[linux-2.6-block.git] / net / mac80211 / aes_cmac.c

// 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);
}
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
765cb46a JM	2	/*
	3	* AES-128-CMAC with TLen 16 for IEEE 802.11w BIP
	4	* Copyright 2008, Jouni Malinen <j@w1.fi>
8de85704	5	* Copyright (C) 2020 Intel Corporation
765cb46a JM	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/types.h>
	10	#include <linux/crypto.h>
4afebd63	11	#include <linux/export.h>
765cb46a	12	#include <linux/err.h>
0cd20a27	13	#include <crypto/aes.h>
765cb46a JM	14
	15	#include <net/mac80211.h>
	16	#include "key.h"
	17	#include "aes_cmac.h"
	18
765cb46a	19	#define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */
56c52da2	20	#define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */
765cb46a JM	21	#define AAD_LEN 20
765cb46a JM	22
26717828	23	static const u8 zero[CMAC_TLEN_256];
765cb46a	24
26717828	25	void ieee80211_aes_cmac(struct crypto_shash tfm, const u8 aad,
765cb46a JM	26	const u8 data, size_t data_len, u8 mic)
765cb46a JM	27	{
26717828 AB	28	SHASH_DESC_ON_STACK(desc, tfm);
26717828 AB	29	u8 out[AES_BLOCK_SIZE];
2d5d4b0a	30	const __le16 *fc;
765cb46a	31
26717828	32	desc->tfm = tfm;
765cb46a	33
26717828 AB	34	crypto_shash_init(desc);
26717828 AB	35	crypto_shash_update(desc, aad, AAD_LEN);
2d5d4b0a JM	36	fc = (const __le16 *)aad;
	37	if (ieee80211_is_beacon(*fc)) {
	38	/* mask Timestamp field to zero */
	39	crypto_shash_update(desc, zero, 8);
	40	crypto_shash_update(desc, data + 8, data_len - 8 - CMAC_TLEN);
	41	} else {
	42	crypto_shash_update(desc, data, data_len - CMAC_TLEN);
	43	}
26717828 AB	44	crypto_shash_finup(desc, zero, CMAC_TLEN, out);
	45
	46	memcpy(mic, out, CMAC_TLEN);
765cb46a JM	47	}
765cb46a JM	48
26717828	49	void ieee80211_aes_cmac_256(struct crypto_shash tfm, const u8 aad,
56c52da2 JM	50	const u8 data, size_t data_len, u8 mic)
56c52da2 JM	51	{
26717828	52	SHASH_DESC_ON_STACK(desc, tfm);
2d5d4b0a	53	const __le16 *fc;
56c52da2	54
26717828	55	desc->tfm = tfm;
56c52da2	56
26717828 AB	57	crypto_shash_init(desc);
26717828 AB	58	crypto_shash_update(desc, aad, AAD_LEN);
2d5d4b0a JM	59	fc = (const __le16 *)aad;
	60	if (ieee80211_is_beacon(*fc)) {
	61	/* mask Timestamp field to zero */
	62	crypto_shash_update(desc, zero, 8);
	63	crypto_shash_update(desc, data + 8,
	64	data_len - 8 - CMAC_TLEN_256);
	65	} else {
	66	crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
	67	}
26717828	68	crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
56c52da2	69	}
765cb46a	70
26717828 AB	71	struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
26717828 AB	72	size_t key_len)
765cb46a	73	{
26717828	74	struct crypto_shash *tfm;
765cb46a	75
26717828	76	tfm = crypto_alloc_shash("cmac(aes)", 0, 0);
8de85704 JB	77	if (!IS_ERR(tfm)) {
	78	int err = crypto_shash_setkey(tfm, key, key_len);
	79
	80	if (err) {
	81	crypto_free_shash(tfm);
	82	return ERR_PTR(err);
	83	}
	84	}
765cb46a JM	85
	86	return tfm;
	87	}
	88
26717828	89	void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm)
765cb46a	90	{
26717828	91	crypto_free_shash(tfm);
765cb46a	92	}