# Task ID: 3
# Title: Implement Secure Credential Management
# Status: done
# Dependencies: None
# Priority: high
# Description: Create a secure system for storing and accessing NextCloud credentials.

# Details:
Implement secure storage for NextCloud tokens and credentials using environment variables. Ensure credentials are never logged or exposed. Add support for token refresh and session management. Implement encryption for any cached NextCloud data.

# Test Strategy:
Perform security testing to ensure credentials cannot be exposed. Test token refresh logic. Verify that credentials are properly secured in memory and storage.

# Subtasks:
## 1. Implement Secure Environment Variable Storage [pending]
### Dependencies: None
### Priority: medium
### Description: Create a system to securely store and retrieve NextCloud credentials using environment variables
### Details:
1. Create a .env file template with placeholders for NEXTCLOUD_URL, NEXTCLOUD_USERNAME, and NEXTCLOUD_PASSWORD/TOKEN variables
2. Implement a credentials manager class that loads these values using dotenv or a similar package
3. Add validation to ensure all required credentials are present
4. Create getter methods that provide access to credentials without exposing them directly
5. Implement safeguards to prevent credentials from being logged or printed
6. Add documentation on how to properly set up environment variables

## 2. Implement Token Refresh and Session Management [pending]
### Dependencies: 3.1
### Priority: medium
### Description: Create a system to manage NextCloud authentication sessions and automatically refresh tokens when needed
### Details:
1. Implement token storage that securely maintains the current access token
2. Add functionality to detect token expiration
3. Create a token refresh mechanism that uses the refresh token to obtain a new access token
4. Implement automatic token refresh when making API calls with expired tokens
5. Add session timeout handling
6. Create session validation methods to verify if the current session is active
7. Implement proper error handling for authentication failures

## 3. Implement Encryption for Cached NextCloud Data [pending]
### Dependencies: 3.1
### Priority: medium
### Description: Create an encryption system to protect any NextCloud data that is cached locally
### Details:
1. Research and select an appropriate encryption library (e.g., node-crypto, crypto-js)
2. Implement a data encryption service that encrypts data before caching
3. Create a secure key management system that generates and stores encryption keys
4. Implement decryption functionality to retrieve cached data
5. Add integrity verification to detect tampering with cached data
6. Create a cache cleanup mechanism to securely delete sensitive data when no longer needed
7. Add configuration options to control encryption strength and algorithms
