Advanced Security

Coming Soon

This lesson will teach you how to implement comprehensive security measures for production chat servers. You’ll learn how to:

• Implement advanced authentication mechanisms (JWT, OAuth2)
• Build fine-grained authorization and access control
• Create rate limiting and DDoS protection
• Implement input validation and sanitization
• Add encryption and secure communication

What You’ll Build

By the end of this lesson, you’ll have implemented:

• JWT-based authentication with refresh tokens
• Role-based access control (RBAC) system
• Rate limiting and abuse prevention
• Input validation and XSS protection
• End-to-end encryption for sensitive messages

Key Concepts Preview

% JWT token validation
validate_jwt_token(Token) ->
    try
        {ok, Claims} = jwt:decode(Token, application:get_env(chat_server, jwt_secret)),
        case maps:get("exp", Claims) > erlang:system_time(second) of
            true -> {ok, Claims};
            false -> {error, token_expired}
        end
    catch
        error:Reason -> {error, invalid_token}
    end.

% Rate limiting
rate_limit_check(UserId, Action) ->
    Key = {rate_limit, UserId, Action},
    case ets:update_counter(rate_limits, Key, 1, {Key, 0}) of
        Count when Count =< get_limit(Action) -> ok;
        _ -> {error, rate_limit_exceeded}
    end.

% Input sanitization
sanitize_message(Message) ->
    CleanMessage = re:replace(Message, "<[^>]*>", "", [global, {return, binary}]),
    validate_length(CleanMessage, 500).

This lesson builds on the hot code reloading from Lesson 29 and prepares you for the scaling strategies we’ll explore in Lesson 31.

This lesson is currently under development. Check back soon for the complete content!