74 lines
2.0 KiB
C
74 lines
2.0 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]);
|
||
|
|
|
||
|
|
bool curve25519_selftest(void);
|
||
|
|
|
||
|
|
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))
|
||
|
|
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))
|
||
|
|
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 */
|