feat: add wasm-utxo backend for cross-chain recovery

Add wasm-utxo implementation for PSBT creation in cross-chain recovery
flows, alongside the existing utxolib implementation. The wasm-utxo
backend is enabled for testnet coins only, while mainnet continues to
use utxolib for compatibility.

Key changes:
- Add support for taproot script types in cross-chain recovery
- Use sequence number feffffff instead of ffffffff
- Add helper functions to detect taproot chains and convert networks

Co-authored-by: llm-git <llm-git@ttll.de>

Ticket: BTC-2892

TICKET: BTC-2892

Author: lcovar

modules/abstract-utxo/src/recovery/crossChainRecovery.ts

@@ -7,6 +7,14 @@ import { decrypt } from '@bitgo/sdk-api';
 import { AbstractUtxoCoin, TransactionInfo } from '../abstractUtxoCoin';
 import { signAndVerifyPsbt } from '../transaction/fixedScript/signPsbt';
 
+import {
+  PsbtBackend,
+  createEmptyWasmPsbt,
+  addWalletInputsToWasmPsbt,
+  addOutputToWasmPsbt,
+  wasmPsbtToUtxolibPsbt,
+} from './psbt';
+
 const { unspentSum } = utxolib.bitgo;
 type RootWalletKeys = utxolib.bitgo.RootWalletKeys;
 type Unspent<TNumber extends number | bigint = number> = utxolib.bitgo.Unspent<TNumber>;
@@ -325,15 +333,15 @@ async function getPrv(xprv?: string, passphrase?: string, wallet?: IWallet | Wal
 }
 
 /**
- * Create a sweep transaction for cross-chain recovery using PSBT
+ * Create a sweep transaction for cross-chain recovery using PSBT (utxolib implementation)
  * @param network
  * @param walletKeys
  * @param unspents
  * @param targetAddress
  * @param feeRateSatVB
  * @return unsigned PSBT
  */
-function createSweepTransaction<TNumber extends number | bigint = number>(
+function createSweepTransactionUtxolib<TNumber extends number | bigint = number>(
   network: utxolib.Network,
   walletKeys: RootWalletKeys,
   unspents: WalletUnspent<TNumber>[],
@@ -372,6 +380,71 @@ function createSweepTransaction<TNumber extends number | bigint = number>(
   return psbt;
 }
 
