chore(psbt): expect sliced pubkey for signable psbt

src/Methods/Order/CreateSignablePsbt.ts

@@ -2,7 +2,6 @@ import { BadRequestError, method } from "@valkyr/api";
 import { payments, Psbt } from "bitcoinjs-lib";
 import Schema, { string } from "computed-types";
 
-import { Wallet } from "../../Libraries/Wallet";
 import { Lookup } from "../../Services/Lookup";
 import { utils } from "../../Utilities";
 import { validate } from "../../Validators";
@@ -16,6 +15,8 @@ export const createSignablePsbt = method({
   }),
   handler: async ({ network, location, maker, pubkey }) => {
     const [hash, index] = utils.parse.location(location);
+    const tapInternalKey = pubkey ? Buffer.from(pubkey, "hex") : undefined;
+    const btcNetwork = utils.bitcoin.getBitcoinNetwork(network);
 
     const address = utils.bitcoin.getBitcoinAddress(maker);
     if (address === undefined) {
@@ -32,18 +33,17 @@ export const createSignablePsbt = method({
       throw new BadRequestError("Provided maker address does not match location output");
     }
 
-    const psbt = new Psbt({ network: utils.bitcoin.getBitcoinNetwork(network) });
+    const psbt = new Psbt({ network: btcNetwork });
 
-    if (pubkey !== undefined) {
-      const wallet = Wallet.fromPublicKey(pubkey, network);
+    if (tapInternalKey !== undefined) {
       psbt.addInput({
         hash,
         index,
         witnessUtxo: {
-          script: wallet.output,
+          script: utils.taproot.getPaymentOutput(tapInternalKey, btcNetwork),
           value: 0,
         },
-        tapInternalKey: wallet.internalPubkey,
+        tapInternalKey,
       });
     } else {
       psbt.addInput({ hash, index });

src/Utilities/Taproot.ts

@@ -20,6 +20,7 @@ export const taproot = {
   generateMnemonic,
   getMasterNode,
   getBip84Account,
+  getPaymentOutput,
 };
 
 /*
@@ -67,3 +68,19 @@ function getBip84Account(masterNode: BIP32Interface, network: Network, account:
     .deriveHardened(network === "mainnet" ? 0 : 1)
     .derive(account);
 }
+
+/**
+ * Get a taproot script output for a specific internal public key.
+ *
+ * @param internalPubkey - Internal public key to generate output for.
+ * @param network        - Network to generate output for.
+ *
+ * @returns taproot script output.
+ */
+function getPaymentOutput(internalPubkey: Buffer, network: btc.Network): Buffer {
+  const { output } = btc.payments.p2tr({ internalPubkey, network });
+  if (output === undefined) {
+    throw new Error("Failed to generate output");
+  }
+  return output;
+}