feat(nargo): Update nargo to use preprocessing interface (#765)

* initial preprocess cmd to test backend changes * cargo lock merge conflicts * initial work using preprocess for nargo proving and verification, still have non-deterministic error on backend with C++ * use fixed up aztec_backend for preprocess * moving preprocess into compile command * use nargo compile to preprocess no more preprocess cmd * remove preprocess cmd file * remove TODO from nargo cargo.toml * add checking of acir file in nargo prove * switch to using circuit_path for pk and vk paths, compare compiled circuit to one written to file * add logic to look at checksum of acir rather than the file byte by bte * remove debug * cargo update * remove unnecessary comments * switch backend reference to updated composer * when build artifacts are not provided to nargo prove, preprocess as a fallback, still needs to be done for verification * move fetch_pk_and_vk into main nargo module, also use hash cs method from acvm * move path specifications to separate method in nargo commands * comment in compile cmd * nit comments and cspell * update aztec_backend commit rev * cargo fmt after merge
noir-lang · Feb 16, 2023 · b3f1556 · b3f1556
1 parent 98acb5a
commit b3f1556
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Showing 10 changed files with 227 additions and 43 deletions.
diff --git a/.gitignore b/.gitignore
@@ -9,5 +9,8 @@ pkg/
 # Nargo output
 *.proof
 *.acir
+*.acir.sha256
 *.tr
+*.pk
+*.vk
 **/Verifier.toml
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/crates/nargo/Cargo.toml b/crates/nargo/Cargo.toml
@@ -31,8 +31,8 @@ termcolor = "1.1.2"
 tempdir = "0.3.7"
 
 # Backends
-aztec_backend = { optional = true, package = "barretenberg_static_lib", git = "https://github.com/noir-lang/aztec_backend", rev = "d0e1257c22618f98f53781faba3c372ef91a0172" }
-aztec_wasm_backend = { optional = true, package = "barretenberg_wasm", git = "https://github.com/noir-lang/aztec_backend", rev = "d0e1257c22618f98f53781faba3c372ef91a0172" }
+aztec_backend = { optional = true, package = "barretenberg_static_lib", git = "https://github.com/noir-lang/aztec_backend", rev = "cff757dca7971161e4bd25e7a744d910c37c22be" }
+aztec_wasm_backend = { optional = true, package = "barretenberg_wasm", git = "https://github.com/noir-lang/aztec_backend", rev = "cff757dca7971161e4bd25e7a744d910c37c22be" }
 marlin_arkworks_backend = { optional = true, git = "https://github.com/noir-lang/marlin_arkworks_backend", rev = "144378edad821bfaa52bf2cacca8ecc87514a4fc" }
 color-eyre = "0.6.2"
 

diff --git a/crates/nargo/src/cli/compile_cmd.rs b/crates/nargo/src/cli/compile_cmd.rs
@@ -1,13 +1,13 @@
-use clap::ArgMatches;
-use std::path::{Path, PathBuf};
-
 use acvm::ProofSystemCompiler;
+use acvm::{acir::circuit::Circuit, hash_constraint_system};
+use clap::ArgMatches;
 use noirc_abi::input_parser::Format;
+use std::path::{Path, PathBuf};
 
 use super::{add_std_lib, create_named_dir, read_inputs_from_file, write_to_file};
 use crate::{
     cli::execute_cmd::save_witness_to_dir,
-    constants::{ACIR_EXT, PROVER_INPUT_FILE, TARGET_DIR},
+    constants::{ACIR_EXT, PK_EXT, PROVER_INPUT_FILE, TARGET_DIR, VK_EXT},
     errors::CliError,
     resolver::Resolver,
 };
@@ -33,7 +33,6 @@ pub(crate) fn run(args: ArgMatches) -> Result<(), CliError> {
     .map(|_| ())
 }
 
-#[allow(deprecated)]
 pub fn generate_circuit_and_witness_to_disk<P: AsRef<Path>>(
     circuit_name: &str,
     program_dir: P,
@@ -42,13 +41,12 @@ pub fn generate_circuit_and_witness_to_disk<P: AsRef<Path>>(
     allow_warnings: bool,
 ) -> Result<PathBuf, CliError> {
     let compiled_program = compile_circuit(program_dir.as_ref(), false, allow_warnings)?;
-    let serialized = compiled_program.circuit.to_bytes();
 
