dkls23/setup/key_export/
receiver.rs

1// Copyright (c) Silence Laboratories Pte. Ltd. All Rights Reserved.
2// This software is licensed under the Silence Laboratories License Agreement.
3
4use super::*;
5
6/// A message used for setting up key export receiving operations in a multi-party computation protocol.
7///
8/// This struct encapsulates all necessary information for receiving an exported key,
9/// including participant information, cryptographic keys, and protocol parameters.
10///
11/// # Type Parameters
12/// * `SK` - The type of signing key used for message signatures
13/// * `VK` - The type of verifying key used to verify message signatures
14/// * `MS` - The type of message signature
15pub struct KeyExportReceiver<
16    SK = NoSigningKey,
17    VK = NoVerifyingKey,
18    MS = NoSignature,
19> {
20    /// ID of the current party
21    party_id: usize,
22    /// Signing key for the current party
23    sk: SK,
24    /// Verifying keys for all participants
25    vk: Vec<VK>,
26    /// Instance identifier for the protocol
27    inst: InstanceId,
28    /// Time-to-live duration for messages
29    ttl: Duration,
30    /// Reference to the keyshare to be received
31    share: Arc<Keyshare>,
32    /// Private key used for decryption
33    enc_key: ReusableSecret,
34    /// Phantom data to hold the message signature type
35    marker: PhantomData<MS>,
36}
37
38impl<SK, VK, MS> KeyExportReceiver<SK, VK, MS> {
39    /// Creates a new setup message for key export receiving operations.
40    ///
41    /// # Arguments
42    /// * `inst` - Instance identifier for the protocol
43    /// * `sk` - Signing key for the current party
44    /// * `party_id` - ID of the current party
45    /// * `vk` - Vector of verifying keys for all participants
46    /// * `share` - Reference to the keyshare to be received
47    /// * `enc_key` - Private key used for decryption
48    ///
49    /// # Returns
50    /// A new `KeyExportReceiver` instance with default TTL
51    pub fn new(
52        inst: InstanceId,
53        sk: SK,
54        party_id: usize,
55        vk: Vec<VK>,
56        share: Arc<Keyshare>,
57        enc_key: ReusableSecret,
58    ) -> Self {
59        Self {
60            party_id,
61            sk,
62            vk,
63            inst,
64            ttl: Duration::from_secs(DEFAULT_TTL),
65            marker: PhantomData,
66            share,
67            enc_key,
68        }
69    }
70
71    /// Sets a custom time-to-live duration for messages.
72    ///
73    /// # Arguments
74    /// * `ttl` - The new time-to-live duration
75    ///
76    /// # Returns
77    /// The modified `KeyExportReceiver` instance
78    pub fn with_ttl(mut self, ttl: Duration) -> Self {
79        self.ttl = ttl;
80        self
81    }
82}
83
84impl<SK, VK, MS> ProtocolParticipant for KeyExportReceiver<SK, VK, MS>
85where
86    SK: Signer<MS>,
87    MS: SignatureEncoding,
88    VK: AsRef<[u8]> + Verifier<MS>,
89{
90    type MessageSignature = MS;
91    type MessageSigner = SK;
92    type MessageVerifier = VK;
93
94    /// Returns the total number of participants in the protocol.
95    fn total_participants(&self) -> usize {
96        self.vk.len()
97    }
98
99    /// Returns the index of the current participant.
100    fn participant_index(&self) -> usize {
101        self.party_id
102    }
103
104    /// Returns the instance identifier for the protocol.
105    fn instance_id(&self) -> &InstanceId {
106        &self.inst
107    }
108
109    /// Returns the time-to-live duration for messages.
110    fn message_ttl(&self) -> Duration {
111        self.ttl
112    }
113
114    /// Returns the verifying key for a specific participant.
115    ///
116    /// # Arguments
117    /// * `index` - The index of the participant
118    ///
119    /// # Returns
120    /// A reference to the verifying key
121    fn verifier(&self, index: usize) -> &Self::MessageVerifier {
122        &self.vk[index]
123    }
124
125    /// Returns the signing key for the current participant.
126    fn signer(&self) -> &Self::MessageSigner {
127        &self.sk
128    }
129}
130
131impl<SK, VK, MS> setup::KeyExportReceiverSetupMessage<ReusableSecret>
132    for KeyExportReceiver<SK, VK, MS>
133where
134    SK: Signer<MS>,
135    MS: SignatureEncoding,
136    VK: AsRef<[u8]> + Verifier<MS>,
137{
138    /// Returns a reference to the keyshare to be received.
139    fn keyshare(&self) -> &Keyshare {
140        &self.share
141    }
142
143    /// Returns the private key used for decryption.
144    fn receiver_private_key(&self) -> &ReusableSecret {
145        &self.enc_key
146    }
147}
dkls23/setup/key_export/receiver.rs

dkls23/setup/key_export/
receiver.rs
