cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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michael_mic.c (3450B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Cryptographic API
      4 *
      5 * Michael MIC (IEEE 802.11i/TKIP) keyed digest
      6 *
      7 * Copyright (c) 2004 Jouni Malinen <j@w1.fi>
      8 */
      9#include <crypto/internal/hash.h>
     10#include <asm/unaligned.h>
     11#include <linux/init.h>
     12#include <linux/module.h>
     13#include <linux/string.h>
     14#include <linux/types.h>
     15
     16
     17struct michael_mic_ctx {
     18	u32 l, r;
     19};
     20
     21struct michael_mic_desc_ctx {
     22	__le32 pending;
     23	size_t pending_len;
     24
     25	u32 l, r;
     26};
     27
     28static inline u32 xswap(u32 val)
     29{
     30	return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
     31}
     32
     33
     34#define michael_block(l, r)	\
     35do {				\
     36	r ^= rol32(l, 17);	\
     37	l += r;			\
     38	r ^= xswap(l);		\
     39	l += r;			\
     40	r ^= rol32(l, 3);	\
     41	l += r;			\
     42	r ^= ror32(l, 2);	\
     43	l += r;			\
     44} while (0)
     45
     46
     47static int michael_init(struct shash_desc *desc)
     48{
     49	struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc);
     50	struct michael_mic_ctx *ctx = crypto_shash_ctx(desc->tfm);
     51	mctx->pending_len = 0;
     52	mctx->l = ctx->l;
     53	mctx->r = ctx->r;
     54
     55	return 0;
     56}
     57
     58
     59static int michael_update(struct shash_desc *desc, const u8 *data,
     60			   unsigned int len)
     61{
     62	struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc);
     63
     64	if (mctx->pending_len) {
     65		int flen = 4 - mctx->pending_len;
     66		if (flen > len)
     67			flen = len;
     68		memcpy((u8 *)&mctx->pending + mctx->pending_len, data, flen);
     69		mctx->pending_len += flen;
     70		data += flen;
     71		len -= flen;
     72
     73		if (mctx->pending_len < 4)
     74			return 0;
     75
     76		mctx->l ^= le32_to_cpu(mctx->pending);
     77		michael_block(mctx->l, mctx->r);
     78		mctx->pending_len = 0;
     79	}
     80
     81	while (len >= 4) {
     82		mctx->l ^= get_unaligned_le32(data);
     83		michael_block(mctx->l, mctx->r);
     84		data += 4;
     85		len -= 4;
     86	}
     87
     88	if (len > 0) {
     89		mctx->pending_len = len;
     90		memcpy(&mctx->pending, data, len);
     91	}
     92
     93	return 0;
     94}
     95
     96
     97static int michael_final(struct shash_desc *desc, u8 *out)
     98{
     99	struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc);
    100	u8 *data = (u8 *)&mctx->pending;
    101
    102	/* Last block and padding (0x5a, 4..7 x 0) */
    103	switch (mctx->pending_len) {
    104	case 0:
    105		mctx->l ^= 0x5a;
    106		break;
    107	case 1:
    108		mctx->l ^= data[0] | 0x5a00;
    109		break;
    110	case 2:
    111		mctx->l ^= data[0] | (data[1] << 8) | 0x5a0000;
    112		break;
    113	case 3:
    114		mctx->l ^= data[0] | (data[1] << 8) | (data[2] << 16) |
    115			0x5a000000;
    116		break;
    117	}
    118	michael_block(mctx->l, mctx->r);
    119	/* l ^= 0; */
    120	michael_block(mctx->l, mctx->r);
    121
    122	put_unaligned_le32(mctx->l, out);
    123	put_unaligned_le32(mctx->r, out + 4);
    124
    125	return 0;
    126}
    127
    128
    129static int michael_setkey(struct crypto_shash *tfm, const u8 *key,
    130			  unsigned int keylen)
    131{
    132	struct michael_mic_ctx *mctx = crypto_shash_ctx(tfm);
    133
    134	if (keylen != 8)
    135		return -EINVAL;
    136
    137	mctx->l = get_unaligned_le32(key);
    138	mctx->r = get_unaligned_le32(key + 4);
    139	return 0;
    140}
    141
    142static struct shash_alg alg = {
    143	.digestsize		=	8,
    144	.setkey			=	michael_setkey,
    145	.init			=	michael_init,
    146	.update			=	michael_update,
    147	.final			=	michael_final,
    148	.descsize		=	sizeof(struct michael_mic_desc_ctx),
    149	.base			=	{
    150		.cra_name		=	"michael_mic",
    151		.cra_driver_name	=	"michael_mic-generic",
    152		.cra_blocksize		=	8,
    153		.cra_ctxsize		=	sizeof(struct michael_mic_ctx),
    154		.cra_module		=	THIS_MODULE,
    155	}
    156};
    157
    158static int __init michael_mic_init(void)
    159{
    160	return crypto_register_shash(&alg);
    161}
    162
    163
    164static void __exit michael_mic_exit(void)
    165{
    166	crypto_unregister_shash(&alg);
    167}
    168
    169
    170subsys_initcall(michael_mic_init);
    171module_exit(michael_mic_exit);
    172
    173MODULE_LICENSE("GPL v2");
    174MODULE_DESCRIPTION("Michael MIC");
    175MODULE_AUTHOR("Jouni Malinen <j@w1.fi>");
    176MODULE_ALIAS_CRYPTO("michael_mic");