1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
4 */
5
6#ifndef _WG_COOKIE_H
7#define _WG_COOKIE_H
8
9#include "messages.h"
10#include <linux/rwsem.h>
11
12struct wg_peer;
13
14struct cookie_checker {
15	u8 secret[NOISE_HASH_LEN];
16	u8 cookie_encryption_key[NOISE_SYMMETRIC_KEY_LEN];
17	u8 message_mac1_key[NOISE_SYMMETRIC_KEY_LEN];
18	u64 secret_birthdate;
19	struct rw_semaphore secret_lock;
20	struct wg_device *device;
21};
22
23struct cookie {
24	u64 birthdate;
25	bool is_valid;
26	u8 cookie[COOKIE_LEN];
27	bool have_sent_mac1;
28	u8 last_mac1_sent[COOKIE_LEN];
29	u8 cookie_decryption_key[NOISE_SYMMETRIC_KEY_LEN];
30	u8 message_mac1_key[NOISE_SYMMETRIC_KEY_LEN];
31	struct rw_semaphore lock;
32};
33
34enum cookie_mac_state {
35	INVALID_MAC,
36	VALID_MAC_BUT_NO_COOKIE,
37	VALID_MAC_WITH_COOKIE_BUT_RATELIMITED,
38	VALID_MAC_WITH_COOKIE
39};
40
41void wg_cookie_checker_init(struct cookie_checker *checker,
42			    struct wg_device *wg);
43void wg_cookie_checker_precompute_device_keys(struct cookie_checker *checker);
44void wg_cookie_checker_precompute_peer_keys(struct wg_peer *peer);
45void wg_cookie_init(struct cookie *cookie);
46
47enum cookie_mac_state wg_cookie_validate_packet(struct cookie_checker *checker,
48						struct sk_buff *skb,
49						bool check_cookie);
50void wg_cookie_add_mac_to_packet(void *message, size_t len,
51				 struct wg_peer *peer);
52
53void wg_cookie_message_create(struct message_handshake_cookie *src,
54			      struct sk_buff *skb, __le32 index,
55			      struct cookie_checker *checker);
56void wg_cookie_message_consume(struct message_handshake_cookie *src,
57			       struct wg_device *wg);
58
59#endif /* _WG_COOKIE_H */
60