/ src / zk / proof.rs
proof.rs
  1  /* This file is part of DarkFi (https://dark.fi)
  2   *
  3   * Copyright (C) 2020-2025 Dyne.org foundation
  4   *
  5   * This program is free software: you can redistribute it and/or modify
  6   * it under the terms of the GNU Affero General Public License as
  7   * published by the Free Software Foundation, either version 3 of the
  8   * License, or (at your option) any later version.
  9   *
 10   * This program is distributed in the hope that it will be useful,
 11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13   * GNU Affero General Public License for more details.
 14   *
 15   * You should have received a copy of the GNU Affero General Public License
 16   * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 17   */
 18  use std::{io, io::Cursor};
 19  
 20  #[cfg(feature = "async-serial")]
 21  use darkfi_serial::async_trait;
 22  
 23  use darkfi_sdk::pasta::{pallas, vesta};
 24  use darkfi_serial::{SerialDecodable, SerialEncodable};
 25  use halo2_proofs::{
 26      helpers::SerdeFormat,
 27      plonk,
 28      plonk::{Circuit, SingleVerifier},
 29      poly::commitment::Params,
 30      transcript::{Blake2bRead, Blake2bWrite},
 31  };
 32  use rand::RngCore;
 33  
 34  #[derive(Clone, Debug)]
 35  pub struct VerifyingKey {
 36      pub params: Params<vesta::Affine>,
 37      pub vk: plonk::VerifyingKey<vesta::Affine>,
 38  }
 39  
 40  impl VerifyingKey {
 41      pub fn build(k: u32, c: &impl Circuit<pallas::Base>) -> Self {
 42          let params = Params::new(k);
 43          let vk = plonk::keygen_vk(&params, c).unwrap();
 44          VerifyingKey { params, vk }
 45      }
 46  
 47      pub fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
 48          let mut params = vec![];
 49          self.params.write(&mut params)?;
 50  
 51          let mut vk = vec![];
 52          self.vk.write(&mut vk, SerdeFormat::RawBytes)?;
 53  
 54          let _ = writer.write(&(params.len() as u32).to_le_bytes())?;
 55          let _ = writer.write(&params)?;
 56          let _ = writer.write(&(vk.len() as u32).to_le_bytes())?;
 57          let _ = writer.write(&vk)?;
 58  
 59          Ok(())
 60      }
 61  
 62      pub fn read<R: io::Read, ConcreteCircuit: Circuit<pallas::Base>>(
 63          reader: &mut R,
 64          circuit: ConcreteCircuit,
 65      ) -> io::Result<Self> {
 66          // The format chosen in write():
 67          // [params.len()<u32>, params..., vk.len()<u32>, vk...]
 68  
 69          let mut params_len = [0u8; 4];
 70          reader.read_exact(&mut params_len)?;
 71          let params_len = u32::from_le_bytes(params_len) as usize;
 72  
 73          let mut params_buf = vec![0u8; params_len];
 74          reader.read_exact(&mut params_buf)?;
 75  
 76          assert!(params_buf.len() == params_len);
 77  
 78          let mut vk_len = [0u8; 4];
 79          reader.read_exact(&mut vk_len)?;
 80          let vk_len = u32::from_le_bytes(vk_len) as usize;
 81  
 82          let mut vk_buf = vec![0u8; vk_len];
 83          reader.read_exact(&mut vk_buf)?;
 84  
 85          assert!(vk_buf.len() == vk_len);
 86  
 87          let mut params_c = Cursor::new(params_buf);
 88          let params: Params<vesta::Affine> = Params::read(&mut params_c)?;
 89  
 90          let mut vk_c = Cursor::new(vk_buf);
 91          let vk: plonk::VerifyingKey<vesta::Affine> =
 92              plonk::VerifyingKey::read::<Cursor<Vec<u8>>, ConcreteCircuit>(
 93                  &mut vk_c,
 94                  SerdeFormat::RawBytes,
 95                  circuit.params(),
 96              )?;
 97  
 98          Ok(Self { params, vk })
 99      }
100  }
101  
102  #[derive(Clone, Debug)]
103  pub struct ProvingKey {
104      pub params: Params<vesta::Affine>,
