mirror of
https://github.com/torvalds/linux.git
synced 2024-12-12 22:23:55 +00:00
a208fa8f33
We need to consistently enforce that keyed hashes cannot be used without setting the key. To do this we need a reliable way to determine whether a given hash algorithm is keyed or not. AF_ALG currently does this by checking for the presence of a ->setkey() method. However, this is actually slightly broken because the CRC-32 algorithms implement ->setkey() but can also be used without a key. (The CRC-32 "key" is not actually a cryptographic key but rather represents the initial state. If not overridden, then a default initial state is used.) Prepare to fix this by introducing a flag CRYPTO_ALG_OPTIONAL_KEY which indicates that the algorithm has a ->setkey() method, but it is not required to be called. Then set it on all the CRC-32 algorithms. The same also applies to the Adler-32 implementation in Lustre. Also, the cryptd and mcryptd templates have to pass through the flag from their underlying algorithm. Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
203 lines
5.0 KiB
C
203 lines
5.0 KiB
C
/* GPL HEADER START
|
|
*
|
|
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 only,
|
|
* as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License version 2 for more details (a copy is included
|
|
* in the LICENSE file that accompanied this code).
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* version 2 along with this program; If not, see http://www.gnu.org/licenses
|
|
*
|
|
* Please visit http://www.xyratex.com/contact if you need additional
|
|
* information or have any questions.
|
|
*
|
|
* GPL HEADER END
|
|
*/
|
|
|
|
/*
|
|
* Copyright 2012 Xyratex Technology Limited
|
|
*
|
|
* Wrappers for kernel crypto shash api to pclmulqdq crc32 imlementation.
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/string.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/crc32.h>
|
|
#include <crypto/internal/hash.h>
|
|
|
|
#include <asm/cpufeatures.h>
|
|
#include <asm/cpu_device_id.h>
|
|
#include <asm/fpu/api.h>
|
|
|
|
#define CHKSUM_BLOCK_SIZE 1
|
|
#define CHKSUM_DIGEST_SIZE 4
|
|
|
|
#define PCLMUL_MIN_LEN 64L /* minimum size of buffer
|
|
* for crc32_pclmul_le_16 */
|
|
#define SCALE_F 16L /* size of xmm register */
|
|
#define SCALE_F_MASK (SCALE_F - 1)
|
|
|
|
u32 crc32_pclmul_le_16(unsigned char const *buffer, size_t len, u32 crc32);
|
|
|
|
static u32 __attribute__((pure))
|
|
crc32_pclmul_le(u32 crc, unsigned char const *p, size_t len)
|
|
{
|
|
unsigned int iquotient;
|
|
unsigned int iremainder;
|
|
unsigned int prealign;
|
|
|
|
if (len < PCLMUL_MIN_LEN + SCALE_F_MASK || !irq_fpu_usable())
|
|
return crc32_le(crc, p, len);
|
|
|
|
if ((long)p & SCALE_F_MASK) {
|
|
/* align p to 16 byte */
|
|
prealign = SCALE_F - ((long)p & SCALE_F_MASK);
|
|
|
|
crc = crc32_le(crc, p, prealign);
|
|
len -= prealign;
|
|
p = (unsigned char *)(((unsigned long)p + SCALE_F_MASK) &
|
|
~SCALE_F_MASK);
|
|
}
|
|
iquotient = len & (~SCALE_F_MASK);
|
|
iremainder = len & SCALE_F_MASK;
|
|
|
|
kernel_fpu_begin();
|
|
crc = crc32_pclmul_le_16(p, iquotient, crc);
|
|
kernel_fpu_end();
|
|
|
|
if (iremainder)
|
