linux/net/mac80211/wep.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Software WEP encryption implementation
 * Copyright 2002, Jouni Malinen <[email protected]>
 * Copyright 2003, Instant802 Networks, Inc.
 * Copyright (C) 2023 Intel Corporation
 */

#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/random.h>
#include <linux/compiler.h>
#include <linux/crc32.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <asm/unaligned.h>

#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "wep.h"


void ieee80211_wep_init(struct ieee80211_local *local)
{ … }

static inline bool ieee80211_wep_weak_iv(u32 iv, int keylen)
{ … }


static void ieee80211_wep_get_iv(struct ieee80211_local *local,
				 int keylen, int keyidx, u8 *iv)
{ … }


static u8 *ieee80211_wep_add_iv(struct ieee80211_local *local,
				struct sk_buff *skb,
				int keylen, int keyidx)
{ … }


static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
				    struct sk_buff *skb,
				    struct ieee80211_key *key)
{ … }


/* Perform WEP encryption using given key. data buffer must have tailroom
 * for 4-byte ICV. data_len must not include this ICV. Note: this function
 * does _not_ add IV. data = RC4(data | CRC32(data)) */
int ieee80211_wep_encrypt_data(struct arc4_ctx *ctx, u8 *rc4key,
			       size_t klen, u8 *data, size_t data_len)
{ … }


/* Perform WEP encryption on given skb. 4 bytes of extra space (IV) in the
 * beginning of the buffer 4 bytes of extra space (ICV) in the end of the
 * buffer will be added. Both IV and ICV will be transmitted, so the
 * payload length increases with 8 bytes.
 *
 * WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
 */
int ieee80211_wep_encrypt(struct ieee80211_local *local,
			  struct sk_buff *skb,
			  const u8 *key, int keylen, int keyidx)
{ … }


/* Perform WEP decryption using given key. data buffer includes encrypted
 * payload, including 4-byte ICV, but _not_ IV. data_len must not include ICV.
 * Return 0 on success and -1 on ICV mismatch. */
int ieee80211_wep_decrypt_data(struct arc4_ctx *ctx, u8 *rc4key,
			       size_t klen, u8 *data, size_t data_len)
{ … }


/* Perform WEP decryption on given skb. Buffer includes whole WEP part of
 * the frame: IV (4 bytes), encrypted payload (including SNAP header),
 * ICV (4 bytes). skb->len includes both IV and ICV.
 *
 * Returns 0 if frame was decrypted successfully and ICV was correct and -1 on
 * failure. If frame is OK, IV and ICV will be removed, i.e., decrypted payload
 * is moved to the beginning of the skb and skb length will be reduced.
 */
static int ieee80211_wep_decrypt(struct ieee80211_local *local,
				 struct sk_buff *skb,
				 struct ieee80211_key *key)
{ … }

ieee80211_rx_result
ieee80211_crypto_wep_decrypt(struct ieee80211_rx_data *rx)
{ … }

static int wep_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
{ … }

ieee80211_tx_result
ieee80211_crypto_wep_encrypt(struct ieee80211_tx_data *tx)
{ … }