Add segwit key derivation as a feature (#447)

* Add segwit key derivation as a feature

* Segwit build script

* Fix descriptor

* Fix descriptor syntax

* Fix xpub

* Undo package rename

Cargo.toml

@@ -24,6 +24,7 @@ required-features = ["server"]
 all = []
 default = []
 web = []
+segwit = []
 server = ["tokio/full", "tower-http/cors"]
 
 [dependencies]

build-segwit.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+wasm-pack build --release --target web --features segwit
+cp pkg/*.ts lib/web
+cp pkg/*.js lib/web
+cp pkg/*.wasm lib/web
+cp pkg/README.md lib/web
+cp pkg/LICENSE* lib/web
+cd lib/web
+npm install
+npm run prepare

lib/web/yarn.lock

@@ -0,0 +1,20 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+"@types/node@^20.8.2":
+  version "20.11.0"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-20.11.0.tgz#8e0b99e70c0c1ade1a86c4a282f7b7ef87c9552f"
+  integrity sha512-o9bjXmDNcF7GbM4CNQpmi+TutCgap/K3w1JyKgxAjqx41zp9qlIAVFi0IhCNsJcXolEqLWhbFbEeL0PvYm4pcQ==
+  dependencies:
+    undici-types "~5.26.4"
+
+typescript@^5.2.2:
+  version "5.3.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.3.3.tgz#b3ce6ba258e72e6305ba66f5c9b452aaee3ffe37"
+  integrity sha512-pXWcraxM0uxAS+tN0AG/BF2TyqmHO014Z070UsJ+pFvYuRSq8KH8DmWpnbXe0pEPDHXZV3FcAbJkijJ5oNEnWw==
+
+undici-types@~5.26.4:
+  version "5.26.5"
+  resolved "https://registry.yarnpkg.com/undici-types/-/undici-types-5.26.5.tgz#bcd539893d00b56e964fd2657a4866b221a65617"
+  integrity sha512-JlCMO+ehdEIKqlFxk6IfVoAUVmgz7cU7zD/h9XZ0qzeosSHmUJVOzSQvvYSYWXkFXC+IfLKSIffhv0sVZup6pA==

src/bitcoin/keys.rs

@@ -1,12 +1,16 @@
 use std::str::FromStr;
 
+#[cfg(feature = "segwit")]
+use bdk::miniscript::Segwitv0;
+#[cfg(not(feature = "segwit"))]
+use bdk::miniscript::Tap;
 use bdk::{
     bitcoin::{
         secp256k1::Secp256k1,
         util::bip32::{ChildNumber, DerivationPath, ExtendedPrivKey, ExtendedPubKey, KeySource},
     },
     keys::{DerivableKey, DescriptorKey, DescriptorKey::Secret as SecretDesc, DescriptorSecretKey},
-    miniscript::{descriptor::DescriptorKeyParseError, Tap},
+    miniscript::descriptor::DescriptorKeyParseError,
 };
 use bip39::{Language, Mnemonic};
 use bitcoin::{KeyPair, Network};
@@ -70,10 +74,16 @@ fn get_descriptor(
     let deriv_descriptor = DerivationPath::from_str(path)?;
     let derived_xprv = &xprv.derive_priv(&secp, &deriv_descriptor)?;
     let origin: KeySource = (xprv.fingerprint(&secp), deriv_descriptor);
+    #[cfg(not(feature = "segwit"))]
     let derived_xprv_desc_key: DescriptorKey<Tap> = derived_xprv.into_descriptor_key(
         Some(origin),
         DerivationPath::default().child(ChildNumber::from_normal_idx(change)?),
     )?;
+    #[cfg(feature = "segwit")]
+    let derived_xprv_desc_key: DescriptorKey<Segwitv0> = derived_xprv.into_descriptor_key(
+        Some(origin),
+        DerivationPath::default().child(ChildNumber::from_normal_idx(change)?),
+    )?;
 
     if let SecretDesc(desc_seckey, _, _) = derived_xprv_desc_key {
         Ok(desc_seckey)
@@ -85,15 +95,25 @@ fn get_descriptor(
 fn xprv_desc(xprv: &ExtendedPrivKey, path: &str, change: u32) -> Result<String, BitcoinKeysError> {
     let xprv = get_descriptor(xprv, path, change)?;
 
-    Ok(format!("tr({xprv})"))
+    #[cfg(not(feature = "segwit"))]
+    let desc = format!("tr({xprv})");
+    #[cfg(feature = "segwit")]
+    let desc = format!("wpkh({xprv})");
+
+    Ok(desc)
 }
 
 fn xpub_desc(xprv: &ExtendedPrivKey, path: &str, change: u32) -> Result<String, BitcoinKeysError> {
     let secp = Secp256k1::new();
     let xprv = get_descriptor(xprv, path, change)?;
     let xpub = xprv.to_public(&secp)?;
 
-    Ok(format!("tr({xpub})"))
+    #[cfg(not(feature = "segwit"))]
+    let desc = format!("tr({xpub})");
+    #[cfg(feature = "segwit")]
+    let desc = format!("wpkh({xpub})");
+
+    Ok(desc)
 }
 
 fn watcher_xpub(
@@ -235,7 +255,11 @@ pub async fn get_marketplace_descriptor() -> Result<Option<SecretString>, Bitcoi
     };
 
     let desc_xpub = DescriptorPublicKey::XPub(desc).to_string();
-    let tap = format!("tr({desc_xpub}/*)");
 
-    Ok(Some(SecretString(tap)))
+    #[cfg(not(feature = "segwit"))]
+    let desc_str = format!("tr({desc_xpub}/*)");
+    #[cfg(feature = "segwit")]
+    let desc_str = format!("wpkh({desc_xpub}/*)");
+
+    Ok(Some(SecretString(desc_str)))
 }

src/constants.rs

@@ -90,8 +90,15 @@ pub async fn get_udas_utxo() -> String {
 }
 
 // Descriptor strings
+#[cfg(not(feature = "segwit"))]
 pub const BTC_MAINNET_PATH: &str = "m/86h/0h/0h";
+#[cfg(not(feature = "segwit"))]
 pub const BTC_TESTNET_PATH: &str = "m/86h/1h/0h";
+#[cfg(feature = "segwit")]
+pub const BTC_MAINNET_PATH: &str = "m/84h/0h/0h";
+#[cfg(feature = "segwit")]
+pub const BTC_TESTNET_PATH: &str = "m/84h/1h/0h";
+
 pub static BTC_PATH: Lazy<RwLock<String>> = Lazy::new(|| {
     RwLock::new(if dot_env("BITCOIN_NETWORK") == "bitcoin" {
         BTC_MAINNET_PATH.to_owned()