fix: try to resolve xudt compatibility issue

contracts/commitment-lock/README.md

@@ -4,6 +4,7 @@ This is a simple commitment lock script for ckb fiber network.
 
 The lock script args is the hash result of blake160(local_delay_epoch || local_delay_pubkey_hash || revocation_pubkey_hash || N * pending_htlc), to unlock this lock, the transaction must provide following fields in the witness:
 
+- `empty_witness_args`: 16 bytes, fixed to 0x10000000100000001000000010000000, for compatibility with the xudt
 - `local_delay_epoch`: 8 bytes, u64 in little endian, must be a relative EpochNumberWithFraction
 - `local_delay_pubkey_hash`: 20 bytes, hash result of blake160(local_delay_pubkey)
 - `revocation_pubkey_hash`: 20 bytes, hash result of blake160(revocation_pubkey)

contracts/commitment-lock/src/main.rs

@@ -40,6 +40,7 @@ pub enum Error {
     InvalidHtlcType,
     ArgsLenError,
     WitnessLenError,
+    EmptyWitnessArgsError,
     WitnessHashError,
     OutputCapacityError,
     OutputLockError,
@@ -68,6 +69,8 @@ pub fn program_entry() -> i8 {
     }
 }
 
+// a placeholder for empty witness args, to resolve the issue of xudt compatibility
+const EMPTY_WITNESS_ARGS: [u8; 16] = [16, 0, 0, 0, 16, 0, 0, 0, 16, 0, 0, 0, 16, 0, 0, 0];
 // min witness script length: 8 (local_delay_epoch) + 20 (local_delay_pubkey_hash) + 20 (revocation_pubkey_hash) = 48
 const MIN_WITNESS_SCRIPT_LEN: usize = 48;
 // HTLC script length: 1 (htlc_type) + 16 (payment_amount) + 20 (payment_hash) + 20 (remote_htlc_pubkey_hash) + 20 (local_htlc_pubkey_hash) + 8 (htlc_expiry) = 85
@@ -120,7 +123,14 @@ fn auth() -> Result<(), Error> {
     if args.len() != 20 {
         return Err(Error::ArgsLenError);
     }
-    let witness = load_witness(0, Source::GroupInput)?;
+    let mut witness = load_witness(0, Source::GroupInput)?;
+    if witness
+        .drain(0..EMPTY_WITNESS_ARGS.len())
+        .collect::<Vec<_>>()
+        != EMPTY_WITNESS_ARGS
+    {
+        return Err(Error::EmptyWitnessArgsError);
+    }
     let witness_len = witness.len();
     if witness_len < MIN_WITNESS_LEN {
         return Err(Error::WitnessLenError);

contracts/funding-lock/README.md

@@ -4,6 +4,7 @@ This is a simple funding lock script for ckb fiber network. It utilizes the [ckb
 
 The lock script args is a blake160 hash of the aggregated public key of the two parties, to unlock this lock, the transaction must provide following fields in the witness:
 
+- `empty_witness_args`: 16 bytes, fixed to 0x10000000100000001000000010000000, for compatibility with the xudt
 - `version`: 8 bytes, u64 in little-endian
 - `funding_out_point`: 36 bytes, out point of the funding transaction
 - `pubkey`: 32 bytes, x only aggregated public key

contracts/funding-lock/src/main.rs

@@ -12,7 +12,7 @@ ckb_std::entry!(program_entry);
 #[cfg(not(test))]
 default_alloc!();
 
-use alloc::ffi::CString;
+use alloc::{ffi::CString, vec::Vec};
 use ckb_std::{
     ckb_constants::Source,
     ckb_types::{bytes::Bytes, core::ScriptHashType, prelude::*},
@@ -34,6 +34,7 @@ pub enum Error {
     // Add customized errors here...
     MultipleInputs,
     WitnessLenError,
+    EmptyWitnessArgsError,
     FundingOutPointError,
     AuthError,
 }
@@ -57,12 +58,22 @@ pub fn program_entry() -> i8 {
     }
 }
 
+// a placeholder for empty witness args, to resolve the issue of xudt compatibility
+const EMPTY_WITNESS_ARGS: [u8; 16] = [16, 0, 0, 0, 16, 0, 0, 0, 16, 0, 0, 0, 16, 0, 0, 0];
+
 fn auth() -> Result<(), Error> {
     // funding lock will be unlocked by the commitment transaction, it should only have one input
     if load_input_since(1, Source::GroupInput).is_ok() {
         return Err(Error::MultipleInputs);
     }
-    let witness = load_witness(0, Source::GroupInput)?;
+    let mut witness = load_witness(0, Source::GroupInput)?;
+    if witness
+        .drain(0..EMPTY_WITNESS_ARGS.len())
+        .collect::<Vec<_>>()
+        != EMPTY_WITNESS_ARGS
+    {
+        return Err(Error::EmptyWitnessArgsError);
+    }
     if witness.len() != 8 + 36 + 32 + 64 {
         return Err(Error::WitnessLenError);
     }

tests/src/tests.rs

@@ -15,8 +15,8 @@ use secp256k1::{
 };
 
 const MAX_CYCLES: u64 = 10_000_000;
-
 const BYTE_SHANNONS: u64 = 100_000_000;
+const EMPTY_WITNESS_ARGS: [u8; 16] = [16, 0, 0, 0, 16, 0, 0, 0, 16, 0, 0, 0, 16, 0, 0, 0];
 
