Secure Coding Best Practices

Secure coding refers to the practice of writing code that is resistant to vulnerabilities and security threats. This lesson will focus on the OWASP Top 10 vulnerabilities and the best practices to mitigate these risks.

The OWASP Top 10 is a list of the most critical security risks to web applications. Familiarity with these vulnerabilities is crucial for secure coding. Here’s a summary:

• Injection
• Broken Authentication
• Sensitive Data Exposure
• XML External Entities (XXE)
• Broken Access Control
• Security Misconfiguration
• Cross-Site Scripting (XSS)
• Insecure Deserialization
• Using Components with Known Vulnerabilities
• Insufficient Logging & Monitoring

3.1 Input Validation

Validate all input to ensure it meets expected formats.

if (!isValidInput(userInput)) {
    throw new Exception("Invalid input");
}

3.2 Authentication

Implement strong authentication mechanisms, including:

• Use multi-factor authentication.
• Limit login attempts.
• Implement password policies.

3.3 Access Control

Ensure users have access only to resources they are authorized to use.

if (!user.hasPermission(resource)) {
    throw new AccessDeniedException();
}

3.4 Secure Data Storage

Use encryption for sensitive data both at rest and in transit.

3.5 Error Handling

Design error handling that does not disclose sensitive information.

try {
    // sensitive code
} catch (Exception e) {
    log.error("An error occurred", e);
    throw new CustomException("An error occurred"); // User-friendly message
}