96 lines
3.8 KiB
Rust
96 lines
3.8 KiB
Rust
//! *Zcash circuits and proofs.*
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//!
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//! `zcash_proofs` contains the zk-SNARK circuits used by Zcash, and the APIs for creating
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//! and verifying proofs.
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// Catch documentation errors caused by code changes.
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#![deny(intra_doc_link_resolution_failure)]
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use bellman::groth16::{prepare_verifying_key, Parameters, PreparedVerifyingKey, VerifyingKey};
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use pairing::bls12_381::Bls12;
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use std::fs::File;
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use std::io::{self, BufReader};
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use std::path::Path;
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pub mod circuit;
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mod hashreader;
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pub mod sapling;
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pub mod sprout;
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#[cfg(feature = "local-prover")]
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pub mod prover;
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pub fn load_parameters(
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spend_path: &Path,
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spend_hash: &str,
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output_path: &Path,
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output_hash: &str,
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sprout_path: Option<&Path>,
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sprout_hash: Option<&str>,
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) -> (
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Parameters<Bls12>,
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PreparedVerifyingKey<Bls12>,
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Parameters<Bls12>,
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PreparedVerifyingKey<Bls12>,
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Option<PreparedVerifyingKey<Bls12>>,
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) {
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// Load from each of the paths
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let spend_fs = File::open(spend_path).expect("couldn't load Sapling spend parameters file");
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let output_fs = File::open(output_path).expect("couldn't load Sapling output parameters file");
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let sprout_fs =
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sprout_path.map(|p| File::open(p).expect("couldn't load Sprout groth16 parameters file"));
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let mut spend_fs = hashreader::HashReader::new(BufReader::with_capacity(1024 * 1024, spend_fs));
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let mut output_fs =
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hashreader::HashReader::new(BufReader::with_capacity(1024 * 1024, output_fs));
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let mut sprout_fs =
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sprout_fs.map(|fs| hashreader::HashReader::new(BufReader::with_capacity(1024 * 1024, fs)));
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// Deserialize params
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let spend_params = Parameters::<Bls12>::read(&mut spend_fs, false)
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.expect("couldn't deserialize Sapling spend parameters file");
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let output_params = Parameters::<Bls12>::read(&mut output_fs, false)
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.expect("couldn't deserialize Sapling spend parameters file");
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// We only deserialize the verifying key for the Sprout parameters, which
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// appears at the beginning of the parameter file. The rest is loaded
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// during proving time.
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let sprout_vk = sprout_fs.as_mut().map(|mut fs| {
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VerifyingKey::<Bls12>::read(&mut fs)
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.expect("couldn't deserialize Sprout Groth16 verifying key")
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});
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// There is extra stuff (the transcript) at the end of the parameter file which is
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// used to verify the parameter validity, but we're not interested in that. We do
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// want to read it, though, so that the BLAKE2b computed afterward is consistent
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// with `b2sum` on the files.
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let mut sink = io::sink();
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io::copy(&mut spend_fs, &mut sink)
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.expect("couldn't finish reading Sapling spend parameter file");
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io::copy(&mut output_fs, &mut sink)
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.expect("couldn't finish reading Sapling output parameter file");
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if let Some(mut sprout_fs) = sprout_fs.as_mut() {
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io::copy(&mut sprout_fs, &mut sink)
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.expect("couldn't finish reading Sprout groth16 parameter file");
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}
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if spend_fs.into_hash() != spend_hash {
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panic!("Sapling spend parameter file is not correct, please clean your `~/.zcash-params/` and re-run `fetch-params`.");
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}
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if output_fs.into_hash() != output_hash {
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panic!("Sapling output parameter file is not correct, please clean your `~/.zcash-params/` and re-run `fetch-params`.");
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}
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if sprout_fs.map(|fs| fs.into_hash()) != sprout_hash.map(|h| h.to_owned()) {
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panic!("Sprout groth16 parameter file is not correct, please clean your `~/.zcash-params/` and re-run `fetch-params`.");
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}
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// Prepare verifying keys
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let spend_vk = prepare_verifying_key(&spend_params.vk);
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let output_vk = prepare_verifying_key(&output_params.vk);
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let sprout_vk = sprout_vk.map(|vk| prepare_verifying_key(&vk));
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(spend_params, spend_vk, output_params, output_vk, sprout_vk)
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}
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