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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
use super::queue::{Job, Queue};
use super::KeyPair;
use super::types::Callbacks;
use super::peer::Peer;
use super::{REJECT_AFTER_MESSAGES, SIZE_TAG};
use super::messages::{TransportHeader, TYPE_TRANSPORT};
use super::device::DecryptionState;
use super::super::{tun, udp, Endpoint};
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
use std::mem;
use ring::aead::{Aad, LessSafeKey, Nonce, UnboundKey, CHACHA20_POLY1305};
use zerocopy::{AsBytes, LayoutVerified};
use spin::Mutex;
struct Inner<E: Endpoint, C: Callbacks, T: tun::Writer, B: udp::Writer<E>> {
ready: AtomicBool,
buffer: Mutex<(Option<E>, Vec<u8>)>, // endpoint & ciphertext buffer
state: Arc<DecryptionState<E, C, T, B>>, // decryption state (keys and replay protector)
}
pub struct ReceiveJob<E: Endpoint, C: Callbacks, T: tun::Writer, B: udp::Writer<E>> {
inner: Arc<Inner<E, C, T, B>>,
}
impl <E: Endpoint, C: Callbacks, T: tun::Writer, B: udp::Writer<E>> ReceiveJob<E, C, T, B> {
fn new(buffer: Vec<u8>, state: Arc<DecryptionState<E, C, T, B>>, endpoint: E) -> Option<ReceiveJob<E, C, T, B>> {
// create job
let inner = Arc::new(Inner{
ready: AtomicBool::new(false),
buffer: Mutex::new((Some(endpoint), buffer)),
state
});
// attempt to add to queue
if state.peer.inbound.push(ReceiveJob{ inner: inner.clone()}) {
Some(ReceiveJob{inner})
} else {
None
}
}
}
impl <E: Endpoint, C: Callbacks, T: tun::Writer, B: udp::Writer<E>> Job for ReceiveJob<E, C, T, B> {
fn queue(&self) -> &Queue<Self> {
&self.inner.state.peer.inbound
}
fn is_ready(&self) -> bool {
self.inner.ready.load(Ordering::Acquire)
}
fn parallel_work(&self) {
// TODO: refactor
// decrypt
{
let job = &self.inner;
let peer = &job.state.peer;
let mut msg = job.buffer.lock();
let failed = || {
// cast to header followed by payload
let (header, packet): (LayoutVerified<&mut [u8], TransportHeader>, &mut [u8]) =
match LayoutVerified::new_from_prefix(&mut msg.1[..]) {
Some(v) => v,
None => {
log::debug!("inbound worker: failed to parse message");
return;
}
};
// authenticate and decrypt payload
{
// create nonce object
let mut nonce = [0u8; 12];
debug_assert_eq!(nonce.len(), CHACHA20_POLY1305.nonce_len());
nonce[4..].copy_from_slice(header.f_counter.as_bytes());
let nonce = Nonce::assume_unique_for_key(nonce);
// do the weird ring AEAD dance
let key = LessSafeKey::new(
UnboundKey::new(&CHACHA20_POLY1305, &job.state.keypair.recv.key[..]).unwrap(),
);
// attempt to open (and authenticate) the body
match key.open_in_place(nonce, Aad::empty(), packet) {
Ok(_) => (),
Err(_) => {
// fault and return early
log::trace!("inbound worker: authentication failure");
msg.1.truncate(0);
return;
}
}
}
// check that counter not after reject
if header.f_counter.get() >= REJECT_AFTER_MESSAGES {
msg.1.truncate(0);
return;
}
// cryptokey route and strip padding
let inner_len = {
let length = packet.len() - SIZE_TAG;
if length > 0 {
peer.device.table.check_route(&peer, &packet[..length])
} else {
Some(0)
}
};
// truncate to remove tag
match inner_len {
None => {
log::trace!("inbound worker: cryptokey routing failed");
msg.1.truncate(0);
}
Some(len) => {
log::trace!(
"inbound worker: good route, length = {} {}",
len,
if len == 0 { "(keepalive)" } else { "" }
);
msg.1.truncate(mem::size_of::<TransportHeader>() + len);
}
}
};
}
// mark ready
self.inner.ready.store(true, Ordering::Release);
}
fn sequential_work(self) {
let job = &self.inner;
let peer = &job.state.peer;
let mut msg = job.buffer.lock();
// cast transport header
let (header, packet): (LayoutVerified<&[u8], TransportHeader>, &[u8]) =
match LayoutVerified::new_from_prefix(&msg.1[..]) {
Some(v) => v,
None => {
// also covers authentication failure
return;
}
};
// check for replay
if !job.state.protector.lock().update(header.f_counter.get()) {
log::debug!("inbound worker: replay detected");
return;
}
// check for confirms key
if !job.state.confirmed.swap(true, Ordering::SeqCst) {
log::debug!("inbound worker: message confirms key");
peer.confirm_key(&job.state.keypair);
}
// update endpoint
*peer.endpoint.lock() = msg.0.take();
// check if should be written to TUN
let mut sent = false;
if packet.len() > 0 {
sent = match peer.device.inbound.write(&packet[..]) {
Err(e) => {
log::debug!("failed to write inbound packet to TUN: {:?}", e);
false
}
Ok(_) => true,
}
} else {
log::debug!("inbound worker: received keepalive")
}
// trigger callback
C::recv(&peer.opaque, msg.1.len(), sent, &job.state.keypair);
}
}
|
