hotshot_types/
vote.rs

1// Copyright (c) 2021-2024 Espresso Systems (espressosys.com)
2// This file is part of the HotShot repository.
3
4// You should have received a copy of the MIT License
5// along with the HotShot repository. If not, see <https://mit-license.org/>.
6
7//! Vote, Accumulator, and Certificate Types
8
9use std::{
10    collections::{BTreeMap, HashMap},
11    future::Future,
12    marker::PhantomData,
13};
14
15use alloy::primitives::{FixedBytes, U256};
16use bitvec::{bitvec, vec::BitVec};
17use committable::{Commitment, Committable};
18use hotshot_utils::anytrace::*;
19use tracing::error;
20
21use crate::{
22    PeerConfig,
23    data::ViewNumber,
24    epoch_membership::EpochMembership,
25    light_client::{LightClientState, StakeTableState},
26    message::UpgradeLock,
27    simple_certificate::{LightClientStateUpdateCertificateV2, Threshold},
28    simple_vote::{LightClientStateUpdateVote2, VersionedVoteData, Voteable},
29    stake_table::{HSStakeTable, StakeTableEntries},
30    traits::{
31        node_implementation::NodeType,
32        signature_key::{
33            LCV2StateSignatureKey, LCV3StateSignatureKey, SignatureKey, StakeTableEntryType,
34            StateSignatureKey,
35        },
36    },
37};
38
39/// A simple vote that has a signer and commitment to the data voted on.
40pub trait Vote<TYPES: NodeType>: HasViewNumber {
41    /// Type of data commitment this vote uses.
42    type Commitment: Voteable<TYPES>;
43
44    /// Get the signature of the vote sender
45    fn signature(&self) -> <TYPES::SignatureKey as SignatureKey>::PureAssembledSignatureType;
46    /// Gets the data which was voted on by this vote
47    fn date(&self) -> &Self::Commitment;
48    /// Gets the Data commitment of the vote
49    fn data_commitment(&self) -> Commitment<Self::Commitment>;
50
51    /// Gets the public signature key of the votes creator/sender
52    fn signing_key(&self) -> TYPES::SignatureKey;
53}
54
55/// Any type that is associated with a view
56pub trait HasViewNumber {
57    /// Returns the view number the type refers to.
58    fn view_number(&self) -> ViewNumber;
59}
60
61/**
62The certificate formed from the collection of signatures a committee.
63The committee is defined by the `Membership` associated type.
64The votes all must be over the `Commitment` associated type.
65*/
66pub trait Certificate<TYPES: NodeType, T>: HasViewNumber {
67    /// The data commitment this certificate certifies.
68    type Voteable: Voteable<TYPES>;
69
70    /// Threshold Functions
71    type Threshold: Threshold<TYPES>;
72
73    /// Build a certificate from the data commitment and the quorum of signers
74    fn create_signed_certificate(
75        vote_commitment: Commitment<VersionedVoteData<TYPES, Self::Voteable>>,
76        data: Self::Voteable,
77        sig: <TYPES::SignatureKey as SignatureKey>::QcType,
78        view: ViewNumber,
79    ) -> Self;
80
81    /// Checks if the cert is valid in the given epoch
82    fn is_valid_cert(
83        &self,
84        stake_table: &[<TYPES::SignatureKey as SignatureKey>::StakeTableEntry],
85        threshold: U256,
86        upgrade_lock: &UpgradeLock<TYPES>,
87    ) -> impl std::future::Future<Output = Result<()>>;
88    /// Get the list of signers given a certificate.
89    fn signers(
90        &self,
91        stake_table: &[<TYPES::SignatureKey as SignatureKey>::StakeTableEntry],
92        threshold: U256,
93    ) -> Result<Vec<<TYPES::SignatureKey as SignatureKey>::VerificationKeyType>>;
94    /// Returns the amount of stake needed to create this certificate
95    // TODO: Make this a static ratio of the total stake of `Membership`
96    fn threshold(membership: &EpochMembership<TYPES>) -> impl Future<Output = U256> + Send;
97
98    /// Get  Stake Table from Membership implementation.
99    fn stake_table(
100        membership: &EpochMembership<TYPES>,
101    ) -> impl Future<Output = HSStakeTable<TYPES>> + Send;
102
103    /// Get Total Nodes from Membership implementation.
104    fn total_nodes(membership: &EpochMembership<TYPES>) -> impl Future<Output = usize> + Send;
105
106    /// Get  `StakeTableEntry` from Membership implementation.
