diff options
Diffstat (limited to 'net/mac80211/michael.c')
| -rw-r--r-- | net/mac80211/michael.c | 75 |
1 files changed, 40 insertions, 35 deletions
diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c index c1e5897fcf7..4e151e0caeb 100644 --- a/net/mac80211/michael.c +++ b/net/mac80211/michael.c @@ -13,46 +13,52 @@ #include "michael.h" -#define michael_block(l, r) \ -do { \ - r ^= rol32(l, 17); \ - l += r; \ - r ^= ((l & 0xff00ff00) >> 8) | ((l & 0x00ff00ff) << 8); \ - l += r; \ - r ^= rol32(l, 3); \ - l += r; \ - r ^= ror32(l, 2); \ - l += r; \ -} while (0) +static void michael_block(struct michael_mic_ctx *mctx, u32 val) +{ + mctx->l ^= val; + mctx->r ^= rol32(mctx->l, 17); + mctx->l += mctx->r; + mctx->r ^= ((mctx->l & 0xff00ff00) >> 8) | + ((mctx->l & 0x00ff00ff) << 8); + mctx->l += mctx->r; + mctx->r ^= rol32(mctx->l, 3); + mctx->l += mctx->r; + mctx->r ^= ror32(mctx->l, 2); + mctx->l += mctx->r; +} + +static void michael_mic_hdr(struct michael_mic_ctx *mctx, + u8 *key, u8 *da, u8 *sa, u8 priority) +{ + mctx->l = get_unaligned_le32(key); + mctx->r = get_unaligned_le32(key + 4); + + /* + * A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC + * calculation, but it is _not_ transmitted + */ + michael_block(mctx, get_unaligned_le32(da)); + michael_block(mctx, get_unaligned_le16(&da[4]) | + (get_unaligned_le16(sa) << 16)); + michael_block(mctx, get_unaligned_le32(&sa[2])); + michael_block(mctx, priority); +} void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority, u8 *data, size_t data_len, u8 *mic) { - u32 l, r, val; + u32 val; size_t block, blocks, left; + struct michael_mic_ctx mctx; - l = get_unaligned_le32(key); - r = get_unaligned_le32(key + 4); - - /* A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC - * calculation, but it is _not_ transmitted */ - l ^= get_unaligned_le32(da); - michael_block(l, r); - l ^= get_unaligned_le16(&da[4]) | (get_unaligned_le16(sa) << 16); - michael_block(l, r); - l ^= get_unaligned_le32(&sa[2]); - michael_block(l, r); - l ^= priority; - michael_block(l, r); + michael_mic_hdr(&mctx, key, da, sa, priority); /* Real data */ blocks = data_len / 4; left = data_len % 4; - for (block = 0; block < blocks; block++) { - l ^= get_unaligned_le32(&data[block * 4]); - michael_block(l, r); - } + for (block = 0; block < blocks; block++) + michael_block(&mctx, get_unaligned_le32(&data[block * 4])); /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make * total length a multiple of 4. */ @@ -62,11 +68,10 @@ 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); - put_unaligned_le32(l, mic); - put_unaligned_le32(r, mic + 4); + michael_block(&mctx, val); + michael_block(&mctx, 0); + + put_unaligned_le32(mctx.l, mic); + put_unaligned_le32(mctx.r, mic + 4); } |