diff options
Diffstat (limited to 'net/ieee80211/ieee80211_crypt_wep.c')
-rw-r--r-- | net/ieee80211/ieee80211_crypt_wep.c | 61 |
1 files changed, 43 insertions, 18 deletions
diff --git a/net/ieee80211/ieee80211_crypt_wep.c b/net/ieee80211/ieee80211_crypt_wep.c index 073aebdf0f6..f8dca31be5d 100644 --- a/net/ieee80211/ieee80211_crypt_wep.c +++ b/net/ieee80211/ieee80211_crypt_wep.c @@ -75,22 +75,14 @@ static void prism2_wep_deinit(void *priv) 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) +/* Add WEP IV/key info to a frame that has at least 4 bytes of headroom */ +static int prism2_wep_build_iv(struct sk_buff *skb, int hdr_len, void *priv) { struct prism2_wep_data *wep = priv; - u32 crc, klen, len; - u8 key[WEP_KEY_LEN + 3]; - u8 *pos, *icv; - struct scatterlist sg; - - if (skb_headroom(skb) < 4 || skb_tailroom(skb) < 4 || - skb->len < hdr_len) + u32 klen, len; + u8 *pos; + + if (skb_headroom(skb) < 4 || skb->len < hdr_len) return -1; len = skb->len - hdr_len; @@ -112,15 +104,47 @@ static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv) } /* 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->iv >> 16) & 0xff; + *pos++ = (wep->iv >> 8) & 0xff; + *pos++ = wep->iv & 0xff; *pos++ = wep->key_idx << 6; + return 0; +} + +/* 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 crc, klen, len; + u8 *pos, *icv; + struct scatterlist sg; + u8 key[WEP_KEY_LEN + 3]; + + /* other checks are in prism2_wep_build_iv */ + if (skb_tailroom(skb) < 4) + return -1; + + /* add the IV to the frame */ + if (prism2_wep_build_iv(skb, hdr_len, priv)) + return -1; + + /* Copy the IV into the first 3 bytes of the key */ + memcpy(key, skb->data + hdr_len, 3); + /* Copy rest of the WEP key (the secret part) */ memcpy(key + 3, wep->key, wep->key_len); + + len = skb->len - hdr_len - 4; + pos = skb->data + hdr_len + 4; + klen = 3 + wep->key_len; - /* Append little-endian CRC32 and encrypt it to produce ICV */ + /* Append little-endian CRC32 over only the data and encrypt it to produce ICV */ crc = ~crc32_le(~0, pos, len); icv = skb_put(skb, 4); icv[0] = crc; @@ -231,6 +255,7 @@ static struct ieee80211_crypto_ops ieee80211_crypt_wep = { .name = "WEP", .init = prism2_wep_init, .deinit = prism2_wep_deinit, + .build_iv = prism2_wep_build_iv, .encrypt_mpdu = prism2_wep_encrypt, .decrypt_mpdu = prism2_wep_decrypt, .encrypt_msdu = NULL, |