1 files changed, 104 insertions, 0 deletions

diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c
new file mode 100644
index 000000000000..0f844f7895f1
--- /dev/null
+++ b/net/mac80211/michael.c
@@ -0,0 +1,104 @@
+/*
+ * Michael MIC implementation - optimized for TKIP MIC operations
+ * Copyright 2002-2003, Instant802 Networks, Inc.
+ *
+ * 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
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+
+#include "michael.h"
+
+static inline u32 rotr(u32 val, int bits)
+{
+        return (val >> bits) | (val << (32 - bits));
+}
+
+
+static inline u32 rotl(u32 val, int bits)
+{
+        return (val << bits) | (val >> (32 - bits));
+}
+
+
+static inline u32 xswap(u32 val)
+{
+        return ((val & 0xff00ff00) >> 8) | ((val & 0x00ff00ff) << 8);
+}
+
+
+#define michael_block(l, r) \
+do { \
+        r ^= rotl(l, 17); \
+        l += r; \
+        r ^= xswap(l); \
+        l += r; \
+        r ^= rotl(l, 3); \
+        l += r; \
+        r ^= rotr(l, 2); \
+        l += r; \
+} while (0)
+
+
+static inline u32 michael_get32(u8 *data)
+{
+        return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
+}
+
+
+static inline void michael_put32(u32 val, u8 *data)
+{
+        data[0] = val & 0xff;
+        data[1] = (val >> 8) & 0xff;
+        data[2] = (val >> 16) & 0xff;
+        data[3] = (val >> 24) & 0xff;
+}
+
+
+void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
+                 u8 *data, size_t data_len, u8 *mic)
+{
+        u32 l, r, val;
+        size_t block, blocks, left;
+
+        l = michael_get32(key);
+        r = michael_get32(key + 4);
+
+        /* 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 ^= da[4] | (da[5] << 8) | (sa[0] << 16) | (sa[1] << 24);
+        michael_block(l, r);
+        l ^= michael_get32(&sa[2]);
+        michael_block(l, r);
+        l ^= priority;
+        michael_block(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);
+        }
+
+        /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make
+         * total length a multiple of 4. */
+        val = 0x5a;
+        while (left > 0) {
+                val <<= 8;
+                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_put32(l, mic);
+        michael_put32(r, mic + 4);
+}