Taproot support

.cirrus.yml

@@ -16,12 +16,19 @@ task:
         matrix:
           - USE_MIN_BITCOIN_VERSION: 'TRUE'
           - USE_MIN_BITCOIN_VERSION: 'FALSE'
+          - USE_TAPROOT: 1
     - name: 'RPC functional tests'
       env:
         TEST_GROUP: tests/test_rpc.py
+        matrix:
+          - USE_TAPROOT: 0
+          - USE_TAPROOT: 1
     - name: 'Chain functional tests'
       env:
         TEST_GROUP: tests/test_chain.py
+        matrix:
+          - USE_TAPROOT: 0
+          - USE_TAPROOT: 1
 
   cargo_registry_cache:
     folders: $CARGO_HOME/registry
@@ -34,7 +41,12 @@ task:
     fingerprint_script:
       - rustc --version
       - cat Cargo.lock
-  lianad_build_script: cargo build --release
+  tests_tools_cache:
+    folder: tests/tools/taproot_signer/target
+    fingerprint_script:
+      - rustc --version
+      - cat tests/tools/taproot_signer/Cargo.lock
+  lianad_build_script: cargo build --release && cd tests/tools/taproot_signer && cargo build --release
 
   deps_script: apt update && apt install -y python3 python3-pip
 

fuzz/fuzz_targets/descriptor_parse.rs

@@ -67,10 +67,12 @@ fuzz_target!(|data: &[u8]| {
         desc.receive_descriptor().derive(der_index, &SECP256K1),
         desc.change_descriptor().derive(der_index, &SECP256K1),
     ];
+    let mut psbt_in = Default::default();
+    let mut psbt_out = Default::default();
     for desc in der_descs {
         desc.address(Network::Bitcoin);
         desc.script_pubkey();
-        desc.witness_script();
-        desc.bip32_derivations();
+        desc.update_psbt_in(&mut psbt_in);
+        desc.update_change_psbt_out(&mut psbt_out);
     }
 });

fuzz/fuzz_targets/descriptors.rs

@@ -101,6 +101,7 @@ struct Config {
     pub recovery_paths: Vec<RecPathConfig>,
     pub der_index: u16,
     pub dummy_psbt: DummyPsbt,
+    pub use_taproot: bool,
 }
 
 fuzz_target!(|config: Config| {
@@ -126,7 +127,12 @@ fuzz_target!(|config: Config| {
     } else {
         return;
     };
-    let policy = if let Ok(policy) = LianaPolicy::new(prim_path_info, rec_paths_info) {
+    let policy = if config.use_taproot {
+        LianaPolicy::new(prim_path_info, rec_paths_info)
+    } else {
+        LianaPolicy::new_legacy(prim_path_info, rec_paths_info)
+    };
+    let policy = if let Ok(policy) = policy {
         policy
     } else {
         return;
@@ -154,11 +160,13 @@ fuzz_target!(|config: Config| {
         desc.receive_descriptor().derive(der_index, &SECP256K1),
         desc.change_descriptor().derive(der_index, &SECP256K1),
     ];
+    let mut psbt_in = Default::default();
+    let mut psbt_out = Default::default();
     for desc in &der_descs {
         desc.address(Network::Bitcoin);
         desc.script_pubkey();
-        desc.witness_script();
-        desc.bip32_derivations();
+        desc.update_psbt_in(&mut psbt_in);
+        desc.update_change_psbt_out(&mut psbt_out);
     }
 
     // Exercise the methods gathering information from a PSBT. TODO: get more useful PSBTs.
@@ -172,12 +180,11 @@ fuzz_target!(|config: Config| {
         // for outputs.
         let rec_desc = &der_descs[0];
         for psbt_in in psbt.inputs.iter_mut() {
-            psbt_in.witness_script = Some(rec_desc.witness_script());
-            psbt_in.bip32_derivation = rec_desc.bip32_derivations();
+            rec_desc.update_psbt_in(psbt_in);
         }
         let change_desc = &der_descs[1];
         for psbt_out in psbt.outputs.iter_mut() {
-            psbt_out.bip32_derivation = change_desc.bip32_derivations();
+            change_desc.update_change_psbt_out(psbt_out);
         }
 
         // Now get the spend info again with these info.

src/bitcoin/d/mod.rs

@@ -45,6 +45,9 @@ const BITCOIND_RETRY_LIMIT: usize = 60;
 // The minimum bitcoind version that can be used with lianad.
 const MIN_BITCOIND_VERSION: u64 = 240000;
 
