linux_dsm_epyc7002/include/crypto/curve25519.h
Jason A. Donenfeld 1579f1bc3b crypto: x86/curve25519 - support assemblers with no adx support
Some older version of GAS do not support the ADX instructions, similarly
to how they also don't support AVX and such. This commit adds the same
build-time detection mechanisms we use for AVX and others for ADX, and
then makes sure that the curve25519 library dispatcher calls the right
functions.

Reported-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-03-05 18:28:09 +11:00

74 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/*
* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#ifndef CURVE25519_H
#define CURVE25519_H
#include <crypto/algapi.h> // For crypto_memneq.
#include <linux/types.h>
#include <linux/random.h>
enum curve25519_lengths {
CURVE25519_KEY_SIZE = 32
};
extern const u8 curve25519_null_point[];
extern const u8 curve25519_base_point[];
void curve25519_generic(u8 out[CURVE25519_KEY_SIZE],
const u8 scalar[CURVE25519_KEY_SIZE],
const u8 point[CURVE25519_KEY_SIZE]);
void curve25519_arch(u8 out[CURVE25519_KEY_SIZE],
const u8 scalar[CURVE25519_KEY_SIZE],
const u8 point[CURVE25519_KEY_SIZE]);
void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE],
const u8 secret[CURVE25519_KEY_SIZE]);
static inline
bool __must_check curve25519(u8 mypublic[CURVE25519_KEY_SIZE],
const u8 secret[CURVE25519_KEY_SIZE],
const u8 basepoint[CURVE25519_KEY_SIZE])
{
if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519) &&
(!IS_ENABLED(CONFIG_CRYPTO_CURVE25519_X86) || IS_ENABLED(CONFIG_AS_ADX)))
curve25519_arch(mypublic, secret, basepoint);
else
curve25519_generic(mypublic, secret, basepoint);
return crypto_memneq(mypublic, curve25519_null_point,
CURVE25519_KEY_SIZE);
}
static inline bool
__must_check curve25519_generate_public(u8 pub[CURVE25519_KEY_SIZE],
const u8 secret[CURVE25519_KEY_SIZE])
{
if (unlikely(!crypto_memneq(secret, curve25519_null_point,
CURVE25519_KEY_SIZE)))
return false;
if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519) &&
(!IS_ENABLED(CONFIG_CRYPTO_CURVE25519_X86) || IS_ENABLED(CONFIG_AS_ADX)))
curve25519_base_arch(pub, secret);
else
curve25519_generic(pub, secret, curve25519_base_point);
return crypto_memneq(pub, curve25519_null_point, CURVE25519_KEY_SIZE);
}
static inline void curve25519_clamp_secret(u8 secret[CURVE25519_KEY_SIZE])
{
secret[0] &= 248;
secret[31] = (secret[31] & 127) | 64;
}
static inline void curve25519_generate_secret(u8 secret[CURVE25519_KEY_SIZE])
{
get_random_bytes_wait(secret, CURVE25519_KEY_SIZE);
curve25519_clamp_secret(secret);
}
#endif /* CURVE25519_H */