1 files changed, 42 insertions, 29 deletions

diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
index 2fb65588490c..0827965455dc 100644
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -1,10 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * AES-128-CMAC with TLen 16 for IEEE 802.11w BIP
  * Copyright 2008, Jouni Malinen <j@w1.fi>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
+ * Copyright (C) 2020 Intel Corporation
  */
 
 #include <linux/kernel.h>
@@ -18,39 +16,48 @@
 #include "key.h"
 #include "aes_cmac.h"
 
-#define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */
-#define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */
 #define AAD_LEN 20
 
-static const u8 zero[CMAC_TLEN_256];
+static const u8 zero[IEEE80211_CMAC_256_MIC_LEN];
 
-void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
-			const u8 *data, size_t data_len, u8 *mic)
+int ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
+		       const u8 *data, size_t data_len, u8 *mic,
+		       unsigned int mic_len)
 {
+	int err;
 	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);
-	crypto_shash_finup(desc, zero, CMAC_TLEN, out);
+	err = crypto_shash_init(desc);
+	if (err)
+		return err;
+	err = crypto_shash_update(desc, aad, AAD_LEN);
+	if (err)
+		return err;
+	fc = (const __le16 *)aad;
+	if (ieee80211_is_beacon(*fc)) {
+		/* mask Timestamp field to zero */
+		err = crypto_shash_update(desc, zero, 8);
+		if (err)
+			return err;
+		err = crypto_shash_update(desc, data + 8,
+					  data_len - 8 - mic_len);
+		if (err)
+			return err;
+	} else {
+		err = crypto_shash_update(desc, data, data_len - mic_len);
+		if (err)
+			return err;
+	}
+	err = crypto_shash_finup(desc, zero, mic_len, out);
+	if (err)
+		return err;
+	memcpy(mic, out, mic_len);
 
-	memcpy(mic, out, CMAC_TLEN);
-}
-
-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);
-
-	desc->tfm = tfm;
-
-	crypto_shash_init(desc);
-	crypto_shash_update(desc, aad, AAD_LEN);
-	crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
-	crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
+	return 0;
 }
 
 struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
@@ -59,8 +66,14 @@ struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
 	struct crypto_shash *tfm;
 
 	tfm = crypto_alloc_shash("cmac(aes)", 0, 0);
-	if (!IS_ERR(tfm))
-		crypto_shash_setkey(tfm, key, key_len);
+	if (!IS_ERR(tfm)) {
+		int err = crypto_shash_setkey(tfm, key, key_len);
+
+		if (err) {
+			crypto_free_shash(tfm);
+			return ERR_PTR(err);
+		}
+	}
 
 	return tfm;
 }