[SR NO 23] Enhanced Security Measures for File System Operations

[priyankeshh]

Overview

This PR addresses issue #349 by implementing comprehensive security measures for file system operations, particularly focusing on secure folder management, encryption, and password validation.

Changes Implemented

1. Secure Folder Management

• Added a dedicated secure folder system with proper isolation
• Implemented .nomedia file creation to prevent media scanning
• Added metadata tracking for secure files

2. Strong Encryption

• Implemented AES-256-GCM encryption for sensitive files
• Added secure key derivation using password-based methods
• Implemented proper salt generation and management

3. Password Security

• Added robust password validation with requirements for:
  • Minimum length (8 characters)
  • Uppercase letters
  • Numbers
• Implemented secure password hashing using modern algorithms
• Added verification methods for password authentication

4. Secure File Operations

• Added functions to securely move files to/from the secure folder
• Implemented proper encryption/decryption during file transfers
• Added secure deletion capabilities with multiple overwrite patterns

5. User Authentication

• Added unlock mechanism for the secure folder
• Implemented status checking for secure folder configuration

Security Considerations

• All cryptographic operations use industry-standard algorithms
• Proper error handling to prevent information leakage
• Secure management of encryption keys

This PR significantly enhances the application's security posture and addresses all the concerns raised in the issue