Secure Coding Practices

Learning Objectives Identify common vulnerabilities like SQL Injection in code snippets. Explain the difference between input validation and input sanitization. Implement parameterized queries (prepared statements) to prevent SQL Injection in a database application. Apply the Principle of Least Privilege when designing a simple user role system. Differentiate between authentication and authorization in a real-world context. Write code that handles errors securely without exposing sensitive system information. Ever wondered how a simple comment on a website could potentially take the whole site down? 💻💥 Let's learn how to build digital fortresses, not glass houses. Writing code that works is the first step, but writing code that is safe and secure is what makes a prof...

TermDefinitionExample Input ValidationThe process of checking if data provided by a user or another program meets certain requirements before it is processed. It ensures the data is in the correct format, type, and range.A registration form checks if a user-provided email address contains an '@' symbol and a '.' It also checks if the password is at least 8 characters long. If not, it rejects the input. Input SanitizationThe process of cleaning or filtering user input to remove or neutralize potentially malicious characters or code. This is done after validation to make the data safe to use.A user posts a comment with `<script>alert('hacked')</script>`. Sanitization would convert the characters `<` and `>` into `<` and `>`, so t...

The 'Never Trust User Input' Rule All data originating from an external source must be treated as potentially hostile. It must be validated and/or sanitized before being used in your application. Apply this rule to any data your program receives that you didn't create yourself. This includes form inputs, URL parameters, file uploads, and data from other APIs. Always check it on the server-side, even if you have client-side checks. Parameterized Query Pattern 1. Define the SQL query with placeholders (e.g., ?, :name). 2. Prepare the statement with the database driver. 3. Bind the user-supplied variables to the placeholders. 4. Execute the query. Use this pattern whenever your SQL query needs to include data that came from a user. This separates the logic (the S...