2020-02-22 13:27:33

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH 1/7] cfg80211: More error messages for key addition failures

These were helpful while working with extensions to NL80211_CMD_NEW_KEY,
so add more explicit error reporting for additional cases that can fail
while that command is being processed.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/wireless/nl80211.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f0112dabe21e..447c388b5905 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3980,8 +3980,10 @@ static int nl80211_new_key(struct sk_buff *skb, struct genl_info *info)
if (err)
return err;

- if (!key.p.key)
+ if (!key.p.key) {
+ GENL_SET_ERR_MSG(info, "no key");
return -EINVAL;
+ }

if (info->attrs[NL80211_ATTR_MAC])
mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
@@ -3995,8 +3997,10 @@ static int nl80211_new_key(struct sk_buff *skb, struct genl_info *info)

/* for now */
if (key.type != NL80211_KEYTYPE_PAIRWISE &&
- key.type != NL80211_KEYTYPE_GROUP)
+ key.type != NL80211_KEYTYPE_GROUP) {
+ GENL_SET_ERR_MSG(info, "key type not pairwise or group");
return -EINVAL;
+ }

if (key.type == NL80211_KEYTYPE_GROUP &&
info->attrs[NL80211_ATTR_VLAN_ID])
@@ -4007,15 +4011,22 @@ static int nl80211_new_key(struct sk_buff *skb, struct genl_info *info)

if (cfg80211_validate_key_settings(rdev, &key.p, key.idx,
key.type == NL80211_KEYTYPE_PAIRWISE,
- mac_addr))
+ mac_addr)) {
+ GENL_SET_ERR_MSG(info, "key setting validation failed");
return -EINVAL;
+ }

wdev_lock(dev->ieee80211_ptr);
err = nl80211_key_allowed(dev->ieee80211_ptr);
- if (!err)
+ if (err)
+ GENL_SET_ERR_MSG(info, "key not allowed");
+ if (!err) {
err = rdev_add_key(rdev, dev, key.idx,
key.type == NL80211_KEYTYPE_PAIRWISE,
mac_addr, &key.p);
+ if (err)
+ GENL_SET_ERR_MSG(info, "key addition failed");
+ }
wdev_unlock(dev->ieee80211_ptr);

return err;
--
2.20.1


2020-02-22 13:27:41

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH 7/7] mac80211: Enable Beacon protection

Now that there is support for BIGTK configuration and AP/STA
functionality for using BIP with Beacon frames, indicate support for the
Beacon protection functionality.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/mac80211/main.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index cae3a34d3503..b32cacb83053 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -591,6 +591,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211);
wiphy_ext_feature_set(wiphy,
NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_MAC_ADDRS);
+ wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_BEACON_PROTECTION);

if (!ops->hw_scan) {
wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN |
--
2.20.1

2020-02-22 13:27:49

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH 2/7] cfg80211: Support key configuration for Beacon protection (BIGTK)

IEEE P802.11-REVmd/D3.0 adds support for protecting Beacon frames using
a new set of keys (BIGTK; key index 6..7) similarly to the way
group-addressed Robust Management frames are protected (IGTK; key index
4..5). Extend cfg80211 and nl80211 to allow the new BIGTK to be
configured. Add an extended feature flag to indicate driver support for
the new key index values to avoid array overflows in driver
implementations and also to indicate to user space when this
functionality is available.

Signed-off-by: Jouni Malinen <[email protected]>
---
include/net/cfg80211.h | 5 ++++
include/uapi/linux/nl80211.h | 6 ++++
net/wireless/nl80211.c | 56 +++++++++++++++++++++++++++++-------
net/wireless/rdev-ops.h | 13 +++++++++
net/wireless/sme.c | 11 +++++--
net/wireless/trace.h | 17 +++++++++++
net/wireless/util.c | 7 ++++-
7 files changed, 101 insertions(+), 14 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 7ea23caa7301..4bb3b3811ebe 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3369,6 +3369,8 @@ struct cfg80211_update_owe_info {
* @set_default_key: set the default key on an interface
*
* @set_default_mgmt_key: set the default management frame key on an interface
+
+ * @set_default_beacon_key: set the default Beacon frame key on an interface
*
* @set_rekey_data: give the data necessary for GTK rekeying to the driver
*
@@ -3702,6 +3704,9 @@ struct cfg80211_ops {
int (*set_default_mgmt_key)(struct wiphy *wiphy,
struct net_device *netdev,
u8 key_index);
+ int (*set_default_beacon_key)(struct wiphy *wiphy,
+ struct net_device *netdev,
+ u8 key_index);

int (*start_ap)(struct wiphy *wiphy, struct net_device *dev,
struct cfg80211_ap_settings *settings);
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 158bccb4a47b..e331038d114b 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -4559,6 +4559,7 @@ enum nl80211_key_default_types {
* See &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_AFTER_LAST: internal
* @NL80211_KEY_MAX: highest key attribute
@@ -4574,6 +4575,7 @@ enum nl80211_key_attributes {
NL80211_KEY_TYPE,
NL80211_KEY_DEFAULT_TYPES,
NL80211_KEY_MODE,
+ NL80211_KEY_DEFAULT_BEACON,

