diff options
Diffstat (limited to 'package/d80211/src/wep.c')
-rw-r--r-- | package/d80211/src/wep.c | 328 |
1 files changed, 0 insertions, 328 deletions
diff --git a/package/d80211/src/wep.c b/package/d80211/src/wep.c deleted file mode 100644 index 6a96ade59e..0000000000 --- a/package/d80211/src/wep.c +++ /dev/null @@ -1,328 +0,0 @@ -/* - * Software WEP encryption implementation - * Copyright 2002, Jouni Malinen <jkmaline@cc.hut.fi> - * Copyright 2003, Instant802 Networks, Inc. - * - * 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/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 <asm/scatterlist.h> - -#include <net/d80211.h> -#include "ieee80211_i.h" -#include "wep.h" - - -int ieee80211_wep_init(struct ieee80211_local *local) -{ - /* start WEP IV from a random value */ - get_random_bytes(&local->wep_iv, WEP_IV_LEN); - - local->wep_tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, - CRYPTO_ALG_ASYNC); - if (IS_ERR(local->wep_tx_tfm)) - return -ENOMEM; - - local->wep_rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, - CRYPTO_ALG_ASYNC); - if (IS_ERR(local->wep_rx_tfm)) { - crypto_free_blkcipher(local->wep_tx_tfm); - return -ENOMEM; - } - - return 0; -} - -void ieee80211_wep_free(struct ieee80211_local *local) -{ - crypto_free_blkcipher(local->wep_tx_tfm); - crypto_free_blkcipher(local->wep_rx_tfm); -} - -static inline int ieee80211_wep_weak_iv(u32 iv, int keylen) -{ - /* 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 ((iv & 0xff00) == 0xff00) { - u8 B = (iv >> 16) & 0xff; - if (B >= 3 && B < 3 + keylen) - return 1; - } - return 0; -} - - -void ieee80211_wep_get_iv(struct ieee80211_local *local, - struct ieee80211_key *key, u8 *iv) -{ - local->wep_iv++; - if (ieee80211_wep_weak_iv(local->wep_iv, key->keylen)) - local->wep_iv += 0x0100; - - if (!iv) - return; - - *iv++ = (local->wep_iv >> 16) & 0xff; - *iv++ = (local->wep_iv >> 8) & 0xff; - *iv++ = local->wep_iv & 0xff; - *iv++ = key->keyidx << 6; -} - - -u8 * ieee80211_wep_add_iv(struct ieee80211_local *local, - struct sk_buff *skb, - struct ieee80211_key *key) -{ - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - u16 fc; - int hdrlen; - u8 *newhdr; - - fc = le16_to_cpu(hdr->frame_control); - fc |= IEEE80211_FCTL_PROTECTED; - hdr->frame_control = cpu_to_le16(fc); - - if ((skb_headroom(skb) < WEP_IV_LEN || - skb_tailroom(skb) < WEP_ICV_LEN)) { - I802_DEBUG_INC(local->tx_expand_skb_head); - if (unlikely(pskb_expand_head(skb, WEP_IV_LEN, WEP_ICV_LEN, - GFP_ATOMIC))) - return NULL; - } - - hdrlen = ieee80211_get_hdrlen(fc); - newhdr = skb_push(skb, WEP_IV_LEN); - memmove(newhdr, newhdr + WEP_IV_LEN, hdrlen); - ieee80211_wep_get_iv(local, key, newhdr + hdrlen); - return newhdr + hdrlen; -} - - -void ieee80211_wep_remove_iv(struct ieee80211_local *local, - struct sk_buff *skb, - struct ieee80211_key *key) -{ - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - u16 fc; - int hdrlen; - - fc = le16_to_cpu(hdr->frame_control); - hdrlen = ieee80211_get_hdrlen(fc); - memmove(skb->data + WEP_IV_LEN, skb->data, hdrlen); - skb_pull(skb, WEP_IV_LEN); -} - - -/* 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)) */ -void ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key, - size_t klen, u8 *data, size_t data_len) -{ - struct blkcipher_desc desc = { .tfm = tfm }; - struct scatterlist sg; - __le32 *icv; - - icv = (__le32 *)(data + data_len); - *icv = cpu_to_le32(~crc32_le(~0, data, data_len)); - - crypto_blkcipher_setkey(tfm, rc4key, klen); - sg.page = virt_to_page(data); - sg.offset = offset_in_page(data); - sg.length = data_len + WEP_ICV_LEN; - crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length); -} - - -/* 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, - struct ieee80211_key *key) -{ - u32 klen; - u8 *rc4key, *iv; - size_t len; - - if (!key || key->alg != ALG_WEP) - return -1; - - klen = 3 + key->keylen; - rc4key = kmalloc(klen, GFP_ATOMIC); - if (!rc4key) - return -1; - - iv = ieee80211_wep_add_iv(local, skb, key); - if (!iv) { - kfree(rc4key); - return -1; - } - - len = skb->len - (iv + WEP_IV_LEN - skb->data); - - /* Prepend 24-bit IV to RC4 key */ - memcpy(rc4key, iv, 3); - - /* Copy rest of the WEP key (the secret part) */ - memcpy(rc4key + 3, key->key, key->keylen); - - /* Add room for ICV */ - skb_put(skb, WEP_ICV_LEN); - - ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, klen, - iv + WEP_IV_LEN, len); - - kfree(rc4key); - - return 0; -} - - -/* 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 crypto_blkcipher *tfm, u8 *rc4key, - size_t klen, u8 *data, size_t data_len) -{ - struct blkcipher_desc desc = { .tfm = tfm }; - struct scatterlist sg; - __le32 crc; - - crypto_blkcipher_setkey(tfm, rc4key, klen); - sg.page = virt_to_page(data); - sg.offset = offset_in_page(data); - sg.length = data_len + WEP_ICV_LEN; - crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length); - - crc = cpu_to_le32(~crc32_le(~0, data, data_len)); - if (memcmp(&crc, data + data_len, WEP_ICV_LEN) != 0) - /* ICV mismatch */ - return -1; - - return 0; -} - - -/* 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. - */ -int ieee80211_wep_decrypt(struct ieee80211_local *local, struct sk_buff *skb, - struct ieee80211_key *key) -{ - u32 klen; - u8 *rc4key; - u8 keyidx; - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - u16 fc; - int hdrlen; - size_t len; - int ret = 0; - - fc = le16_to_cpu(hdr->frame_control); - if (!(fc & IEEE80211_FCTL_PROTECTED)) - return -1; - - hdrlen = ieee80211_get_hdrlen(fc); - - if (skb->len < 8 + hdrlen) - return -1; - - len = skb->len - hdrlen - 8; - - keyidx = skb->data[hdrlen + 3] >> 6; - - if (!key || keyidx != key->keyidx || key->alg != ALG_WEP) - return -1; - - klen = 3 + key->keylen; - - rc4key = kmalloc(klen, GFP_ATOMIC); - if (!rc4key) - return -1; - - /* Prepend 24-bit IV to RC4 key */ - memcpy(rc4key, skb->data + hdrlen, 3); - - /* Copy rest of the WEP key (the secret part) */ - memcpy(rc4key + 3, key->key, key->keylen); - - if (ieee80211_wep_decrypt_data(local->wep_rx_tfm, rc4key, klen, - skb->data + hdrlen + WEP_IV_LEN, - len)) { - printk(KERN_DEBUG "WEP decrypt failed (ICV)\n"); - ret = -1; - } - - kfree(rc4key); - - /* Trim ICV */ - skb_trim(skb, skb->len - WEP_ICV_LEN); - - /* Remove IV */ - memmove(skb->data + WEP_IV_LEN, skb->data, hdrlen); - skb_pull(skb, WEP_IV_LEN); - - return ret; -} - - -int ieee80211_wep_get_keyidx(struct sk_buff *skb) -{ - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - u16 fc; - int hdrlen; - - fc = le16_to_cpu(hdr->frame_control); - if (!(fc & IEEE80211_FCTL_PROTECTED)) - return -1; - - hdrlen = ieee80211_get_hdrlen(fc); - - if (skb->len < 8 + hdrlen) - return -1; - - return skb->data[hdrlen + 3] >> 6; -} - - -u8 * ieee80211_wep_is_weak_iv(struct sk_buff *skb, struct ieee80211_key *key) -{ - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - u16 fc; - int hdrlen; - u8 *ivpos; - u32 iv; - - fc = le16_to_cpu(hdr->frame_control); - if (!(fc & IEEE80211_FCTL_PROTECTED)) - return NULL; - - hdrlen = ieee80211_get_hdrlen(fc); - ivpos = skb->data + hdrlen; - iv = (ivpos[0] << 16) | (ivpos[1] << 8) | ivpos[2]; - - if (ieee80211_wep_weak_iv(iv, key->keylen)) - return ivpos; - - return NULL; -} |