1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#ifndef _WG_MESSAGES_H
#define _WG_MESSAGES_H
#include <crypto/curve25519.h>
#include <crypto/chacha20poly1305.h>
#include <crypto/blake2s.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/skbuff.h>
enum noise_lengths {
NOISE_PUBLIC_KEY_LEN = CURVE25519_KEY_SIZE,
NOISE_SYMMETRIC_KEY_LEN = CHACHA20POLY1305_KEY_SIZE,
NOISE_TIMESTAMP_LEN = sizeof(u64) + sizeof(u32),
NOISE_AUTHTAG_LEN = CHACHA20POLY1305_AUTHTAG_SIZE,
NOISE_HASH_LEN = BLAKE2S_HASH_SIZE
};
#define noise_encrypted_len(plain_len) ((plain_len) + NOISE_AUTHTAG_LEN)
enum cookie_values {
COOKIE_SECRET_MAX_AGE = 2 * 60,
COOKIE_SECRET_LATENCY = 5,
COOKIE_NONCE_LEN = XCHACHA20POLY1305_NONCE_SIZE,
COOKIE_LEN = 16
};
enum counter_values {
COUNTER_BITS_TOTAL = 8192,
COUNTER_REDUNDANT_BITS = BITS_PER_LONG,
COUNTER_WINDOW_SIZE = COUNTER_BITS_TOTAL - COUNTER_REDUNDANT_BITS
};
enum limits {
REKEY_AFTER_MESSAGES = 1ULL << 60,
REJECT_AFTER_MESSAGES = U64_MAX - COUNTER_WINDOW_SIZE - 1,
REKEY_TIMEOUT = 5,
REKEY_TIMEOUT_JITTER_MAX_JIFFIES = HZ / 3,
REKEY_AFTER_TIME = 120,
REJECT_AFTER_TIME = 180,
INITIATIONS_PER_SECOND = 50,
MAX_PEERS_PER_DEVICE = 1U << 20,
KEEPALIVE_TIMEOUT = 10,
MAX_TIMER_HANDSHAKES = 90 / REKEY_TIMEOUT,
MAX_QUEUED_INCOMING_HANDSHAKES = 4096, /* TODO: replace this with DQL */
MAX_STAGED_PACKETS = 128,
MAX_QUEUED_PACKETS = 1024 /* TODO: replace this with DQL */
};
enum message_type {
MESSAGE_INVALID = 0,
MESSAGE_HANDSHAKE_INITIATION = 1,
MESSAGE_HANDSHAKE_RESPONSE = 2,
MESSAGE_HANDSHAKE_COOKIE = 3,
MESSAGE_DATA = 4
};
struct message_header {
/* The actual layout of this that we want is:
* u8 type
* u8 reserved_zero[3]
*
* But it turns out that by encoding this as little endian,
* we achieve the same thing, and it makes checking faster.
*/
__le32 type;
};
struct message_macs {
u8 mac1[COOKIE_LEN];
u8 mac2[COOKIE_LEN];
};
struct message_handshake_initiation {
struct message_header header;
__le32 sender_index;
u8 unencrypted_ephemeral[NOISE_PUBLIC_KEY_LEN];
u8 encrypted_static[noise_encrypted_len(NOISE_PUBLIC_KEY_LEN)];
u8 encrypted_timestamp[noise_encrypted_len(NOISE_TIMESTAMP_LEN)];
struct message_macs macs;
};
struct message_handshake_response {
struct message_header header;
__le32 sender_index;
__le32 receiver_index;
u8 unencrypted_ephemeral[NOISE_PUBLIC_KEY_LEN];
u8 encrypted_nothing[noise_encrypted_len(0)];
struct message_macs macs;
};
struct message_handshake_cookie {
struct message_header header;
__le32 receiver_index;
u8 nonce[COOKIE_NONCE_LEN];
u8 encrypted_cookie[noise_encrypted_len(COOKIE_LEN)];
};
struct message_data {
struct message_header header;
__le32 key_idx;
__le64 counter;
u8 encrypted_data[];
};
#define message_data_len(plain_len) \
(noise_encrypted_len(plain_len) + sizeof(struct message_data))
enum message_alignments {
MESSAGE_PADDING_MULTIPLE = 16,
MESSAGE_MINIMUM_LENGTH = message_data_len(0)
};
#define SKB_HEADER_LEN \
(max(sizeof(struct iphdr), sizeof(struct ipv6hdr)) + \
sizeof(struct udphdr) + NET_SKB_PAD)
#define DATA_PACKET_HEAD_ROOM \
ALIGN(sizeof(struct message_data) + SKB_HEADER_LEN, 4)
enum { HANDSHAKE_DSCP = 0x88 /* AF41, plus 00 ECN */ };
#endif /* _WG_MESSAGES_H */
|
