linux/net/mac80211/tkip.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2002-2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright (C) 2016 Intel Deutschland GmbH
 */
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/netdevice.h>
#include <linux/export.h>
#include <asm/unaligned.h>

#include <net/mac80211.h>
#include "driver-ops.h"
#include "key.h"
#include "tkip.h"
#include "wep.h"

#define PHASE1_LOOP_COUNT …

/*
 * 2-byte by 2-byte subset of the full AES S-box table; second part of this
 * table is identical to first part but byte-swapped
 */
static const u16 tkip_sbox[256] = …;

static u16 tkipS(u16 val)
{ … }

static u8 *write_tkip_iv(u8 *pos, u16 iv16)
{ … }

/*
 * P1K := Phase1(TA, TK, TSC)
 * TA = transmitter address (48 bits)
 * TK = dot11DefaultKeyValue or dot11KeyMappingValue (128 bits)
 * TSC = TKIP sequence counter (48 bits, only 32 msb bits used)
 * P1K: 80 bits
 */
static void tkip_mixing_phase1(const u8 *tk, struct tkip_ctx *ctx,
			       const u8 *ta, u32 tsc_IV32)
{ … }

static void tkip_mixing_phase2(const u8 *tk, struct tkip_ctx *ctx,
			       u16 tsc_IV16, u8 *rc4key)
{ … }

/* Add TKIP IV and Ext. IV at @pos. @iv0, @iv1, and @iv2 are the first octets
 * of the IV. Returns pointer to the octet following IVs (i.e., beginning of
 * the packet payload). */
u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key_conf *keyconf, u64 pn)
{ … }
EXPORT_SYMBOL_GPL(…);

static void ieee80211_compute_tkip_p1k(struct ieee80211_key *key, u32 iv32)
{ … }

void ieee80211_get_tkip_p1k_iv(struct ieee80211_key_conf *keyconf,
			       u32 iv32, u16 *p1k)
{ … }
EXPORT_SYMBOL(…);

void ieee80211_get_tkip_rx_p1k(struct ieee80211_key_conf *keyconf,
			       const u8 *ta, u32 iv32, u16 *p1k)
{ … }
EXPORT_SYMBOL(…);

void ieee80211_get_tkip_p2k(struct ieee80211_key_conf *keyconf,
			    struct sk_buff *skb, u8 *p2k)
{ … }
EXPORT_SYMBOL(…);

/*
 * Encrypt packet payload with TKIP using @key. @pos is a pointer to the
 * beginning of the buffer containing payload. This payload must include
 * the IV/Ext.IV and space for (taildroom) four octets for ICV.
 * @payload_len is the length of payload (_not_ including IV/ICV length).
 * @ta is the transmitter addresses.
 */
int ieee80211_tkip_encrypt_data(struct arc4_ctx *ctx,
				struct ieee80211_key *key,
				struct sk_buff *skb,
				u8 *payload, size_t payload_len)
{ … }

/* Decrypt packet payload with TKIP using @key. @pos is a pointer to the
 * beginning of the buffer containing IEEE 802.11 header payload, i.e.,
 * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the
 * length of payload, including IV, Ext. IV, MIC, ICV.  */
int ieee80211_tkip_decrypt_data(struct arc4_ctx *ctx,
				struct ieee80211_key *key,
				u8 *payload, size_t payload_len, u8 *ta,
				u8 *ra, int only_iv, int queue,
				u32 *out_iv32, u16 *out_iv16)
{ … }