Autorizadores de API Gateway
Implemente varios autorizadores de API Gateway, incluidos autorizadores personalizados de Lambda y autorizadores JWT, para una autenticación sólida.
Autorizadores de API Gateway es una lección gratuita de Serverless Backend with AWS Lambda & API Gateway en CoddyKit. Esta es la lección 2 de 4. Puedes leer la lección completa abajo gratuitamente — luego la practicas en el navegador con un editor de código integrado y un tutor de IA 24/7. Forma parte de la ruta de aprendizaje de Serverless Backend with AWS Lambda & API Gateway, y tu progreso se sincroniza en la web y la app de CoddyKit. El curso de Serverless Backend with AWS Lambda & API Gateway incluye 4 lecciones en total.
Partes de esta lección aún no han sido traducidas y se muestran en inglés.
API Gateway Authorizers Intro
Welcome! In this lesson, we'll learn how to secure your serverless APIs using API Gateway Authorizers. These are crucial for controlling who can access your backend services.
Think of an authorizer as a security guard at the entrance of your API. Before any request reaches your Lambda function or other backend service, the authorizer checks the request's credentials.
Why Use API Gateway Authorizers?
Authorizers provide robust authentication and authorization for your APIs. Here's why they are essential:
- Protect Backend Resources: Prevent unauthorized access to your Lambda functions and other services.
- Decouple Auth Logic: Separate authentication logic from your main business logic, keeping your functions cleaner.
- Fine-Grained Access: Control access to specific API methods or resources based on user identity or roles.
Types of Authorizers
API Gateway offers several types of authorizers. Today, we'll focus on the two most flexible and commonly used:
- Lambda Custom Authorizers: A Lambda function you write to perform custom authentication.
- JWT Authorizers: API Gateway's native support for validating JSON Web Tokens (JWTs).
There's also IAM Authorizers, which use AWS IAM roles and policies, but we'll focus on the custom and JWT types here.
Lambda Custom Authorizers Explained
A Lambda Custom Authorizer is a Lambda function that you provide. API Gateway invokes this function with the incoming request's authorization token (e.g., from the Authorization header).
Your Lambda function then processes this token, performs its custom authentication logic (e.g., checks a database, calls an identity provider), and returns an IAM policy.
The Authorization Policy
The core output of your Lambda authorizer is an IAM policy document. This policy tells API Gateway whether to Allow or Deny the request to the target API endpoint.
It includes a principalId (the authenticated user's identifier) and a policyDocument specifying the permissions. If Allow, the request proceeds; if Deny, it's rejected with a 401 Unauthorized error.
Lambda Authorizer Code Example
Here's a simple Python Lambda function acting as an authorizer. It checks for a specific token and returns an 'Allow' or 'Deny' policy based on it.
Try changing the token in the test event to see different outputs!
def lambda_handler(event, context):
token = event.get('authorizationToken')
method_arn = event.get('methodArn')
if token == "my-secret-token-123":
# Allow access
return {
"principalId": "user123",
"policyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Action": "execute-api:Invoke",
"Effect": "Allow",
"Resource": method_arn
}
]
}
}
else:
# Deny access
return {
"principalId": "anonymous",
"policyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Action": "execute-api:Invoke",
"Effect": "Deny",
"Resource": method_arn
}
]
}
}
# --- Local Test (for demonstration) ---
if __name__ == "__main__":
print("Testing with 'my-secret-token-123':")
event_allow = {
"authorizationToken": "my-secret-token-123",
"methodArn": "arn:aws:execute-api:us-east-1:123456789012:/test/GET/items"
}
print(lambda_handler(event_allow, None))
print("\nTesting with 'invalid-token':")
event_deny = {
"authorizationToken": "invalid-token",
"methodArn": "arn:aws:execute-api:us-east-1:123456789012:/test/GET/items"
}
print(lambda_handler(event_deny, None))JWT Authorizers Explained
JWT (JSON Web Token) Authorizers allow API Gateway to natively validate JWTs. Instead of writing a Lambda function, you configure API Gateway with details about your JWT issuer.
