Merge branch '94-refactor/utils-privKey' into 'dev'

refactor readPrivateKeyFromFile to read privKey with base64pad encoding

Closes #94

See merge request ergo/rosen-bridge/rosenet!56

.changeset/stale-baboons-yawn.md

@@ -0,0 +1,5 @@
+---
+'@rosen-bridge/rosenet-utils': minor
+---
+
+Refactor readPrivateKeyFromFile to read privKey with base64pad encoding

.gitignore

@@ -137,3 +137,4 @@ tests/*/*.tfstate*
 tests/*/terraform.tfvars
 
 .vscode/settings.json
+.idea

packages/utils/lib/readPrivateKeyFromFile.ts

@@ -1,6 +1,10 @@
 import { generateKeyPair, marshalPrivateKey } from '@libp2p/crypto/keys';
 import { readFile, writeFile } from 'fs/promises';
 import { resolve } from 'path';
+import {
+  fromString as uint8ArrayFromString,
+  toString as uint8ArrayToString,
+} from 'uint8arrays';
 
 /**
  * read private key from a file and return its string representation, creating
@@ -10,16 +14,23 @@ import { resolve } from 'path';
 const readPrivateKeyFromFile = async (path: string) => {
   const fullPath = resolve(path);
   try {
-    return await readFile(fullPath, 'utf-8');
+    const fileData = await readFile(fullPath, 'utf-8');
+    const nodeDataJson = JSON.parse(fileData);
+    const privKeyUint8Array = uint8ArrayFromString(
+      nodeDataJson.privKey,
+      'base64pad',
+    );
+    return Buffer.from(privKeyUint8Array).toString('hex');
   } catch (error) {
     const privateKey = await generateKeyPair('Ed25519');
-    const privateKeyString = Buffer.from(
-      marshalPrivateKey(privateKey),
-    ).toString('hex');
+    const marshalPrivKey = marshalPrivateKey(privateKey);
+    const privateKeyString = uint8ArrayToString(marshalPrivKey, 'base64pad');
+    const nodeDataJson = {
+      privKey: privateKeyString,
+    };
+    await writeFile(fullPath, JSON.stringify(nodeDataJson), 'utf-8');
 
-    await writeFile(fullPath, privateKeyString, 'utf-8');
-
-    return privateKeyString;
+    return Buffer.from(marshalPrivKey).toString('hex');
   }
 };