Add support for Extended Key ID as defined in IEEE 802.11-2016.
- Implement the nl80211 API for Extended Key ID
- Extend mac80211 API to allow drivers to support Extended Key ID
- Enable Extended Key ID by default for drivers only supporting SW
crypto (e.g. mac80211_hwsim)
- Allow unicast Tx usage to be supressed (IEEE80211_KEY_FLAG_NO_AUTO_TX)
- Select the decryption key based on the MPDU keyid
- Enforce existing assumptions in the code that rekeys don't change the
cipher
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
[remove module parameter]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
* @IEEE80211_KEY_FLAG_PUT_MIC_SPACE: This flag should be set by the driver for
* a TKIP key if it only requires MIC space. Do not set together with
* @IEEE80211_KEY_FLAG_GENERATE_MMIC on the same key.
+ * @IEEE80211_KEY_FLAG_NO_AUTO_TX: Key needs explicit Tx activation.
*/
enum ieee80211_key_flags {
IEEE80211_KEY_FLAG_GENERATE_IV_MGMT = BIT(0),
IEEE80211_KEY_FLAG_RX_MGMT = BIT(6),
IEEE80211_KEY_FLAG_RESERVE_TAILROOM = BIT(7),
IEEE80211_KEY_FLAG_PUT_MIC_SPACE = BIT(8),
+ IEEE80211_KEY_FLAG_NO_AUTO_TX = BIT(9),
};
/**
* @IEEE80211_HW_SUPPORTS_ONLY_HE_MULTI_BSSID: Hardware supports multi BSSID
* only for HE APs. Applies if @IEEE80211_HW_SUPPORTS_MULTI_BSSID is set.
*
+ * @IEEE80211_HW_EXT_KEY_ID_NATIVE: Driver and hardware are supporting Extended
+ * Key ID and can handle two unicast keys per station for Rx and Tx.
+ *
* @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
*/
enum ieee80211_hw_flags {
IEEE80211_HW_TX_STATUS_NO_AMPDU_LEN,
IEEE80211_HW_SUPPORTS_MULTI_BSSID,
IEEE80211_HW_SUPPORTS_ONLY_HE_MULTI_BSSID,
+ IEEE80211_HW_EXT_KEY_ID_NATIVE,
/* keep last, obviously */
NUM_IEEE80211_HW_FLAGS
return 0;
}
+static int ieee80211_set_tx(struct ieee80211_sub_if_data *sdata,
+ const u8 *mac_addr, u8 key_idx)
+{
+ struct ieee80211_local *local = sdata->local;
+ struct ieee80211_key *key;
+ struct sta_info *sta;
+ int ret = -EINVAL;
+
+ if (!wiphy_ext_feature_isset(local->hw.wiphy,
+ NL80211_EXT_FEATURE_EXT_KEY_ID))
+ return -EINVAL;
+
+ sta = sta_info_get_bss(sdata, mac_addr);
+
+ if (!sta)
+ return -EINVAL;
+
+ if (sta->ptk_idx == key_idx)
+ return 0;
+
+ mutex_lock(&local->key_mtx);
+ key = key_mtx_dereference(local, sta->ptk[key_idx]);
+
+ if (key && key->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX)
+ ret = ieee80211_set_tx_key(key);
+
+ mutex_unlock(&local->key_mtx);
+ return ret;
+}
+
static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
u8 key_idx, bool pairwise, const u8 *mac_addr,
struct key_params *params)
if (!ieee80211_sdata_running(sdata))
return -ENETDOWN;
+ if (pairwise && params->mode == NL80211_KEY_SET_TX)
+ return ieee80211_set_tx(sdata, mac_addr, key_idx);
+
/* reject WEP and TKIP keys if WEP failed to initialize */
switch (params->cipher) {
case WLAN_CIPHER_SUITE_WEP40:
if (pairwise)
key->conf.flags |= IEEE80211_KEY_FLAG_PAIRWISE;
+ if (params->mode == NL80211_KEY_NO_TX)
+ key->conf.flags |= IEEE80211_KEY_FLAG_NO_AUTO_TX;
+
mutex_lock(&local->sta_mtx);
if (mac_addr) {
FLAG(TX_STATUS_NO_AMPDU_LEN),
FLAG(SUPPORTS_MULTI_BSSID),
FLAG(SUPPORTS_ONLY_HE_MULTI_BSSID),
+ FLAG(EXT_KEY_ID_NATIVE),
#undef FLAG
};
/*
* Key mutex, protects sdata's key_list and sta_info's
- * key pointers (write access, they're RCU.)
+ * key pointers and ptk_idx (write access, they're RCU.)
