Implement libsodium vrf signature verification

.github/workflows/validate.yml

@@ -20,13 +20,31 @@ jobs:
       - name: Checkout sources
         uses: actions/checkout@v2
 
+      - name: Install build dependencies macOS
+        if: matrix.os == 'macOS-latest'
+        run: brew install autoconf automake libtool
+
+      - name: Install msys2 Windows
+        if: matrix.os == 'windows-latest'
+        uses: msys2/setup-msys2@v2
+        with:
+          update: true
+          install: >-
+            base-devel
+            autoconf
+            automake
+            libtool
+          pacboy: >-
+            toolchain:p
+
       - name: Install stable toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: ${{ matrix.rust }}
 
       - name: Run cargo check Windows
         if: matrix.os == 'windows-latest'
+        shell: msys2 {0}
         run: cargo check --no-default-features --features num
 
       - name: Run cargo check
@@ -55,12 +73,25 @@ jobs:
       - name: Checkout sources
         uses: actions/checkout@v2
 
+      - name: Install msys2 Windows
+        uses: msys2/setup-msys2@v2
+        with:
+          update: true
+          install: >-
+            base-devel
+            autoconf
+            automake
+            libtool
+          pacboy: >-
+            toolchain:p
+
       - name: Install stable toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
 
       - name: Run cargo test
+        shell: msys2 {0}
         run: cargo test --no-default-features --features num
 
   lints:

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "pallas-crypto/contrib/libsodium"]
+	path = pallas-crypto/contrib/libsodium
+	url = https://github.com/input-output-hk/libsodium

pallas-crypto/Cargo.toml

@@ -8,7 +8,12 @@ homepage = "https://github.com/txpipe/pallas"
 documentation = "https://docs.rs/pallas-crypto"
 license = "Apache-2.0"
 readme = "README.md"
-authors = ["Nicolas Di Prima <[email protected]>"]
+authors = [
+    "Nicolas Di Prima <[email protected]>",
+    "Andrew Westberg <[email protected]>",
+]
+build = "build.rs"
+links = "libsodium"
 
 [dependencies]
 hex = "0.4"
@@ -24,3 +29,7 @@ quickcheck = "1.0"
 quickcheck_macros = "1.0"
 rand = "0.8"
 serde_test = "1.0.143"
+
+[build-dependencies]
+autotools = "0.2"
+pkg-config = "0.3"

pallas-crypto/README.md

@@ -8,7 +8,7 @@ Crate with all the cryptographic material to support Cardano protocol:
 - [x] Ed25519 Extended asymmetric key pair
 - [ ] Bip32-Ed25519 key derivation
 - [ ] BIP39 mnemonics
-- [ ] VRF
+- [x] VRF
 - [ ] KES
 - [ ] SECP256k1
 - [x] Nonce calculations

pallas-crypto/build.rs

@@ -0,0 +1,46 @@
+use std::process::Command;
+
+macro_rules! ok (($expression:expr) => ($expression.unwrap()));
+macro_rules! log {
+    ($fmt:expr) => (println!(concat!("pallas-crypto/build.rs:{}: ", $fmt), line!()));
+    ($fmt:expr, $($arg:tt)*) => (println!(concat!("pallas-crypto/build.rs:{}: ", $fmt),
+    line!(), $($arg)*));
+}
+
+fn main() {
+    // Build and link libsodium
+    run("git", |command| {
+        command
+            .arg("submodule")
+            .arg("update")
+            .arg("--init")
+            .arg("--recursive")
+            .arg("--force")
+    });
+
+    // Build libsodium automatically (as part of rust build)
+    let libsodium = autotools::Config::new("contrib/libsodium/")
+        .reconf("-vfi")
+        .enable_static()
+        .disable_shared()
+        .build();
+    println!(
+        "cargo:rustc-link-search=native={}",
+        libsodium.join("lib").display()
+    );
+    println!("cargo:rustc-link-lib=static=sodium");
+    println!("cargo:rerun-if-changed=build.rs");
+}
+
+fn run<F>(name: &str, mut configure: F)
+where
+    F: FnMut(&mut Command) -> &mut Command,
+{
+    let mut command = Command::new(name);
+    let configured = configure(&mut command);
+    log!("Executing {:?}", configured);
+    if !ok!(configured.status()).success() {
+        panic!("failed to execute {:?}", configured);
+    }
+    log!("Command {:?} finished successfully", configured);
+}

pallas-crypto/src/lib.rs

@@ -2,3 +2,4 @@ pub mod hash;
 pub mod key;
 pub mod memsec;
 pub mod nonce;
+pub mod vrf;

