1use anyhow::Result;
 2use plonky2::hash::merkle_tree::MerkleTree;
 3use plonky2::hash::poseidon::PoseidonHash;
 4use plonky2::iop::witness::PartialWitness;
 5use plonky2::plonk::circuit_builder::CircuitBuilder;
 6use plonky2::plonk::circuit_data::{CircuitConfig, VerifierCircuitData};
 7use plonky2::plonk::config::Hasher;
 8use plonky2::plonk::proof::ProofWithPublicInputs;
 9
10use crate::signal::{Digest, Signal, C, F};
11
12pub struct AccessSet(pub MerkleTree<F, PoseidonHash>);
13
14impl AccessSet {
15    // Verify the plonky2 proof of the given nullifier (in the signal structure) and topic.
16    pub fn verify_signal(
17        &self,
18        topic: Digest,
19        signal: Signal,
20        verifier_data: &VerifierCircuitData<F, C, 2>,
21    ) -> Result<()> {
22        let public_inputs: Vec<F> = self
23            .0
24            .cap
25            .0
26            .iter()
27            .flat_map(|h| h.elements)
28            .chain(signal.nullifier)
29            .chain(topic)
30            .collect();
31
32        verifier_data.verify(ProofWithPublicInputs {
33            proof: signal.proof,
34            public_inputs,
35        })
36    }
37
38    // Generate the plonky2 proof for the given key pair and topic.
39    pub fn make_signal(
40        &self,
41        private_key: Digest,
42        topic: Digest,
43        public_key_index: usize,
44    ) -> Result<(Signal, VerifierCircuitData<F, C, 2>)> {
45        let nullifier = PoseidonHash::hash_no_pad(&[private_key, topic].concat()).elements;
46        let config = CircuitConfig::standard_recursion_zk_config();
47        let mut builder = CircuitBuilder::new(config);
48        let mut pw = PartialWitness::new();
49
50        let targets = self.semaphore_circuit(&mut builder);
51        self.fill_semaphore_targets(&mut pw, private_key, topic, public_key_index, targets)?;
52
53        let data = builder.build();
54        let proof = data.prove(pw)?;
55
56        Ok((
57            Signal {
58                nullifier,
59                proof: proof.proof,
60            },
61            data.verifier_data(),
62        ))
63    }
64}