feat: add bulletproof_plus to wasm (#107)

Added bulletproof_plus interfaces to wasm

README.md

@@ -26,6 +26,10 @@ To generate a module for use in node.js, use this command:
 
     $ wasm-pack build --target nodejs -d tari_js . -- --features "wasm"
 
+To run the wasm bindings unit tests, use this command:
+
+    $ wasm-pack test --node --features wasm
+
 Note: Node v10+ is needed for the WASM
 
 ## Example (Node.js)

src/wasm/range_proofs.rs

@@ -25,10 +25,16 @@ use tari_utilities::hex::Hex;
 use wasm_bindgen::prelude::*;
 
 use crate::{
+    extended_range_proof::ExtendedRangeProofService,
     range_proof::RangeProofService,
     ristretto::{
+        bulletproofs_plus::BulletproofsPlusService,
         dalek_range_proof::DalekRangeProofService,
-        pedersen::{commitment_factory::PedersenCommitmentFactory, PedersenCommitment},
+        pedersen::{
+            commitment_factory::PedersenCommitmentFactory,
+            extended_commitment_factory::ExtendedPedersenCommitmentFactory,
+            PedersenCommitment,
+        },
         RistrettoSecretKey,
     },
     tari_utilities::hex::from_hex,
@@ -46,6 +52,12 @@ pub struct VerificationResult {
     error: String,
 }
 
+#[derive(Default, Serialize, Deserialize)]
+pub struct RecoverResult {
+    mask: String,
+    error: String,
+}
+
 #[wasm_bindgen]
 pub struct RangeProofFactory {
     rpf: DalekRangeProofService,
@@ -106,6 +118,144 @@ impl Default for RangeProofFactory {
     }
 }
 
+#[wasm_bindgen]
+pub struct ExtendedRangeProofFactory {
+    rpf: BulletproofsPlusService,
+}
+
+#[wasm_bindgen]
+impl ExtendedRangeProofFactory {
+    /// Create a new `RangeProofFactory`
+    pub fn new() -> Self {
+        let cf = ExtendedPedersenCommitmentFactory::default();
+        let rpf = BulletproofsPlusService::init(64, 1, cf).unwrap();
+        ExtendedRangeProofFactory { rpf }
+    }
+
+    /// Creates a new range proof for the given key-value pair.
+    pub fn create_proof(&self, key: &str, value: u64) -> JsValue {
+        let mut result = RangeProofResult::default();
+        let key = match RistrettoSecretKey::from_hex(key) {
+            Ok(k) => k,
+            _ => {
+                result.error = "Invalid private key".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        match self.rpf.construct_proof(&key, value) {
+            Ok(p) => result.proof = p.to_hex(),
+            Err(e) => result.error = e.to_string(),
+        };
+        JsValue::from_serde(&result).unwrap()
+    }
+
+    /// Verifies the given range proof and commitment.
+    pub fn verify(&self, commitment: &str, proof: &str) -> JsValue {
+        let mut result = VerificationResult::default();
+        let commitment = match PedersenCommitment::from_hex(commitment) {
+            Ok(commitment) => commitment,
+            _ => {
+                result.error = "Invalid private key".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        let proof = match from_hex(proof) {
+            Ok(v) => v,
+            Err(e) => {
+                result.error = format!("Range proof is invalid. {}", e);
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        result.valid = self.rpf.verify(&proof, &commitment);
+        JsValue::from_serde(&result).unwrap()
+    }
+
+    pub fn construct_proof_with_recovery_seed_nonce(&self, mask: &str, value: u64, seed_nonce: &str) -> JsValue {
+        let mut result = RangeProofResult::default();
+        let mask = match RistrettoSecretKey::from_hex(mask) {
+            Ok(k) => k,
+            _ => {
+                result.error = "Invalid mask".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        let seed_nonce = match RistrettoSecretKey::from_hex(seed_nonce) {
+            Ok(k) => k,
+            _ => {
+                result.error = "Invalid seed nonce".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        match self
+            .rpf
+            .construct_proof_with_recovery_seed_nonce(&mask, value, &seed_nonce)
+        {
+            Ok(p) => result.proof = p.to_hex(),
+            Err(e) => result.error = e.to_string(),
+        };
+        JsValue::from_serde(&result).unwrap()
+    }
+
+    pub fn recover_mask(&self, proof: &str, commitment: &str, seed_nonce: &str) -> JsValue {
+        let mut result = RecoverResult::default();
+        let proof = match from_hex(proof) {
+            Ok(v) => v,
+            Err(e) => {
+                result.error = format!("Range proof is invalid. {}", e);
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        let commitment = match PedersenCommitment::from_hex(commitment) {
+            Ok(commitment) => commitment,
+            _ => {
+                result.error = "Invalid commitment".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        let seed_nonce = match RistrettoSecretKey::from_hex(seed_nonce) {
+            Ok(k) => k,
+            _ => {
+                result.error = "Invalid seed nonce".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        match self.rpf.recover_mask(&proof, &commitment, &seed_nonce) {
+            Ok(p) => result.mask = p.to_hex(),
+            Err(e) => result.error = e.to_string(),
+        };
+        JsValue::from_serde(&result).unwrap()
+    }
+
+    pub fn verify_mask(&self, commitment: &str, mask: &str, value: u64) -> JsValue {
+        let mut result = VerificationResult::default();
+        let commitment = match PedersenCommitment::from_hex(commitment) {
+            Ok(commitment) => commitment,
+            _ => {
+                result.error = "Invalid commitment".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        let mask = match RistrettoSecretKey::from_hex(mask) {
+            Ok(k) => k,
+            _ => {
+                result.error = "Invalid mask".to_string();
+                return JsValue::from_serde(&result).unwrap();
+            },
+        };
+        match self.rpf.verify_mask(&commitment, &mask, value) {
+            Ok(p) => result.valid = p,
+            Err(e) => result.error = e.to_string(),
+        };
+        JsValue::from_serde(&result).unwrap()
+    }
+}
+
+impl Default for ExtendedRangeProofFactory {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use rand::rngs::OsRng;
@@ -115,15 +265,15 @@ mod test {
     use crate::{commitment::HomomorphicCommitmentFactory, keys::PublicKey, ristretto::RistrettoPublicKey};
 
