From 91b5ab628929d97357108594610e7c07be93e2fd Mon Sep 17 00:00:00 2001 From: Eliad Peller Date: Fri, 9 Jun 2017 13:08:42 +0100 Subject: [PATCH] cfg80211: support 4-way handshake offloading for WPA/WPA2-PSK Let drivers advertise support for station-mode 4-way handshake offloading with a new NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK flag. Extend use of NL80211_ATTR_PMK attribute indicating it might be passed as part of NL80211_CMD_CONNECT command, and contain the PSK (which is the PMK, hence the name.) The driver/device is assumed to handle the 4-way handshake by itself in this case (including key derivations, etc.), instead of relying on the supplicant. This patch is somewhat based on this one (by Vladimir Kondratiev): https://patchwork.kernel.org/patch/1309561/. Signed-off-by: Vladimir Kondratiev Signed-off-by: Eliad Peller Signed-off-by: Luca Coelho [arend.vanspriel@broadcom.com rebase dealing with existing ATTR_PMK] Signed-off-by: Arend van Spriel [reword NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK docs to indicate that this offload might be required] Signed-off-by: Johannes Berg --- include/linux/ieee80211.h | 1 + include/net/cfg80211.h | 2 ++ include/uapi/linux/nl80211.h | 22 ++++++++++++++++++++-- net/wireless/nl80211.c | 9 +++++++++ 4 files changed, 32 insertions(+), 2 deletions(-) diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 69033353d0d1..e97ca3a9a67b 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -2401,6 +2401,7 @@ enum ieee80211_sa_query_action { #define WLAN_MAX_KEY_LEN 32 #define WLAN_PMKID_LEN 16 +#define WLAN_PMK_LEN 32 #define WLAN_OUI_WFA 0x506f9a #define WLAN_OUI_TYPE_WFA_P2P 9 diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index fa25fbb67cb6..1b288bac5d1a 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -649,6 +649,7 @@ struct survey_info { * @wep_keys: static WEP keys, if not NULL points to an array of * CFG80211_MAX_WEP_KEYS WEP keys * @wep_tx_key: key index (0..3) of the default TX static WEP key + * @psk: PSK (for devices supporting 4-way-handshake offload) */ struct cfg80211_crypto_settings { u32 wpa_versions; @@ -662,6 +663,7 @@ struct cfg80211_crypto_settings { bool control_port_no_encrypt; struct key_params *wep_keys; int wep_tx_key; + const u8 *psk; }; /** diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index b8c44b98f12d..f1f7da25bca4 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -172,6 +172,18 @@ * Multiple such rules can be created. */ +/** + * DOC: WPA/WPA2 EAPOL handshake offload + * + * By setting @NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK flag drivers + * can indicate they support offloading EAPOL handshakes for WPA/WPA2 + * preshared key authentication. In %NL80211_CMD_CONNECT the preshared + * key should be specified using %NL80211_ATTR_PMK. Drivers supporting + * this offload may reject the %NL80211_CMD_CONNECT when no preshared + * key material is provided, for example when that driver does not + * support setting the temporal keys through %CMD_NEW_KEY. + */ + /** * DOC: FILS shared key authentication offload * @@ -2080,8 +2092,10 @@ enum nl80211_commands { * identifying the scope of PMKSAs. This is used with * @NL80211_CMD_SET_PMKSA and @NL80211_CMD_DEL_PMKSA. * - * @NL80211_ATTR_PMK: PMK for the PMKSA identified by %NL80211_ATTR_PMKID. - * This is used with @NL80211_CMD_SET_PMKSA. + * @NL80211_ATTR_PMK: attribute for passing PMK key material. Used with + * %NL80211_CMD_SET_PMKSA for the PMKSA identified by %NL80211_ATTR_PMKID. + * For %NL80211_CMD_CONNECT it is used to provide PSK for offloading 4-way + * handshake for WPA/WPA2-PSK networks. * * @NL80211_ATTR_SCHED_SCAN_MULTI: flag attribute which user-space shall use to * indicate that it supports multiple active scheduled scan requests. @@ -4852,6 +4866,9 @@ enum nl80211_feature_flags { * RSSI threshold values to monitor rather than exactly one threshold. * @NL80211_EXT_FEATURE_FILS_SK_OFFLOAD: Driver SME supports FILS shared key * authentication with %NL80211_CMD_CONNECT. + * @NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK: Device wants to do 4-way + * handshake with PSK in station mode (PSK is passed as part of the connect + * and associate commands), doing it in the host might not be supported. * * @NUM_NL80211_EXT_FEATURES: number of extended features. * @MAX_NL80211_EXT_FEATURES: highest extended feature index. @@ -4872,6 +4889,7 @@ enum nl80211_ext_feature_index { NL80211_EXT_FEATURE_SCHED_SCAN_RELATIVE_RSSI, NL80211_EXT_FEATURE_CQM_RSSI_LIST, NL80211_EXT_FEATURE_FILS_SK_OFFLOAD, + NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK, /* add new features before the definition below */ NUM_NL80211_EXT_FEATURES, diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 9eb59196a378..2c6863aee4e4 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -8168,6 +8168,15 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev, memcpy(settings->akm_suites, data, len); } + if (info->attrs[NL80211_ATTR_PMK]) { + if (nla_len(info->attrs[NL80211_ATTR_PMK]) != WLAN_PMK_LEN) + return -EINVAL; + if (!wiphy_ext_feature_isset(&rdev->wiphy, + NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK)) + return -EINVAL; + settings->psk = nla_data(info->attrs[NL80211_ATTR_PMK]); + } + return 0; } -- 2.45.2