diff options
Diffstat (limited to 'net/mac80211/aes_cmac.c')
-rw-r--r-- | net/mac80211/aes_cmac.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c new file mode 100644 index 000000000..2fb655884 --- /dev/null +++ b/net/mac80211/aes_cmac.c @@ -0,0 +1,71 @@ +/* + * 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/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]; + + 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); + + 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); +} + +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)) + crypto_shash_setkey(tfm, key, key_len); + + return tfm; +} + +void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm) +{ + crypto_free_shash(tfm); +} |