/* keep last */
__NL80211_KEY_AFTER_LAST,
@@ -5552,6 +5554,9 @@ enum nl80211_feature_flags {
* can use src and dst MAC addresses with control port over nl80211 rx
* and tx operations.
*
+ * @NL80211_EXT_FEATURE_BEACON_PROTECTION: The driver supports Beacon protection
+ * and can receive key configuration for BIGTK using key indexes 6 and 7.
+ *
* @NUM_NL80211_EXT_FEATURES: number of extended features.
* @MAX_NL80211_EXT_FEATURES: highest extended feature index.
*/
@@ -5600,6 +5605,7 @@ enum nl80211_ext_feature_index {
NL80211_EXT_FEATURE_VLAN_OFFLOAD,
NL80211_EXT_FEATURE_AQL,
NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_MAC_ADDRS,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION,

/* add new features before the definition below */
NUM_NL80211_EXT_FEATURES,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 447c388b5905..fac699731417 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -368,7 +368,7 @@ const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
[NL80211_ATTR_KEY] = { .type = NLA_NESTED, },
[NL80211_ATTR_KEY_DATA] = { .type = NLA_BINARY,
.len = WLAN_MAX_KEY_LEN },
- [NL80211_ATTR_KEY_IDX] = NLA_POLICY_MAX(NLA_U8, 5),
+ [NL80211_ATTR_KEY_IDX] = NLA_POLICY_MAX(NLA_U8, 7),
[NL80211_ATTR_KEY_CIPHER] = { .type = NLA_U32 },
[NL80211_ATTR_KEY_DEFAULT] = { .type = NLA_FLAG },
[NL80211_ATTR_KEY_SEQ] = { .type = NLA_BINARY, .len = 16 },
@@ -1039,7 +1039,7 @@ struct key_parse {
struct key_params p;
int idx;
int type;
- bool def, defmgmt;
+ bool def, defmgmt, defbeacon;
bool def_uni, def_multi;
};

@@ -1055,12 +1055,13 @@ static int nl80211_parse_key_new(struct genl_info *info, struct nlattr *key,

k->def = !!tb[NL80211_KEY_DEFAULT];
k->defmgmt = !!tb[NL80211_KEY_DEFAULT_MGMT];
+ k->defbeacon = !!tb[NL80211_KEY_DEFAULT_BEACON];

if (k->def) {
k->def_uni = true;
k->def_multi = true;
}
- if (k->defmgmt)
+ if (k->defmgmt || k->defbeacon)
k->def_multi = true;

if (tb[NL80211_KEY_IDX])
@@ -1167,14 +1168,17 @@ static int nl80211_parse_key(struct genl_info *info, struct key_parse *k)
if (err)
return err;

- if (k->def && k->defmgmt) {
- GENL_SET_ERR_MSG(info, "key with def && defmgmt is invalid");
+ if ((k->def ? 1 : 0) + (k->defmgmt ? 1 : 0) +
+ (k->defbeacon ? 1 : 0) > 1) {
+ GENL_SET_ERR_MSG(info,
+ "key with multiple default flags is invalid");
return -EINVAL;
}

- if (k->defmgmt) {
+ if (k->defmgmt || k->defbeacon) {
if (k->def_uni || !k->def_multi) {
- GENL_SET_ERR_MSG(info, "defmgmt key must be mcast");
+ GENL_SET_ERR_MSG(info,
+ "defmgmt/defbeacon key must be mcast");
return -EINVAL;
}
}
@@ -1186,14 +1190,20 @@ static int nl80211_parse_key(struct genl_info *info, struct key_parse *k)
"defmgmt key idx not 4 or 5");
return -EINVAL;
}
+ } else if (k->defbeacon) {
+ if (k->idx < 6 || k->idx > 7) {
+ GENL_SET_ERR_MSG(info,
+ "defbeacon key idx not 6 or 7");
+ return -EINVAL;
+ }
} else if (k->def) {
if (k->idx < 0 || k->idx > 3) {
GENL_SET_ERR_MSG(info, "def key idx not 0-3");
return -EINVAL;
}
} else {
- if (k->idx < 0 || k->idx > 5) {
- GENL_SET_ERR_MSG(info, "key idx not 0-5");
+ if (k->idx < 0 || k->idx > 7) {
+ GENL_SET_ERR_MSG(info, "key idx not 0-7");
return -EINVAL;
}
}
@@ -3819,8 +3829,14 @@ static int nl80211_get_key(struct sk_buff *skb, struct genl_info *info)
void *hdr;
struct sk_buff *msg;

