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	 f0706e828e
			
		
	
	
		f0706e828e
		
	
	
	
	
		
			
			Add mac80211, the IEEE 802.11 software MAC layer. Signed-off-by: Jiri Benc <jbenc@suse.cz> Signed-off-by: John W. Linville <linville@tuxdriver.com>
		
			
				
	
	
		
			105 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			105 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Michael MIC implementation - optimized for TKIP MIC operations
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|  * Copyright 2002-2003, Instant802 Networks, Inc.
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  */
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| 
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| #include <linux/types.h>
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| 
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| #include "michael.h"
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| 
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| static inline u32 rotr(u32 val, int bits)
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| {
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| 	return (val >> bits) | (val << (32 - bits));
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| }
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| 
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| 
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| static inline u32 rotl(u32 val, int bits)
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| {
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| 	return (val << bits) | (val >> (32 - bits));
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| }
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| 
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| 
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| static inline u32 xswap(u32 val)
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| {
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| 	return ((val & 0xff00ff00) >> 8) | ((val & 0x00ff00ff) << 8);
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| }
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| 
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| 
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| #define michael_block(l, r) \
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| do { \
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| 	r ^= rotl(l, 17); \
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| 	l += r; \
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| 	r ^= xswap(l); \
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| 	l += r; \
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| 	r ^= rotl(l, 3); \
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| 	l += r; \
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| 	r ^= rotr(l, 2); \
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| 	l += r; \
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| } while (0)
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| 
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| 
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| static inline u32 michael_get32(u8 *data)
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| {
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| 	return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
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| }
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| 
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| 
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| static inline void michael_put32(u32 val, u8 *data)
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| {
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| 	data[0] = val & 0xff;
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| 	data[1] = (val >> 8) & 0xff;
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| 	data[2] = (val >> 16) & 0xff;
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| 	data[3] = (val >> 24) & 0xff;
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| }
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| 
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| 
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| void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
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| 		 u8 *data, size_t data_len, u8 *mic)
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| {
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| 	u32 l, r, val;
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| 	size_t block, blocks, left;
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| 
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| 	l = michael_get32(key);
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| 	r = michael_get32(key + 4);
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| 
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| 	/* A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC
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| 	 * calculation, but it is _not_ transmitted */
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| 	l ^= michael_get32(da);
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| 	michael_block(l, r);
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| 	l ^= da[4] | (da[5] << 8) | (sa[0] << 16) | (sa[1] << 24);
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| 	michael_block(l, r);
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| 	l ^= michael_get32(&sa[2]);
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| 	michael_block(l, r);
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| 	l ^= priority;
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| 	michael_block(l, r);
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| 
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| 	/* Real data */
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| 	blocks = data_len / 4;
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| 	left = data_len % 4;
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| 
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| 	for (block = 0; block < blocks; block++) {
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| 		l ^= michael_get32(&data[block * 4]);
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| 		michael_block(l, r);
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| 	}
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| 
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| 	/* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make
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| 	 * total length a multiple of 4. */
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| 	val = 0x5a;
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| 	while (left > 0) {
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| 		val <<= 8;
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| 		left--;
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| 		val |= data[blocks * 4 + left];
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| 	}
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| 	l ^= val;
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| 	michael_block(l, r);
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| 	/* last block is zero, so l ^ 0 = l */
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| 	michael_block(l, r);
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| 
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| 	michael_put32(l, mic);
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| 	michael_put32(r, mic + 4);
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| }
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