107    fn stake_table_entry(
108        membership: &EpochMembership<TYPES>,
109        pub_key: &TYPES::SignatureKey,
110    ) -> impl Future<Output = Option<PeerConfig<TYPES>>> + Send;
111
112    /// Get the commitment which was voted on
113    fn data(&self) -> &Self::Voteable;
114
115    /// Get the vote commitment which the votes commit to
116    fn data_commitment(
117        &self,
118        upgrade_lock: &UpgradeLock<TYPES>,
119    ) -> impl std::future::Future<Output = Result<Commitment<VersionedVoteData<TYPES, Self::Voteable>>>>;
120}
121/// Mapping of vote commitment to signatures and bitvec
122type SignersMap<COMMITMENT, KEY> = HashMap<
123    COMMITMENT,
124    (
125        BitVec,
126        Vec<<KEY as SignatureKey>::PureAssembledSignatureType>,
127    ),
128>;
129
130#[allow(clippy::type_complexity)]
131/// Accumulates votes until a certificate is formed.  This implementation works for all simple vote and certificate pairs
132pub struct VoteAccumulator<
133    TYPES: NodeType,
134    VOTE: Vote<TYPES>,
135    CERT: Certificate<TYPES, VOTE::Commitment, Voteable = VOTE::Commitment>,
136> {
137    /// Map of all signatures accumulated so far
138    pub vote_outcomes: VoteMap2<
139        Commitment<VersionedVoteData<TYPES, <VOTE as Vote<TYPES>>::Commitment>>,
140        TYPES::SignatureKey,
141        <TYPES::SignatureKey as SignatureKey>::PureAssembledSignatureType,
142    >,
143    /// A bitvec to indicate which node is active and send out a valid signature for certificate aggregation, this automatically do uniqueness check
144    /// And a list of valid signatures for certificate aggregation
145    pub signers: SignersMap<
146        Commitment<VersionedVoteData<TYPES, <VOTE as Vote<TYPES>>::Commitment>>,
147        TYPES::SignatureKey,
148    >,
149    /// Phantom data to specify the types this accumulator is for
150    pub phantom: PhantomData<(TYPES, VOTE, CERT)>,
151    /// version information
152    pub upgrade_lock: UpgradeLock<TYPES>,
153}
154
155impl<
156    TYPES: NodeType,
157    VOTE: Vote<TYPES>,
158    CERT: Certificate<TYPES, VOTE::Commitment, Voteable = VOTE::Commitment>,
159> VoteAccumulator<TYPES, VOTE, CERT>
160{
161    /// Add a vote to the total accumulated votes for the given epoch.
162    /// Returns the accumulator or the certificate if we
163    /// have accumulated enough votes to exceed the threshold for creating a certificate.
164    pub async fn accumulate(
165        &mut self,
166        vote: &VOTE,
167        membership: EpochMembership<TYPES>,
168    ) -> Option<CERT> {
169        let key = vote.signing_key();
170
171        let vote_commitment = match VersionedVoteData::new(
172            vote.date().clone(),
173            vote.view_number(),
174            &self.upgrade_lock,
175        )
176        .await
177        {
178            Ok(data) => data.commit(),
179            Err(e) => {
180                tracing::warn!("Failed to generate versioned vote data: {e}");
181                return None;
182            },
183        };
184
185        if !key.validate(&vote.signature(), vote_commitment.as_ref()) {
186            error!("Invalid vote! Vote Data {:?}", vote.date());
187            return None;
188        }
189
190        let stake_table_entry = CERT::stake_table_entry(&membership, &key).await?;
191        let stake_table = CERT::stake_table(&membership).await;
192        let total_nodes = CERT::total_nodes(&membership).await;
193        let threshold = CERT::threshold(&membership).await;
194
195        let vote_node_id = stake_table
196            .iter()
197            .position(|x| *x == stake_table_entry.clone())?;
198
199        let original_signature: <TYPES::SignatureKey as SignatureKey>::PureAssembledSignatureType =
200            vote.signature();
201
202        let (total_stake_casted, total_vote_map) = self
203            .vote_outcomes
204            .entry(vote_commitment)
205            .or_insert_with(|| (U256::from(0), BTreeMap::new()));
206
207        // Check for duplicate vote
208        if total_vote_map.contains_key(&key) {
209            return None;
210        }
211        let (signers, sig_list) = self
212            .signers
213            .entry(vote_commitment)
214            .or_insert((bitvec![0; total_nodes], Vec::new()));
215        if signers.get(vote_node_id).as_deref() == Some(&true) {
216            error!("Node id is already in signers list");
217            return None;
218        }
219        signers.set(vote_node_id, true);
220        sig_list.push(original_signature);
221
222        *total_stake_casted += stake_table_entry.stake_table_entry.stake();
223        total_vote_map.insert(key, (vote.signature(), vote_commitment));
224
225        if *total_stake_casted >= threshold {
226            // Assemble QC
227            let stake_table_entries = StakeTableEntries::<TYPES>::from(stake_table).0;
228            let real_qc_pp: <<TYPES as NodeType>::SignatureKey as SignatureKey>::QcParams<'_> =
229                <TYPES::SignatureKey as SignatureKey>::public_parameter(
230                    &stake_table_entries,
231                    threshold,
232                );
233
234            let real_qc_sig = <TYPES::SignatureKey as SignatureKey>::assemble(
235                &real_qc_pp,
236                signers.as_bitslice(),
237                &sig_list[..],
238            );
239
240            let cert = CERT::create_signed_certificate(
241                vote_commitment,
242                vote.date().clone(),
243                real_qc_sig,
244                vote.view_number(),
245            );
246            return Some(cert);
247        }
248        None
249    }
250}
251
252/// Mapping of commitments to vote tokens by key.
