2008-03-25 23:12:51

by Harvey Harrison

[permalink] [raw]
Subject: [PATCH 3/3] mac80211: michael.c fold initial xor into block helper

Signed-off-by: Harvey Harrison <[email protected]>
---
net/mac80211/michael.c | 27 ++++++++++-----------------
1 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c
index 76940be..36bb3bb 100644
--- a/net/mac80211/michael.c
+++ b/net/mac80211/michael.c
@@ -14,8 +14,9 @@

#include "michael.h"

-static void michael_block(u32 *l, u32 *r)
+static void michael_block(u32 val, u32 *l, u32 *r)
{
+ *l ^= val;
*r ^= rol32(*l, 17);
*l += *r;
*r ^= ((*l & 0xff00ff00) >> 8) | ((*l & 0x00ff00ff) << 8);
@@ -52,23 +53,17 @@ void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,

/* A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC
* calculation, but it is _not_ transmitted */
- l ^= michael_get32(da);
- michael_block(&l, &r);
- l ^= michael_get16(da) | (michael_get16(sa) << 16);
- michael_block(&l, &r);
- l ^= michael_get32(&sa[2]);
- michael_block(&l, &r);
- l ^= priority;
- michael_block(&l, &r);
+ michael_block(michael_get32(da), &l, &r);
+ michael_block(michael_get16(da) | (michael_get16(sa) << 16), &l, &r);
+ michael_block(michael_get32(&sa[2]), &l, &r);
+ michael_block(priority, &l, &r);

/* Real data */
blocks = data_len / 4;
left = data_len % 4;

- for (block = 0; block < blocks; block++) {
- l ^= michael_get32(&data[block * 4]);
- michael_block(&l, &r);
- }
+ for (block = 0; block < blocks; block++)
+ michael_block(michael_get32(&data[block * 4]), &l, &r);

/* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make
* total length a multiple of 4. */
@@ -78,10 +73,8 @@ void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
left--;
val |= data[blocks * 4 + left];
}
- l ^= val;
- michael_block(&l, &r);
- /* last block is zero, so l ^ 0 = l */
- michael_block(&l, &r);
+ michael_block(val, &l, &r);
+ michael_block(0, &l, &r);

michael_put32(l, mic);
michael_put32(r, mic + 4);
--
1.5.5.rc0.139.g9315d