1 files changed, 92 insertions, 0 deletions
diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
new file mode 100644
index 000000000..48c04f89d
--- /dev/null
+++ b/net/mac80211/aes_cmac.c
@@ -0,0 +1,92 @@
+// 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>
+ * Copyright (C) 2020 Intel Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/export.h>
+#include <linux/err.h>
+#include <crypto/aes.h>
+
+#include <net/mac80211.h>
+#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];
+
+void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
+			const u8 *data, size_t data_len, u8 *mic)
+{
+	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);
+	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);
+}
+
+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);
+	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);
+}
+
+struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
+						  size_t key_len)
+{
+	struct crypto_shash *tfm;
+
+	tfm = crypto_alloc_shash("cmac(aes)", 0, 0);
+	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;
+}
+
+void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm)
+{
+	crypto_free_shash(tfm);
+}