mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
e1b2d980f0
The Michael MIC driver uses the cra_alignmask to ensure that pointers presented to its update and finup/final methods are 32-bit aligned. However, due to the way the shash API works, this is no guarantee that the 32-bit reads occurring in the update method are also aligned, as the size of the buffer presented to update may be of uneven length. For instance, an update() of 3 bytes followed by a misaligned update() of 4 or more bytes will result in a misaligned access using an accessor that is not suitable for this. On most architectures, this does not matter, and so setting the cra_alignmask is pointless. On architectures where this does matter, setting the cra_alignmask does not actually solve the problem. So let's get rid of the cra_alignmask, and use unaligned accessors instead, where appropriate. Cc: <stable@vger.kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
176 lines
3.4 KiB
C
176 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Cryptographic API
|
|
*
|
|
* Michael MIC (IEEE 802.11i/TKIP) keyed digest
|
|
*
|
|
* Copyright (c) 2004 Jouni Malinen <j@w1.fi>
|
|
*/
|
|
#include <crypto/internal/hash.h>
|
|
#include <asm/unaligned.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/string.h>
|
|
#include <linux/types.h>
|
|
|
|
|
|
struct michael_mic_ctx {
|
|
u32 l, r;
|
|
};
|
|
|
|
struct michael_mic_desc_ctx {
|
|
__le32 pending;
|
|
size_t pending_len;
|
|
|
|
u32 l, r;
|
|
};
|
|
|
|
static inline u32 xswap(u32 val)
|
|
{
|
|
return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
|
|
}
|
|
|
|
|
|
#define michael_block(l, r) \
|
|
do { \
|
|
r ^= rol32(l, 17); \
|
|
l += r; \
|
|
r ^= xswap(l); \
|
|
l += r; \
|
|
r ^= rol32(l, 3); \
|
|
l += r; \
|
|
r ^= ror32(l, 2); \
|
|
l += r; \
|
|
} while (0)
|
|
|
|
|
|
static int michael_init(struct shash_desc *desc)
|
|
{
|
|
struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc);
|
|
struct michael_mic_ctx *ctx = crypto_shash_ctx(desc->tfm);
|
|
mctx->pending_len = 0;
|
|
mctx->l = ctx->l;
|
|
mctx->r = ctx->r;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int michael_update(struct shash_desc *desc, const u8 *data,
|
|
unsigned int len)
|
|
{
|
|
struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc);
|
|
|
|
if (mctx->pending_len) {
|
|
int flen = 4 - mctx->pending_len;
|
|
if (flen > len)
|
|
flen = len;
|
|
memcpy((u8 *)&mctx->pending + mctx->pending_len, data, flen);
|
|
mctx->pending_len += flen;
|
|
data += flen;
|
|
len -= flen;
|
|
|
|
if (mctx->pending_len < 4)
|
|
return 0;
|
|
|
|
mctx->l ^= le32_to_cpu(mctx->pending);
|
|
michael_block(mctx->l, mctx->r);
|
|
mctx->pending_len = 0;
|
|
}
|
|
|
|
while (len >= 4) {
|
|
mctx->l ^= get_unaligned_le32(data);
|
|
michael_block(mctx->l, mctx->r);
|
|
data += 4;
|
|
len -= 4;
|
|
}
|
|
|
|
if (len > 0) {
|
|
mctx->pending_len = len;
|
|
memcpy(&mctx->pending, data, len);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int michael_final(struct shash_desc *desc, u8 *out)
|
|
{
|
|
struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc);
|
|
u8 *data = (u8 *)&mctx->pending;
|
|
|
|
/* Last block and padding (0x5a, 4..7 x 0) */
|
|
switch (mctx->pending_len) {
|
|
case 0:
|
|
mctx->l ^= 0x5a;
|
|
break;
|
|
case 1:
|
|
mctx->l ^= data[0] | 0x5a00;
|
|
break;
|
|
case 2:
|
|
mctx->l ^= data[0] | (data[1] << 8) | 0x5a0000;
|
|
break;
|
|
case 3:
|
|
mctx->l ^= data[0] | (data[1] << 8) | (data[2] << 16) |
|
|
0x5a000000;
|
|
break;
|
|
}
|
|
michael_block(mctx->l, mctx->r);
|
|
/* l ^= 0; */
|
|
michael_block(mctx->l, mctx->r);
|
|
|
|
put_unaligned_le32(mctx->l, out);
|
|
put_unaligned_le32(mctx->r, out + 4);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int michael_setkey(struct crypto_shash *tfm, const u8 *key,
|
|
unsigned int keylen)
|
|
{
|
|
struct michael_mic_ctx *mctx = crypto_shash_ctx(tfm);
|
|
|
|
if (keylen != 8)
|
|
return -EINVAL;
|
|
|
|
mctx->l = get_unaligned_le32(key);
|
|
mctx->r = get_unaligned_le32(key + 4);
|
|
return 0;
|
|
}
|
|
|
|
static struct shash_alg alg = {
|
|
.digestsize = 8,
|
|
.setkey = michael_setkey,
|
|
.init = michael_init,
|
|
.update = michael_update,
|
|
.final = michael_final,
|
|
.descsize = sizeof(struct michael_mic_desc_ctx),
|
|
.base = {
|
|
.cra_name = "michael_mic",
|
|
.cra_driver_name = "michael_mic-generic",
|
|
.cra_blocksize = 8,
|
|
.cra_ctxsize = sizeof(struct michael_mic_ctx),
|
|
.cra_module = THIS_MODULE,
|
|
}
|
|
};
|
|
|
|
static int __init michael_mic_init(void)
|
|
{
|
|
return crypto_register_shash(&alg);
|
|
}
|
|
|
|
|
|
static void __exit michael_mic_exit(void)
|
|
{
|
|
crypto_unregister_shash(&alg);
|
|
}
|
|
|
|
|
|
subsys_initcall(michael_mic_init);
|
|
module_exit(michael_mic_exit);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_DESCRIPTION("Michael MIC");
|
|
MODULE_AUTHOR("Jouni Malinen <j@w1.fi>");
|
|
MODULE_ALIAS_CRYPTO("michael_mic");
|