-    let mut circuit_path = create_named_dir(circuit_dir.as_ref(), "build");
-    circuit_path.push(circuit_name);
-    circuit_path.set_extension(ACIR_EXT);
-    let path = write_to_file(serialized.as_slice(), &circuit_path);
-    println!("Generated ACIR code into {path}");
+    preprocess_with_path(circuit_name, circuit_dir.as_ref(), compiled_program.circuit.clone())?;
+
+    let mut circuit_path =
+        save_acir_to_dir(compiled_program.circuit.clone(), circuit_name, circuit_dir.as_ref());
+    println!("Generated ACIR code into {}", circuit_path.display());
 
     if generate_witness {
         // Parse the initial witness values from Prover.toml
@@ -82,3 +80,58 @@ pub fn compile_circuit<P: AsRef<Path>>(
         .into_compiled_program(backend.np_language(), show_ssa, allow_warnings)
         .map_err(|_| std::process::exit(1))
 }
+
+pub fn preprocess_with_path<P: AsRef<Path>>(
+    key_name: &str,
+    preprocess_dir: P,
+    circuit: Circuit,
+) -> Result<(PathBuf, PathBuf), CliError> {
+    let backend = crate::backends::ConcreteBackend;
+
+    let (proving_key, verification_key) = backend.preprocess(circuit);
+
+    let pk_path = save_key_to_dir(proving_key, key_name, &preprocess_dir, true)?;
+    println!("Proving key saved to {}", pk_path.display());
+    let vk_path = save_key_to_dir(verification_key, key_name, preprocess_dir, false)?;
+    println!("Verification key saved to {}", vk_path.display());
+
+    Ok((pk_path, vk_path))
+}
+
+fn save_acir_to_dir<P: AsRef<Path>>(
+    circuit: Circuit,
+    circuit_name: &str,
+    circuit_dir: P,
+) -> PathBuf {
+    let mut circuit_path = create_named_dir(circuit_dir.as_ref(), "target");
+    circuit_path.push(circuit_name);
+
+    // Save a checksum of the circuit to compare against during proving and verification
+    let acir_hash = hash_constraint_system(&circuit);
+    circuit_path.set_extension(ACIR_EXT.to_owned() + ".sha256");
+    write_to_file(hex::encode(acir_hash).as_bytes(), &circuit_path);
+
+    let mut serialized = Vec::new();
+    circuit.write(&mut serialized).expect("could not serialize circuit");
+
+    circuit_path.set_extension(ACIR_EXT);
+    write_to_file(serialized.as_slice(), &circuit_path);
+
+    circuit_path
+}
+
+fn save_key_to_dir<P: AsRef<Path>>(
+    key: Vec<u8>,
+    key_name: &str,
+    key_dir: P,
+    is_proving_key: bool,
+) -> Result<PathBuf, CliError> {
+    let mut key_path = create_named_dir(key_dir.as_ref(), key_name);
+    key_path.push(key_name);
+    let extension = if is_proving_key { PK_EXT } else { VK_EXT };
+    key_path.set_extension(extension);
+
+    write_to_file(hex::encode(key).as_bytes(), &key_path);
+
+    Ok(key_path)
+}
diff --git a/crates/nargo/src/cli/mod.rs b/crates/nargo/src/cli/mod.rs
@@ -1,6 +1,9 @@
 use acvm::{
-    acir::{circuit::PublicInputs, native_types::Witness},
-    FieldElement,
+    acir::{
+        circuit::{Circuit, PublicInputs},
+        native_types::Witness,
+    },
+    hash_constraint_system, FieldElement, ProofSystemCompiler,
 };
 pub use check_cmd::check_from_path;
 use clap::{App, AppSettings, Arg};
@@ -20,7 +23,10 @@ use std::{
 extern crate tempdir;
 use tempdir::TempDir;
 
