cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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curve25519.h (2065B)

      1/* SPDX-License-Identifier: GPL-2.0 OR MIT */
      2/*
      3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
      4 */
      5
      6#ifndef CURVE25519_H
      7#define CURVE25519_H
      8
      9#include <crypto/algapi.h> // For crypto_memneq.
     10#include <linux/types.h>
     11#include <linux/random.h>
     12
     13enum curve25519_lengths {
     14	CURVE25519_KEY_SIZE = 32
     15};
     16
     17extern const u8 curve25519_null_point[];
     18extern const u8 curve25519_base_point[];
     19
     20void curve25519_generic(u8 out[CURVE25519_KEY_SIZE],
     21			const u8 scalar[CURVE25519_KEY_SIZE],
     22			const u8 point[CURVE25519_KEY_SIZE]);
     23
     24void curve25519_arch(u8 out[CURVE25519_KEY_SIZE],
     25		     const u8 scalar[CURVE25519_KEY_SIZE],
     26		     const u8 point[CURVE25519_KEY_SIZE]);
     27
     28void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE],
     29			  const u8 secret[CURVE25519_KEY_SIZE]);
     30
     31bool curve25519_selftest(void);
     32
     33static inline
     34bool __must_check curve25519(u8 mypublic[CURVE25519_KEY_SIZE],
     35			     const u8 secret[CURVE25519_KEY_SIZE],
     36			     const u8 basepoint[CURVE25519_KEY_SIZE])
     37{
     38	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519))
     39		curve25519_arch(mypublic, secret, basepoint);
     40	else
     41		curve25519_generic(mypublic, secret, basepoint);
     42	return crypto_memneq(mypublic, curve25519_null_point,
     43			     CURVE25519_KEY_SIZE);
     44}
     45
     46static inline bool
     47__must_check curve25519_generate_public(u8 pub[CURVE25519_KEY_SIZE],
     48					const u8 secret[CURVE25519_KEY_SIZE])
     49{
     50	if (unlikely(!crypto_memneq(secret, curve25519_null_point,
     51				    CURVE25519_KEY_SIZE)))
     52		return false;
     53
     54	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519))
     55		curve25519_base_arch(pub, secret);
     56	else
     57		curve25519_generic(pub, secret, curve25519_base_point);
     58	return crypto_memneq(pub, curve25519_null_point, CURVE25519_KEY_SIZE);
     59}
     60
     61static inline void curve25519_clamp_secret(u8 secret[CURVE25519_KEY_SIZE])
     62{
     63	secret[0] &= 248;
     64	secret[31] = (secret[31] & 127) | 64;
     65}
     66
     67static inline void curve25519_generate_secret(u8 secret[CURVE25519_KEY_SIZE])
     68{
     69	get_random_bytes_wait(secret, CURVE25519_KEY_SIZE);
     70	curve25519_clamp_secret(secret);
     71}
     72
     73#endif /* CURVE25519_H */