- if (info->attrs[NL80211_ATTR_KEY_IDX])
+ if (info->attrs[NL80211_ATTR_KEY_IDX]) {
key_idx = nla_get_u8(info->attrs[NL80211_ATTR_KEY_IDX]);
+ if (key_idx > 5 &&
+ !wiphy_ext_feature_isset(
+ &rdev->wiphy,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION))
+ return -EINVAL;
+ }

if (info->attrs[NL80211_ATTR_MAC])
mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
@@ -3896,7 +3912,7 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
/* Only support setting default key and
* Extended Key ID action NL80211_KEY_SET_TX.
*/
- if (!key.def && !key.defmgmt &&
+ if (!key.def && !key.defmgmt && !key.defbeacon &&
!(key.p.mode == NL80211_KEY_SET_TX))
return -EINVAL;

@@ -3943,6 +3959,24 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
#ifdef CONFIG_CFG80211_WEXT
dev->ieee80211_ptr->wext.default_mgmt_key = key.idx;
#endif
+ } else if (key.defbeacon) {
+ if (key.def_uni || !key.def_multi) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (!rdev->ops->set_default_beacon_key) {
+ err = -EOPNOTSUPP;
+ goto out;
+ }
+
+ err = nl80211_key_allowed(dev->ieee80211_ptr);
+ if (err)
+ goto out;
+
+ err = rdev_set_default_beacon_key(rdev, dev, key.idx);
+ if (err)
+ goto out;
} else if (key.p.mode == NL80211_KEY_SET_TX &&
wiphy_ext_feature_isset(&rdev->wiphy,
NL80211_EXT_FEATURE_EXT_KEY_ID)) {
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index 5ea34c1b60fe..9063035b2902 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -136,6 +136,19 @@ rdev_set_default_mgmt_key(struct cfg80211_registered_device *rdev,
return ret;
}

+static inline int
+rdev_set_default_beacon_key(struct cfg80211_registered_device *rdev,
+ struct net_device *netdev, u8 key_index)
+{
+ int ret;
+
+ trace_rdev_set_default_beacon_key(&rdev->wiphy, netdev, key_index);
+ ret = rdev->ops->set_default_beacon_key(&rdev->wiphy, netdev,
+ key_index);
+ trace_rdev_return_int(&rdev->wiphy, ret);
+ return ret;
+}
+
static inline int rdev_start_ap(struct cfg80211_registered_device *rdev,
struct net_device *dev,
struct cfg80211_ap_settings *settings)
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index d32a2ec4d96a..ac3e60aa1fc8 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -1111,9 +1111,16 @@ void __cfg80211_disconnected(struct net_device *dev, const u8 *ie,
* Delete all the keys ... pairwise keys can't really
* exist any more anyway, but default keys might.
*/
- if (rdev->ops->del_key)
- for (i = 0; i < 6; i++)
+ if (rdev->ops->del_key) {
+ int max_key_idx = 5;
+
+ if (wiphy_ext_feature_isset(
+ wdev->wiphy,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION))
+ max_key_idx = 7;
+ for (i = 0; i <= max_key_idx; i++)
rdev_del_key(rdev, dev, i, false, NULL);
+ }

rdev_set_qos_map(rdev, dev, NULL);

diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index b6b60e3aea41..63754c528a62 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -510,6 +510,23 @@ TRACE_EVENT(rdev_set_default_mgmt_key,
WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->key_index)
);

