Add group_mgmt network parameter for PMF cipher selection

The new wpa_supplicant network parameter group_mgmt can be used to
specify which group management ciphers (AES-128-CMAC, BIP-GMAC-128,
BIP-GMAC-256, BIP-CMAC-256) are allowed for the network. If not
specified, the current behavior is maintained (i.e., follow what the AP
advertises). The parameter can list multiple space separate ciphers.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

src/common/wpa_common.c

@@ -2072,6 +2072,14 @@ int wpa_parse_cipher(const char *value)
 			val |= WPA_CIPHER_NONE;
 		else if (os_strcmp(start, "GTK_NOT_USED") == 0)
 			val |= WPA_CIPHER_GTK_NOT_USED;
+		else if (os_strcmp(start, "AES-128-CMAC") == 0)
+			val |= WPA_CIPHER_AES_128_CMAC;
+		else if (os_strcmp(start, "BIP-GMAC-128") == 0)
+			val |= WPA_CIPHER_BIP_GMAC_128;
+		else if (os_strcmp(start, "BIP-GMAC-256") == 0)
+			val |= WPA_CIPHER_BIP_GMAC_256;
+		else if (os_strcmp(start, "BIP-CMAC-256") == 0)
+			val |= WPA_CIPHER_BIP_CMAC_256;
 		else {
 			os_free(buf);
 			return -1;
@@ -2127,6 +2135,34 @@ int wpa_write_ciphers(char *start, char *end, int ciphers, const char *delim)
 			return -1;
 		pos += ret;
 	}
+	if (ciphers & WPA_CIPHER_AES_128_CMAC) {
+		ret = os_snprintf(pos, end - pos, "%sAES-128-CMAC",
+				  pos == start ? "" : delim);
+		if (os_snprintf_error(end - pos, ret))
+			return -1;
+		pos += ret;
+	}
+	if (ciphers & WPA_CIPHER_BIP_GMAC_128) {
+		ret = os_snprintf(pos, end - pos, "%sBIP-GMAC-128",
+				  pos == start ? "" : delim);
+		if (os_snprintf_error(end - pos, ret))
+			return -1;
+		pos += ret;
+	}
+	if (ciphers & WPA_CIPHER_BIP_GMAC_256) {
+		ret = os_snprintf(pos, end - pos, "%sBIP-GMAC-256",
+				  pos == start ? "" : delim);
+		if (os_snprintf_error(end - pos, ret))
+			return -1;
+		pos += ret;
+	}
+	if (ciphers & WPA_CIPHER_BIP_CMAC_256) {
+		ret = os_snprintf(pos, end - pos, "%sBIP-CMAC-256",
+				  pos == start ? "" : delim);
+		if (os_snprintf_error(end - pos, ret))
+			return -1;
+		pos += ret;
+	}
 	if (ciphers & WPA_CIPHER_NONE) {
 		ret = os_snprintf(pos, end - pos, "%sNONE",
 				  pos == start ? "" : delim);

src/common/wpa_common.h

@@ -29,6 +29,9 @@ WPA_CIPHER_GCMP_256 | WPA_CIPHER_CCMP_256)
 (WPA_CIPHER_CCMP | WPA_CIPHER_GCMP | WPA_CIPHER_TKIP | \
 WPA_CIPHER_GCMP_256 | WPA_CIPHER_CCMP_256 | \
 WPA_CIPHER_GTK_NOT_USED)
+#define WPA_ALLOWED_GROUP_MGMT_CIPHERS \
+(WPA_CIPHER_AES_128_CMAC | WPA_CIPHER_BIP_GMAC_128 | WPA_CIPHER_BIP_GMAC_256 | \
+WPA_CIPHER_BIP_CMAC_256)
 
 #define WPA_SELECTOR_LEN 4
 #define WPA_VERSION 1

src/drivers/driver.h

@@ -814,7 +814,7 @@ struct wpa_driver_associate_params {
 	 * WPA information element to be included in (Re)Association
 	 * Request (including information element id and length). Use
 	 * of this WPA IE is optional. If the driver generates the WPA
-	 * IE, it can use pairwise_suite, group_suite, and
+	 * IE, it can use pairwise_suite, group_suite, group_mgmt_suite, and
 	 * key_mgmt_suite to select proper algorithms. In this case,
 	 * the driver has to notify wpa_supplicant about the used WPA
 	 * IE by generating an event that the interface code will
@@ -853,6 +853,13 @@ struct wpa_driver_associate_params {
 	 */
 	unsigned int group_suite;
 
