[PATCH] Update my email address from jkmaline@cc.hut.fi to j@w1.fi

[powerpc.git] / net / ieee80211 / ieee80211_crypt_ccmp.c

diff --git a/net/ieee80211/ieee80211_crypt_ccmp.c b/net/ieee80211/ieee80211_crypt_ccmp.c
index fdfe770..7ec8314 100644 (file)
--- a/net/ieee80211/ieee80211_crypt_ccmp.c
+++ b/net/ieee80211/ieee80211_crypt_ccmp.c
@@ -1,7 +1,7 @@
 /*
  * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
  *
- * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright (c) 2003-2004, Jouni Malinen <j@w1.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
@@ -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 "