rs_matter/
group_keys.rs

1/*
2 *
3 *    Copyright (c) 2022-2026 Project CHIP Authors
4 *
5 *    Licensed under the Apache License, Version 2.0 (the "License");
6 *    you may not use this file except in compliance with the License.
7 *    You may obtain a copy of the License at
8 *
9 *        http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *    Unless required by applicable law or agreed to in writing, software
12 *    distributed under the License is distributed on an "AS IS" BASIS,
13 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *    See the License for the specific language governing permissions and
15 *    limitations under the License.
16 */
17
18use crate::crypto::{self, CanonAeadKey, CanonAeadKeyRef, Crypto, Kdf};
19use crate::error::{Error, ErrorCode};
20use crate::tlv::{FromTLV, ToTLV};
21use crate::utils::init::{init, Init};
22#[cfg(feature = "groups")]
23use crate::utils::storage::Vec;
24
25#[cfg(feature = "groups")]
26pub const GROUP_MAX_EPOCH_KEYS: usize = 3;
27
28/// A stored group key set entry.
29#[cfg(feature = "groups")]
30#[derive(Debug, Clone, Default, FromTLV, ToTLV)]
31#[cfg_attr(feature = "defmt", derive(defmt::Format))]
32pub struct GroupEpochKeyEntry {
33    pub epoch_key: CanonAeadKey,
34    pub epoch_start_time: u64,
35}
36
37/// A stored group key set entry.
38#[cfg(feature = "groups")]
39#[derive(Debug, Clone, Default, FromTLV, ToTLV)]
40#[cfg_attr(feature = "defmt", derive(defmt::Format))]
41pub struct GroupKeySet {
42    pub group_key_set_id: u16,
43    pub group_key_security_policy: u8,
44    pub epoch_keys: Vec<GroupEpochKeyEntry, GROUP_MAX_EPOCH_KEYS>,
45}
46
47#[derive(Debug, Default, FromTLV, ToTLV)]
48#[cfg_attr(feature = "defmt", derive(defmt::Format))]
49pub struct KeySet {
50    pub epoch_key: CanonAeadKey,
51    pub op_key: CanonAeadKey,
52}
53
54impl KeySet {
55    pub const fn new() -> Self {
56        Self {
57            epoch_key: crypto::AEAD_KEY_ZEROED,
58            op_key: crypto::AEAD_KEY_ZEROED,
59        }
60    }
61
62    pub fn init() -> impl Init<Self> {
63        init!(Self {
64            epoch_key <- CanonAeadKey::init(),
65            op_key <- CanonAeadKey::init(),
66        })
67    }
68
69    pub fn update<C: Crypto>(
70        &mut self,
71        crypto: C,
72        epoch_key: CanonAeadKeyRef<'_>,
73        compressed_fabric_id: &u64,
74    ) -> Result<(), Error> {
75        const GRP_KEY_INFO: &[u8] = &[
76            0x47, 0x72, 0x6f, 0x75, 0x70, 0x4b, 0x65, 0x79, 0x20, 0x76, 0x31, 0x2e, 0x30,
77        ];
78
79        crypto
80            .kdf()?
81            .expand(
82                &compressed_fabric_id.to_be_bytes(),
83                epoch_key,
84                GRP_KEY_INFO,
85                &mut self.op_key,
86            )
87            .map_err(|_| ErrorCode::InvalidData)?;
88
89        self.epoch_key.load(epoch_key);
90
91        Ok(())
92    }
93
94    pub fn op_key(&self) -> CanonAeadKeyRef<'_> {
95        self.op_key.reference()
96    }
97
98    pub fn epoch_key(&self) -> CanonAeadKeyRef<'_> {
99        self.epoch_key.reference()
100    }
101}
rs_matter/group_keys.rs

rs_matter/
group_keys.rs