+TRACE_EVENT(rdev_set_default_beacon_key,
+ TP_PROTO(struct wiphy *wiphy, struct net_device *netdev, u8 key_index),
+ TP_ARGS(wiphy, netdev, key_index),
+ TP_STRUCT__entry(
+ WIPHY_ENTRY
+ NETDEV_ENTRY
+ __field(u8, key_index)
+ ),
+ TP_fast_assign(
+ WIPHY_ASSIGN;
+ NETDEV_ASSIGN;
+ __entry->key_index = key_index;
+ ),
+ TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", key index: %u",
+ WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->key_index)
+);
+
TRACE_EVENT(rdev_start_ap,
TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
struct cfg80211_ap_settings *settings),
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 8481e9ac33da..72926f87c913 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -231,7 +231,12 @@ int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
struct key_params *params, int key_idx,
bool pairwise, const u8 *mac_addr)
{
- if (key_idx < 0 || key_idx > 5)
+ int max_key_idx = 5;
+
+ if (wiphy_ext_feature_isset(&rdev->wiphy,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION))
+ max_key_idx = 7;
+ if (key_idx < 0 || key_idx > max_key_idx)
return -EINVAL;

if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
--
2.20.1

2020-02-22 13:27:50

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH 6/7] mac80211: Beacon protection using the new BIGTK (STA)

This adds support for mac80211 to verify that received Beacon frames
have a valid MME in station mode when a BIGTK is configured.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/mac80211/rx.c | 79 ++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 67 insertions(+), 12 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index ec3a04a1db20..6bd24123456d 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -983,7 +983,8 @@ static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
return -1;

- if (!ieee80211_is_robust_mgmt_frame(skb))
+ if (!ieee80211_is_robust_mgmt_frame(skb) &&
+ !ieee80211_is_beacon(hdr->frame_control))
return -1; /* not a robust management frame */

mmie = (struct ieee80211_mmie *)
@@ -1868,6 +1869,41 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
return RX_CONTINUE;
} /* ieee80211_rx_h_sta_process */

+static struct ieee80211_key *
+ieee80211_rx_get_bigtk(struct ieee80211_rx_data *rx, int idx)
+{
+ struct ieee80211_key *key = NULL;
+ struct ieee80211_sub_if_data *sdata = rx->sdata;
+ int idx2;
+
+ /* Make sure key gets set if either BIGTK key index is set so that
+ * ieee80211_drop_unencrypted_mgmt() can properly drop both unprotected
+ * Beacon frames and Beacon frames that claim to use another BIGTK key
+ * index (i.e., a key that we do not have).
+ */
+
+ if (idx < 0) {
+ idx = NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS;
+ idx2 = idx + 1;
+ } else {
+ if (idx == NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
+ idx2 = idx + 1;
+ else
+ idx2 = idx - 1;
+ }
+
+ if (rx->sta)
+ key = rcu_dereference(rx->sta->gtk[idx]);
+ if (!key)
+ key = rcu_dereference(sdata->keys[idx]);
+ if (!key && rx->sta)
+ key = rcu_dereference(rx->sta->gtk[idx2]);
+ if (!key)
+ key = rcu_dereference(sdata->keys[idx2]);
+
+ return key;
+}
+
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
{
@@ -1885,17 +1921,18 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
/*
* Key selection 101
*
- * There are four types of keys:
+ * There are five types of keys:
* - GTK (group keys)
* - IGTK (group keys for management frames)
+ * - BIGTK (group keys for Beacon frames)
* - PTK (pairwise keys)
* - STK (station-to-station pairwise keys)
*
* When selecting a key, we have to distinguish between multicast
* (including broadcast) and unicast frames, the latter can only
- * use PTKs and STKs while the former always use GTKs and IGTKs.
- * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
- * unicast frames can also use key indices like GTKs. Hence, if we
+ * use PTKs and STKs while the former always use GTKs, IGTKs, and
+ * BIGTKs. Unless, of course, actual WEP keys ("pre-RSNA") are used,
+ * then unicast frames can also use key indices like GTKs. Hence, if we
* don't have a PTK/STK we check the key index for a WEP key.
*
* Note that in a regular BSS, multicast frames are sent by the
@@ -1939,6 +1976,20 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
/* Skip decryption if the frame is not protected. */
if (!ieee80211_has_protected(fc))
return RX_CONTINUE;
+ } else if (mmie_keyidx >= 0 && ieee80211_is_beacon(fc)) {
+ /* Broadcast/multicast robust management frame / BIP */
+ if ((status->flag & RX_FLAG_DECRYPTED) &&
+ (status->flag & RX_FLAG_IV_STRIPPED))
+ return RX_CONTINUE;
+
+ if (mmie_keyidx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS ||
+ mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
+ NUM_DEFAULT_BEACON_KEYS)
+ return RX_DROP_MONITOR; /* unexpected BIP keyidx */
+
+ rx->key = ieee80211_rx_get_bigtk(rx, mmie_keyidx);
+ if (!rx->key)
+ return RX_CONTINUE; /* Beacon protection not in use */
} else if (mmie_keyidx >= 0) {
/* Broadcast/multicast robust management frame / BIP */
if ((status->flag & RX_FLAG_DECRYPTED) &&
@@ -1968,11 +2019,12 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
struct ieee80211_sub_if_data *sdata = rx->sdata;
int i;