+/**
+ * Create a sweep transaction for cross-chain recovery using wasm-utxo
+ * @param network
+ * @param walletKeys
+ * @param unspents
+ * @param targetAddress
+ * @param feeRateSatVB
+ * @return unsigned PSBT
+ */
+function createSweepTransactionWasm<TNumber extends number | bigint = number>(
+  network: utxolib.Network,
+  walletKeys: RootWalletKeys,
+  unspents: WalletUnspent<TNumber>[],
+  targetAddress: string,
+  feeRateSatVB: number
+): utxolib.bitgo.UtxoPsbt {
+  const inputValue = unspentSum<bigint>(
+    unspents.map((u) => ({ ...u, value: BigInt(u.value) })),
+    'bigint'
+  );
+
+  // Create PSBT with wasm-utxo and add wallet inputs using shared utilities
+  const unspentsBigint = unspents.map((u) => ({ ...u, value: BigInt(u.value) }));
+  const wasmPsbt = createEmptyWasmPsbt(network, walletKeys);
+  addWalletInputsToWasmPsbt(wasmPsbt, unspentsBigint, walletKeys);
+
+  // Convert to utxolib PSBT temporarily for dimension calculation
+  const tempPsbt = wasmPsbtToUtxolibPsbt(wasmPsbt, network);
+  const vsize = Dimensions.fromPsbt(tempPsbt)
+    .plus(Dimensions.fromOutput({ script: utxolib.address.toOutputScript(targetAddress, network) }))
+    .getVSize();
+  const fee = BigInt(Math.round(vsize * feeRateSatVB));
+
+  // Add output to wasm PSBT
+  addOutputToWasmPsbt(wasmPsbt, targetAddress, inputValue - fee, network);
+
+  // Convert to utxolib PSBT for signing and return
+  return wasmPsbtToUtxolibPsbt(wasmPsbt, network);
+}
+
+/**
+ * Create a sweep transaction for cross-chain recovery using PSBT
+ * @param network
+ * @param walletKeys
+ * @param unspents
+ * @param targetAddress
+ * @param feeRateSatVB
+ * @param backend - Which backend to use for PSBT creation (default: 'wasm-utxo')
+ * @return unsigned PSBT
+ */
+function createSweepTransaction<TNumber extends number | bigint = number>(
+  network: utxolib.Network,
+  walletKeys: RootWalletKeys,
+  unspents: WalletUnspent<TNumber>[],
+  targetAddress: string,
+  feeRateSatVB: number,
+  backend: PsbtBackend = 'wasm-utxo'
+): utxolib.bitgo.UtxoPsbt {
+  if (backend === 'wasm-utxo') {
+    return createSweepTransactionWasm(network, walletKeys, unspents, targetAddress, feeRateSatVB);
+  } else {
+    return createSweepTransactionUtxolib(network, walletKeys, unspents, targetAddress, feeRateSatVB);
+  }
+}
+
 type RecoverParams = {
   /** Wallet ID (can be v1 wallet or v2 wallet) */
   walletId: string;
@@ -420,12 +493,15 @@ export async function recoverCrossChain<TNumber extends number | bigint = number
   const feeRateSatVB = await getFeeRateSatVB(params.sourceCoin);
 
   // Create PSBT for both signed and unsigned recovery
+  // Use wasm-utxo for testnet coins only, utxolib for mainnet
+  const backend: PsbtBackend = utxolib.isTestnet(params.sourceCoin.network) ? 'wasm-utxo' : 'utxolib';
   const psbt = createSweepTransaction<TNumber>(
     params.sourceCoin.network,
     walletKeys,
     walletUnspents,
     params.recoveryAddress,
-    feeRateSatVB
+    feeRateSatVB,
+    backend
   );
 
   // For unsigned recovery, return unsigned PSBT hex

modules/abstract-utxo/src/recovery/psbt.ts

@@ -19,7 +19,7 @@ export type PsbtBackend = 'wasm-utxo' | 'utxolib';
 /**
  * Check if a chain code is for a taproot script type
  */
-function isTaprootChain(chain: ChainCode): boolean {
+export function isTaprootChain(chain: ChainCode): boolean {
   return (
     (chainCodesP2tr as readonly number[]).includes(chain) || (chainCodesP2trMusig2 as readonly number[]).includes(chain)
   );
@@ -28,7 +28,7 @@ function isTaprootChain(chain: ChainCode): boolean {
 /**
  * Convert utxolib Network to wasm-utxo network name
  */
-function toNetworkName(network: utxolib.Network): utxolibCompat.UtxolibName {
+export function toNetworkName(network: utxolib.Network): utxolibCompat.UtxolibName {
   const networkName = utxolib.getNetworkName(network);
   if (!networkName) {
     throw new Error(`Invalid network`);
@@ -129,32 +129,53 @@ const ZCASH_DEFAULT_BLOCK_HEIGHTS: Record<string, number> = {
 };
 