+	/**
+	 * mgmt_group_suite - Selected group management cipher suite (WPA_CIPHER_*)
+	 *
+	 * This is usually ignored if @wpa_ie is used.
+	 */
+	unsigned int mgmt_group_suite;
+
 	/**
 	 * key_mgmt_suite - Selected key management suite (WPA_KEY_MGMT_*)
 	 *

tests/hwsim/wpasupplicant.py

@@ -1027,7 +1027,8 @@ class WpaSupplicant:
                        "bssid_whitelist", "mem_only_psk", "eap_workaround",
                        "engine", "fils_dh_group", "bssid_hint",
                        "dpp_csign", "dpp_csign_expiry",
-                       "dpp_netaccesskey", "dpp_netaccesskey_expiry" ]
+                       "dpp_netaccesskey", "dpp_netaccesskey_expiry",
+                       "group_mgmt" ]
         for field in not_quoted:
             if field in kwargs and kwargs[field]:
                 self.set_network(id, field, kwargs[field])

wpa_supplicant/config.c

@@ -1148,6 +1148,40 @@ static char * wpa_config_write_group(const struct parse_data *data,
 #endif /* NO_CONFIG_WRITE */
 
 
+static int wpa_config_parse_group_mgmt(const struct parse_data *data,
+				       struct wpa_ssid *ssid, int line,
+				       const char *value)
+{
+	int val;
+
+	val = wpa_config_parse_cipher(line, value);
+	if (val == -1)
+		return -1;
+
+	if (val & ~WPA_ALLOWED_GROUP_MGMT_CIPHERS) {
+		wpa_printf(MSG_ERROR,
+			   "Line %d: not allowed group management cipher (0x%x).",
+			   line, val);
+		return -1;
+	}
+
+	if (ssid->group_mgmt_cipher == val)
+		return 1;
+	wpa_printf(MSG_MSGDUMP, "group_mgmt: 0x%x", val);
+	ssid->group_mgmt_cipher = val;
+	return 0;
+}
+
+
+#ifndef NO_CONFIG_WRITE
+static char * wpa_config_write_group_mgmt(const struct parse_data *data,
+					  struct wpa_ssid *ssid)
+{
+	return wpa_config_write_cipher(ssid->group_mgmt_cipher);
+}
+#endif /* NO_CONFIG_WRITE */
+
+
 static int wpa_config_parse_auth_alg(const struct parse_data *data,
 				     struct wpa_ssid *ssid, int line,
 				     const char *value)
@@ -2086,6 +2120,7 @@ static const struct parse_data ssid_fields[] = {
 	{ INT(bg_scan_period) },
 	{ FUNC(pairwise) },
 	{ FUNC(group) },
+	{ FUNC(group_mgmt) },
 	{ FUNC(auth_alg) },
 	{ FUNC(scan_freq) },
 	{ FUNC(freq_list) },

wpa_supplicant/config_file.c

@@ -593,6 +593,22 @@ static void write_group(FILE *f, struct wpa_ssid *ssid)
 }
 
 
+static void write_group_mgmt(FILE *f, struct wpa_ssid *ssid)
+{
+	char *value;
+
+	if (!ssid->group_mgmt_cipher)
+		return;
+
+	value = wpa_config_get(ssid, "group_mgmt");
+	if (!value)
+		return;
+	if (value[0])
+		fprintf(f, "\tgroup_mgmt=%s\n", value);
+	os_free(value);
+}
+
+
 static void write_auth_alg(FILE *f, struct wpa_ssid *ssid)
 {
 	char *value;
@@ -734,6 +750,7 @@ static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid)
 	INT_DEF(bg_scan_period, DEFAULT_BG_SCAN_PERIOD);
 	write_pairwise(f, ssid);
 	write_group(f, ssid);
+	write_group_mgmt(f, ssid);
 	write_auth_alg(f, ssid);
 	STR(bgscan);
 	STR(autoscan);

wpa_supplicant/config_ssid.h

@@ -209,6 +209,15 @@ struct wpa_ssid {
 	 */
 	int group_cipher;
 
+	/**
+	 * group_mgmt_cipher - Bitfield of allowed group management ciphers
+	 *
+	 * This is a bitfield of WPA_CIPHER_AES_128_CMAC and WPA_CIPHER_BIP_*
+	 * values. If 0, no constraint is used for the cipher, i.e., whatever
+	 * the AP uses is accepted.
+	 */
+	int group_mgmt_cipher;
+
 	/**
 	 * key_mgmt - Bitfield of allowed key management protocols
 	 *

wpa_supplicant/events.c

@@ -565,6 +565,14 @@ static int wpa_supplicant_ssid_bss_match(struct wpa_supplicant *wpa_s,
 			break;
 		}
 
+		if (ssid->group_mgmt_cipher &&
+		    !(ie.mgmt_group_cipher & ssid->group_mgmt_cipher)) {
+			if (debug_print)
+				wpa_dbg(wpa_s, MSG_DEBUG,
+					"   skip RSN IE - group mgmt cipher mismatch");
+			break;
+		}
+
 		if (!(ie.key_mgmt & ssid->key_mgmt)) {
 			if (debug_print)
 				wpa_dbg(wpa_s, MSG_DEBUG,

wpa_supplicant/sme.c

@@ -1227,6 +1227,7 @@ void sme_associate(struct wpa_supplicant *wpa_s, enum wpas_mode mode,
 	params.wpa_ie_len = wpa_s->sme.assoc_req_ie_len;
 	params.pairwise_suite = wpa_s->pairwise_cipher;
 	params.group_suite = wpa_s->group_cipher;
+	params.mgmt_group_suite = wpa_s->mgmt_group_cipher;
 	params.key_mgmt_suite = wpa_s->key_mgmt;
 	params.wpa_proto = wpa_s->wpa_proto;
 #ifdef CONFIG_HT_OVERRIDES