*/
struct mutex key_mtx;
sta ? sta->sta.addr : bcast_addr, ret);
}
+int ieee80211_set_tx_key(struct ieee80211_key *key)
+{
+ struct sta_info *sta = key->sta;
+ struct ieee80211_local *local = key->local;
+ struct ieee80211_key *old;
+
+ assert_key_lock(local);
+
+ old = key_mtx_dereference(local, sta->ptk[sta->ptk_idx]);
+ sta->ptk_idx = key->conf.keyidx;
+ ieee80211_check_fast_xmit(sta);
+
+ return 0;
+}
+
static int ieee80211_hw_key_replace(struct ieee80211_key *old_key,
struct ieee80211_key *new_key,
- bool ptk0rekey)
+ bool pairwise)
{
struct ieee80211_sub_if_data *sdata;
struct ieee80211_local *local;
assert_key_lock(old_key->local);
sta = old_key->sta;
- /* PTK only using key ID 0 needs special handling on rekey */
- if (new_key && sta && ptk0rekey) {
+ /* Unicast rekey without Extended Key ID needs special handling */
+ if (new_key && sta && pairwise &&
+ rcu_access_pointer(sta->ptk[sta->ptk_idx]) == old_key) {
local = old_key->local;
sdata = old_key->sdata;
if (old) {
idx = old->conf.keyidx;
- /* TODO: proper implement and test "Extended Key ID for
- * Individually Addressed Frames" from IEEE 802.11-2016.
- * Till then always assume only key ID 0 is used for
- * pairwise keys.*/
ret = ieee80211_hw_key_replace(old, new, pairwise);
} else {
/* new must be provided in case old is not */
if (sta) {
if (pairwise) {
rcu_assign_pointer(sta->ptk[idx], new);
- sta->ptk_idx = idx;
- if (new) {
+ if (new &&
+ !(new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX)) {
+ sta->ptk_idx = idx;
clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
ieee80211_check_fast_xmit(sta);
}
} else {
rcu_assign_pointer(sta->gtk[idx], new);
}
- if (new)
+ /* Only needed for transition from no key -> key.
+ * Still triggers unnecessary when using Extended Key ID
+ * and installing the second key ID the first time.
+ */
+ if (new && !old)
ieee80211_check_fast_rx(sta);
} else {
defunikey = old &&
* can cause warnings to appear.
*/
bool delay_tailroom = sdata->vif.type == NL80211_IFTYPE_STATION;
- int ret;
+ int ret = -EOPNOTSUPP;
mutex_lock(&sdata->local->key_mtx);
- if (sta && pairwise)
+ if (sta && pairwise) {
+ struct ieee80211_key *alt_key;
+
old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
- else if (sta)
+ alt_key = key_mtx_dereference(sdata->local, sta->ptk[idx ^ 1]);
+
+ /* The rekey code assumes that the old and new key are using
+ * the same cipher. Enforce the assumption for pairwise keys.
+ */
+ if (key &&
+ ((alt_key && alt_key->conf.cipher != key->conf.cipher) ||
+ (old_key && old_key->conf.cipher != key->conf.cipher)))
+ goto out;
+ } else if (sta) {
old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
- else
+ } else {
old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
+ }
+
+ /* Non-pairwise keys must also not switch the cipher on rekey */
+ if (!pairwise) {
+ if (key && old_key && old_key->conf.cipher != key->conf.cipher)
+ goto out;
+ }
/*
* Silently accept key re-installation without really installing the
#define NUM_DEFAULT_KEYS 4
#define NUM_DEFAULT_MGMT_KEYS 2
+#define INVALID_PTK_KEYIDX 2 /* Keyidx always pointing to a NULL key for PTK */
struct ieee80211_local;
struct ieee80211_sub_if_data;
int ieee80211_key_link(struct ieee80211_key *key,
struct ieee80211_sub_if_data *sdata,
struct sta_info *sta);
+int ieee80211_set_tx_key(struct ieee80211_key *key);
void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom);
void ieee80211_key_free_unused(struct ieee80211_key *key);
void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
}
}
+ if (!local->ops->set_key ||
+ ieee80211_hw_check(&local->hw, EXT_KEY_ID_NATIVE))
+ wiphy_ext_feature_set(local->hw.wiphy,
+ NL80211_EXT_FEATURE_EXT_KEY_ID);
+
/*
* Calculate scan IE length -- we need this to alloc
* memory and to subtract from the driver limit. It
return -1;
}
-static int ieee80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
- struct sk_buff *skb)
+static int ieee80211_get_keyid(struct sk_buff *skb,
+ const struct ieee80211_cipher_scheme *cs)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
__le16 fc;
int hdrlen;
+ int minlen;
+ u8 key_idx_off;
+ u8 key_idx_shift;
u8 keyid;
fc = hdr->frame_control;
hdrlen = ieee80211_hdrlen(fc);
- if (skb->len < hdrlen + cs->hdr_len)
+ if (cs) {
+ minlen = hdrlen + cs->hdr_len;
+ key_idx_off = hdrlen + cs->key_idx_off;
+ key_idx_shift = cs->key_idx_shift;
+ } else {
