Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
crypto: arm/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-neon" kpp algorithm.
Note that the underlying NEON 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/20250906213523.84915-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
+1
-77
-1
arch/arm/crypto/Kconfig
-1
arch/arm/crypto/Kconfig
+1
-76
arch/arm/crypto/curve25519-glue.c
+1
-76
arch/arm/crypto/curve25519-glue.c
···
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#include <asm/hwcap.h>
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#include <asm/neon.h>
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#include <asm/simd.h>
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-
#include <crypto/internal/kpp.h>
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#include <crypto/internal/simd.h>
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/jump_label.h>
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#include <linux/scatterlist.h>
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#include <crypto/curve25519.h>
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asmlinkage void curve25519_neon(u8 mypublic[CURVE25519_KEY_SIZE],
···
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}
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EXPORT_SYMBOL(curve25519_base_arch);
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static int curve25519_set_secret(struct crypto_kpp *tfm, const void *buf,
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unsigned int len)
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{
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u8 *secret = kpp_tfm_ctx(tfm);
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-
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if (!len)
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curve25519_generate_secret(secret);
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else if (len == CURVE25519_KEY_SIZE &&
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crypto_memneq(buf, curve25519_null_point, CURVE25519_KEY_SIZE))
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memcpy(secret, buf, CURVE25519_KEY_SIZE);
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else
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return -EINVAL;
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return 0;
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}
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-
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static int curve25519_compute_value(struct kpp_request *req)
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{
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struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
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const u8 *secret = kpp_tfm_ctx(tfm);
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u8 public_key[CURVE25519_KEY_SIZE];
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u8 buf[CURVE25519_KEY_SIZE];
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int copied, nbytes;
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u8 const *bp;
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if (req->src) {
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copied = sg_copy_to_buffer(req->src,
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sg_nents_for_len(req->src,
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CURVE25519_KEY_SIZE),
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public_key, CURVE25519_KEY_SIZE);
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if (copied != CURVE25519_KEY_SIZE)
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return -EINVAL;
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bp = public_key;
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} else {
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bp = curve25519_base_point;
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}
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curve25519_arch(buf, secret, bp);
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/* might want less than we've got */
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nbytes = min_t(size_t, CURVE25519_KEY_SIZE, req->dst_len);
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copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst,
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nbytes),
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buf, nbytes);
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if (copied != nbytes)
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return -EINVAL;
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return 0;
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}
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static unsigned int curve25519_max_size(struct crypto_kpp *tfm)
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{
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return CURVE25519_KEY_SIZE;
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}
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static struct kpp_alg curve25519_alg = {
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.base.cra_name = "curve25519",
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.base.cra_driver_name = "curve25519-neon",
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.base.cra_priority = 200,
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.base.cra_module = THIS_MODULE,
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.base.cra_ctxsize = CURVE25519_KEY_SIZE,
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.set_secret = curve25519_set_secret,
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.generate_public_key = curve25519_compute_value,
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.compute_shared_secret = curve25519_compute_value,
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.max_size = curve25519_max_size,
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};
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static int __init arm_curve25519_init(void)
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{
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if (elf_hwcap & HWCAP_NEON) {
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if (elf_hwcap & HWCAP_NEON)
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static_branch_enable(&have_neon);
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return IS_REACHABLE(CONFIG_CRYPTO_KPP) ?
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crypto_register_kpp(&curve25519_alg) : 0;
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}
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return 0;
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}
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static void __exit arm_curve25519_exit(void)
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{
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if (IS_REACHABLE(CONFIG_CRYPTO_KPP) && elf_hwcap & HWCAP_NEON)
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crypto_unregister_kpp(&curve25519_alg);
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}
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module_init(arm_curve25519_init);
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module_exit(arm_curve25519_exit);
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MODULE_ALIAS_CRYPTO("curve25519");
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MODULE_ALIAS_CRYPTO("curve25519-neon");
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MODULE_DESCRIPTION("Public key crypto: Curve25519 (NEON-accelerated)");
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MODULE_LICENSE("GPL v2");