When a request with a JWT comes in, API Gateway automatically performs validation steps like:
- Signature verification
- Expiration checks
- Audience and issuer validation
Configuring a JWT Authorizer
To set up a JWT authorizer, you typically provide API Gateway with:
- Issuer URL: The URL of the identity provider (e.g.,
https://cognito-idp.us-east-1.amazonaws.com/us-east-1_XXXXXXXfor Cognito). - Audience(s): A list of valid audiences for the token, ensuring the token is intended for your API.
- Identity Source: The header where the JWT is expected (e.g.,
$request.header.Authorization).
API Gateway then uses these details to fetch public keys and validate incoming JWTs.
When to Use Which Authorizer?
Choosing between Lambda and JWT authorizers depends on your needs:
- Lambda Authorizer: Use for highly custom authentication logic, integration with legacy systems, or identity providers not supporting standard OIDC/OAuth2. Offers maximum flexibility.
- JWT Authorizer: Ideal when using standard identity providers like AWS Cognito User Pools, Auth0, Okta, etc. It's simpler to set up and has less operational overhead.
For most modern applications using standard identity providers, JWT authorizers are often the preferred choice.
Authorizer Quick Check
Time for a quick check on what you've learned about API Gateway Authorizers!
Recap: Securing with Authorizers
You've now learned about API Gateway Authorizers, a vital component for securing your serverless APIs!
- Authorizers act as a front-door security check for your API endpoints.
- Lambda Custom Authorizers offer maximum flexibility for custom authentication logic.
- JWT Authorizers provide native, easy-to-configure validation for standard JSON Web Tokens.
By implementing authorizers, you ensure only legitimate requests access your backend services, enhancing the security of your applications.
Preguntas frecuentes
¿La lección «Autorizadores de API Gateway» es gratis?
Sí — el texto completo de «Autorizadores de API Gateway» es gratis para leer aquí en la web. Para practicarla de forma interactiva (editor de código integrado y tutor de IA 24/7) y desbloquear el resto del curso de Serverless Backend with AWS Lambda & API Gateway, actualiza a CoddyKit PRO. El curso de Serverless Backend with AWS Lambda & API Gateway incluye 4 lecciones en total.
¿Qué aprenderé en «Autorizadores de API Gateway»?
Implemente varios autorizadores de API Gateway, incluidos autorizadores personalizados de Lambda y autorizadores JWT, para una autenticación sólida. Practicas Serverless Backend with AWS Lambda & API Gateway con código real que ejecutas directamente en el navegador, y un tutor de IA 24/7 responde tus preguntas mientras trabajas en la lección.
¿Necesito experiencia previa para empezar Serverless Backend with AWS Lambda & API Gateway?
No se requiere experiencia previa. Serverless Backend with AWS Lambda & API Gateway en CoddyKit está estructurado para principiantes hasta estudiantes avanzados, así que puedes empezar aquí o desde el inicio y avanzar a tu ritmo. Esta es la lección 2 de 4.
¿Cuánto tiempo toma la lección «Autorizadores de API Gateway»?
La mayoría de las lecciones de CoddyKit toman alrededor de 5–10 minutos. Cada una es compacta e interactiva, así que avanzas constantemente y retomas exactamente por donde dejaste en la web y la app.
¿Puedo escribir y ejecutar código en esta lección de Serverless Backend with AWS Lambda & API Gateway?
Sí. Cada lección de Serverless Backend with AWS Lambda & API Gateway incluye un editor de código integrado, así que escribes y ejecutas código real directamente en tu navegador y obtienes retroalimentación instantánea de IA — sin configuración local necesaria.
Todas las lecciones de este curso
- Roles y permisos de IAM
- Autorizadores de API Gateway
- Protección de Lambda con VPC
- Protección de secretos con AWS Secrets Manager