+ /* WEP, TKIP, CCMP and GCMP */
+ minlen = hdrlen + IEEE80211_WEP_IV_LEN;
+ key_idx_off = hdrlen + 3;
+ key_idx_shift = 6;
+ }
+
+ if (unlikely(skb->len < minlen))
return -EINVAL;
- skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
- keyid &= cs->key_idx_mask;
- keyid >>= cs->key_idx_shift;
+ skb_copy_bits(skb, key_idx_off, &keyid, 1);
+
+ if (cs)
+ keyid &= cs->key_idx_mask;
+ keyid >>= key_idx_shift;
+
+ /* cs could use more than the usual two bits for the keyid */
+ if (unlikely(keyid >= NUM_DEFAULT_KEYS))
+ return -EINVAL;
return keyid;
}
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
int keyidx;
- int hdrlen;
ieee80211_rx_result result = RX_DROP_UNUSABLE;
struct ieee80211_key *sta_ptk = NULL;
+ struct ieee80211_key *ptk_idx = NULL;
int mmie_keyidx = -1;
__le16 fc;
const struct ieee80211_cipher_scheme *cs = NULL;
if (rx->sta) {
int keyid = rx->sta->ptk_idx;
+ sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
- if (ieee80211_has_protected(fc) && rx->sta->cipher_scheme) {
+ if (ieee80211_has_protected(fc)) {
cs = rx->sta->cipher_scheme;
- keyid = ieee80211_get_cs_keyid(cs, rx->skb);
+ keyid = ieee80211_get_keyid(rx->skb, cs);
+
if (unlikely(keyid < 0))
return RX_DROP_UNUSABLE;
+
+ ptk_idx = rcu_dereference(rx->sta->ptk[keyid]);
}
- sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
}
if (!ieee80211_has_protected(fc))
mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
- rx->key = sta_ptk;
+ rx->key = ptk_idx ? ptk_idx : sta_ptk;
if ((status->flag & RX_FLAG_DECRYPTED) &&
(status->flag & RX_FLAG_IV_STRIPPED))
return RX_CONTINUE;
}
return RX_CONTINUE;
} else {
- u8 keyid;
-
/*
* The device doesn't give us the IV so we won't be
* able to look up the key. That's ok though, we
(status->flag & RX_FLAG_IV_STRIPPED))
return RX_CONTINUE;
- hdrlen = ieee80211_hdrlen(fc);
-
- if (cs) {
- keyidx = ieee80211_get_cs_keyid(cs, rx->skb);
+ keyidx = ieee80211_get_keyid(rx->skb, cs);
- if (unlikely(keyidx < 0))
- return RX_DROP_UNUSABLE;
- } else {
- if (rx->skb->len < 8 + hdrlen)
- return RX_DROP_UNUSABLE; /* TODO: count this? */
- /*
- * no need to call ieee80211_wep_get_keyidx,
- * it verifies a bunch of things we've done already
- */
- skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
- keyidx = keyid >> 6;
- }
+ if (unlikely(keyidx < 0))
+ return RX_DROP_UNUSABLE;
/* check per-station GTK first, if multicast packet */
if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
case WLAN_CIPHER_SUITE_GCMP_256:
break;
default:
- /* we also don't want to deal with WEP or cipher scheme
- * since those require looking up the key idx in the
- * frame, rather than assuming the PTK is used
- * (we need to revisit this once we implement the real
- * PTK index, which is now valid in the spec, but we
- * haven't implemented that part yet)
+ /* We also don't want to deal with
+ * WEP or cipher scheme.
*/
goto clear_rcu;
}
sta->sta.max_rx_aggregation_subframes =
local->hw.max_rx_aggregation_subframes;
+ /* Extended Key ID needs to install keys for keyid 0 and 1 Rx-only.
+ * The Tx path starts to use a key as soon as the key slot ptk_idx
+ * references to is not NULL. To not use the initial Rx-only key
+ * prematurely for Tx initialize ptk_idx to an impossible PTK keyid
+ * which always will refer to a NULL key.
+ */
+ BUILD_BUG_ON(ARRAY_SIZE(sta->ptk) <= INVALID_PTK_KEYIDX);
+ sta->ptk_idx = INVALID_PTK_KEYIDX;
+
sta->local = local;
sta->sdata = sdata;
sta->rx_stats.last_rx = jiffies;
switch (build.key->conf.cipher) {
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_CCMP_256:
- /* add fixed key ID */
- if (gen_iv) {
- (build.hdr + build.hdr_len)[3] =
- 0x20 | (build.key->conf.keyidx << 6);
+ if (gen_iv)
build.pn_offs = build.hdr_len;
- }
if (gen_iv || iv_spc)
build.hdr_len += IEEE80211_CCMP_HDR_LEN;
break;
case WLAN_CIPHER_SUITE_GCMP:
case WLAN_CIPHER_SUITE_GCMP_256:
- /* add fixed key ID */
- if (gen_iv) {
- (build.hdr + build.hdr_len)[3] =
- 0x20 | (build.key->conf.keyidx << 6);
+ if (gen_iv)
build.pn_offs = build.hdr_len;
- }
if (gen_iv || iv_spc)
build.hdr_len += IEEE80211_GCMP_HDR_LEN;
break;
pn = atomic64_inc_return(&key->conf.tx_pn);
crypto_hdr[0] = pn;
crypto_hdr[1] = pn >> 8;
+ crypto_hdr[3] = 0x20 | (key->conf.keyidx << 6);
crypto_hdr[4] = pn >> 16;
crypto_hdr[5] = pn >> 24;
crypto_hdr[6] = pn >> 32;
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