1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. |
4 | */ |
5 | #ifndef _WG_NOISE_H |
6 | #define _WG_NOISE_H |
7 | |
8 | #include "messages.h" |
9 | #include "peerlookup.h" |
10 | |
11 | #include <linux/types.h> |
12 | #include <linux/spinlock.h> |
13 | #include <linux/atomic.h> |
14 | #include <linux/rwsem.h> |
15 | #include <linux/mutex.h> |
16 | #include <linux/kref.h> |
17 | |
18 | struct noise_replay_counter { |
19 | u64 counter; |
20 | spinlock_t lock; |
21 | unsigned long backtrack[COUNTER_BITS_TOTAL / BITS_PER_LONG]; |
22 | }; |
23 | |
24 | struct noise_symmetric_key { |
25 | u8 key[NOISE_SYMMETRIC_KEY_LEN]; |
26 | u64 birthdate; |
27 | bool is_valid; |
28 | }; |
29 | |
30 | struct noise_keypair { |
31 | struct index_hashtable_entry entry; |
32 | struct noise_symmetric_key sending; |
33 | atomic64_t sending_counter; |
34 | struct noise_symmetric_key receiving; |
35 | struct noise_replay_counter receiving_counter; |
36 | __le32 remote_index; |
37 | bool i_am_the_initiator; |
38 | struct kref refcount; |
39 | struct rcu_head rcu; |
40 | u64 internal_id; |
41 | }; |
42 | |
43 | struct noise_keypairs { |
44 | struct noise_keypair __rcu *current_keypair; |
45 | struct noise_keypair __rcu *previous_keypair; |
46 | struct noise_keypair __rcu *next_keypair; |
47 | spinlock_t keypair_update_lock; |
48 | }; |
49 | |
50 | struct noise_static_identity { |
51 | u8 static_public[NOISE_PUBLIC_KEY_LEN]; |
52 | u8 static_private[NOISE_PUBLIC_KEY_LEN]; |
53 | struct rw_semaphore lock; |
54 | bool has_identity; |
55 | }; |
56 | |
57 | enum noise_handshake_state { |
58 | HANDSHAKE_ZEROED, |
59 | HANDSHAKE_CREATED_INITIATION, |
60 | HANDSHAKE_CONSUMED_INITIATION, |
61 | HANDSHAKE_CREATED_RESPONSE, |
62 | HANDSHAKE_CONSUMED_RESPONSE |
63 | }; |
64 | |
65 | struct noise_handshake { |
66 | struct index_hashtable_entry entry; |
67 | |
68 | enum noise_handshake_state state; |
69 | u64 last_initiation_consumption; |
70 | |
71 | struct noise_static_identity *static_identity; |
72 | |
73 | u8 ephemeral_private[NOISE_PUBLIC_KEY_LEN]; |
74 | u8 remote_static[NOISE_PUBLIC_KEY_LEN]; |
75 | u8 remote_ephemeral[NOISE_PUBLIC_KEY_LEN]; |
76 | u8 precomputed_static_static[NOISE_PUBLIC_KEY_LEN]; |
77 | |
78 | u8 preshared_key[NOISE_SYMMETRIC_KEY_LEN]; |
79 | |
80 | u8 hash[NOISE_HASH_LEN]; |
81 | u8 chaining_key[NOISE_HASH_LEN]; |
82 | |
83 | u8 latest_timestamp[NOISE_TIMESTAMP_LEN]; |
84 | __le32 remote_index; |
85 | |
86 | /* Protects all members except the immutable (after noise_handshake_ |
87 | * init): remote_static, precomputed_static_static, static_identity. |
88 | */ |
89 | struct rw_semaphore lock; |
90 | }; |
91 | |
92 | struct wg_device; |
93 | |
94 | void wg_noise_init(void); |
95 | void wg_noise_handshake_init(struct noise_handshake *handshake, |
96 | struct noise_static_identity *static_identity, |
97 | const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN], |
98 | const u8 peer_preshared_key[NOISE_SYMMETRIC_KEY_LEN], |
99 | struct wg_peer *peer); |
100 | void wg_noise_handshake_clear(struct noise_handshake *handshake); |
101 | static inline void wg_noise_reset_last_sent_handshake(atomic64_t *handshake_ns) |
102 | { |
103 | atomic64_set(v: handshake_ns, i: ktime_get_coarse_boottime_ns() - |
104 | (u64)(REKEY_TIMEOUT + 1) * NSEC_PER_SEC); |
105 | } |
106 | |
107 | void wg_noise_keypair_put(struct noise_keypair *keypair, bool unreference_now); |
108 | struct noise_keypair *wg_noise_keypair_get(struct noise_keypair *keypair); |
109 | void wg_noise_keypairs_clear(struct noise_keypairs *keypairs); |
110 | bool wg_noise_received_with_keypair(struct noise_keypairs *keypairs, |
111 | struct noise_keypair *received_keypair); |
112 | void wg_noise_expire_current_peer_keypairs(struct wg_peer *peer); |
113 | |
114 | void wg_noise_set_static_identity_private_key( |
115 | struct noise_static_identity *static_identity, |
116 | const u8 private_key[NOISE_PUBLIC_KEY_LEN]); |
117 | void wg_noise_precompute_static_static(struct wg_peer *peer); |
118 | |
119 | bool |
120 | wg_noise_handshake_create_initiation(struct message_handshake_initiation *dst, |
121 | struct noise_handshake *handshake); |
122 | struct wg_peer * |
123 | wg_noise_handshake_consume_initiation(struct message_handshake_initiation *src, |
124 | struct wg_device *wg); |
125 | |
126 | bool wg_noise_handshake_create_response(struct message_handshake_response *dst, |
127 | struct noise_handshake *handshake); |
128 | struct wg_peer * |
129 | wg_noise_handshake_consume_response(struct message_handshake_response *src, |
130 | struct wg_device *wg); |
131 | |
132 | bool wg_noise_handshake_begin_session(struct noise_handshake *handshake, |
133 | struct noise_keypairs *keypairs); |
134 | |
135 | #endif /* _WG_NOISE_H */ |
136 | |