136 lines
3.5 KiB
C
Executable file
136 lines
3.5 KiB
C
Executable file
// SPDX-License-Identifier: GPL-2.0 OR MIT
|
|
/*
|
|
* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
|
|
*
|
|
* Based on public domain code from Daniel J. Bernstein and Peter Schwabe. This
|
|
* began from SUPERCOP's curve25519/neon2/scalarmult.s, but has subsequently been
|
|
* manually reworked for use in kernel space.
|
|
*/
|
|
|
|
#include <asm/hwcap.h>
|
|
#include <asm/neon.h>
|
|
#include <asm/simd.h>
|
|
#include <crypto/internal/kpp.h>
|
|
#include <linux/types.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/jump_label.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <crypto/curve25519.h>
|
|
|
|
asmlinkage void curve25519_neon(u8 mypublic[CURVE25519_KEY_SIZE],
|
|
const u8 secret[CURVE25519_KEY_SIZE],
|
|
const u8 basepoint[CURVE25519_KEY_SIZE]);
|
|
|
|
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
|
|
|
|
void curve25519_arch(u8 out[CURVE25519_KEY_SIZE],
|
|
const u8 scalar[CURVE25519_KEY_SIZE],
|
|
const u8 point[CURVE25519_KEY_SIZE])
|
|
{
|
|
if (static_branch_likely(&have_neon) && may_use_simd()) {
|
|
kernel_neon_begin();
|
|
curve25519_neon(out, scalar, point);
|
|
kernel_neon_end();
|
|
} else {
|
|
curve25519_generic(out, scalar, point);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(curve25519_arch);
|
|
|
|
void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE],
|
|
const u8 secret[CURVE25519_KEY_SIZE])
|
|
{
|
|
return curve25519_arch(pub, secret, curve25519_base_point);
|
|
}
|
|
EXPORT_SYMBOL(curve25519_base_arch);
|
|
|
|
static int curve25519_set_secret(struct crypto_kpp *tfm, const void *buf,
|
|
unsigned int len)
|
|
{
|
|
u8 *secret = kpp_tfm_ctx(tfm);
|
|
|
|
if (!len)
|
|
curve25519_generate_secret(secret);
|
|
else if (len == CURVE25519_KEY_SIZE &&
|
|
crypto_memneq(buf, curve25519_null_point, CURVE25519_KEY_SIZE))
|
|
memcpy(secret, buf, CURVE25519_KEY_SIZE);
|
|
else
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static int curve25519_compute_value(struct kpp_request *req)
|
|
{
|
|
struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
|
|
const u8 *secret = kpp_tfm_ctx(tfm);
|
|
u8 public_key[CURVE25519_KEY_SIZE];
|
|
u8 buf[CURVE25519_KEY_SIZE];
|
|
int copied, nbytes;
|
|
u8 const *bp;
|
|
|
|
if (req->src) {
|
|
copied = sg_copy_to_buffer(req->src,
|
|
sg_nents_for_len(req->src,
|
|
CURVE25519_KEY_SIZE),
|
|
public_key, CURVE25519_KEY_SIZE);
|
|
if (copied != CURVE25519_KEY_SIZE)
|
|
return -EINVAL;
|
|
bp = public_key;
|
|
} else {
|
|
bp = curve25519_base_point;
|
|
}
|
|
|
|
curve25519_arch(buf, secret, bp);
|
|
|
|
/* might want less than we've got */
|
|
nbytes = min_t(size_t, CURVE25519_KEY_SIZE, req->dst_len);
|
|
copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst,
|
|
nbytes),
|
|
buf, nbytes);
|
|
if (copied != nbytes)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int curve25519_max_size(struct crypto_kpp *tfm)
|
|
{
|
|
return CURVE25519_KEY_SIZE;
|
|
}
|
|
|
|
static struct kpp_alg curve25519_alg = {
|
|
.base.cra_name = "curve25519",
|
|
.base.cra_driver_name = "curve25519-neon",
|
|
.base.cra_priority = 200,
|
|
.base.cra_module = THIS_MODULE,
|
|
.base.cra_ctxsize = CURVE25519_KEY_SIZE,
|
|
|
|
.set_secret = curve25519_set_secret,
|
|
.generate_public_key = curve25519_compute_value,
|
|
.compute_shared_secret = curve25519_compute_value,
|
|
.max_size = curve25519_max_size,
|
|
};
|
|
|
|
static int __init mod_init(void)
|
|
{
|
|
if (elf_hwcap & HWCAP_NEON) {
|
|
static_branch_enable(&have_neon);
|
|
return IS_REACHABLE(CONFIG_CRYPTO_KPP) ?
|
|
crypto_register_kpp(&curve25519_alg) : 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void __exit mod_exit(void)
|
|
{
|
|
if (IS_REACHABLE(CONFIG_CRYPTO_KPP) && elf_hwcap & HWCAP_NEON)
|
|
crypto_unregister_kpp(&curve25519_alg);
|
|
}
|
|
|
|
module_init(mod_init);
|
|
module_exit(mod_exit);
|
|
|
|
MODULE_ALIAS_CRYPTO("curve25519");
|
|
MODULE_ALIAS_CRYPTO("curve25519-neon");
|
|
MODULE_LICENSE("GPL v2");
|