0Pricing
Erlang OTP: Distributed & Fault-Tolerant Systems Programming · Leçon

Authentification et autorisation

Mettez en œuvre des mécanismes robustes d’authentification et d’autorisation pour les processus et les utilisateurs qui accèdent à vos services Erlang.

Authentification et autorisation est une leçon Erlang OTP: Distributed & Fault-Tolerant Systems Programming gratuite sur CoddyKit. Ceci est la leçon 2 sur 4. Tu peux lire la leçon complète ci-dessous gratuitement — puis la pratiquer en direct dans le navigateur avec un éditeur de code intégré et un tuteur IA 24/7. Elle fait partie du parcours d'apprentissage Erlang OTP: Distributed & Fault-Tolerant Systems Programming, et ta progression se synchronise sur le web et l'application CoddyKit. Le cours Erlang OTP: Distributed & Fault-Tolerant Systems Programming comprend 4 leçons au total.

Certaines parties de cette leçon n'ont pas encore été traduites et s'affichent en anglais.

AuthN & AuthZ Explained

In distributed systems, knowing who is accessing your services and what they are allowed to do is critical for security. This is where authentication and authorization come in.

  • Authentication (AuthN): Verifies the identity of a user or process. It answers the question, "Who are you?"
  • Authorization (AuthZ): Determines if an authenticated user or process has permission to perform a specific action or access a resource. It answers, "What are you allowed to do?"

They work hand-in-hand to secure your Erlang applications.

Identifying Users

For user authentication, we typically verify credentials like a username and password. In Erlang, you might have a dedicated service (often a GenServer) responsible for managing user accounts and validating login attempts.

This service would receive a login request, check the provided credentials against stored data, and respond with either success or failure. On success, it might issue a session ID or token.

Building an Auth GenServer

Let's create a very basic auth_service using GenServer. For simplicity, it will store a hardcoded user and password. In a real system, you'd integrate with a database and securely hash passwords.

Our auth_service will have a login/2 function that clients can call to authenticate.

Runnable Auth Service

Try running this simple authentication service. You can call auth_service:login("user", "pass") and auth_service:login("wrong", "pass") to see the different responses.

-module(auth_service).
-behaviour(gen_server).

-export([start_link/0, login/2]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
             terminate/2, code_change/3]).

% Client API
start_link() ->
    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).

login(Username, Password) ->
    gen_server:call(?MODULE, {login, Username, Password}).

% GenServer Callbacks
init([]) ->
    % Store a simple user/pass for demonstration
    Users = #{<<"user">> => <<"pass">>},
    {ok, Users}.

handle_call({login, Username, Password}, _From, State) ->
    case maps:get(Username, State, undefined) of
        Password ->
            {reply, {ok, <<"authenticated">>}, State};
        _ ->
            {reply, {error, <<"invalid_credentials">>}, State}
    end;
handle_call(_Request, _From, State) ->
    {reply, {error, unknown_request}, State}.

handle_cast(_Msg, State) ->
    {noreply, State}.

handle_info(_Info, State) ->
    {noreply, State}.

terminate(_Reason, _State) ->
    ok.

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

What Can You Do?

Once a user is authenticated, the next step is authorization. This means deciding what actions they are allowed to perform. A common way to manage this is through Role-Based Access Control (RBAC).

  • Roles: Groups of permissions (e.g., admin, editor, viewer).
  • Permissions: Specific actions (e.g., create_post, edit_post, delete_post).

Users are assigned roles, and roles are assigned permissions.

Role-Based Access Control

We can extend our auth_service (or a separate service) to manage roles and permissions. It would need to know:

  • Which roles a user has.
  • Which permissions each role grants.

Then, when a service needs to check if a user can perform an action, it asks the authorization service.

Auth Service with RBAC

Here's an updated auth_service that includes a basic RBAC mechanism. It defines roles and permissions and allows checking if a user has a specific permission.

Try calling auth_service:check_permission("user", "read_data") and auth_service:check_permission("user", "delete_data") after logging in.

-module(auth_service).
-behaviour(gen_server).

-export([start_link/0, login/2, check_permission/2]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
             terminate/2, code_change/3]).

% Client API
start_link() ->
    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).

login(Username, Password) ->
    gen_server:call(?MODULE, {login, Username, Password}).

check_permission(Username, Permission) ->
    gen_server:call(?MODULE, {check_permission, Username, Permission}).

