From ef827533c1d10fdcc620c39205259239fd6d6627 Mon Sep 17 00:00:00 2001
From: Tomasz Slabon <tomasz.slabon@keep.network>
Date: Tue, 26 Sep 2023 18:25:50 +0200
Subject: [PATCH] Updated calculating of deposit script hash

---
 typescript/src/bitcoin.ts | 12 ++++++++++++
 typescript/src/deposit.ts | 16 +++++++++-------
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/typescript/src/bitcoin.ts b/typescript/src/bitcoin.ts
index 63936a464..75b0f4163 100644
--- a/typescript/src/bitcoin.ts
+++ b/typescript/src/bitcoin.ts
@@ -524,6 +524,7 @@ export function createKeyRing(
  * @param text - Text the HASH160 is computed for.
  * @returns Hash as a 20-byte un-prefixed hex string.
  */
+// TODO: Make it use Hex for input and return values.
 export function computeHash160(text: string): string {
   const sha256Hash = utils.sha256(
     Hex.from(Buffer.from(text, "hex")).toPrefixedString()
@@ -533,6 +534,17 @@ export function computeHash160(text: string): string {
   return Hex.from(hash160).toString()
 }
 
+/**
+ * Computes the single SHA256 for the given text.
+ * @param text - Text the single SHA256 is computed for.
+ * @returns Hash as a 32-byte un-prefixed hex string.
+ */
+// TODO: Consider adding unit tests.
+export function computeSha256(text: Hex): Hex {
+  const hash = utils.sha256(text.toPrefixedString())
+  return Hex.from(hash)
+}
+
 /**
  * Computes the double SHA256 for the given text.
  * @param text - Text the double SHA256 is computed for.
diff --git a/typescript/src/deposit.ts b/typescript/src/deposit.ts
index c95726283..b3b38441e 100644
--- a/typescript/src/deposit.ts
+++ b/typescript/src/deposit.ts
@@ -9,11 +9,11 @@ import {
   UnspentTransactionOutput,
   TransactionHash,
   isPublicKeyHashLength,
+  computeSha256,
+  computeHash256,
+  computeHash160,
 } from "./bitcoin"
-import {
-  BitcoinNetwork,
-  toBitcoinJsLibNetwork,
-} from "./bitcoin-network"
+import { BitcoinNetwork, toBitcoinJsLibNetwork } from "./bitcoin-network"
 import { Bridge, Event, Identifier } from "./chain"
 import { Hex } from "./hex"
 
@@ -343,11 +343,13 @@ export async function calculateDepositScriptHash(
   witness: boolean
 ): Promise<Buffer> {
   const script = await assembleDepositScript(deposit)
-  // Parse the script from HEX string.
-  const parsedScript = bcoin.Script.fromRaw(Buffer.from(script, "hex"))
   // If witness script hash should be produced, SHA256 should be used.
   // Legacy script hash needs HASH160.
-  return witness ? parsedScript.sha256() : parsedScript.hash160()
+  if (witness) {
+    return computeSha256(Hex.from(script)).toBuffer()
+  }
+
+  return Buffer.from(computeHash160(script), "hex")
 }
 
 /**