From ae211c88d9235dd9c6ed2abc218cfd4cb3c9d31a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andrei=20B=C4=83ncioiu?= <andrei.bancioiu@gmail.com>
Date: Wed, 8 Nov 2023 13:14:24 +0200
Subject: [PATCH] Fix applySignature(). Handle buffers in a better way.

---
 src/signableMessage.ts |  7 ++-----
 src/signature.ts       | 12 +++++++++++-
 src/transaction.ts     | 16 +++-------------
 3 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/src/signableMessage.ts b/src/signableMessage.ts
index fbdb8f67..4aee73fa 100644
--- a/src/signableMessage.ts
+++ b/src/signableMessage.ts
@@ -1,5 +1,6 @@
 import { Address } from "./address";
 import { ISignature } from "./interface";
+import { interpretSignatureAsBuffer } from "./signature";
 const createKeccakHash = require("keccak");
 
 export const MESSAGE_PREFIX = "\x17Elrond Signed Message:\n";
@@ -57,11 +58,7 @@ export class SignableMessage {
   }
 
   applySignature(signature: ISignature | Buffer) {
-    if (signature instanceof Buffer) {
-      this.signature = signature;
-    } else {
-      this.signature = Buffer.from(signature.hex(), "hex");
-    }
+    this.signature = interpretSignatureAsBuffer(signature);
   }
 
   getMessageSize(): Buffer {
diff --git a/src/signature.ts b/src/signature.ts
index 9ff9e9a3..e307a225 100644
--- a/src/signature.ts
+++ b/src/signature.ts
@@ -1,4 +1,4 @@
-import  * as errors from "./errors";
+import * as errors from "./errors";
 
 
 const SIGNATURE_LENGTH = 64;
@@ -58,3 +58,13 @@ export class Signature {
         return this.valueHex;
     }
 }
+
+export function interpretSignatureAsBuffer(signature: { hex(): string; } | Uint8Array): Buffer {
+    if (ArrayBuffer.isView(signature)) {
+        return Buffer.from(signature);
+    } else if ((<any>signature).hex != null) {
+        return Buffer.from(signature.hex(), "hex");
+    }
+
+    throw new Error(`Object cannot be interpreted as a signature: ${signature}`);
+}
diff --git a/src/transaction.ts b/src/transaction.ts
index 092aae7d..e8926c44 100644
--- a/src/transaction.ts
+++ b/src/transaction.ts
@@ -8,7 +8,7 @@ import { IAddress, IChainID, IGasLimit, IGasPrice, INonce, IPlainTransactionObje
 import { INetworkConfig } from "./interfaceOfNetwork";
 import { TransactionOptions, TransactionVersion } from "./networkParams";
 import { ProtoSerializer } from "./proto";
-import { Signature } from "./signature";
+import { Signature, interpretSignatureAsBuffer } from "./signature";
 import { TransactionPayload } from "./transactionPayload";
 import { guardNotEmpty } from "./utils";
 
@@ -372,27 +372,17 @@ export class Transaction {
    * @param signature The signature, as computed by a signer.
    */
   applySignature(signature: ISignature | Uint8Array) {
-    this.signature = this.interpretSignatureAsBuffer(signature);
+    this.signature = interpretSignatureAsBuffer(signature);
     this.hash = TransactionHash.compute(this);
   }
 
-  private interpretSignatureAsBuffer(signature: ISignature | Uint8Array): Buffer {
-    if (ArrayBuffer.isView(signature)) {
-      return Buffer.from(signature);
-    } else if ((<any>signature).hex != null) {
-      return Buffer.from(signature.hex(), "hex");
-    }
-
-    throw new Error(`Object cannot be interpreted as a signature: ${signature}`);
-  }
-
   /**
    * Applies the guardian signature on the transaction.
    *
    * @param guardianSignature The signature, as computed by a signer.
    */
   applyGuardianSignature(guardianSignature: ISignature | Uint8Array) {
-    this.guardianSignature = this.interpretSignatureAsBuffer(guardianSignature);
+    this.guardianSignature = interpretSignatureAsBuffer(guardianSignature);
     this.hash = TransactionHash.compute(this);
   }