% GenServer Callbacks
init([]) ->
    Users = #{
        <<"user">> => #{
            password => <<"pass">>,
            roles => [<<"viewer">>, <<"editor">>]
        },
        <<"admin">> => #{
            password => <<"admin_pass">>,
            roles => [<<"admin">>, <<"viewer">>]
        }
    },
    Roles = #{
        <<"viewer">> => [<<"read_data">>],
        <<"editor">> => [<<"read_data">>, <<"write_data">>],
        <<"admin">> => [<<"read_data">>, <<"write_data">>, <<"delete_data">>]
    },
    {ok, #{users => Users, roles => Roles}}.

handle_call({login, Username, Password}, _From, State) ->
    Users = maps:get(users, State),
    case maps:get(Username, Users, undefined) of
        #{password := Password} ->
            {reply, {ok, <<"authenticated">>}, State};
        _ ->
            {reply, {error, <<"invalid_credentials">>}, State}
    end;

handle_call({check_permission, Username, Permission}, _From, State) ->
    Users = maps:get(users, State),
    Roles = maps:get(roles, State),
    case maps:get(Username, Users, undefined) of
        #{roles := UserRoles} ->
            HasPermission = lists:any(
                fun(Role) ->
                    case maps:get(Role, Roles, []) of
                        RolePermissions when is_list(RolePermissions) ->
                            lists:member(Permission, RolePermissions);
                        _ -> false
                    end
                end,
                UserRoles
            ),
            {reply, HasPermission, State};
        _ ->
            {reply, false, State} % User not found or not authenticated
    end;

handle_call(_Request, _From, State) ->
    {reply, {error, unknown_request}, State}.

handle_cast(_Msg, State) ->
    {noreply, State}.

handle_info(_Info, State) ->
    {noreply, State}.

terminate(_Reason, _State) ->
    ok.

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

Securing Your Services

Once you have an authentication and authorization service, other services in your system can use it. A typical flow looks like this:

  1. Client Authenticates: Calls auth_service:login/2.
  2. Receives Session/Token: If successful, the client gets a session ID or token (e.g., a process ID, or a more complex JWT).
  3. Client Makes Authorized Request: When calling another service (e.g., data_service), the client includes its session/token and the action it wants to perform.
  4. Service Authorizes: The data_service calls auth_service:check_permission/2 using the client's identity and the requested action.
  5. Service Responds: If authorized, the action proceeds; otherwise, an error is returned.

Beyond Basic Auth

While our examples are simple, real-world systems need more:

  • Password Hashing: Never store plaintext passwords. Use strong hashing algorithms like bcrypt or pbkdf2.
  • Session Management: Securely generate, store, and validate session tokens. Ensure they expire and can be revoked.
  • Auditing: Log all authentication attempts and authorization checks for security monitoring and forensics.
  • External Identity Providers: Integrate with OAuth2/OpenID Connect for single sign-on.

Erlang's concurrency makes it great for building robust auth services.

AuthN vs AuthZ Check

Consider a user trying to access a secure document in an Erlang application.

Recap: Securing Services

We've covered the fundamentals of authentication and authorization in Erlang:

  • Authentication (AuthN) verifies identity ("Who are you?").
  • Authorization (AuthZ) determines permissions ("What can you do?").
  • We built a simple auth_service using GenServer for both user login and role-based access control (RBAC).
  • Understanding how to integrate these services is key to building secure and robust distributed Erlang applications.

Next, explore how to protect sensitive data itself within your Erlang applications.

Questions Fréquemment Posées

La leçon « Authentification et autorisation » est-elle gratuite ?

Oui — le texte complet de « Authentification et autorisation » est gratuit à lire ici sur le web. Pour la pratiquer de manière interactive (un éditeur de code intégré et un tuteur IA 24/7) et déverrouiller le reste du cours Erlang OTP: Distributed & Fault-Tolerant Systems Programming, passe à CoddyKit PRO. Le cours Erlang OTP: Distributed & Fault-Tolerant Systems Programming comprend 4 leçons au total.

Qu'est-ce que j'apprendrai dans « Authentification et autorisation » ?

Mettez en œuvre des mécanismes robustes d’authentification et d’autorisation pour les processus et les utilisateurs qui accèdent à vos services Erlang. Tu pratiques Erlang OTP: Distributed & Fault-Tolerant Systems Programming avec du code pratique que tu exécutes directement dans le navigateur, et un tuteur IA 24/7 répond à tes questions au fur et à mesure que tu avances dans la leçon.

Dois-je avoir de l'expérience pour commencer Erlang OTP: Distributed & Fault-Tolerant Systems Programming ?

Aucune expérience préalable n'est requise. Erlang OTP: Distributed & Fault-Tolerant Systems Programming sur CoddyKit est structuré pour les débutants jusqu'aux apprenants avancés, donc tu peux commencer ici ou depuis le début et avancer à ton rythme. Ceci est la leçon 2 sur 4.

Combien de temps prend la leçon « Authentification et autorisation » ?

La plupart des leçons CoddyKit prennent environ 5–10 minutes. Chacune est courte et interactive, tu progresses régulièrement et tu repiques exactement où tu t'es arrêté sur le web et l'app.

Peux-tu écrire et exécuter du code dans cette leçon Erlang OTP: Distributed & Fault-Tolerant Systems Programming ?

Oui. Chaque leçon Erlang OTP: Distributed & Fault-Tolerant Systems Programming inclut un éditeur de code intégré, tu écris et exécutes du vrai code directement dans ton navigateur et tu reçois des retours IA instantanés — aucune configuration locale requise.

Toutes les leçons de ce cours

  1. Sécurisation des communications entre nœuds (TLS)
  2. Authentification et autorisation
  3. Protection des données sensibles
  4. Renforcer la sécurité du cookie de distribution et l’accès aux nœuds
← Retour à Erlang OTP: Distributed & Fault-Tolerant Systems Programming