1 files changed, 135 insertions, 0 deletions
diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
new file mode 100644
index 0000000..3d097b3
--- /dev/null
+++ b/net/mac80211/aes_cmac.c
@@ -0,0 +1,135 @@
+/*
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/err.h>
+
+#include <net/mac80211.h>
+#include "key.h"
+#include "aes_cmac.h"
+
+#define AES_BLOCK_SIZE 16
+#define AES_CMAC_KEY_LEN 16
+#define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */
+#define AAD_LEN 20
+
+
+static void gf_mulx(u8 *pad)
+{
+	int i, carry;
+
+	carry = pad[0] & 0x80;
+	for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
+		pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
+	pad[AES_BLOCK_SIZE - 1] <<= 1;
+	if (carry)
+		pad[AES_BLOCK_SIZE - 1] ^= 0x87;
+}
+
+
+static void aes_128_cmac_vector(struct crypto_cipher *tfm, u8 *scratch,
+				size_t num_elem,
+				const u8 *addr[], const size_t *len, u8 *mac)
+{
+	u8 *cbc, *pad;
+	const u8 *pos, *end;
+	size_t i, e, left, total_len;
+
+	cbc = scratch;
+	pad = scratch + AES_BLOCK_SIZE;
+
+	memset(cbc, 0, AES_BLOCK_SIZE);
+
+	total_len = 0;
+	for (e = 0; e < num_elem; e++)
+		total_len += len[e];
+	left = total_len;
+
+	e = 0;
+	pos = addr[0];
+	end = pos + len[0];
+
+	while (left >= AES_BLOCK_SIZE) {
+		for (i = 0; i < AES_BLOCK_SIZE; i++) {
+			cbc[i] ^= *pos++;
+			if (pos >= end) {
+				e++;
+				pos = addr[e];
+				end = pos + len[e];
+			}
+		}
+		if (left > AES_BLOCK_SIZE)
+			crypto_cipher_encrypt_one(tfm, cbc, cbc);
+		left -= AES_BLOCK_SIZE;
+	}
+
+	memset(pad, 0, AES_BLOCK_SIZE);
+	crypto_cipher_encrypt_one(tfm, pad, pad);
+	gf_mulx(pad);
+
+	if (left || total_len == 0) {
+		for (i = 0; i < left; i++) {
+			cbc[i] ^= *pos++;
+			if (pos >= end) {
+				e++;
+				pos = addr[e];
+				end = pos + len[e];
+			}
+		}
+		cbc[left] ^= 0x80;
+		gf_mulx(pad);
+	}
+
+	for (i = 0; i < AES_BLOCK_SIZE; i++)
+		pad[i] ^= cbc[i];
+	crypto_cipher_encrypt_one(tfm, pad, pad);
+	memcpy(mac, pad, CMAC_TLEN);
+}
+
+
+void ieee80211_aes_cmac(struct crypto_cipher *tfm, u8 *scratch, const u8 *aad,
+			const u8 *data, size_t data_len, u8 *mic)
+{
+	const u8 *addr[3];
+	size_t len[3];
+	u8 zero[CMAC_TLEN];
+
+	memset(zero, 0, CMAC_TLEN);
+	addr[0] = aad;
+	len[0] = AAD_LEN;
+	addr[1] = data;
+	len[1] = data_len - CMAC_TLEN;
+	addr[2] = zero;
+	len[2] = CMAC_TLEN;
+
+	aes_128_cmac_vector(tfm, scratch, 3, addr, len, mic);
+}
+
+
+struct crypto_cipher * ieee80211_aes_cmac_key_setup(const u8 key[])
+{
+	struct crypto_cipher *tfm;
+
+	tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm))
+		return NULL;
+
+	crypto_cipher_setkey(tfm, key, AES_CMAC_KEY_LEN);
+
+	return tfm;
+}
+
+
+void ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm)
+{
+	if (tfm)
+		crypto_free_cipher(tfm);
+}