047,7 +3047,8 @@ SM_STATE(WPA_PTK_GROUP, REKEYNEGOTIATING)
SM_ENTRY_MA(WPA_PTK_GROUP, REKEYNEGOTIATING, wpa_ptk_group);
sm->GTimeoutCtr++;
- if (sm->GTimeoutCtr > (int) dot11RSNAConfigGroupUpdateCount) {
+ if (sm->GTimeoutCtr >
+ (u64) sm->wpa_auth->conf.wpa_group_update_count) {
/* No point in sending the EAPOL-Key - we will disconnect
* immediately following this. */
return;
@@ -3145,7 +3146,7 @@ SM_STEP(WPA_PTK_GROUP)
!sm->EAPOLKeyPairwise && sm->MICVerified)
SM_ENTER(WPA_PTK_GROUP, REKEYESTABLISHED);
else if (sm->GTimeoutCtr >
- (int) dot11RSNAConfigGroupUpdateCount)
+ (u64) sm->wpa_auth->conf.wpa_group_update_count)
SM_ENTER(WPA_PTK_GROUP, KEYERROR);
else if (sm->TimeoutEvt)
SM_ENTER(WPA_PTK_GROUP, REKEYNEGOTIATING);
@@ -3605,8 +3606,8 @@ int wpa_get_mib(struct wpa_authenticator *wpa_auth, char *buf, size_t buflen)
"dot11RSNAConfigNumberOfGTKSAReplayCounters=0\n",
RSN_VERSION,
!!wpa_auth->conf.wpa_strict_rekey,
- dot11RSNAConfigGroupUpdateCount,
- dot11RSNAConfigPairwiseUpdateCount,
+ wpa_auth->conf.wpa_group_update_count,
+ wpa_auth->conf.wpa_pairwise_update_count,
wpa_cipher_key_len(wpa_auth->conf.wpa_group) * 8,
dot11RSNAConfigPMKLifetime,
dot11RSNAConfigPMKReauthThreshold,
diff --git a/src/ap/wpa_auth.h b/src/ap/wpa_auth.h
index 743f2e6..fadf11b 100644
--- a/src/ap/wpa_auth.h
+++ b/src/ap/wpa_auth.h
@@ -144,6 +144,8 @@ struct wpa_auth_config {
int wpa_strict_rekey;
int wpa_gmk_rekey;
int wpa_ptk_rekey;
+ u32 wpa_group_update_count;
+ u32 wpa_pairwise_update_count;
int rsn_pairwise;
int rsn_preauth;
int eapol_version;
diff --git a/src/ap/wpa_auth_glue.c b/src/ap/wpa_auth_glue.c
index aabac36..c3ea9e4 100644
--- a/src/ap/wpa_auth_glue.c
+++ b/src/ap/wpa_auth_glue.c
@@ -41,6 +41,8 @@ static void hostapd_wpa_auth_conf(struct hostapd_bss_config *conf,
wconf->wpa_strict_rekey = conf->wpa_strict_rekey;
wconf->wpa_gmk_rekey = conf->wpa_gmk_rekey;
wconf->wpa_ptk_rekey = conf->wpa_ptk_rekey;
+ wconf->wpa_group_update_count = conf->wpa_group_update_count;
+ wconf->wpa_pairwise_update_count = conf->wpa_pairwise_update_count;
wconf->rsn_pairwise = conf->rsn_pairwise;
wconf->rsn_preauth = conf->rsn_preauth;
wconf->eapol_version = conf->eapol_version;
diff --git a/src/ap/wpa_auth_i.h b/src/ap/wpa_auth_i.h
index 0c5a457..1bac12e 100644
--- a/src/ap/wpa_auth_i.h
+++ b/src/ap/wpa_auth_i.h
@@ -48,8 +48,8 @@ struct wpa_state_machine {
Boolean AuthenticationRequest;
Boolean ReAuthenticationRequest;
Boolean Disconnect;
- int TimeoutCtr;
- int GTimeoutCtr;
+ u64 TimeoutCtr;
+ u64 GTimeoutCtr;
Boolean TimeoutEvt;
Boolean EAPOLKeyReceived;
Boolean EAPOLKeyPairwise;
--
2.10.2.101.g2cc9ff1
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