-use crate::errors::CliError;
+use crate::{
+    constants::{ACIR_EXT, PK_EXT, VK_EXT},
+    errors::CliError,
+};
 
 mod check_cmd;
 mod compile_cmd;
@@ -79,6 +85,9 @@ pub fn start_cli() {
             App::new("verify")
                 .about("Given a proof and a program, verify whether the proof is valid")
                 .arg(Arg::with_name("proof").help("The proof to verify").required(true))
+                .arg(Arg::with_name("circuit_name").help(
+                    "The name of the circuit build files (ACIR, proving and verification keys)",
+                ))
                 .arg(allow_warnings.clone()),
         )
         .subcommand(
@@ -87,6 +96,9 @@ pub fn start_cli() {
                     "Create proof for this program. The proof is returned as a hex encoded string.",
                 )
                 .arg(Arg::with_name("proof_name").help("The name of the proof"))
+                .arg(Arg::with_name("circuit_name").help(
+                    "The name of the circuit build files (ACIR, proving and verification keys)",
+                ))
                 .arg(Arg::with_name("verify").long("verify").help("Verify proof after proving"))
                 .arg(show_ssa.clone())
                 .arg(allow_warnings.clone()),
@@ -134,7 +146,7 @@ pub fn start_cli() {
                         .takes_value(true),
                 )
                 .arg(show_ssa)
-                .arg(allow_warnings),
+                .arg(allow_warnings.clone()),
         )
         .setting(AppSettings::SubcommandRequiredElseHelp)
         .get_matches();
@@ -228,6 +240,7 @@ pub fn prove_and_verify(proof_name: &str, prg_dir: &Path, show_ssa: bool) -> boo
         Some(proof_name),
         prg_dir,
         &tmp_dir.into_path(),
+        None,
         true,
         show_ssa,
         false,
@@ -289,6 +302,64 @@ pub(crate) fn dedup_public_input_indices_values(
     )
 }
 
+pub fn load_hex_data<P: AsRef<Path>>(path: P) -> Result<Vec<u8>, CliError> {
+    let hex_data: Vec<_> =
+        std::fs::read(&path).map_err(|_| CliError::PathNotValid(path.as_ref().to_path_buf()))?;
+
+    let raw_bytes = hex::decode(hex_data).map_err(CliError::HexArtifactNotValid)?;
+
+    Ok(raw_bytes)
+}
+
+fn fetch_pk_and_vk<P: AsRef<Path>>(
+    circuit: Circuit,
+    circuit_build_path: Option<P>,
+    prove_circuit: bool,
+    check_proof: bool,
+) -> Result<(Vec<u8>, Vec<u8>), CliError> {
+    let backend = crate::backends::ConcreteBackend;
+    if let Some(circuit_build_path) = circuit_build_path {
+        let mut acir_hash_path = PathBuf::new();
+        acir_hash_path.push(circuit_build_path.as_ref());
+        acir_hash_path.set_extension(ACIR_EXT.to_owned() + ".sha256");
+        let expected_acir_hash = load_hex_data(acir_hash_path.clone())?;
+
+        let new_acir_hash = hash_constraint_system(&circuit);
+
+        if new_acir_hash[..] != expected_acir_hash {
+            return Err(CliError::MismatchedAcir(acir_hash_path));
+        }
+
+        // This flag exists to avoid an unnecessary read of the proving key during verification
+        // as this method is used by both `nargo prove` and `nargo verify`
+        let proving_key = if prove_circuit {
+            let mut proving_key_path = PathBuf::new();
+            proving_key_path.push(circuit_build_path.as_ref());
+            proving_key_path.set_extension(PK_EXT);
+            load_hex_data(proving_key_path)?
+        } else {
+            // We can return an empty Vec here as `prove_circuit` should only be false when running `nargo verify`
+            vec![]
+        };
+
+        let verification_key = if check_proof {
+            let mut verification_key_path = PathBuf::new();
+            verification_key_path.push(circuit_build_path);
+            verification_key_path.set_extension(VK_EXT);
+            load_hex_data(verification_key_path)?
+        } else {
+            // We can return an empty Vec here as the verification key is used only is `check_proof` is true
+            vec![]
+        };
+
+        Ok((proving_key, verification_key))
+    } else {
+        // If a path to the circuit's build dir has not been provided, run preprocess and generate the proving and verification keys
+        let (proving_key, verification_key) = backend.preprocess(circuit);
+        Ok((proving_key, verification_key))
+    }
+}
+
 // FIXME: I not sure that this is the right place for this tests.
 #[cfg(test)]
 mod tests {