105      pub pk: plonk::ProvingKey<vesta::Affine>,
106  }
107  
108  impl ProvingKey {
109      pub fn build(k: u32, c: &impl Circuit<pallas::Base>) -> Self {
110          let params = Params::new(k);
111          let vk = plonk::keygen_vk(&params, c).unwrap();
112          let pk = plonk::keygen_pk(&params, vk, c).unwrap();
113          ProvingKey { params, pk }
114      }
115  
116      pub fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
117          let mut params = vec![];
118          self.params.write(&mut params)?;
119  
120          let mut pk = vec![];
121          self.pk.write(&mut pk, SerdeFormat::RawBytes)?;
122  
123          let _ = writer.write(&(params.len() as u32).to_le_bytes())?;
124          let _ = writer.write(&params)?;
125          let _ = writer.write(&(pk.len() as u32).to_le_bytes())?;
126          let _ = writer.write(&pk)?;
127  
128          Ok(())
129      }
130  
131      pub fn read<R: io::Read, ConcreteCircuit: Circuit<pallas::Base>>(
132          reader: &mut R,
133          circuit: ConcreteCircuit,
134      ) -> io::Result<Self> {
135          let mut params_len = [0u8; 4];
136          reader.read_exact(&mut params_len)?;
137          let params_len = u32::from_le_bytes(params_len) as usize;
138  
139          let mut params_buf = vec![0u8; params_len];
140          reader.read_exact(&mut params_buf)?;
141  
142          assert!(params_buf.len() == params_len);
143  
144          let mut pk_len = [0u8; 4];
145          reader.read_exact(&mut pk_len)?;
146          let pk_len = u32::from_le_bytes(pk_len) as usize;
147  
148          let mut pk_buf = vec![0u8; pk_len];
149          reader.read_exact(&mut pk_buf)?;
150  
151          assert!(pk_buf.len() == pk_len);
152  
153          let mut params_c = Cursor::new(params_buf);
154          let params: Params<vesta::Affine> = Params::read(&mut params_c)?;
155  
156          let mut pk_c = Cursor::new(pk_buf);
157          let pk: plonk::ProvingKey<vesta::Affine> =
158              plonk::ProvingKey::read::<Cursor<Vec<u8>>, ConcreteCircuit>(
159                  &mut pk_c,
160                  SerdeFormat::RawBytes,
161                  circuit.params(),
162              )?;
163  
164          Ok(Self { params, pk })
165      }
166  }
167  
168  #[derive(Clone, Default, PartialEq, Eq, SerialEncodable, SerialDecodable)]
169  pub struct Proof(Vec<u8>);
170  
171  impl AsRef<[u8]> for Proof {
172      fn as_ref(&self) -> &[u8] {
173          &self.0
174      }
175  }
176  
177  impl core::fmt::Debug for Proof {
178      fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
179          write!(f, "Proof({:?})", self.0)
180      }
181  }
182  
183  impl Proof {
184      pub fn create(
185          pk: &ProvingKey,
186          circuits: &[impl Circuit<pallas::Base>],
187          instances: &[pallas::Base],
188          mut rng: impl RngCore,
189      ) -> std::result::Result<Self, plonk::Error> {
190          let mut transcript = Blake2bWrite::<_, vesta::Affine, _>::init(vec![]);
191          plonk::create_proof(
192              &pk.params,
193              &pk.pk,
194              circuits,
195              &[&[instances]],
196              &mut rng,
197              &mut transcript,
198          )?;
199  
200          Ok(Proof(transcript.finalize()))
201      }
202  
203      pub fn verify(
204          &self,
205          vk: &VerifyingKey,
206          instances: &[pallas::Base],
207      ) -> std::result::Result<(), plonk::Error> {
208          let strategy = SingleVerifier::new(&vk.params);
209          let mut transcript = Blake2bRead::init(&self.0[..]);
210  
211          plonk::verify_proof(&vk.params, &vk.vk, strategy, &[&[instances]], &mut transcript)
212      }
213  
214      pub fn new(bytes: Vec<u8>) -> Self {
215          Proof(bytes)
216      }
217  }