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
189
190
191
use super::{
KeyDescriptorLookup, KeyIdentifierMode, SecurityContext, SecurityControl,
};
use byte::{BytesExt, TryRead, TryWrite, LE};
use cipher::{consts::U16, BlockCipher, NewBlockCipher};
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct AuxiliarySecurityHeader {
pub control: SecurityControl,
pub(crate) frame_counter: u32,
pub key_identifier: Option<KeyIdentifier>,
}
impl AuxiliarySecurityHeader {
pub fn get_octet_size(&self) -> usize {
let length = 1
+ 4
+ match self.key_identifier {
Some(key_id) => match key_id.key_source {
Some(source) => match source {
KeySource::Short(_) => 5,
KeySource::Long(_) => 9,
},
None => 1,
},
None => 0,
};
length
}
pub fn new(
control: SecurityControl,
key_identifier: Option<KeyIdentifier>,
) -> Self {
Self {
control,
key_identifier,
frame_counter: 0,
}
}
pub unsafe fn new_unsafe(
control: SecurityControl,
key_identifier: Option<KeyIdentifier>,
frame_counter: u32,
) -> Self {
Self {
control,
key_identifier,
frame_counter,
}
}
pub fn get_frame_counter(&self) -> u32 {
self.frame_counter
}
}
impl TryRead<'_> for AuxiliarySecurityHeader {
fn try_read(bytes: &[u8], _ctx: ()) -> byte::Result<(Self, usize)> {
let offset = &mut 0;
let control: SecurityControl = bytes.read(offset)?;
let frame_counter = bytes.read_with(offset, LE)?;
let mut header = AuxiliarySecurityHeader {
control,
frame_counter,
key_identifier: None,
};
if control.key_id_mode != KeyIdentifierMode::None {
let mut key_identifier = KeyIdentifier {
key_source: None,
key_index: 0,
};
match control.key_id_mode {
KeyIdentifierMode::KeySource4 => {
key_identifier.key_source =
Some(KeySource::Short(bytes.read(offset)?));
}
KeyIdentifierMode::KeySource8 => {
key_identifier.key_source =
Some(KeySource::Long(bytes.read(offset)?));
}
_ => {}
}
let key_index = bytes.read(offset)?;
key_identifier.key_index = key_index;
header.key_identifier = Some(key_identifier);
}
Ok((header, *offset))
}
}
impl<AEADBLKCIPH, KEYDESCLO> TryWrite<&SecurityContext<AEADBLKCIPH, KEYDESCLO>>
for AuxiliarySecurityHeader
where
AEADBLKCIPH: NewBlockCipher + BlockCipher<BlockSize = U16>,
KEYDESCLO: KeyDescriptorLookup<AEADBLKCIPH::KeySize>,
{
fn try_write(
mut self,
bytes: &mut [u8],
sec_ctx: &SecurityContext<AEADBLKCIPH, KEYDESCLO>,
) -> byte::Result<usize> {
let offset = &mut 0;
self.control.key_id_mode = match self.key_identifier {
Some(key_id) => match key_id.key_source {
Some(key_source) => match key_source {
KeySource::Short(_) => KeyIdentifierMode::KeySource4,
KeySource::Long(_) => KeyIdentifierMode::KeySource8,
},
None => KeyIdentifierMode::KeyIndex,
},
None => KeyIdentifierMode::None,
};
bytes.write(offset, self.control)?;
bytes.write(offset, sec_ctx.frame_counter)?;
match self.key_identifier {
Some(key_identifier) => {
bytes.write(offset, key_identifier)?;
}
_ => {}
}
Ok(*offset)
}
}
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct KeyIdentifier {
pub key_source: Option<KeySource>,
pub key_index: u8,
}
impl TryWrite for KeyIdentifier {
fn try_write(self, bytes: &mut [u8], _ctx: ()) -> byte::Result<usize> {
let offset = &mut 0;
match self.key_source {
Some(source) => match source {
KeySource::Short(src) => bytes.write(offset, src)?,
KeySource::Long(src) => bytes.write(offset, src)?,
},
_ => {}
}
bytes.write(offset, self.key_index)?;
Ok(*offset)
}
}
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub enum KeySource {
Short(u32),
Long(u64),
}