pallas-crypto/src/vrf/mod.rs

@@ -0,0 +1,129 @@
+use thiserror::Error;
+
+#[link(name = "sodium", kind = "static")]
+extern "C" {
+    // int crypto_vrf_ietfdraft03_prove(unsigned char *proof, const unsigned char *sk, const unsigned char *m, unsigned long long mlen);
+    fn crypto_vrf_ietfdraft03_prove(proof: *mut u8, sk: *const u8, m: *const u8, mlen: u64) -> i32;
+
+    // int crypto_vrf_ietfdraft03_proof_to_hash(unsigned char *hash, const unsigned char *proof);
+    fn crypto_vrf_ietfdraft03_proof_to_hash(hash: *mut u8, proof: *const u8) -> i32;
+
+    // int crypto_vrf_ietfdraft03_verify(unsigned char *output, const unsigned char *pk, const unsigned char *proof, const unsigned char *m, unsigned long long mlen)
+    fn crypto_vrf_ietfdraft03_verify(
+        output: *mut u8,
+        pk: *const u8,
+        proof: *const u8,
+        m: *const u8,
+        mlen: u64,
+    ) -> i32;
+}
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("{0}")]
+    Libsodium(String),
+}
+
+/// Sign a seed value with a vrf secret key and produce a proof signature
+pub fn sodium_crypto_vrf_prove(secret_key: &[u8], seed: &[u8]) -> Result<Vec<u8>, Error> {
+    let mut proof: Vec<u8> = Vec::with_capacity(80);
+    unsafe {
+        let rc = crypto_vrf_ietfdraft03_prove(
+            proof.as_mut_ptr(),
+            secret_key.as_ptr(),
+            seed.as_ptr(),
+            seed.len() as u64,
+        );
+        if rc != 0 {
+            Err(Error::Libsodium(format!(
+                "libsodium crypto_vrf_ietfdraft03_prove() failed, returned {rc}, expected 0"
+            )))
+        } else {
+            proof.set_len(80);
+            Ok(proof)
+        }
+    }
+}
+
+/// Convert a proof signature to a hash
+pub fn sodium_crypto_vrf_proof_to_hash(proof: &[u8]) -> Result<Vec<u8>, Error> {
+    let mut hash: Vec<u8> = Vec::with_capacity(64);
+    unsafe {
+        let rc = crypto_vrf_ietfdraft03_proof_to_hash(hash.as_mut_ptr(), proof.as_ptr());
+        if rc != 0 {
+            Err(Error::Libsodium(format!(
+                "libsodium crypto_vrf_ietfdraft03_proof_to_hash() failed, returned {rc}, expected 0"
+            )))
+        } else {
+            hash.set_len(64);
+            Ok(hash)
+        }
+    }
+}
+
+/// Verify a proof signature with a vrf public key. This will return a hash to compare with the original
+/// signature hash.
+pub fn sodium_crypto_vrf_verify(
+    public_key: &[u8],
+    signature: &[u8],
+    seed: &[u8],
+) -> Result<Vec<u8>, Error> {
+    let mut verification: Vec<u8> = Vec::with_capacity(64);
+    unsafe {
+        let rc = crypto_vrf_ietfdraft03_verify(
+            verification.as_mut_ptr(),
+            public_key.as_ptr(),
+            signature.as_ptr(),
+            seed.as_ptr(),
+            seed.len() as u64,
+        );
+        if rc != 0 {
+            Err(Error::Libsodium(format!(
+                "libsodium crypto_vrf_ietfdraft03_verify() failed, returned {rc}, expected 0"
+            )))
+        } else {
+            verification.set_len(64);
+            Ok(verification)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use rand::{thread_rng, Rng};
+
+    #[test]
+    fn sodium_crypto_vrf_prove_and_verify() {
+        // Node operational VRF-Verification-Key: pool.vrf.vkey
+        // {
+        //    "type": "VrfVerificationKey_PraosVRF",
+        //    "description": "VRF Verification Key",
+        //    "cborHex": "5820e0ff2371508ac339431b50af7d69cde0f120d952bb876806d3136f9a7fda4381"
+        // }
+        //
+        // Node operational VRF-Signing-Key: pool.vrf.skey
+        // {
+        //    "type": "VrfSigningKey_PraosVRF",
+        //    "description": "VRF Signing Key",
+        //    "cborHex": "5840adb9c97bec60189aa90d01d113e3ef405f03477d82a94f81da926c90cd46a374e0ff2371508ac339431b50af7d69cde0f120d952bb876806d3136f9a7fda4381"
+        // }
+
+        let vrf_skey = hex::decode("adb9c97bec60189aa90d01d113e3ef405f03477d82a94f81da926c90cd46a374e0ff2371508ac339431b50af7d69cde0f120d952bb876806d3136f9a7fda4381").unwrap();
+        let vrf_vkey =
+            hex::decode("e0ff2371508ac339431b50af7d69cde0f120d952bb876806d3136f9a7fda4381")
+                .unwrap();
+
+        // random seed to sign with vrf_skey
+        let mut seed = [0u8; 64];
+        thread_rng().fill(&mut seed);
+
+        // create a proof signature and hash of the seed
+        let proof_signature = sodium_crypto_vrf_prove(&vrf_skey, &seed).unwrap();
+        let proof_hash = sodium_crypto_vrf_proof_to_hash(&proof_signature).unwrap();
+
+        // verify the proof signature with the public vrf public key
+        let verified_hash = sodium_crypto_vrf_verify(&vrf_vkey, &proof_signature, &seed).unwrap();
+        assert_eq!(proof_hash, verified_hash);
+    }
+}