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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788// SPDX-License-Identifier: GPL-2.0-only/* * Michael MIC implementation - optimized for TKIP MIC operations * Copyright 2002-2003, Instant802 Networks, Inc. */#include <linux/types.h>#include <linux/bitops.h>#include <linux/export.h>#include <linux/ieee80211.h>#include <linux/unaligned.h>
struct michael_mic_ctx { u32 l, r;};
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, const u8 *key, struct ieee80211_hdr *hdr){ u8 *da, *sa, tid;
da = ieee80211_get_DA(hdr); sa = ieee80211_get_SA(hdr); if (ieee80211_is_data_qos(hdr->frame_control)) tid = ieee80211_get_tid(hdr); else tid = 0;
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, tid);}
void michael_mic(const u8 *key, struct ieee80211_hdr *hdr, const u8 *data, size_t data_len, u8 *mic){ u32 val; size_t block, blocks, left; struct michael_mic_ctx mctx;
michael_mic_hdr(&mctx, key, hdr);
/* Real data */ blocks = data_len / 4; left = data_len % 4;
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. */ val = 0x5a; while (left > 0) { val <<= 8; left--; val |= data[blocks * 4 + left]; }
michael_block(&mctx, val); michael_block(&mctx, 0);
put_unaligned_le32(mctx.l, mic); put_unaligned_le32(mctx.r, mic + 4);}EXPORT_SYMBOL_GPL(michael_mic);