Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
crypto: x86/curve25519 - Remove unused kpp support
Curve25519 is used only via the library API, not the crypto_kpp API. In
preparation for removing the unused crypto_kpp API for Curve25519,
remove the unused "curve25519-x86" kpp algorithm.
Note that the underlying x86_64 optimized Curve25519 code remains fully
supported and accessible via the library API.
It's also worth noting that even if the kpp support for Curve25519 comes
back later, there is no need for arch-specific kpp glue code like this,
as a single kpp algorithm that wraps the library API is sufficient.
Link: https://lore.kernel.org/r/20250906213523.84915-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
+1
-98
-1
arch/x86/crypto/Kconfig
-1
arch/x86/crypto/Kconfig
+1
-97
arch/x86/crypto/curve25519-x86_64.c
+1
-97
arch/x86/crypto/curve25519-x86_64.c
···
5
5
*/
6
6
7
7
#include <crypto/curve25519.h>
8
-
#include <crypto/internal/kpp.h>
9
8
10
9
#include <linux/export.h>
11
10
#include <linux/types.h>
12
11
#include <linux/jump_label.h>
13
12
#include <linux/kernel.h>
14
13
#include <linux/module.h>
15
-
#include <linux/scatterlist.h>
16
14
17
15
#include <asm/cpufeature.h>
18
16
#include <asm/processor.h>
···
1611
1613
}
1612
1614
EXPORT_SYMBOL(curve25519_base_arch);
1613
1615
1614
-
static int curve25519_set_secret(struct crypto_kpp *tfm, const void *buf,
1615
-
unsigned int len)
1616
-
{
1617
-
u8 *secret = kpp_tfm_ctx(tfm);
1618
-
1619
-
if (!len)
1620
-
curve25519_generate_secret(secret);
1621
-
else if (len == CURVE25519_KEY_SIZE &&
1622
-
crypto_memneq(buf, curve25519_null_point, CURVE25519_KEY_SIZE))
1623
-
memcpy(secret, buf, CURVE25519_KEY_SIZE);
1624
-
else
1625
-
return -EINVAL;
1626
-
return 0;
1627
-
}
1628
-
1629
-
static int curve25519_generate_public_key(struct kpp_request *req)
1630
-
{
1631
-
struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
1632
-
const u8 *secret = kpp_tfm_ctx(tfm);
1633
-
u8 buf[CURVE25519_KEY_SIZE];
1634
-
int copied, nbytes;
1635
-
1636
-
if (req->src)
1637
-
return -EINVAL;
1638
-
1639
-
curve25519_base_arch(buf, secret);
1640
-
1641
-
/* might want less than we've got */
1642
-
nbytes = min_t(size_t, CURVE25519_KEY_SIZE, req->dst_len);
1643
-
copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst,
1644
-
nbytes),
1645
-
buf, nbytes);
1646
-
if (copied != nbytes)
1647
-
return -EINVAL;
1648
-
return 0;
1649
-
}
1650
-
1651
-
static int curve25519_compute_shared_secret(struct kpp_request *req)
1652
-
{
1653
-
struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
1654
-
const u8 *secret = kpp_tfm_ctx(tfm);
1655
-
u8 public_key[CURVE25519_KEY_SIZE];
1656
-
u8 buf[CURVE25519_KEY_SIZE];
1657
-
int copied, nbytes;
1658
-
1659
-
if (!req->src)
1660
-
return -EINVAL;
1661
-
1662
-
copied = sg_copy_to_buffer(req->src,
1663
-
sg_nents_for_len(req->src,
1664
-
CURVE25519_KEY_SIZE),
1665
-
public_key, CURVE25519_KEY_SIZE);
1666
-
if (copied != CURVE25519_KEY_SIZE)
1667
-
return -EINVAL;
1668
-
1669
-
curve25519_arch(buf, secret, public_key);
1670
-
1671
-
/* might want less than we've got */
1672
-
nbytes = min_t(size_t, CURVE25519_KEY_SIZE, req->dst_len);
1673
-
copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst,
1674
-
nbytes),
1675
-
buf, nbytes);
1676
-
if (copied != nbytes)
1677
-
return -EINVAL;
1678
-
return 0;
1679
-
}
1680
-
1681
-
static unsigned int curve25519_max_size(struct crypto_kpp *tfm)
1682
-
{
1683
-
return CURVE25519_KEY_SIZE;
1684
-
}
1685
-
1686
-
static struct kpp_alg curve25519_alg = {
1687
-
.base.cra_name = "curve25519",
1688
-
.base.cra_driver_name = "curve25519-x86",
1689
-
.base.cra_priority = 200,
1690
-
.base.cra_module = THIS_MODULE,
1691
-
.base.cra_ctxsize = CURVE25519_KEY_SIZE,
1692
-
1693
-
.set_secret = curve25519_set_secret,
1694
-
.generate_public_key = curve25519_generate_public_key,
1695
-
.compute_shared_secret = curve25519_compute_shared_secret,
1696
-
.max_size = curve25519_max_size,
1697
-
};
1698
-
1699
-
1700
1616
static int __init curve25519_mod_init(void)
1701
1617
{
1702
1618
if (boot_cpu_has(X86_FEATURE_BMI2) && boot_cpu_has(X86_FEATURE_ADX))
1703
1619
static_branch_enable(&curve25519_use_bmi2_adx);
1704
-
else
1705
-
return 0;
1706
-
return IS_REACHABLE(CONFIG_CRYPTO_KPP) ?
1707
-
crypto_register_kpp(&curve25519_alg) : 0;
1620
+
return 0;
1708
1621
}
1709
1622
1710
1623
static void __exit curve25519_mod_exit(void)
1711
1624
{
1712
-
if (IS_REACHABLE(CONFIG_CRYPTO_KPP) &&
1713
-
static_branch_likely(&curve25519_use_bmi2_adx))
1714
-
crypto_unregister_kpp(&curve25519_alg);
1715
1625
}
1716
1626
1717
1627
module_init(curve25519_mod_init);
1718
1628
module_exit(curve25519_mod_exit);
1719
1629
1720
-
MODULE_ALIAS_CRYPTO("curve25519");
1721
-
MODULE_ALIAS_CRYPTO("curve25519-x86");
1722
1630
MODULE_DESCRIPTION("Curve25519 algorithm, ADX optimized");
1723
1631
MODULE_LICENSE("GPL v2");
1724
1632
MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");