mac80211: 802.11w - Use BIP (AES-128-CMAC)

Add mechanism for managing BIP keys (IGTK) and integrate BIP into the
TX/RX paths.

Signed-off-by: Jouni Malinen <j@w1.fi>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 60 insertions, 2 deletions

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index b0a025c9b615..19b480de4bbc 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -18,6 +18,7 @@
 #include "ieee80211_i.h"
 #include "debugfs_key.h"
 #include "aes_ccm.h"
+#include "aes_cmac.h"
 
 
 /**
@@ -215,13 +216,38 @@ void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx)
         spin_unlock_irqrestore(&sdata->local->key_lock, flags);
 }
 
+static void
+__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
+{
+        struct ieee80211_key *key = NULL;
+
+        if (idx >= NUM_DEFAULT_KEYS &&
+            idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
+                key = sdata->keys[idx];
+
+        rcu_assign_pointer(sdata->default_mgmt_key, key);
+
+        if (key)
+                add_todo(key, KEY_FLAG_TODO_DEFMGMTKEY);
+}
+
+void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
+                                    int idx)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&sdata->local->key_lock, flags);
+        __ieee80211_set_default_mgmt_key(sdata, idx);
+        spin_unlock_irqrestore(&sdata->local->key_lock, flags);
+}
+
 
 static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
                                     struct sta_info *sta,
                                     struct ieee80211_key *old,
                                     struct ieee80211_key *new)
 {
-        int idx, defkey;
+        int idx, defkey, defmgmtkey;
 
         if (new)
                 list_add(&new->list, &sdata->key_list);
@@ -237,13 +263,19 @@ static void __ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
                         idx = new->conf.keyidx;
 
                 defkey = old && sdata->default_key == old;
+                defmgmtkey = old && sdata->default_mgmt_key == old;
 
                 if (defkey && !new)
                         __ieee80211_set_default_key(sdata, -1);
+                if (defmgmtkey && !new)
+                        __ieee80211_set_default_mgmt_key(sdata, -1);
 
                 rcu_assign_pointer(sdata->keys[idx], new);
                 if (defkey && new)
                         __ieee80211_set_default_key(sdata, new->conf.keyidx);
+                if (defmgmtkey && new)
+                        __ieee80211_set_default_mgmt_key(sdata,
+                                                         new->conf.keyidx);
         }
 
         if (old) {
@@ -262,7 +294,7 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
 {
         struct ieee80211_key *key;
 
-        BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS);
+        BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
 
         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
         if (!key)
@@ -291,6 +323,10 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
                 key->conf.iv_len = CCMP_HDR_LEN;
                 key->conf.icv_len = CCMP_MIC_LEN;
                 break;
+        case ALG_AES_CMAC:
+                key->conf.iv_len = 0;
+                key->conf.icv_len = sizeof(struct ieee80211_mmie);
+                break;
         }
         memcpy(key->conf.key, key_data, key_len);
         INIT_LIST_HEAD(&key->list);
@@ -308,6 +344,19 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
                 }
         }
 
+        if (alg == ALG_AES_CMAC) {
+                /*
+                 * Initialize AES key state here as an optimization so that
+                 * it does not need to be initialized for every packet.
+                 */
+                key->u.aes_cmac.tfm =
+                        ieee80211_aes_cmac_key_setup(key_data);
+                if (!key->u.aes_cmac.tfm) {
+                        kfree(key);
+                        return NULL;
+                }
+        }
+
         return key;
 }
 
@@ -461,6 +510,8 @@ static void __ieee80211_key_destroy(struct ieee80211_key *key)
 
         if (key->conf.alg == ALG_CCMP)
                 ieee80211_aes_key_free(key->u.ccmp.tfm);
+        if (key->conf.alg == ALG_AES_CMAC)
+                ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
         ieee80211_debugfs_key_remove(key);
 
         kfree(key);
@@ -483,6 +534,7 @@ static void __ieee80211_key_todo(void)
                 list_del_init(&key->todo);
                 todoflags = key->flags & (KEY_FLAG_TODO_ADD_DEBUGFS |
                                           KEY_FLAG_TODO_DEFKEY |
+                                          KEY_FLAG_TODO_DEFMGMTKEY |
                                           KEY_FLAG_TODO_HWACCEL_ADD |
                                           KEY_FLAG_TODO_HWACCEL_REMOVE |
                                           KEY_FLAG_TODO_DELETE);
@@ -500,6 +552,11 @@ static void __ieee80211_key_todo(void)
                         ieee80211_debugfs_key_add_default(key->sdata);
                         work_done = true;
                 }
+                if (todoflags & KEY_FLAG_TODO_DEFMGMTKEY) {
+                        ieee80211_debugfs_key_remove_mgmt_default(key->sdata);
+                        ieee80211_debugfs_key_add_mgmt_default(key->sdata);
+                        work_done = true;
+                }
                 if (todoflags & KEY_FLAG_TODO_HWACCEL_ADD) {
                         ieee80211_key_enable_hw_accel(key);
                         work_done = true;
@@ -535,6 +592,7 @@ void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata)
         ieee80211_key_lock();
 
         ieee80211_debugfs_key_remove_default(sdata);
+        ieee80211_debugfs_key_remove_mgmt_default(sdata);
 
         spin_lock_irqsave(&sdata->local->key_lock, flags);
         list_for_each_entry_safe(key, tmp, &sdata->key_list, list)