253type VoteMap2<COMMITMENT, PK, SIG> = HashMap<COMMITMENT, (U256, BTreeMap<PK, (SIG, COMMITMENT)>)>;
254
255/// Accumulator for light client state update vote
256#[allow(clippy::type_complexity)]
257pub struct LightClientStateUpdateVoteAccumulator<TYPES: NodeType> {
258    pub vote_outcomes: HashMap<
259        (LightClientState, StakeTableState, FixedBytes<32>),
260        (
261            U256,
262            HashMap<
263                TYPES::StateSignatureKey,
264                (
265                    <TYPES::StateSignatureKey as StateSignatureKey>::StateSignature, // LCV3 signature
266                    <TYPES::StateSignatureKey as StateSignatureKey>::StateSignature, // LCV2 signature
267                ),
268            >,
269        ),
270    >,
271
272    pub upgrade_lock: UpgradeLock<TYPES>,
273}
274
275impl<TYPES: NodeType> LightClientStateUpdateVoteAccumulator<TYPES> {
276    /// Add a vote to the total accumulated votes for the given epoch.
277    /// Returns the accumulator or the certificate if we
278    /// have accumulated enough votes to exceed the threshold for creating a certificate.
279    pub async fn accumulate(
280        &mut self,
281        key: &TYPES::SignatureKey,
282        vote: &LightClientStateUpdateVote2<TYPES>,
283        membership: &EpochMembership<TYPES>,
284    ) -> Option<LightClientStateUpdateCertificateV2<TYPES>> {
285        let epoch = membership.epoch()?;
286        let threshold = membership.success_threshold().await;
287        let PeerConfig {
288            stake_table_entry,
289            state_ver_key,
290            ..
291        } = membership.stake(key).await?;
292
293        if !<TYPES::StateSignatureKey as LCV2StateSignatureKey>::verify_state_sig(
294            &state_ver_key,
295            &vote.v2_signature,
296            &vote.light_client_state,
297            &vote.next_stake_table_state,
298        ) {
299            error!("Invalid light client state update vote {vote:?}");
300            return None;
301        }
302        // only verify the new state signature on the new version
303        if self
304            .upgrade_lock
305            .proposal2_version(ViewNumber::new(vote.light_client_state.view_number))
306            && !<TYPES::StateSignatureKey as LCV3StateSignatureKey>::verify_state_sig(
307                &state_ver_key,
308                &vote.signature,
309                vote.signed_state_digest,
310            )
311        {
312            error!("Invalid light client state update vote {vote:?}");
313            return None;
314        }
315        let (total_stake_casted, vote_map) = self
316            .vote_outcomes
317            .entry((
318                vote.light_client_state,
319                vote.next_stake_table_state,
320                vote.auth_root,
321            ))
322            .or_insert_with(|| (U256::from(0), HashMap::new()));
323
324        // Check for duplicate vote
325        if vote_map.contains_key(&state_ver_key) {
326            tracing::warn!("Duplicate vote (key: {key:?}, vote: {vote:?})");
327            return None;
328        }
329
330        *total_stake_casted += stake_table_entry.stake();
331        vote_map.insert(
332            state_ver_key.clone(),
333            (vote.signature.clone(), vote.v2_signature.clone()),
334        );
335
336        if *total_stake_casted >= threshold {
337            return Some(LightClientStateUpdateCertificateV2 {
338                epoch,
339                light_client_state: vote.light_client_state,
340                next_stake_table_state: vote.next_stake_table_state,
341                signatures: Vec::from_iter(
342                    vote_map
343                        .iter()
344                        .map(|(k, (v3, v2))| (k.clone(), v3.clone(), v2.clone())),
345                ),
346                auth_root: vote.auth_root,
347            });
348        }
349        None
350    }
351}
hotshot_types/vote.rs

hotshot_types/
vote.rs
