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	Based on 2 normalized pattern(s): 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
		
			
				
	
	
		
			83 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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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#include <linux/types.h>
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#include <linux/bitops.h>
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#include <linux/ieee80211.h>
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#include <asm/unaligned.h>
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#include "michael.h"
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static void michael_block(struct michael_mic_ctx *mctx, u32 val)
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{
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	mctx->l ^= val;
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	mctx->r ^= rol32(mctx->l, 17);
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	mctx->l += mctx->r;
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	mctx->r ^= ((mctx->l & 0xff00ff00) >> 8) |
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		   ((mctx->l & 0x00ff00ff) << 8);
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	mctx->l += mctx->r;
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	mctx->r ^= rol32(mctx->l, 3);
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	mctx->l += mctx->r;
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	mctx->r ^= ror32(mctx->l, 2);
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	mctx->l += mctx->r;
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}
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static void michael_mic_hdr(struct michael_mic_ctx *mctx, const u8 *key,
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			    struct ieee80211_hdr *hdr)
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{
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	u8 *da, *sa, tid;
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	da = ieee80211_get_DA(hdr);
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	sa = ieee80211_get_SA(hdr);
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	if (ieee80211_is_data_qos(hdr->frame_control))
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		tid = ieee80211_get_tid(hdr);
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	else
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		tid = 0;
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	mctx->l = get_unaligned_le32(key);
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	mctx->r = get_unaligned_le32(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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	 */
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	michael_block(mctx, get_unaligned_le32(da));
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	michael_block(mctx, get_unaligned_le16(&da[4]) |
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			    (get_unaligned_le16(sa) << 16));
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	michael_block(mctx, get_unaligned_le32(&sa[2]));
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	michael_block(mctx, tid);
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}
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void michael_mic(const u8 *key, struct ieee80211_hdr *hdr,
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		 const u8 *data, size_t data_len, u8 *mic)
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{
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	u32 val;
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	size_t block, blocks, left;
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	struct michael_mic_ctx mctx;
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	michael_mic_hdr(&mctx, key, hdr);
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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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	for (block = 0; block < blocks; block++)
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		michael_block(&mctx, get_unaligned_le32(&data[block * 4]));
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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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	michael_block(&mctx, val);
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	michael_block(&mctx, 0);
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	put_unaligned_le32(mctx.l, mic);
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	put_unaligned_le32(mctx.r, mic + 4);
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}
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