- if (ieee80211_is_mgmt(fc) &&
- is_multicast_ether_addr(hdr->addr1) &&
- (key = rcu_dereference(rx->sdata->default_mgmt_key)))
- rx->key = key;
- else {
+ if (ieee80211_is_beacon(fc)) {
+ key = ieee80211_rx_get_bigtk(rx, -1);
+ } else if (ieee80211_is_mgmt(fc) &&
+ is_multicast_ether_addr(hdr->addr1)) {
+ key = rcu_dereference(rx->sdata->default_mgmt_key);
+ } else {
if (rx->sta) {
for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
key = rcu_dereference(rx->sta->gtk[i]);
@@ -1987,9 +2039,9 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
break;
}
}
- if (key)
- rx->key = key;
}
+ if (key)
+ rx->key = key;
return RX_CONTINUE;
} else {
/*
@@ -2358,6 +2410,9 @@ static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
rx->skb->len);
return -EACCES;
}
+ if (unlikely(ieee80211_is_beacon(fc) && rx->key &&
+ ieee80211_get_mmie_keyidx(rx->skb) < 0))
+ return -EACCES;
/*
* When using MFP, Action frames are not allowed prior to
* having configured keys.
--
2.20.1

2020-02-22 13:27:59

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH 4/7] mac80211: Update BIP to support Beacon frames

When BIP is used to protect Beacon frames, the Timestamp field is masked
to zero. Otherwise, the BIP processing is identical to the way it was
already used with group-addressed Robust Management frames.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/mac80211/aes_cmac.c | 21 +++++++++++++++++++--
net/mac80211/aes_gmac.c | 24 ++++++++++++++++++------
2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
index 57748cab0e28..b31f1021ad9c 100644
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -26,12 +26,20 @@ void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
{
SHASH_DESC_ON_STACK(desc, tfm);
u8 out[AES_BLOCK_SIZE];
+ const __le16 *fc;

desc->tfm = tfm;

crypto_shash_init(desc);
crypto_shash_update(desc, aad, AAD_LEN);
- crypto_shash_update(desc, data, data_len - CMAC_TLEN);
+ fc = (const __le16 *)aad;
+ if (ieee80211_is_beacon(*fc)) {
+ /* mask Timestamp field to zero */
+ crypto_shash_update(desc, zero, 8);
+ crypto_shash_update(desc, data + 8, data_len - 8 - CMAC_TLEN);
+ } else {
+ crypto_shash_update(desc, data, data_len - CMAC_TLEN);
+ }
crypto_shash_finup(desc, zero, CMAC_TLEN, out);

memcpy(mic, out, CMAC_TLEN);
@@ -41,12 +49,21 @@ void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
const u8 *data, size_t data_len, u8 *mic)
{
SHASH_DESC_ON_STACK(desc, tfm);
+ const __le16 *fc;

desc->tfm = tfm;

crypto_shash_init(desc);
crypto_shash_update(desc, aad, AAD_LEN);
- crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
+ fc = (const __le16 *)aad;
+ if (ieee80211_is_beacon(*fc)) {
+ /* mask Timestamp field to zero */
+ crypto_shash_update(desc, zero, 8);
+ crypto_shash_update(desc, data + 8,
+ data_len - 8 - CMAC_TLEN_256);
+ } else {
+ crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
+ }
crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
}

diff --git a/net/mac80211/aes_gmac.c b/net/mac80211/aes_gmac.c
index 363ad1c1dc0c..16ba09cb5def 100644
--- a/net/mac80211/aes_gmac.c
+++ b/net/mac80211/aes_gmac.c
@@ -17,10 +17,11 @@
int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce,
const u8 *data, size_t data_len, u8 *mic)
{
- struct scatterlist sg[4];
+ struct scatterlist sg[5];
u8 *zero, *__aad, iv[AES_BLOCK_SIZE];
struct aead_request *aead_req;
int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
+ const __le16 *fc;

if (data_len < GMAC_MIC_LEN)
return -EINVAL;
@@ -33,11 +34,22 @@ int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce,
__aad = zero + GMAC_MIC_LEN;
memcpy(__aad, aad, GMAC_AAD_LEN);

