+++ /dev/null
-/*
- * Host AP crypt: host-based WEP encryption implementation for Host AP driver
- *
- * Copyright (c) 2002-2004, Jouni Malinen <jkmaline@cc.hut.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. See README and COPYING for
- * more details.
- */
-
-#include <linux/version.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/random.h>
-#include <linux/skbuff.h>
-#include <asm/string.h>
-
-#include "ieee80211.h"
-
-#include <linux/crypto.h>
-#include <linux/scatterlist.h>
-#include <linux/crc32.h>
-
-MODULE_AUTHOR("Jouni Malinen");
-MODULE_DESCRIPTION("Host AP crypt: WEP");
-MODULE_LICENSE("GPL");
-
-struct prism2_wep_data {
- u32 iv;
-#define WEP_KEY_LEN 13
- u8 key[WEP_KEY_LEN + 1];
- u8 key_len;
- u8 key_idx;
- struct crypto_blkcipher *tx_tfm;
- struct crypto_blkcipher *rx_tfm;
-};
-
-
-static void * prism2_wep_init(int keyidx)
-{
- struct prism2_wep_data *priv;
-
- priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
- if (priv == NULL)
- goto fail;
- priv->key_idx = keyidx;
-
- priv->tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(priv->tx_tfm)) {
- printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
- "crypto API arc4\n");
- priv->tx_tfm = NULL;
- goto fail;
- }
- priv->rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(priv->rx_tfm)) {
- printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
- "crypto API arc4\n");
- priv->rx_tfm = NULL;
- goto fail;
- }
-
- /* start WEP IV from a random value */
- get_random_bytes(&priv->iv, 4);
-
- return priv;
-
-fail:
- if (priv) {
- if (priv->tx_tfm)
- crypto_free_blkcipher(priv->tx_tfm);
- if (priv->rx_tfm)
- crypto_free_blkcipher(priv->rx_tfm);
- kfree(priv);
- }
-
- return NULL;
-}
-
-
-static void prism2_wep_deinit(void *priv)
-{
- struct prism2_wep_data *_priv = priv;
-
- if (_priv) {
- if (_priv->tx_tfm)
- crypto_free_blkcipher(_priv->tx_tfm);
- if (_priv->rx_tfm)
- crypto_free_blkcipher(_priv->rx_tfm);
- }
- kfree(priv);
-}
-
-/* Perform WEP encryption on given skb that has at least 4 bytes of headroom
- * for IV and 4 bytes of tailroom for ICV. 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))
- */
-static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
-{
- struct prism2_wep_data *wep = priv;
- u32 klen, len;
- u8 key[WEP_KEY_LEN + 3];
- u8 *pos;
- cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
- struct blkcipher_desc desc = { .tfm = wep->tx_tfm };
- u32 crc;
- u8 *icv;
- struct scatterlist sg;
- if (skb_headroom(skb) < 4 || skb_tailroom(skb) < 4 ||
- skb->len < hdr_len)
- return -1;
-
- len = skb->len - hdr_len;
- pos = skb_push(skb, 4);
- memmove(pos, pos + 4, hdr_len);
- pos += hdr_len;
-
- klen = 3 + wep->key_len;
-
- wep->iv++;
-
- /* Fluhrer, Mantin, and Shamir have reported weaknesses in the key
- * scheduling algorithm of RC4. At least IVs (KeyByte + 3, 0xff, N)
- * can be used to speedup attacks, so avoid using them. */
- if ((wep->iv & 0xff00) == 0xff00) {
- u8 B = (wep->iv >> 16) & 0xff;
- if (B >= 3 && B < klen)
- wep->iv += 0x0100;
- }
-
- /* Prepend 24-bit IV to RC4 key and TX frame */
- *pos++ = key[0] = (wep->iv >> 16) & 0xff;
- *pos++ = key[1] = (wep->iv >> 8) & 0xff;
- *pos++ = key[2] = wep->iv & 0xff;
- *pos++ = wep->key_idx << 6;
-
- /* Copy rest of the WEP key (the secret part) */
- memcpy(key + 3, wep->key, wep->key_len);
-
- if (!tcb_desc->bHwSec)
- {
-
- /* Append little-endian CRC32 and encrypt it to produce ICV */
- crc = ~crc32_le(~0, pos, len);
- icv = skb_put(skb, 4);
- icv[0] = crc;
- icv[1] = crc >> 8;
- icv[2] = crc >> 16;
- icv[3] = crc >> 24;
-
- crypto_blkcipher_setkey(wep->tx_tfm, key, klen);
- sg_init_one(&sg, pos, len+4);
-
- return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
- }
-
- return 0;
-}
-
-
-/* Perform WEP decryption on given buffer. Buffer includes whole WEP part of
- * the frame: IV (4 bytes), encrypted payload (including SNAP header),
- * ICV (4 bytes). 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.