 /**
- * Create a backup key recovery PSBT using wasm-utxo
+ * Options for creating an empty wasm-utxo PSBT
  */
-function createBackupKeyRecoveryPsbtWasm(
+export interface CreateEmptyWasmPsbtOptions {
+  /** Block height for Zcash networks (required to determine consensus branch ID) */
+  blockHeight?: number;
+}
+
+/**
+ * Create an empty wasm-utxo BitGoPsbt for a given network.
+ * Handles Zcash networks specially by using ZcashBitGoPsbt.
+ *
+ * @param network - The network for the PSBT
+ * @param rootWalletKeys - The wallet keys
+ * @param options - Optional settings (e.g., blockHeight for Zcash)
+ * @returns A wasm-utxo BitGoPsbt instance
+ */
+export function createEmptyWasmPsbt(
   network: utxolib.Network,
   rootWalletKeys: RootWalletKeys,
-  unspents: WalletUnspent<bigint>[],
-  options: CreateBackupKeyRecoveryPsbtOptions
-): utxolib.bitgo.UtxoPsbt {
-  const { feeRateSatVB, recoveryDestination, keyRecoveryServiceFee, keyRecoveryServiceFeeAddress } = options;
-
+  options?: CreateEmptyWasmPsbtOptions
+): fixedScriptWallet.BitGoPsbt {
   const networkName = toNetworkName(network);
 
-  // Create PSBT with wasm-utxo and add wallet inputs
-  // wasm-utxo's RootWalletKeys.from() accepts utxolib's RootWalletKeys format (IWalletKeys interface)
-  let wasmPsbt: fixedScriptWallet.BitGoPsbt;
-
   if (isZcashNetwork(networkName)) {
     // For Zcash, use ZcashBitGoPsbt which requires block height to determine consensus branch ID
-    const blockHeight = options.blockHeight ?? ZCASH_DEFAULT_BLOCK_HEIGHTS[networkName];
-    wasmPsbt = fixedScriptWallet.ZcashBitGoPsbt.createEmpty(networkName as 'zcash' | 'zcashTest', rootWalletKeys, {
+    const blockHeight = options?.blockHeight ?? ZCASH_DEFAULT_BLOCK_HEIGHTS[networkName];
+    return fixedScriptWallet.ZcashBitGoPsbt.createEmpty(networkName as 'zcash' | 'zcashTest', rootWalletKeys, {
       blockHeight,
     });
-  } else {
-    wasmPsbt = fixedScriptWallet.BitGoPsbt.createEmpty(networkName, rootWalletKeys);
   }
 
+  return fixedScriptWallet.BitGoPsbt.createEmpty(networkName, rootWalletKeys);
+}
+
+/**
+ * Add wallet inputs from unspents to a wasm-utxo BitGoPsbt.
+ * Handles taproot inputs by setting the appropriate signPath.
+ *
+ * @param wasmPsbt - The wasm-utxo BitGoPsbt to add inputs to
+ * @param unspents - The wallet unspents to add as inputs
+ * @param rootWalletKeys - The wallet keys
+ */
+export function addWalletInputsToWasmPsbt(
+  wasmPsbt: fixedScriptWallet.BitGoPsbt,
+  unspents: WalletUnspent<bigint>[],
+  rootWalletKeys: RootWalletKeys
+): void {
   unspents.forEach((unspent) => {
     const { txid, vout } = utxolib.bitgo.parseOutputId(unspent.id);
     const signPath: fixedScriptWallet.SignPath | undefined = isTaprootChain(unspent.chain)
@@ -178,11 +199,59 @@ function createBackupKeyRecoveryPsbtWasm(
       }
     );
   });
+}
 
-  // Convert wasm-utxo PSBT to utxolib PSBT for dimension calculation and output addition
-  const psbt = utxolib.bitgo.createPsbtFromBuffer(Buffer.from(wasmPsbt.serialize()), network);
+/**
+ * Add an output to a wasm-utxo BitGoPsbt.
+ *
+ * @param wasmPsbt - The wasm-utxo BitGoPsbt to add the output to
+ * @param address - The destination address
+ * @param value - The output value in satoshis
+ * @param network - The network (used to convert address to script)
+ * @returns The output index
+ */
+export function addOutputToWasmPsbt(
+  wasmPsbt: fixedScriptWallet.BitGoPsbt,
+  address: string,
+  value: bigint,
+  network: utxolib.Network
+): number {
+  const script = utxolib.address.toOutputScript(address, network);
+  return wasmPsbt.addOutput({ script: new Uint8Array(script), value });
+}
 