|
crc = crc32_le(crc, p + iquotient, iremainder);
|
|
|
|
return crc;
|
|
}
|
|
|
|
static int crc32_pclmul_cra_init(struct crypto_tfm *tfm)
|
|
{
|
|
u32 *key = crypto_tfm_ctx(tfm);
|
|
|
|
*key = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crc32_pclmul_setkey(struct crypto_shash *hash, const u8 *key,
|
|
unsigned int keylen)
|
|
{
|
|
u32 *mctx = crypto_shash_ctx(hash);
|
|
|
|
if (keylen != sizeof(u32)) {
|
|
crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
|
|
return -EINVAL;
|
|
}
|
|
*mctx = le32_to_cpup((__le32 *)key);
|
|
return 0;
|
|
}
|
|
|
|
static int crc32_pclmul_init(struct shash_desc *desc)
|
|
{
|
|
u32 *mctx = crypto_shash_ctx(desc->tfm);
|
|
u32 *crcp = shash_desc_ctx(desc);
|
|
|
|
*crcp = *mctx;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crc32_pclmul_update(struct shash_desc *desc, const u8 *data,
|
|
unsigned int len)
|
|
{
|
|
u32 *crcp = shash_desc_ctx(desc);
|
|
|
|
*crcp = crc32_pclmul_le(*crcp, data, len);
|
|
return 0;
|
|
}
|
|
|
|
/* No final XOR 0xFFFFFFFF, like crc32_le */
|
|
static int __crc32_pclmul_finup(u32 *crcp, const u8 *data, unsigned int len,
|
|
u8 *out)
|
|
{
|
|
*(__le32 *)out = cpu_to_le32(crc32_pclmul_le(*crcp, data, len));
|
|
return 0;
|
|
}
|
|
|
|
static int crc32_pclmul_finup(struct shash_desc *desc, const u8 *data,
|
|
unsigned int len, u8 *out)
|
|
{
|
|
return __crc32_pclmul_finup(shash_desc_ctx(desc), data, len, out);
|
|
}
|
|
|
|
static int crc32_pclmul_final(struct shash_desc *desc, u8 *out)
|
|
{
|
|
u32 *crcp = shash_desc_ctx(desc);
|
|
|
|
*(__le32 *)out = cpu_to_le32p(crcp);
|
|
return 0;
|
|
}
|
|
|
|
static int crc32_pclmul_digest(struct shash_desc *desc, const u8 *data,
|
|
unsigned int len, u8 *out)
|
|
{
|
|
return __crc32_pclmul_finup(crypto_shash_ctx(desc->tfm), data, len,
|
|
out);
|
|
}
|
|
|
|
static struct shash_alg alg = {
|
|
.setkey = crc32_pclmul_setkey,
|
|
.init = crc32_pclmul_init,
|
|
.update = crc32_pclmul_update,
|
|
.final = crc32_pclmul_final,
|
|
.finup = crc32_pclmul_finup,
|
|
.digest = crc32_pclmul_digest,
|
|
.descsize = sizeof(u32),
|
|
.digestsize = CHKSUM_DIGEST_SIZE,
|
|
.base = {
|
|
.cra_name = "crc32",
|
|
.cra_driver_name = "crc32-pclmul",
|
|
.cra_priority = 200,
|
|
.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
|
|
.cra_blocksize = CHKSUM_BLOCK_SIZE,
|
|
.cra_ctxsize = sizeof(u32),
|
|
.cra_module = THIS_MODULE,
|
|
.cra_init = crc32_pclmul_cra_init,
|
|
}
|
|
};
|
|
|
|
static const struct x86_cpu_id crc32pclmul_cpu_id[] = {
|
|
X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(x86cpu, crc32pclmul_cpu_id);
|
|
|
|
|
|
static int __init crc32_pclmul_mod_init(void)
|
|
{
|
|
|
|
if (!x86_match_cpu(crc32pclmul_cpu_id)) {
|
|
pr_info("PCLMULQDQ-NI instructions are not detected.\n");
|
|
return -ENODEV;
|
|
}
|
|
return crypto_register_shash(&alg);
|
|
}
|
|
|
|
static void __exit crc32_pclmul_mod_fini(void)
|
|
{
|
|
crypto_unregister_shash(&alg);
|
|
}
|
|
|
|
module_init(crc32_pclmul_mod_init);
|
|
module_exit(crc32_pclmul_mod_fini);
|
|
|
|
MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
MODULE_ALIAS_CRYPTO("crc32");
|
|
MODULE_ALIAS_CRYPTO("crc32-pclmul");
|