+// The minimum bitcoind version that can be used with lianad and a Taproot descriptor.
+const MIN_TAPROOT_BITCOIND_VERSION: u64 = 260000;
+
 /// An error in the bitcoind interface.
 #[derive(Debug)]
 pub enum BitcoindError {
@@ -129,8 +132,8 @@ impl std::fmt::Display for BitcoindError {
             BitcoindError::InvalidVersion(v) => {
                 write!(
                     f,
-                    "Invalid bitcoind version '{}', minimum supported is '{}'.",
-                    v, MIN_BITCOIND_VERSION
+                    "Invalid bitcoind version '{}', minimum supported is '{}' and minimum supported if using Taproot is '{}'.",
+                    v, MIN_BITCOIND_VERSION, MIN_TAPROOT_BITCOIND_VERSION
                 )
             }
             BitcoindError::NetworkMismatch(conf_net, bitcoind_net) => {
@@ -699,12 +702,16 @@ impl BitcoinD {
     pub fn node_sanity_checks(
         &self,
         config_network: bitcoin::Network,
+        is_taproot: bool,
     ) -> Result<(), BitcoindError> {
         // Check the minimum supported bitcoind version
         let version = self.get_bitcoind_version();
         if version < MIN_BITCOIND_VERSION {
             return Err(BitcoindError::InvalidVersion(version));
         }
+        if is_taproot && version < MIN_TAPROOT_BITCOIND_VERSION {
+            return Err(BitcoindError::InvalidVersion(version));
+        }
 
         // Check bitcoind is running on the right network
         let bitcoind_net = self.get_network_bip70();
@@ -747,13 +754,27 @@ impl BitcoinD {
         // Check our main descriptor is imported in this wallet.
         let receive_desc = main_descriptor.receive_descriptor();
         let change_desc = main_descriptor.change_descriptor();
-        let desc_list: Vec<String> = self
+        let desc_list: Vec<_> = self
             .list_descriptors()
             .into_iter()
-            .map(|entry| entry.desc)
+            .filter_map(|entry| {
+                match descriptor::Descriptor::<descriptor::DescriptorPublicKey>::from_str(
+                    &entry.desc,
+                ) {
+                    Ok(desc) => Some(desc),
+                    Err(e) => {
+                        log::error!(
+                            "Error deserializing descriptor: {}. Descriptor: {}.",
+                            e,
+                            entry.desc
+                        );
+                        None
+                    }
+                }
+            })
             .collect();
-        if !desc_list.contains(&receive_desc.to_string())
-            || !desc_list.contains(&change_desc.to_string())
+        if !desc_list.iter().any(|desc| *receive_desc == *desc)
+            || !desc_list.iter().any(|desc| *change_desc == *desc)
         {
             return Err(BitcoindError::Wallet(
                 self.watchonly_wallet_path.clone(),

src/commands/mod.rs

@@ -591,6 +591,12 @@ impl DaemonControl {
                 psbtin
                     .partial_sigs
                     .extend(db_psbtin.partial_sigs.clone().into_iter());
+                psbtin
+                    .tap_script_sigs
+                    .extend(db_psbtin.tap_script_sigs.clone().into_iter());
+                if psbtin.tap_key_sig.is_none() {
+                    psbtin.tap_key_sig = db_psbtin.tap_key_sig;
+                }
             }
         } else {
             // If the transaction doesn't exist in DB already, sanity check its inputs.

src/config.rs

@@ -14,7 +14,7 @@ where
 {
     let string = String::deserialize(deserializer)?;
     T::from_str(&string)
-        .map_err(|e| de::Error::custom(format!("Error parsing descriptor '{}': '{}'", string, e)))
+        .map_err(|e| de::Error::custom(format!("Error parsing '{}': {}", string, e)))
 }
 
 pub fn serialize_to_string<T: std::fmt::Display, S: Serializer>(
@@ -319,6 +319,26 @@ mod tests {
         #[cfg(unix)] // On non-UNIX there is no 'daemon' member.
         assert_eq!(toml_str, serialized);
 
+        // A valid, round-tripping, config for a Taproot descriptor.
+        let toml_str = r#"
+            data_dir = '/home/wizardsardine/custom/folder/'
+            daemon = false
+            log_level = 'TRACE'
+            main_descriptor = 'tr([abcdef01]xpub6Eze7yAT3Y1wGrnzedCNVYDXUqa9NmHVWck5emBaTbXtURbe1NWZbK9bsz1TiVE7Cz341PMTfYgFw1KdLWdzcM1UMFTcdQfCYhhXZ2HJvTW/<0;1>/*,and_v(v:pk([abcdef01]xpub688Hn4wScQAAiYJLPg9yH27hUpfZAUnmJejRQBCiwfP5PEDzjWMNW1wChcninxr5gyavFqbbDjdV1aK5USJz8NDVjUy7FRQaaqqXHh5SbXe/<0;1>/*),older(52560)))#0mt7e93c'
+
+            [bitcoin_config]
+            network = 'bitcoin'
+            poll_interval_secs = 18
+
+            [bitcoind_config]
+            cookie_path = '/home/user/.bitcoin/.cookie'
+            addr = '127.0.0.1:8332'
+            "#.trim_start().replace("            ", "");
+        let parsed = toml::from_str::<Config>(&toml_str).expect("Deserializing toml_str");
+        let serialized = toml::to_string_pretty(&parsed).expect("Serializing to toml");
+        #[cfg(unix)] // On non-UNIX there is no 'daemon' member.
+        assert_eq!(toml_str, serialized);
+
         // A valid, round-tripping, config with `auth` instead of `cookie_path`
         let toml_str = r#"
             data_dir = '/home/wizardsardine/custom/folder/'