- sg_init_table(sg, 4);
- sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN);
- sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN);
- sg_set_buf(&sg[2], zero, GMAC_MIC_LEN);
- sg_set_buf(&sg[3], mic, GMAC_MIC_LEN);
+ fc = (const __le16 *)aad;
+ if (ieee80211_is_beacon(*fc)) {
+ /* mask Timestamp field to zero */
+ sg_init_table(sg, 5);
+ sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN);
+ sg_set_buf(&sg[1], zero, 8);
+ sg_set_buf(&sg[2], data + 8, data_len - 8 - GMAC_MIC_LEN);
+ sg_set_buf(&sg[3], zero, GMAC_MIC_LEN);
+ sg_set_buf(&sg[4], mic, GMAC_MIC_LEN);
+ } else {
+ sg_init_table(sg, 4);
+ sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN);
+ sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN);
+ sg_set_buf(&sg[2], zero, GMAC_MIC_LEN);
+ sg_set_buf(&sg[3], mic, GMAC_MIC_LEN);
+ }

memcpy(iv, nonce, GMAC_NONCE_LEN);
memset(iv + GMAC_NONCE_LEN, 0, sizeof(iv) - GMAC_NONCE_LEN);
--
2.20.1

2020-02-22 13:28:12

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH 3/7] mac80211: Support BIGTK configuration for Beacon protection

Extend mac80211 key configuration to support the new BIGTK with key
index values 6 and 7. Support for actually protecting Beacon frames
(adding the MME in AP mode and checking it in STA mode) is covered in
separate commits.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/mac80211/cfg.c | 15 +++++++++++++-
net/mac80211/debugfs_key.c | 31 +++++++++++++++++++++++++++++
net/mac80211/debugfs_key.h | 10 ++++++++++
net/mac80211/ieee80211_i.h | 6 +++++-
net/mac80211/key.c | 40 ++++++++++++++++++++++++++++++++++++--
net/mac80211/key.h | 3 +++
net/mac80211/sta_info.h | 4 +++-
7 files changed, 104 insertions(+), 5 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index a66eff1ee26a..a762ba6e4c5d 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -568,7 +568,8 @@ static int ieee80211_get_key(struct wiphy *wiphy, struct net_device *dev,
if (pairwise && key_idx < NUM_DEFAULT_KEYS)
key = rcu_dereference(sta->ptk[key_idx]);
else if (!pairwise &&
- key_idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
+ key_idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
+ NUM_DEFAULT_BEACON_KEYS)
key = rcu_dereference(sta->gtk[key_idx]);
} else
key = rcu_dereference(sdata->keys[key_idx]);
@@ -680,6 +681,17 @@ static int ieee80211_config_default_mgmt_key(struct wiphy *wiphy,
return 0;
}

+static int ieee80211_config_default_beacon_key(struct wiphy *wiphy,
+ struct net_device *dev,
+ u8 key_idx)
+{
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+ ieee80211_set_default_beacon_key(sdata, key_idx);
+
+ return 0;
+}
+
void sta_set_rate_info_tx(struct sta_info *sta,
const struct ieee80211_tx_rate *rate,
struct rate_info *rinfo)
@@ -3885,6 +3897,7 @@ const struct cfg80211_ops mac80211_config_ops = {
.get_key = ieee80211_get_key,
.set_default_key = ieee80211_config_default_key,
.set_default_mgmt_key = ieee80211_config_default_mgmt_key,
+ .set_default_beacon_key = ieee80211_config_default_beacon_key,
.start_ap = ieee80211_start_ap,
.change_beacon = ieee80211_change_beacon,
.stop_ap = ieee80211_stop_ap,
diff --git a/net/mac80211/debugfs_key.c b/net/mac80211/debugfs_key.c
index 7b8735ced2a1..98a713475e0f 100644
--- a/net/mac80211/debugfs_key.c
+++ b/net/mac80211/debugfs_key.c
@@ -433,6 +433,37 @@ void ieee80211_debugfs_key_remove_mgmt_default(struct ieee80211_sub_if_data *sda
sdata->debugfs.default_mgmt_key = NULL;
}