diff --git a/crates/nargo/src/cli/prove_cmd.rs b/crates/nargo/src/cli/prove_cmd.rs
@@ -5,21 +5,22 @@ use clap::ArgMatches;
 use noirc_abi::input_parser::Format;
 
 use super::{
-    create_named_dir, dedup_public_input_indices, read_inputs_from_file, write_inputs_to_file,
-    write_to_file,
+    create_named_dir, dedup_public_input_indices, fetch_pk_and_vk, read_inputs_from_file,
+    write_inputs_to_file, write_to_file,
 };
 use crate::{
     cli::{
         execute_cmd::{execute_program, extract_public_inputs},
         verify_cmd::verify_proof,
     },
-    constants::{PROOFS_DIR, PROOF_EXT, PROVER_INPUT_FILE, VERIFIER_INPUT_FILE},
+    constants::{PROOFS_DIR, PROOF_EXT, PROVER_INPUT_FILE, TARGET_DIR, VERIFIER_INPUT_FILE},
     errors::CliError,
 };
 
 pub(crate) fn run(args: ArgMatches) -> Result<(), CliError> {
     let args = args.subcommand_matches("prove").unwrap();
     let proof_name = args.value_of("proof_name");
+    let circuit_name = args.value_of("circuit_name");
     let check_proof = args.is_present("verify");
     let show_ssa = args.is_present("show-ssa");
     let allow_warnings = args.is_present("allow-warnings");
@@ -30,7 +31,24 @@ pub(crate) fn run(args: ArgMatches) -> Result<(), CliError> {
     let mut proof_dir = program_dir.clone();
     proof_dir.push(PROOFS_DIR);
 
-    prove_with_path(proof_name, program_dir, proof_dir, check_proof, show_ssa, allow_warnings)?;
+    let circuit_build_path = if let Some(circuit_name) = circuit_name {
+        let mut circuit_build_path = program_dir.clone();
+        circuit_build_path.push(TARGET_DIR);
+        circuit_build_path.push(circuit_name);
+        Some(circuit_build_path)
+    } else {
+        None
+    };
+
+    prove_with_path(
+        proof_name,
+        program_dir,
+        proof_dir,
+        circuit_build_path,
+        check_proof,
+        show_ssa,
+        allow_warnings,
+    )?;
 
     Ok(())
 }
@@ -39,12 +57,19 @@ pub fn prove_with_path<P: AsRef<Path>>(
     proof_name: Option<&str>,
     program_dir: P,
     proof_dir: P,
+    circuit_build_path: Option<P>,
     check_proof: bool,
     show_ssa: bool,
     allow_warnings: bool,
 ) -> Result<Option<PathBuf>, CliError> {
     let compiled_program =
         super::compile_cmd::compile_circuit(program_dir.as_ref(), show_ssa, allow_warnings)?;
+    let (proving_key, verification_key) = fetch_pk_and_vk(
+        compiled_program.circuit.clone(),
+        circuit_build_path.as_ref(),
+        true,
+        check_proof,
+    )?;
 
     // Parse the initial witness values from Prover.toml
     let inputs_map = read_inputs_from_file(
@@ -67,11 +92,11 @@ pub fn prove_with_path<P: AsRef<Path>>(
     prover_circuit.public_inputs = dedup_public_input_indices(prover_circuit.public_inputs);
 
     let backend = crate::backends::ConcreteBackend;
-    let proof = backend.prove_with_meta(prover_circuit, solved_witness);
+    let proof = backend.prove_with_pk(prover_circuit, solved_witness, proving_key);
 
     println!("Proof successfully created");
     if check_proof {
-        let valid_proof = verify_proof(compiled_program, public_inputs, &proof)?;
+        let valid_proof = verify_proof(compiled_program, public_inputs, &proof, verification_key)?;
         println!("Proof verified : {valid_proof}");
         if !valid_proof {
             return Err(CliError::Generic("Could not verify generated proof".to_owned()));