wifi: cfg80211: add LTF keyseed support for secure ranging

Currently there is no way to install an LTF key seed that can be
used in non-trigger-based (NTB) and trigger-based (TB) FTM ranging
to protect NDP frames. Without this, drivers cannot enable PHY-layer
security for peer measurement sessions, leaving ranging measurements
vulnerable to eavesdropping and manipulation.

Introduce NL80211_KEY_LTF_SEED attribute and the dedicated extended
feature flag NL80211_EXT_FEATURE_SET_KEY_LTF_SEED to allow drivers
to advertise and install LTF key seeds via nl80211. The key seed
must be configured beforehand to ensure the peer measurement session
is secure. The driver must advertise both NL80211_EXT_FEATURE_SECURE_LTF
and NL80211_EXT_FEATURE_SET_KEY_LTF_SEED for the key seed installation
to be permitted.

The LTF key seed is pairwise key material and must only be used with
pairwise key type. Reject attempts to use it with other key types.

Signed-off-by: Peddolla Harshavardhan Reddy <peddolla.reddy@oss.qualcomm.com>
Link: https://patch.msgid.link/20260420090856.2152905-13-peddolla.reddy@oss.qualcomm.com
[fix policy coding style]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 23f9df9be83728cb866be9254488dc197252196f..11106589acc6fd3f1f694889e5ef3b4f4c9e3e90 100644 (file)
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -2236,6 +2236,7 @@ struct ieee80211_multiple_bssid_configuration {
 #define WLAN_AKM_SUITE_WFA_DPP                 SUITE(WLAN_OUI_WFA, 2)
 
 #define WLAN_MAX_KEY_LEN               32
+#define WLAN_MAX_SECURE_LTF_KEYSEED_LEN        48
 
 #define WLAN_PMK_NAME_LEN              16
 #define WLAN_PMKID_LEN                 16

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index fdc8363b296c8e0877fbfc6654649f2f398348e3..13e035fecf7f16d8eed008fc88e838bd8578c75f 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -830,6 +830,8 @@ struct vif_params {
  * @seq_len: length of @seq.
  * @vlan_id: vlan_id for VLAN group key (if nonzero)
  * @mode: key install mode (RX_TX, NO_TX or SET_TX)
+ * @ltf_keyseed: LTF key seed material
+ * @ltf_keyseed_len: length of LTF key seed material
  */
 struct key_params {
        const u8 *key;
@@ -839,6 +841,8 @@ struct key_params {
        u16 vlan_id;
        u32 cipher;
        enum nl80211_key_mode mode;
+       const u8 *ltf_keyseed;
+       size_t ltf_keyseed_len;
 };
 
 /**

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 1da4dc3fc816fa87156c13f1f49726ca16ff4e1b..6c7e6c05b9a873e741821a09a5d10c5d2143a721 100644 (file)
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -5814,6 +5814,18 @@ enum nl80211_key_default_types {
  * @NL80211_KEY_MODE: the mode from enum nl80211_key_mode.
  *     Defaults to @NL80211_KEY_RX_TX.
  * @NL80211_KEY_DEFAULT_BEACON: flag indicating default Beacon frame key
+ * @NL80211_KEY_LTF_SEED: LTF key seed is used by the driver to generate
+ *     secure LTF keys used in case of peer measurement request with FTM
+ *     request type as either %NL80211_PMSR_FTM_REQ_ATTR_NON_TRIGGER_BASED
+ *     or %NL80211_PMSR_FTM_REQ_ATTR_TRIGGER_BASED. Secure LTF key seeds
+ *     will help enable PHY security in peer measurement session.
+ *     The LTF key seed is installed along with the TK (Temporal Key) using
+ *     %NL80211_CMD_NEW_KEY. The TK is configured using the
+ *     %NL80211_ATTR_KEY_DATA attribute, while the LTF key seed is configured
+ *     using this attribute. Both keys must be configured before initiation
+ *     of peer measurement to ensure peer measurement session is secure.
+ *     Only valid if %NL80211_EXT_FEATURE_SET_KEY_LTF_SEED is set. This
+ *     attribute is restricted to pairwise keys (%NL80211_KEYTYPE_PAIRWISE).
  *
  * @__NL80211_KEY_AFTER_LAST: internal
  * @NL80211_KEY_MAX: highest key attribute
@@ -5830,6 +5842,7 @@ enum nl80211_key_attributes {
        NL80211_KEY_DEFAULT_TYPES,
        NL80211_KEY_MODE,
        NL80211_KEY_DEFAULT_BEACON,
+       NL80211_KEY_LTF_SEED,
 