+void
+ieee80211_debugfs_key_add_beacon_default(struct ieee80211_sub_if_data *sdata)
+{
+ char buf[50];
+ struct ieee80211_key *key;
+
+ if (!sdata->vif.debugfs_dir)
+ return;
+
+ key = key_mtx_dereference(sdata->local,
+ sdata->default_beacon_key);
+ if (key) {
+ sprintf(buf, "../keys/%d", key->debugfs.cnt);
+ sdata->debugfs.default_beacon_key =
+ debugfs_create_symlink("default_beacon_key",
+ sdata->vif.debugfs_dir, buf);
+ } else {
+ ieee80211_debugfs_key_remove_beacon_default(sdata);
+ }
+}
+
+void
+ieee80211_debugfs_key_remove_beacon_default(struct ieee80211_sub_if_data *sdata)
+{
+ if (!sdata)
+ return;
+
+ debugfs_remove(sdata->debugfs.default_beacon_key);
+ sdata->debugfs.default_beacon_key = NULL;
+}
+
void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key,
struct sta_info *sta)
{
diff --git a/net/mac80211/debugfs_key.h b/net/mac80211/debugfs_key.h
index 1cd7b8bff56c..af7cf495f8d1 100644
--- a/net/mac80211/debugfs_key.h
+++ b/net/mac80211/debugfs_key.h
@@ -10,6 +10,10 @@ void ieee80211_debugfs_key_add_mgmt_default(
struct ieee80211_sub_if_data *sdata);
void ieee80211_debugfs_key_remove_mgmt_default(
struct ieee80211_sub_if_data *sdata);
+void ieee80211_debugfs_key_add_beacon_default(
+ struct ieee80211_sub_if_data *sdata);
+void ieee80211_debugfs_key_remove_beacon_default(
+ struct ieee80211_sub_if_data *sdata);
void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key,
struct sta_info *sta);
#else
@@ -26,6 +30,12 @@ static inline void ieee80211_debugfs_key_add_mgmt_default(
static inline void ieee80211_debugfs_key_remove_mgmt_default(
struct ieee80211_sub_if_data *sdata)
{}
+static inline void ieee80211_debugfs_key_add_beacon_default(
+ struct ieee80211_sub_if_data *sdata)
+{}
+static inline void ieee80211_debugfs_key_remove_beacon_default(
+ struct ieee80211_sub_if_data *sdata)
+{}
static inline void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key,
struct sta_info *sta)
{}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index da9eaa9ee37e..46f9e8e5b4d7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -901,10 +901,13 @@ struct ieee80211_sub_if_data {
/* bit field of ACM bits (BIT(802.1D tag)) */
u8 wmm_acm;

- struct ieee80211_key __rcu *keys[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
+ struct ieee80211_key __rcu *keys[NUM_DEFAULT_KEYS +
+ NUM_DEFAULT_MGMT_KEYS +
+ NUM_DEFAULT_BEACON_KEYS];
struct ieee80211_key __rcu *default_unicast_key;
struct ieee80211_key __rcu *default_multicast_key;
struct ieee80211_key __rcu *default_mgmt_key;
+ struct ieee80211_key __rcu *default_beacon_key;

u16 sequence_number;
__be16 control_port_protocol;
@@ -978,6 +981,7 @@ struct ieee80211_sub_if_data {
struct dentry *default_unicast_key;
struct dentry *default_multicast_key;
struct dentry *default_mgmt_key;
+ struct dentry *default_beacon_key;
} debugfs;
#endif

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 54934eff4ac1..6354491c5a09 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -407,6 +407,31 @@ void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
mutex_unlock(&sdata->local->key_mtx);
}

+static void
+__ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ struct ieee80211_key *key = NULL;
+
+ assert_key_lock(sdata->local);
+
+ if (idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS &&
+ idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
+ NUM_DEFAULT_BEACON_KEYS)
+ key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
+
+ rcu_assign_pointer(sdata->default_beacon_key, key);
+
+ ieee80211_debugfs_key_update_default(sdata);
+}
+
+void ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata,
+ int idx)
+{
+ mutex_lock(&sdata->local->key_mtx);
+ __ieee80211_set_default_beacon_key(sdata, idx);
+ mutex_unlock(&sdata->local->key_mtx);
+}
+
static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta,
bool pairwise,
@@ -415,7 +440,7 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
{
int idx;
int ret = 0;
- bool defunikey, defmultikey, defmgmtkey;
+ bool defunikey, defmultikey, defmgmtkey, defbeaconkey;