- */
-static int prism2_wep_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
-{
- struct prism2_wep_data *wep = priv;
- u32 klen, plen;
- u8 key[WEP_KEY_LEN + 3];
- u8 keyidx, *pos;
- cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
- struct blkcipher_desc desc = { .tfm = wep->rx_tfm };
- u32 crc;
- u8 icv[4];
- struct scatterlist sg;
- if (skb->len < hdr_len + 8)
- return -1;
-
- pos = skb->data + hdr_len;
- key[0] = *pos++;
- key[1] = *pos++;
- key[2] = *pos++;
- keyidx = *pos++ >> 6;
- if (keyidx != wep->key_idx)
- return -1;
-
- klen = 3 + wep->key_len;
-
- /* Copy rest of the WEP key (the secret part) */
- memcpy(key + 3, wep->key, wep->key_len);
-
- /* Apply RC4 to data and compute CRC32 over decrypted data */
- plen = skb->len - hdr_len - 8;
-
- if (!tcb_desc->bHwSec)
- {
- crypto_blkcipher_setkey(wep->rx_tfm, key, klen);
- sg_init_one(&sg, pos, plen + 4);
-
- if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4))
- return -7;
-
- crc = ~crc32_le(~0, pos, plen);
- icv[0] = crc;
- icv[1] = crc >> 8;
- icv[2] = crc >> 16;
- icv[3] = crc >> 24;
- if (memcmp(icv, pos + plen, 4) != 0) {
- /* ICV mismatch - drop frame */
- return -2;
- }
- }
- /* Remove IV and ICV */
- memmove(skb->data + 4, skb->data, hdr_len);
- skb_pull(skb, 4);
- skb_trim(skb, skb->len - 4);
-
- return 0;
-}
-
-
-static int prism2_wep_set_key(void *key, int len, u8 *seq, void *priv)
-{
- struct prism2_wep_data *wep = priv;
-
- if (len < 0 || len > WEP_KEY_LEN)
- return -1;
-
- memcpy(wep->key, key, len);
- wep->key_len = len;
-
- return 0;
-}
-
-
-static int prism2_wep_get_key(void *key, int len, u8 *seq, void *priv)
-{
- struct prism2_wep_data *wep = priv;
-
- if (len < wep->key_len)
- return -1;
-
- memcpy(key, wep->key, wep->key_len);
-
- return wep->key_len;
-}
-
-
-static char * prism2_wep_print_stats(char *p, void *priv)
-{
- struct prism2_wep_data *wep = priv;
- p += sprintf(p, "key[%d] alg=WEP len=%d\n",
- wep->key_idx, wep->key_len);
- return p;
-}
-
-
-static struct ieee80211_crypto_ops ieee80211_crypt_wep = {
- .name = "WEP",
- .init = prism2_wep_init,
- .deinit = prism2_wep_deinit,
- .encrypt_mpdu = prism2_wep_encrypt,
- .decrypt_mpdu = prism2_wep_decrypt,
- .encrypt_msdu = NULL,
- .decrypt_msdu = NULL,
- .set_key = prism2_wep_set_key,
- .get_key = prism2_wep_get_key,
- .print_stats = prism2_wep_print_stats,
- .extra_prefix_len = 4, /* IV */
- .extra_postfix_len = 4, /* ICV */
- .owner = THIS_MODULE,
-};
-
-int ieee80211_crypto_wep_init(void)
-{
- return ieee80211_register_crypto_ops(&ieee80211_crypt_wep);
-}
-
-void ieee80211_crypto_wep_exit(void)
-{
- ieee80211_unregister_crypto_ops(&ieee80211_crypt_wep);
-}
-
-void ieee80211_wep_null(void)
-{
- return;
-}
projects / mv-sheeva.git / blobdiff