mac80211: expose AES-CMAC subkey calculation

Expose a function for the AES-CMAC subkey calculation
to drivers. This is the first step of the AES-CMAC
cipher key setup and may be required for CMAC hardware
offloading.

Signed-off-by: Assaf Krauss <assaf.krauss@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
index a04752e91023..493353534a0f 100644
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -126,3 +126,20 @@ void ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm)
 {
         crypto_free_cipher(tfm);
 }
+
+void ieee80211_aes_cmac_calculate_k1_k2(struct ieee80211_key_conf *keyconf,
+                                        u8 *k1, u8 *k2)
+{
+        u8 l[AES_BLOCK_SIZE] = {};
+        struct ieee80211_key *key =
+                container_of(keyconf, struct ieee80211_key, conf);
+
+        crypto_cipher_encrypt_one(key->u.aes_cmac.tfm, l, l);
+
+        memcpy(k1, l, AES_BLOCK_SIZE);
+        gf_mulx(k1);
+
+        memcpy(k2, k1, AES_BLOCK_SIZE);
+        gf_mulx(k2);
+}
+EXPORT_SYMBOL(ieee80211_aes_cmac_calculate_k1_k2);