     #[wasm_bindgen_test]
-    fn it_fails_with_invalid_hex_input() {
+    fn dalek_range_proof_fails_with_invalid_hex_input() {
         let factory = RangeProofFactory::new();
         let result = factory.create_proof("", 123).into_serde::<RangeProofResult>().unwrap();
         assert!(!result.error.is_empty());
         assert!(result.proof.is_empty());
     }
 
     #[wasm_bindgen_test]
-    fn it_creates_a_valid_proof() {
+    fn dalek_range_proof_creates_a_valid_proof() {
         let factory = RangeProofFactory::new();
         let (sk, _) = RistrettoPublicKey::random_keypair(&mut OsRng);
         let result = factory
@@ -138,4 +288,55 @@ mod test {
             .unwrap();
         assert!(result.valid);
     }
+
+    #[wasm_bindgen_test]
+    fn bulletproof_plus_fails_with_invalid_hex_input() {
+        let factory = ExtendedRangeProofFactory::new();
+        let result = factory.create_proof("", 123).into_serde::<RangeProofResult>().unwrap();
+        assert!(!result.error.is_empty());
+        assert!(result.proof.is_empty());
+    }
+
+    #[wasm_bindgen_test]
+    fn bulletproof_plus_creates_a_valid_proof() {
+        let factory = ExtendedRangeProofFactory::new();
+        let (sk, _) = RistrettoPublicKey::random_keypair(&mut OsRng);
+        let value = 123;
+        let commitment = ExtendedPedersenCommitmentFactory::default().commit_value(&sk, value);
+
+        // Non-rewindable range proof
+        let proof_result = factory
+            .create_proof(&sk.to_hex(), value)
+            .into_serde::<RangeProofResult>()
+            .unwrap();
+        let proof_verification_result = factory
+            .verify(&commitment.to_hex(), &proof_result.proof)
+            .into_serde::<VerificationResult>()
+            .unwrap();
+        assert!(proof_verification_result.valid);
+
+        // Rewindable range proof
+        // - Create
+        let (seed_nonce, _) = RistrettoPublicKey::random_keypair(&mut OsRng);
+        let proof_result = factory
+            .construct_proof_with_recovery_seed_nonce(&sk.to_hex(), value, &seed_nonce.to_hex())
+            .into_serde::<RangeProofResult>()
+            .unwrap();
+        assert!(factory.rpf.verify(&from_hex(&proof_result.proof).unwrap(), &commitment));
+        // - Recover the blinding factor (mask)
+        let recover_result = factory
+            .recover_mask(&proof_result.proof, &commitment.to_hex(), &seed_nonce.to_hex())
+            .into_serde::<RecoverResult>()
+            .unwrap();
+        let mask_verification_result = factory
+            .verify_mask(&commitment.to_hex(), &recover_result.mask, value)
+            .into_serde::<VerificationResult>()
+            .unwrap();
+        assert!(mask_verification_result.valid);
+
+        // To print to `console.log`:
+        // use crate::wasm::range_proofs::test::__rt::log;
+        // log(&format_args!("blinding_factor: {}", &sk.to_hex()));
+        // log(&format_args!("mask           : {}", &recover_result.mask));
+    }
 }