From 1136195d359a089c4c34bd41be9ff8b039eacf03 Mon Sep 17 00:00:00 2001
From: eum602 <eum602@gmail.com>
Date: Wed, 2 Aug 2023 15:55:16 -0500
Subject: [PATCH] fix: type of checksum

---
 lib/lac1/lac1Did.js | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/lib/lac1/lac1Did.js b/lib/lac1/lac1Did.js
index 3268ad8..28fddfd 100644
--- a/lib/lac1/lac1Did.js
+++ b/lib/lac1/lac1Did.js
@@ -92,10 +92,11 @@ export default class DIDLac1 extends DID {
   }
 
   static checksum(payload) {
-    return Buffer.from(
+    const trimmed = Buffer.from(
       keccak256(Buffer.concat(payload)).replace("0x", ""),
       "hex"
     ).subarray(0, 4);
+    return Buffer.from(trimmed);
   }
 
   static encode(didType, chainId, address, didRegistry, didVersion) {
@@ -124,27 +125,27 @@ export default class DIDLac1 extends DID {
     const trimmed = did.replace("did:lac1:", "");
     const data = Buffer.from(base58.decode(trimmed));
     const len = data.length;
-    const encodedPayload = data.subarray(0, len - 4);
+    const encodedPayload = Buffer.from(data.subarray(0, len - 4));
     const computedChecksum = DIDLac1.checksum([encodedPayload]);
-    const checksum = data.subarray(len - 4, len);
+    const checksum = Buffer.from(data.subarray(len - 4, len));
     if (!computedChecksum.equals(checksum)) {
       const message = "Checksum mismatch";
       throw new Error(message);
     }
-    const version = data.subarray(0, 2).toString("hex");
-    const didType = data.subarray(2, 4).toString("hex");
+    const version = Buffer.from(data.subarray(0, 2)).toString("hex");
+    const didType = Buffer.from(data.subarray(2, 4)).toString("hex");
     // TODO handle better versioning
     if (didType !== LAC1_DID_TYPE_CODE) {
       const message = "Unsupported did type";
       throw new Error(message);
     }
     const address = ethers.utils.getAddress(
-      "0x" + data.subarray(4, 24).toString("hex")
+      "0x" + Buffer.from(data.subarray(4, 24)).toString("hex")
     );
     const didRegistryAddress = ethers.utils.getAddress(
-      "0x" + data.subarray(24, 44).toString("hex")
+      "0x" + Buffer.from(data.subarray(24, 44)).toString("hex")
     );
-    let c = data.subarray(44, len - 4).toString("hex");
+    let c = Buffer.from(data.subarray(44, len - 4)).toString("hex");
     if (c[0] === "0") {
       c = c.substring(1);
     }