        /* keep last */
        __NL80211_KEY_AFTER_LAST,
@@ -7059,6 +7072,10 @@ enum nl80211_feature_flags {
  *     forward frames with a matching MAC address to userspace during
  *     the off-channel period.
  *
+ * @NL80211_EXT_FEATURE_SET_KEY_LTF_SEED: Driver supports installing the
+ *     LTF key seed via %NL80211_KEY_LTF_SEED. The seed is used to generate
+ *     secure LTF keys for secure LTF measurement sessions.
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -7139,6 +7156,7 @@ enum nl80211_ext_feature_index {
        NL80211_EXT_FEATURE_ASSOC_FRAME_ENCRYPTION,
        NL80211_EXT_FEATURE_IEEE8021X_AUTH,
        NL80211_EXT_FEATURE_ROC_ADDR_FILTER,
+       NL80211_EXT_FEATURE_SET_KEY_LTF_SEED,
 
        /* add new features before the definition below */
        NUM_NL80211_EXT_FEATURES,

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b33f688b983ad90306b410b4c92f08d19ef849e6..61b1716daf1ef471f124af1c5f21994730048460 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1103,6 +1103,10 @@ static const struct nla_policy nl80211_key_policy[NL80211_KEY_MAX + 1] = {
        [NL80211_KEY_TYPE] = NLA_POLICY_MAX(NLA_U32, NUM_NL80211_KEYTYPES - 1),
        [NL80211_KEY_DEFAULT_TYPES] = { .type = NLA_NESTED },
        [NL80211_KEY_MODE] = NLA_POLICY_RANGE(NLA_U8, 0, NL80211_KEY_SET_TX),
+       [NL80211_KEY_LTF_SEED] = {
+               .type = NLA_BINARY,
+               .len = WLAN_MAX_SECURE_LTF_KEYSEED_LEN,
+       },
 };
 
 /* policy for the key default flags */
@@ -1634,6 +1638,11 @@ static int nl80211_parse_key_new(struct genl_info *info, struct nlattr *key,
        if (tb[NL80211_KEY_MODE])
                k->p.mode = nla_get_u8(tb[NL80211_KEY_MODE]);
 
+       if (tb[NL80211_KEY_LTF_SEED]) {
+               k->p.ltf_keyseed = nla_data(tb[NL80211_KEY_LTF_SEED]);
+               k->p.ltf_keyseed_len = nla_len(tb[NL80211_KEY_LTF_SEED]);
+       }
+
        return 0;
 }
 

diff --git a/net/wireless/util.c b/net/wireless/util.c
index b638e205c71eaa9994e9c312eda9645fcab5bb53..8dd7545b909774026589db0352cb51ba93aaf7cf 100644 (file)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -434,6 +434,21 @@ int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
        if (!cfg80211_supported_cipher_suite(&rdev->wiphy, params->cipher))
                return -EINVAL;
 
+       if (params->ltf_keyseed) {
+               if (!wiphy_ext_feature_isset(&rdev->wiphy,
+                                            NL80211_EXT_FEATURE_SECURE_LTF) ||
+                   !wiphy_ext_feature_isset(&rdev->wiphy,
+                                            NL80211_EXT_FEATURE_SET_KEY_LTF_SEED))
+                       return -EOPNOTSUPP;
+
+               /*
+                * LTF key seed is pairwise key material and must only be
+                * used with a pairwise key
+                */
+               if (!pairwise)
+                       return -EINVAL;
+       }
+
        return 0;
 }