hotshot_types/
stake_table.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//! Types and structs related to the stake table
8
9use alloy::primitives::U256;
10use ark_ff::PrimeField;
11use derive_more::derive::{Deref, DerefMut};
12use jf_crhf::CRHF;
13use jf_rescue::crhf::VariableLengthRescueCRHF;
14use serde::{Deserialize, Serialize};
15
16use crate::{
17    light_client::{CircuitField, StakeTableState, ToFieldsLightClientCompat},
18    traits::signature_key::{SignatureKey, StakeTableEntryType},
19    NodeType, PeerConfig,
20};
21
22/// Stake table entry
23#[derive(Serialize, Deserialize, PartialEq, Debug, Clone, Hash, Eq)]
24#[serde(bound(deserialize = ""))]
25pub struct StakeTableEntry<K: SignatureKey> {
26    /// The public key
27    pub stake_key: K,
28    /// The associated stake amount
29    pub stake_amount: U256,
30}
31
32impl<K: SignatureKey> StakeTableEntryType<K> for StakeTableEntry<K> {
33    /// Get the stake amount
34    fn stake(&self) -> U256 {
35        self.stake_amount
36    }
37
38    /// Get the public key
39    fn public_key(&self) -> K {
40        self.stake_key.clone()
41    }
42}
43
44impl<K: SignatureKey> StakeTableEntry<K> {
45    /// Get the public key
46    pub fn key(&self) -> &K {
47        &self.stake_key
48    }
49}
50
51#[derive(Debug, Clone, PartialEq, Eq, Hash, Default, Deref, DerefMut)]
52pub struct HSStakeTable<TYPES: NodeType>(pub Vec<PeerConfig<TYPES>>);
53
54impl<TYPES: NodeType> From<Vec<PeerConfig<TYPES>>> for HSStakeTable<TYPES> {
55    fn from(peers: Vec<PeerConfig<TYPES>>) -> Self {
56        Self(peers)
57    }
58}
59
60#[inline]
61/// A helper function to compute the quorum threshold given a total amount of stake.
62pub fn one_honest_threshold(total_stake: U256) -> U256 {
63    total_stake / U256::from(3) + U256::from(1)
64}
65
66#[inline]
67fn u256_to_field(amount: U256) -> CircuitField {
68    let amount_bytes: [u8; 32] = amount.to_le_bytes();
69    CircuitField::from_le_bytes_mod_order(&amount_bytes)
70}
71
72impl<TYPES: NodeType> std::iter::IntoIterator for HSStakeTable<TYPES> {
73    type Item = PeerConfig<TYPES>;
74    type IntoIter = std::vec::IntoIter<PeerConfig<TYPES>>;
75
76    fn into_iter(self) -> Self::IntoIter {
77        self.0.into_iter()
78    }
79}
80
81impl<TYPES: NodeType> HSStakeTable<TYPES> {
82    pub fn commitment(&self, stake_table_capacity: usize) -> anyhow::Result<StakeTableState> {
83        if stake_table_capacity < self.0.len() {
84            return Err(anyhow::anyhow!(
85                "Stake table over capacity: {} < {}",
86                stake_table_capacity,
87                self.0.len(),
88            ));
89        }
90        let padding_len = stake_table_capacity - self.0.len();
91        let mut bls_preimage = vec![];
92        let mut schnorr_preimage = vec![];
93        let mut amount_preimage = vec![];
94        let mut total_stake = U256::from(0);
95        for peer in &self.0 {
96            bls_preimage.extend(peer.stake_table_entry.public_key().to_fields());
97            schnorr_preimage.extend(peer.state_ver_key.to_fields());
98            amount_preimage.push(u256_to_field(peer.stake_table_entry.stake()));
99            total_stake += peer.stake_table_entry.stake();
100        }
101        bls_preimage.resize(
102            <TYPES::SignatureKey as ToFieldsLightClientCompat>::SIZE * stake_table_capacity,
103            CircuitField::default(),
104        );
105        // Nasty tech debt
106        schnorr_preimage.extend(
107            std::iter::repeat_n(TYPES::StateSignatureKey::default().to_fields(), padding_len)
108                .flatten(),
109        );
110        amount_preimage.resize(stake_table_capacity, CircuitField::default());
111        let threshold = u256_to_field(one_honest_threshold(total_stake));
112        Ok(StakeTableState {
113            bls_key_comm: VariableLengthRescueCRHF::<CircuitField, 1>::evaluate(bls_preimage)
114                .unwrap()[0],
115            schnorr_key_comm: VariableLengthRescueCRHF::<CircuitField, 1>::evaluate(
116                schnorr_preimage,
117            )
118            .unwrap()[0],
119            amount_comm: VariableLengthRescueCRHF::<CircuitField, 1>::evaluate(amount_preimage)
120                .unwrap()[0],
121            threshold,
122        })
123    }
124
125    pub fn total_stakes(&self) -> U256 {
126        self.0
127            .iter()
128            .map(|peer| peer.stake_table_entry.stake())
129            .sum()
130    }
131}
132
133pub struct StakeTableEntries<TYPES: NodeType>(
134    pub Vec<<<TYPES as NodeType>::SignatureKey as SignatureKey>::StakeTableEntry>,
135);
136
137impl<TYPES: NodeType> From<Vec<PeerConfig<TYPES>>> for StakeTableEntries<TYPES> {
138    fn from(peers: Vec<PeerConfig<TYPES>>) -> Self {
139        Self(
140            peers
141                .into_iter()
142                .map(|peer| peer.stake_table_entry)
143                .collect::<Vec<_>>(),
144        )
145    }
146}
147
148impl<TYPES: NodeType> From<HSStakeTable<TYPES>> for StakeTableEntries<TYPES> {
149    fn from(stake_table: HSStakeTable<TYPES>) -> Self {
150        Self::from(stake_table.0)
151    }
152}
hotshot_types/stake_table.rs

hotshot_types/
stake_table.rs