/* caller must provide at least one old/new */
if (WARN_ON(!new && !old))
@@ -480,6 +505,9 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
defmgmtkey = old &&
old == key_mtx_dereference(sdata->local,
sdata->default_mgmt_key);
+ defbeaconkey = old &&
+ old == key_mtx_dereference(sdata->local,
+ sdata->default_beacon_key);

if (defunikey && !new)
__ieee80211_set_default_key(sdata, -1, true, false);
@@ -487,6 +515,8 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
__ieee80211_set_default_key(sdata, -1, false, true);
if (defmgmtkey && !new)
__ieee80211_set_default_mgmt_key(sdata, -1);
+ if (defbeaconkey && !new)
+ __ieee80211_set_default_beacon_key(sdata, -1);

rcu_assign_pointer(sdata->keys[idx], new);
if (defunikey && new)
@@ -498,6 +528,9 @@ static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
if (defmgmtkey && new)
__ieee80211_set_default_mgmt_key(sdata,
new->conf.keyidx);
+ if (defbeaconkey && new)
+ __ieee80211_set_default_beacon_key(sdata,
+ new->conf.keyidx);
}

if (old)
@@ -515,7 +548,9 @@ ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
struct ieee80211_key *key;
int i, j, err;

- if (WARN_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS))
+ if (WARN_ON(idx < 0 ||
+ idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
+ NUM_DEFAULT_BEACON_KEYS))
return ERR_PTR(-EINVAL);

key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
@@ -978,6 +1013,7 @@ static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
sdata->crypto_tx_tailroom_pending_dec = 0;

ieee80211_debugfs_key_remove_mgmt_default(sdata);
+ ieee80211_debugfs_key_remove_beacon_default(sdata);

list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
ieee80211_key_replace(key->sdata, key->sta,
diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index d6d6e89cf7dd..7ad72e9b4991 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -17,6 +17,7 @@

#define NUM_DEFAULT_KEYS 4
#define NUM_DEFAULT_MGMT_KEYS 2
+#define NUM_DEFAULT_BEACON_KEYS 2
#define INVALID_PTK_KEYIDX 2 /* Keyidx always pointing to a NULL key for PTK */

struct ieee80211_local;
@@ -153,6 +154,8 @@ void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
bool uni, bool multi);
void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
int idx);
+void ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata,
+ int idx);
void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
bool force_synchronize);
void ieee80211_free_sta_keys(struct ieee80211_local *local,
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index c00e28585f9d..364a35414d05 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -533,7 +533,9 @@ struct sta_info {
u8 addr[ETH_ALEN];
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
- struct ieee80211_key __rcu *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
+ struct ieee80211_key __rcu *gtk[NUM_DEFAULT_KEYS +
+ NUM_DEFAULT_MGMT_KEYS +
+ NUM_DEFAULT_BEACON_KEYS];
struct ieee80211_key __rcu *ptk[NUM_DEFAULT_KEYS];
u8 ptk_idx;
struct rate_control_ref *rate_ctrl;
--
2.20.1

2020-02-22 13:28:58

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH 5/7] mac80211: Beacon protection using the new BIGTK (AP)

This adds support for mac80211 to add an MME into Beacon frames in AP
mode when a BIGTK is configured.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/mac80211/tx.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 8dd93072f6e6..484918a331fc 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -4664,6 +4664,28 @@ bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
}
EXPORT_SYMBOL(ieee80211_csa_is_complete);

+static int ieee80211_beacon_protect(struct sk_buff *skb,
+ struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata)
+{
+ ieee80211_tx_result res;
+ struct ieee80211_tx_data tx;
+
+ memset(&tx, 0, sizeof(tx));
+ tx.key = rcu_dereference(sdata->default_beacon_key);
+ if (!tx.key)
+ return 0;
+ tx.local = local;
+ tx.sdata = sdata;
+ __skb_queue_head_init(&tx.skbs);
+ __skb_queue_tail(&tx.skbs, skb);
+ res = ieee80211_tx_h_encrypt(&tx);
+ if (WARN_ON_ONCE(res != TX_CONTINUE))
+ return -1;
+
+ return 0;
+}
+
static struct sk_buff *
__ieee80211_beacon_get(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
@@ -4731,6 +4753,9 @@ __ieee80211_beacon_get(struct ieee80211_hw *hw,
if (beacon->tail)
skb_put_data(skb, beacon->tail,
beacon->tail_len);
+
+ if (ieee80211_beacon_protect(skb, local, sdata) < 0)
+ goto out;
} else
goto out;
} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
--
2.20.1

2020-02-22 16:19:11

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/7] cfg80211: More error messages for key addition failures

On Sat, 2020-02-22 at 15:25 +0200, Jouni Malinen wrote:
>
> - if (!err)
> + if (err)
> + GENL_SET_ERR_MSG(info, "key not allowed");
> + if (!err) {
> err = rdev_add_key(rdev, dev, key.idx,

[...]

Had to read this twice, but I don't see any reason not to put an else
there? :)

I can fix it up later when I apply it.

Thanks, btw, BIGTK was definitely something we were also looking into
now.

johannes