cfg80211: Allow user space to specify non-IEs to SAE Authentication

SAE extends Authentication frames with fields that are not information
elements. NL80211_ATTR_IE is not suitable for these, so introduce a new
attribute that can be used to specify the fields needed for SAE in
station mode.

Signed-off-by: Jouni Malinen <j@w1.fi>
[change to verify that SAE is only used with authenticate command]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 48 insertions, 12 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0418a6d5c1a6..74d8123ada77 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -23,7 +23,6 @@
 #include "nl80211.h"
 #include "reg.h"
 
-static bool nl80211_valid_auth_type(enum nl80211_auth_type auth_type);
 static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
                                    struct genl_info *info,
                                    struct cfg80211_crypto_settings *settings,
@@ -355,6 +354,7 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
         [NL80211_ATTR_BG_SCAN_PERIOD] = { .type = NLA_U16 },
         [NL80211_ATTR_WDEV] = { .type = NLA_U64 },
         [NL80211_ATTR_USER_REG_HINT_TYPE] = { .type = NLA_U32 },
+        [NL80211_ATTR_SAE_DATA] = { .type = NLA_BINARY, },
 };
 
 /* policy for the key attributes */
@@ -2490,6 +2490,30 @@ static bool nl80211_get_ap_channel(struct cfg80211_registered_device *rdev,
         return ret;
 }
 
+static bool nl80211_valid_auth_type(struct cfg80211_registered_device *rdev,
+                                    enum nl80211_auth_type auth_type,
+                                    enum nl80211_commands cmd)
+{
+        if (auth_type > NL80211_AUTHTYPE_MAX)
+                return false;
+
+        switch (cmd) {
+        case NL80211_CMD_AUTHENTICATE:
+                if (!(rdev->wiphy.features & NL80211_FEATURE_SAE) &&
+                    auth_type == NL80211_AUTHTYPE_SAE)
+                        return false;
+                return true;
+        case NL80211_CMD_CONNECT:
+        case NL80211_CMD_START_AP:
+                /* SAE not supported yet */
+                if (auth_type == NL80211_AUTHTYPE_SAE)
+                        return false;
+                return true;
+        default:
+                return false;
+        }
+}
+
 static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -2559,7 +2583,8 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
         if (info->attrs[NL80211_ATTR_AUTH_TYPE]) {
                 params.auth_type = nla_get_u32(
                         info->attrs[NL80211_ATTR_AUTH_TYPE]);
-                if (!nl80211_valid_auth_type(params.auth_type))
+                if (!nl80211_valid_auth_type(rdev, params.auth_type,
+                                             NL80211_CMD_START_AP))
                         return -EINVAL;
         } else
                 params.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
@@ -4852,11 +4877,6 @@ static int nl80211_dump_survey(struct sk_buff *skb,
         return res;
 }
 
-static bool nl80211_valid_auth_type(enum nl80211_auth_type auth_type)
-{
-        return auth_type <= NL80211_AUTHTYPE_MAX;
-}
-
 static bool nl80211_valid_wpa_versions(u32 wpa_versions)
 {
         return !(wpa_versions & ~(NL80211_WPA_VERSION_1 |
@@ -4868,8 +4888,8 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
         struct cfg80211_registered_device *rdev = info->user_ptr[0];
         struct net_device *dev = info->user_ptr[1];
         struct ieee80211_channel *chan;
-        const u8 *bssid, *ssid, *ie = NULL;
-        int err, ssid_len, ie_len = 0;
+        const u8 *bssid, *ssid, *ie = NULL, *sae_data = NULL;
+        int err, ssid_len, ie_len = 0, sae_data_len = 0;
         enum nl80211_auth_type auth_type;
         struct key_parse key;
         bool local_state_change;
@@ -4945,9 +4965,23 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
         }
 
         auth_type = nla_get_u32(info->attrs[NL80211_ATTR_AUTH_TYPE]);
-        if (!nl80211_valid_auth_type(auth_type))
+        if (!nl80211_valid_auth_type(rdev, auth_type, NL80211_CMD_AUTHENTICATE))
                 return -EINVAL;
 
+        if (auth_type == NL80211_AUTHTYPE_SAE &&
+            !info->attrs[NL80211_ATTR_SAE_DATA])
+                return -EINVAL;
+
+        if (info->attrs[NL80211_ATTR_SAE_DATA]) {
+                if (auth_type != NL80211_AUTHTYPE_SAE)
+                        return -EINVAL;
+                sae_data = nla_data(info->attrs[NL80211_ATTR_SAE_DATA]);
+                sae_data_len = nla_len(info->attrs[NL80211_ATTR_SAE_DATA]);
+                /* need to include at least Auth Transaction and Status Code */
+                if (sae_data_len < 4)
+                        return -EINVAL;
+        }
+
         local_state_change = !!info->attrs[NL80211_ATTR_LOCAL_STATE_CHANGE];
 
         /*
@@ -4959,7 +4993,8 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
 
         return cfg80211_mlme_auth(rdev, dev, chan, auth_type, bssid,
                                   ssid, ssid_len, ie, ie_len,
-                                  key.p.key, key.p.key_len, key.idx);
+                                  key.p.key, key.p.key_len, key.idx,
+                                  sae_data, sae_data_len);
 }
 
 static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
@@ -5596,7 +5631,8 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
         if (info->attrs[NL80211_ATTR_AUTH_TYPE]) {
                 connect.auth_type =
                         nla_get_u32(info->attrs[NL80211_ATTR_AUTH_TYPE]);
-                if (!nl80211_valid_auth_type(connect.auth_type))
+                if (!nl80211_valid_auth_type(rdev, connect.auth_type,
+                                             NL80211_CMD_CONNECT))
                         return -EINVAL;
         } else
                 connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;