wpa_supplicant/wpa_supplicant.c

@@ -1232,9 +1232,24 @@ int wpa_supplicant_set_suites(struct wpa_supplicant *wpa_s,
 			ie.pairwise_cipher = ssid->pairwise_cipher;
 			ie.key_mgmt = ssid->key_mgmt;
 #ifdef CONFIG_IEEE80211W
+			ie.mgmt_group_cipher = 0;
+			if (ssid->ieee80211w != NO_MGMT_FRAME_PROTECTION) {
+				if (ssid->group_mgmt_cipher &
+				    WPA_CIPHER_BIP_GMAC_256)
 					ie.mgmt_group_cipher =
-				ssid->ieee80211w != NO_MGMT_FRAME_PROTECTION ?
-				WPA_CIPHER_AES_128_CMAC : 0;
+						WPA_CIPHER_BIP_GMAC_256;
+				else if (ssid->group_mgmt_cipher &
+					 WPA_CIPHER_BIP_CMAC_256)
+					ie.mgmt_group_cipher =
+						WPA_CIPHER_BIP_CMAC_256;
+				else if (ssid->group_mgmt_cipher &
+					 WPA_CIPHER_BIP_GMAC_128)
+					ie.mgmt_group_cipher =
+						WPA_CIPHER_BIP_GMAC_128;
+				else
+					ie.mgmt_group_cipher =
+						WPA_CIPHER_AES_128_CMAC;
+			}
 #endif /* CONFIG_IEEE80211W */
 			wpa_dbg(wpa_s, MSG_DEBUG, "WPA: Set cipher suites "
 				"based on configuration");
@@ -1387,6 +1402,8 @@ int wpa_supplicant_set_suites(struct wpa_supplicant *wpa_s,
 
 #ifdef CONFIG_IEEE80211W
 	sel = ie.mgmt_group_cipher;
+	if (ssid->group_mgmt_cipher)
+		sel &= ssid->group_mgmt_cipher;
 	if (wpas_get_ssid_pmf(wpa_s, ssid) == NO_MGMT_FRAME_PROTECTION ||
 	    !(ie.capabilities & WPA_CAPABILITY_MFPC))
 		sel = 0;
@@ -2301,7 +2318,7 @@ static void wpas_start_assoc_cb(struct wpa_radio_work *work, int deinit)
 	size_t wpa_ie_len;
 	int use_crypt, ret, i, bssid_changed;
 	int algs = WPA_AUTH_ALG_OPEN;
-	unsigned int cipher_pairwise, cipher_group;
+	unsigned int cipher_pairwise, cipher_group, cipher_group_mgmt;
 	struct wpa_driver_associate_params params;
 	int wep_keys_set = 0;
 	int assoc_failed = 0;
@@ -2665,6 +2682,7 @@ static void wpas_start_assoc_cb(struct wpa_radio_work *work, int deinit)
 	use_crypt = 1;
 	cipher_pairwise = wpa_s->pairwise_cipher;
 	cipher_group = wpa_s->group_cipher;
+	cipher_group_mgmt = wpa_s->mgmt_group_cipher;
 	if (wpa_s->key_mgmt == WPA_KEY_MGMT_NONE ||
 	    wpa_s->key_mgmt == WPA_KEY_MGMT_IEEE8021X_NO_WPA) {
 		if (wpa_s->key_mgmt == WPA_KEY_MGMT_NONE)
@@ -2748,6 +2766,7 @@ static void wpas_start_assoc_cb(struct wpa_radio_work *work, int deinit)
 	params.wpa_ie_len = wpa_ie_len;
 	params.pairwise_suite = cipher_pairwise;
 	params.group_suite = cipher_group;
+	params.mgmt_group_suite = cipher_group_mgmt;
 	params.key_mgmt_suite = wpa_s->key_mgmt;
 	params.wpa_proto = wpa_s->wpa_proto;
 	params.auth_alg = algs;

wpa_supplicant/wpa_supplicant.conf

@@ -879,6 +879,14 @@ fast_reauth=1
 # WEP40 = WEP (Wired Equivalent Privacy) with 40-bit key [IEEE 802.11]
 # If not set, this defaults to: CCMP TKIP WEP104 WEP40
 #
+# group_mgmt: list of accepted group management ciphers for RSN (PMF)
+# AES-128-CMAC = BIP-CMAC-128
+# BIP-GMAC-128
+# BIP-GMAC-256
+# BIP-CMAC-256
+# If not set, no constraint on the cipher, i.e., accept whichever cipher the AP
+# indicates.
+#
 # psk: WPA preshared key; 256-bit pre-shared key
 # The key used in WPA-PSK mode can be entered either as 64 hex-digits, i.e.,
 # 32 bytes or as an ASCII passphrase (in which case, the real PSK will be