diff options
Diffstat (limited to 'net/wireless')
| -rw-r--r-- | net/wireless/Makefile | 2 | ||||
| -rw-r--r-- | net/wireless/michael-mic.c | 86 |
2 files changed, 87 insertions, 1 deletions
diff --git a/net/wireless/Makefile b/net/wireless/Makefile index 62a83faf0e07..a77fd5ba6368 100644 --- a/net/wireless/Makefile +++ b/net/wireless/Makefile @@ -8,7 +8,7 @@ obj-$(CONFIG_WEXT_PRIV) += wext-priv.o cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o cfg80211-y += mlme.o ibss.o sme.o chan.o ethtool.o mesh.o ap.o trace.o ocb.o -cfg80211-y += pmsr.o +cfg80211-y += michael-mic.o pmsr.o cfg80211-$(CONFIG_OF) += of.o cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o cfg80211-$(CONFIG_CFG80211_WEXT) += wext-compat.o wext-sme.o diff --git a/net/wireless/michael-mic.c b/net/wireless/michael-mic.c new file mode 100644 index 000000000000..50cdb67f0503 --- /dev/null +++ b/net/wireless/michael-mic.c @@ -0,0 +1,86 @@ +// 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/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); |