lightning: implement the htlc script

Cargo.toml

@@ -10,6 +10,7 @@ members = [
   "ark-rust-secp256k1",
   "ark-dlc-sample",
   "ark-rs",
+  "ark-lightning",
 ]
 
 resolver = "2"

ark-lightning/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "ark-lightning"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+ark-core = { path = "../ark-core" }
+bitcoin = { version = "0.32.4", features = ["base64", "rand", "serde"] }
+musig = { package = "ark-secp256k1", path = "../ark-rust-secp256k1", features = ["serde", "rand"] }
+serde = { version = "1.0", features = ["derive"] }
+thiserror = "1.0"
+
+[dev-dependencies]
+hex = "0.4"
+serde_json = "1.0"
+
+[[example]]
+name = "vhtlc_example"
+path = "examples/vhtlc_example.rs"

ark-lightning/examples/vhtlc_example.rs

@@ -0,0 +1,56 @@
+use ark_lightning::vhtlc::VhtlcOptions;
+use ark_lightning::vhtlc::VhtlcScript;
+use bitcoin::Sequence;
+use bitcoin::XOnlyPublicKey;
+use std::str::FromStr;
+
+fn main() {
+    // Create test keys for sender, receiver, and server
+    let sender = XOnlyPublicKey::from_str(
+        "18845781f631c48f1c9709e23092067d06837f30aa0cd0544ac887fe91ddd166",
+    )
+    .unwrap();
+
+    let receiver = XOnlyPublicKey::from_str(
+        "28845781f631c48f1c9709e23092067d06837f30aa0cd0544ac887fe91ddd166",
+    )
+    .unwrap();
+
+    let server = XOnlyPublicKey::from_str(
+        "38845781f631c48f1c9709e23092067d06837f30aa0cd0544ac887fe91ddd166",
+    )
+    .unwrap();
+
+    // Create a preimage hash (in a real scenario, this would be the hash of a secret)
+    let preimage_hash = [42u8; 20];
+
+    // Configure the VHTLC options
+    let options = VhtlcOptions {
+        sender,
+        receiver,
+        server,
+        preimage_hash,
+        refund_locktime: 100000, // Block height for CLTV
+        unilateral_claim_delay: Sequence::from_seconds_ceil(3600).unwrap(), // 1 hour
+        unilateral_refund_delay: Sequence::from_seconds_ceil(7200).unwrap(), // 2 hours
+        unilateral_refund_without_receiver_delay: Sequence::from_seconds_ceil(10800).unwrap(), /* 3 hours */
+    };
+
+    // Create the VHTLC script
+    let vhtlc = VhtlcScript::new(options).expect("Failed to create VHTLC");
+
+    // Get the taproot output key and script pubkey
+    if let Some(taproot_info) = vhtlc.taproot_info() {
+        println!("Taproot output key: {}", taproot_info.output_key());
+
+        if let Some(script_pubkey) = vhtlc.script_pubkey() {
+            println!("Script pubkey: {}", script_pubkey);
+        }
+    }
+
+    // Display all available spending paths
+    println!("\nAvailable spending paths:");
+    for (name, script) in vhtlc.get_script_map() {
+        println!("  {} - {} bytes", name, script.len());
+    }
+}

ark-lightning/scripts/generate_ts_vectors.js

@@ -0,0 +1,58 @@
+// Script to generate test vectors from TypeScript SDK for comparison
+// Run this in the arkade-os/ts-sdk repository to get the expected hex values
+
+const { VhtlcScript } = require('../path/to/ts-sdk'); // Adjust path as needed
+
+// Test data from fixtures (same as used in Rust tests)
+const testData = {
+  preimageHash: Buffer.from('4d487dd3753a89bc9fe98401d1196523058251fc', 'hex'),
+  receiver: Buffer.from('021e1bb85455fe3f5aed60d101aa4dbdb9e7714f6226769a97a17a5331dadcd53b', 'hex'),
+  sender: Buffer.from('030192e796452d6df9697c280542e1560557bcf79a347d925895043136225c7cb4', 'hex'),
+  server: Buffer.from('03aad52d58162e9eefeafc7ad8a1cdca8060b5f01df1e7583362d052e266208f88', 'hex'),
+  refundLocktime: 265,
+  unilateralClaimDelay: { type: 'blocks', value: 17 },
+  unilateralRefundDelay: { type: 'blocks', value: 144 },
+  unilateralRefundWithoutReceiverDelay: { type: 'blocks', value: 144 }
+};
+
+try {
+  // Create VHTLC instance
+  const vhtlc = new VhtlcScript(testData);
+
+  console.log('=== TypeScript SDK VHTLC Script Vectors ===\n');
+
+  // Export all script hex values
+  const vectors = {
+    claim: vhtlc.claim().script.toString('hex'),
+    refund: vhtlc.refund().script.toString('hex'),
+    refundWithoutReceiver: vhtlc.refundWithoutReceiver().script.toString('hex'),
+    unilateralClaim: vhtlc.unilateralClaim().script.toString('hex'),
+    unilateralRefund: vhtlc.unilateralRefund().script.toString('hex'),
+    unilateralRefundWithoutReceiver: vhtlc.unilateralRefundWithoutReceiver().script.toString('hex')
+  };
+
+  // Output for comparison
+  console.log('TypeScript SDK Script Vectors:');
+  console.log('1. Claim Script:                          ', vectors.claim);
+  console.log('2. Refund Script:                         ', vectors.refund);
+  console.log('3. Refund Without Receiver Script:        ', vectors.refundWithoutReceiver);
+  console.log('4. Unilateral Claim Script:               ', vectors.unilateralClaim);
+  console.log('5. Unilateral Refund Script:              ', vectors.unilateralRefund);
+  console.log('6. Unilateral Refund Without Receiver:    ', vectors.unilateralRefundWithoutReceiver);
+
+  // Also output as JSON for easy parsing
+  console.log('\n=== JSON Format ===');
+  console.log(JSON.stringify(vectors, null, 2));
+
+  // Export taproot address for comparison
+  const address = vhtlc.address('testnet'); // or 'mainnet'
+  console.log('\n=== Address ===');
+  console.log('TypeScript SDK Address:', address);
+
+} catch (error) {
+  console.error('Error generating TypeScript vectors:', error);
+  console.log('\nPlease ensure:');
+  console.log('1. You are running this in the arkade-os/ts-sdk directory');
+  console.log('2. The path to VhtlcScript is correct');
+  console.log('3. All dependencies are installed (npm install)');
+}

ark-lightning/src/lib.rs

@@ -0,0 +1,5 @@
+//! Lightning Network Module for the Ark Lightning Swap
+//!
+//! Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
+
+pub mod vhtlc;