 #[test]
 fn test_funding_lock() {
@@ -152,6 +152,7 @@ fn test_funding_lock() {
     println!("signature: {:?}", aggregated_signature_1.to_bytes());
 
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         version.to_vec(),
         funding_out_point.to_vec(),
         x_only_pub_key.to_vec(),
@@ -250,7 +251,13 @@ fn test_commitment_lock_no_pending_htlcs() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0xFF], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0xFF],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -284,7 +291,13 @@ fn test_commitment_lock_no_pending_htlcs() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script, vec![0xFF], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script,
+        vec![0xFF],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -400,7 +413,13 @@ fn test_commitment_lock_with_two_pending_htlcs() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0xFF], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0xFF],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -434,7 +453,13 @@ fn test_commitment_lock_with_two_pending_htlcs() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0xFF], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0xFF],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -488,6 +513,7 @@ fn test_commitment_lock_with_two_pending_htlcs() {
         .unwrap()
         .serialize();
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         witness_script.clone(),
         vec![0x00],
         signature.clone(),
@@ -503,6 +529,7 @@ fn test_commitment_lock_with_two_pending_htlcs() {
 
     // sign with remote_htlc_pubkey and wrong preimage should fail
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         witness_script.clone(),
         vec![0x00],
         signature.clone(),
@@ -519,7 +546,13 @@ fn test_commitment_lock_with_two_pending_htlcs() {
     println!("error: {}", error);
 
     // sign with remote_htlc_pubkey and empty preimage should fail
-    let witness = [witness_script.clone(), vec![0x00], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0x00],
+        signature,
+    ]
+    .concat();
 
     let fail_tx = tx.as_advanced_builder().witness(witness.pack()).build();
 
@@ -556,7 +589,13 @@ fn test_commitment_lock_with_two_pending_htlcs() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0x00], signature.clone()].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0x00],
+        signature.clone(),
+    ]
+    .concat();
 
     let success_tx = tx.as_advanced_builder().witness(witness.pack()).build();
     let cycles = context
@@ -586,7 +625,13 @@ fn test_commitment_lock_with_two_pending_htlcs() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0x00], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0x00],
+        signature,
+    ]
+    .concat();
 
     let fail_tx = tx.as_advanced_builder().witness(witness.pack()).build();
     let error = context
@@ -637,7 +682,13 @@ fn test_commitment_lock_with_two_pending_htlcs() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0x01], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0x01],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -673,6 +724,7 @@ fn test_commitment_lock_with_two_pending_htlcs() {
         .unwrap()
         .serialize();
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         witness_script.clone(),
         vec![0x01],
         signature.clone(),
@@ -688,6 +740,7 @@ fn test_commitment_lock_with_two_pending_htlcs() {
 
     // sign with local_htlc_pubkey and wrong preimage should fail
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         witness_script.clone(),
         vec![0x01],
         signature.clone(),
@@ -702,7 +755,13 @@ fn test_commitment_lock_with_two_pending_htlcs() {
     println!("error: {}", error);
 
     // sign with local_htlc_pubkey and empty preimage should fail
-    let witness = [witness_script.clone(), vec![0x01], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0x01],
+        signature,
+    ]
+    .concat();
 
     let fail_tx = tx.as_advanced_builder().witness(witness.pack()).build();
     let error = context
@@ -828,7 +887,13 @@ fn test_commitment_lock_with_two_pending_htlcs_and_sudt() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0xFF], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0xFF],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -862,7 +927,13 @@ fn test_commitment_lock_with_two_pending_htlcs_and_sudt() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0xFF], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0xFF],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -920,6 +991,7 @@ fn test_commitment_lock_with_two_pending_htlcs_and_sudt() {
         .unwrap()
         .serialize();
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         witness_script.clone(),
         vec![0x00],
         signature,
@@ -965,6 +1037,7 @@ fn test_commitment_lock_with_two_pending_htlcs_and_sudt() {
         .unwrap()
         .serialize();
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         witness_script.clone(),
         vec![0x00],
         signature,
@@ -1028,7 +1101,13 @@ fn test_commitment_lock_with_two_pending_htlcs_and_sudt() {
         .sign_recoverable(&message.into())
         .unwrap()
         .serialize();
-    let witness = [witness_script.clone(), vec![0x01], signature].concat();
+    let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
+        witness_script.clone(),
+        vec![0x01],
+        signature,
+    ]
+    .concat();
 
     let tx = tx.as_advanced_builder().witness(witness.pack()).build();
     println!("tx: {:?}", tx);
@@ -1065,6 +1144,7 @@ fn test_commitment_lock_with_two_pending_htlcs_and_sudt() {
         .unwrap()
         .serialize();
     let witness = [
+        EMPTY_WITNESS_ARGS.to_vec(),
         witness_script.clone(),
         vec![0x01],
         signature,