added NAS configuration file; updated MediaViewer to support thumbnail carousel; improved error handling in NASAPI and NASAUTH; refactored various comments for clarity

src/services/CredentialEncryption.js

@@ -1,24 +1,19 @@
 import * as Crypto from 'expo-crypto';
 
 /**
- * Credential Encryption Service
- *
- * Uses expo-crypto for password hashing (SHA-256)
- * Uses base64 encoding for storing account data objects in the database
+ * Handles password hashing (SHA-256) and base64 encoding of account data objects
  */
 class CredentialEncryption {
   /**
-   * Hash a password using SHA-256 via expo-crypto
-   * Returns a hex digest string
+   * Hash a password with SHA-256 and return a hex digest
    */
   async hashPassword(password) {
     try {
       if (!password) throw new Error('Password is required');
-      const digest = await Crypto.digestStringAsync(
+      return await Crypto.digestStringAsync(
         Crypto.CryptoDigestAlgorithm.SHA256,
         password
       );
-      return digest;
     } catch (error) {
       console.error('Password hashing error:', error);
       throw new Error('Failed to hash password: ' + error.message);
@@ -26,7 +21,7 @@ class CredentialEncryption {
   }
 
   /**
-   * Verify a password against a stored hash
+   * Compare a plaintext password against a stored hash
    */
   async verifyPassword(password, storedHash) {
     try {
@@ -39,15 +34,13 @@ class CredentialEncryption {
   }
 
   /**
-   * Encrypt an object for database storage (base64-encoded JSON)
+   * Encode an object as a base64 JSON string for database storage
    */
   encrypt(data) {
     try {
       if (!data) throw new Error('No data provided to encrypt');
       const jsonString = JSON.stringify(data);
-      // btoa is available in React Native / Hermes
-      const encoded = btoa(unescape(encodeURIComponent(jsonString)));
-      return encoded;
+      return btoa(unescape(encodeURIComponent(jsonString)));
     } catch (error) {
       console.error('Encryption error:', error);
       throw new Error('Failed to encrypt data: ' + error.message);
@@ -55,7 +48,7 @@ class CredentialEncryption {
   }
 
   /**
-   * Decrypt a base64-encoded JSON string back to an object
+   * Decode a base64 JSON string back to an object
    */
   decrypt(encryptedData) {
     try {
@@ -70,4 +63,3 @@ class CredentialEncryption {
 }
 
 export default new CredentialEncryption();
-