xref: /freebsd/contrib/wireguard-tools/curve25519.h (revision adf376485712c8fffbf3be330d505a969647f479)
1*adf37648SKyle Evans /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2*adf37648SKyle Evans /*
3*adf37648SKyle Evans  * Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
4*adf37648SKyle Evans  */
5*adf37648SKyle Evans 
6*adf37648SKyle Evans #ifndef CURVE25519_H
7*adf37648SKyle Evans #define CURVE25519_H
8*adf37648SKyle Evans 
9*adf37648SKyle Evans #include <stdint.h>
10*adf37648SKyle Evans #include <sys/types.h>
11*adf37648SKyle Evans 
12*adf37648SKyle Evans enum curve25519_lengths {
13*adf37648SKyle Evans 	CURVE25519_KEY_SIZE = 32
14*adf37648SKyle Evans };
15*adf37648SKyle Evans 
16*adf37648SKyle Evans void curve25519(uint8_t mypublic[static CURVE25519_KEY_SIZE], const uint8_t secret[static CURVE25519_KEY_SIZE], const uint8_t basepoint[static CURVE25519_KEY_SIZE]);
17*adf37648SKyle Evans void curve25519_generate_public(uint8_t pub[static CURVE25519_KEY_SIZE], const uint8_t secret[static CURVE25519_KEY_SIZE]);
curve25519_clamp_secret(uint8_t secret[static CURVE25519_KEY_SIZE])18*adf37648SKyle Evans static inline void curve25519_clamp_secret(uint8_t secret[static CURVE25519_KEY_SIZE])
19*adf37648SKyle Evans {
20*adf37648SKyle Evans 	secret[0] &= 248;
21*adf37648SKyle Evans 	secret[31] = (secret[31] & 127) | 64;
22*adf37648SKyle Evans }
23*adf37648SKyle Evans 
24*adf37648SKyle Evans #endif
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