-  let dimensions = Dimensions.fromPsbt(psbt).plus(
+/**
+ * Convert a wasm-utxo BitGoPsbt to a utxolib UtxoPsbt.
+ *
+ * @param wasmPsbt - The wasm-utxo BitGoPsbt to convert
+ * @param network - The network
+ * @returns A utxolib UtxoPsbt
+ */
+export function wasmPsbtToUtxolibPsbt(
+  wasmPsbt: fixedScriptWallet.BitGoPsbt,
+  network: utxolib.Network
+): utxolib.bitgo.UtxoPsbt {
+  return utxolib.bitgo.createPsbtFromBuffer(Buffer.from(wasmPsbt.serialize()), network);
+}
+
+/**
+ * Create a backup key recovery PSBT using wasm-utxo
+ */
+function createBackupKeyRecoveryPsbtWasm(
+  network: utxolib.Network,
+  rootWalletKeys: RootWalletKeys,
+  unspents: WalletUnspent<bigint>[],
+  options: CreateBackupKeyRecoveryPsbtOptions
+): utxolib.bitgo.UtxoPsbt {
+  const { feeRateSatVB, recoveryDestination, keyRecoveryServiceFee, keyRecoveryServiceFeeAddress } = options;
+
+  // Create PSBT with wasm-utxo and add wallet inputs using shared utilities
+  const wasmPsbt = createEmptyWasmPsbt(network, rootWalletKeys, { blockHeight: options.blockHeight });
+  addWalletInputsToWasmPsbt(wasmPsbt, unspents, rootWalletKeys);
+
+  // Convert to utxolib PSBT temporarily for dimension calculation
+  const tempPsbt = wasmPsbtToUtxolibPsbt(wasmPsbt, network);
+  let dimensions = Dimensions.fromPsbt(tempPsbt).plus(
     Dimensions.fromOutput({ script: utxolib.address.toOutputScript(recoveryDestination, network) })
   );
 
@@ -202,16 +271,15 @@ function createBackupKeyRecoveryPsbtWasm(
     throw new InsufficientFundsError(totalInputAmount, approximateFee, keyRecoveryServiceFee, recoveryAmount);
   }
 
-  psbt.addOutput({ script: utxolib.address.toOutputScript(recoveryDestination, network), value: recoveryAmount });
+  // Add outputs to wasm PSBT
+  addOutputToWasmPsbt(wasmPsbt, recoveryDestination, recoveryAmount, network);
 
   if (keyRecoveryServiceFeeAddress) {
-    psbt.addOutput({
-      script: utxolib.address.toOutputScript(keyRecoveryServiceFeeAddress, network),
-      value: keyRecoveryServiceFee,
-    });
+    addOutputToWasmPsbt(wasmPsbt, keyRecoveryServiceFeeAddress, keyRecoveryServiceFee, network);
   }
 
-  return psbt;
+  // Convert to utxolib PSBT for signing and return
+  return wasmPsbtToUtxolibPsbt(wasmPsbt, network);
 }
 
 /**

modules/abstract-utxo/test/unit/fixtures/tbch/recovery/crossChainRecovery-tbsv-signed.json

@@ -1,7 +1,7 @@
 {
   "version": 2,
   "walletId": "5abacebe28d72fbd07e0b8cbba0ff39e",
-  "txHex": "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",
+  "txHex": "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",
   "sourceCoin": "tbch",
   "recoveryCoin": "tbsv",
   "recoveryAmount": 99992200

modules/abstract-utxo/test/unit/fixtures/tbch/recovery/crossChainRecovery-tbsv-unsigned.json

@@ -1,5 +1,5 @@
 {
-  "txHex": "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",
+  "txHex": "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",
   "walletId": "5abacebe28d72fbd07e0b8cbba0ff39e",
   "address": "2N7VWEhmfT8CzGSW2bCVeKJ3GCwSD1nsL2V",
   "coin": "tbch"