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(handshake_ns, 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