xref: /openbmc/linux/drivers/net/wireguard/cookie.h (revision 99a15348)
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 
12 struct wg_peer;
13 
14 struct 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 
23 struct 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 
34 enum 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 
41 void wg_cookie_checker_init(struct cookie_checker *checker,
42 			    struct wg_device *wg);
43 void wg_cookie_checker_precompute_device_keys(struct cookie_checker *checker);
44 void wg_cookie_checker_precompute_peer_keys(struct wg_peer *peer);
45 void wg_cookie_init(struct cookie *cookie);
46 
47 enum cookie_mac_state wg_cookie_validate_packet(struct cookie_checker *checker,
48 						struct sk_buff *skb,
49 						bool check_cookie);
50 void wg_cookie_add_mac_to_packet(void *message, size_t len,
51 				 struct wg_peer *peer);
52 
53 void wg_cookie_message_create(struct message_handshake_cookie *src,
54 			      struct sk_buff *skb, __le32 index,
55 			      struct cookie_checker *checker);
56 void wg_cookie_message_consume(struct message_handshake_cookie *src,
57 			       struct wg_device *wg);
58 
59 #endif /* _WG_COOKIE_H */
60