diff options
Diffstat (limited to 'net/ieee80211/ieee80211_crypt_ccmp.c')
| -rw-r--r-- | net/ieee80211/ieee80211_crypt_ccmp.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/net/ieee80211/ieee80211_crypt_ccmp.c b/net/ieee80211/ieee80211_crypt_ccmp.c index fdfe7704a469..35aa3426c3fa 100644 --- a/net/ieee80211/ieee80211_crypt_ccmp.c +++ b/net/ieee80211/ieee80211_crypt_ccmp.c @@ -263,6 +263,27 @@ static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv) return 0; } +/* + * deal with seq counter wrapping correctly. + * refer to timer_after() for jiffies wrapping handling + */ +static inline int ccmp_replay_check(u8 *pn_n, u8 *pn_o) +{ + u32 iv32_n, iv16_n; + u32 iv32_o, iv16_o; + + iv32_n = (pn_n[0] << 24) | (pn_n[1] << 16) | (pn_n[2] << 8) | pn_n[3]; + iv16_n = (pn_n[4] << 8) | pn_n[5]; + + iv32_o = (pn_o[0] << 24) | (pn_o[1] << 16) | (pn_o[2] << 8) | pn_o[3]; + iv16_o = (pn_o[4] << 8) | pn_o[5]; + + if ((s32)iv32_n - (s32)iv32_o < 0 || + (iv32_n == iv32_o && iv16_n <= iv16_o)) + return 1; + return 0; +} + static int ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv) { struct ieee80211_ccmp_data *key = priv; @@ -315,7 +336,7 @@ static int ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv) pn[5] = pos[0]; pos += 8; - if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) { + if (ccmp_replay_check(pn, key->rx_pn)) { if (net_ratelimit()) { printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT " previous PN %02x%02x%02x%02x%02x%02x " |