What is Lambda authorizer?

What is Lambda authorizer?

A Lambda authorizer (formerly known as a custom authorizer) is an API Gateway feature that uses a Lambda function to control access to your API. A token-based Lambda authorizer (also called a TOKEN authorizer) receives the caller’s identity in a bearer token, such as a JSON Web Token (JWT) or an OAuth token.

What is JWT authorizer?

JWT Authorizers are a new type of Authorizer which, as the name suggests, use JSON Web Tokens (JWTs) to provide access control to your API endpoints. JWT Authorizers build on the industry standards of the OpenID Connect (OIDC) spec and the OAuth 2.0 protocol.

What is methodArn?

The methodArn is the ARN of the incoming method request and is populated by API Gateway in accordance with the Lambda authorizer configuration. The API caller can set the path parameters, headers, and query string parameters.

How do I test my Lambda authorizer?

You can select the Lambda authorizer function we created in step one by using the Lambda function field. You can test this authorizer by clicking on Test. It will open a modal where you can provide your token and test the response from the Lambda authorizer function. Now, we need to enable this authorizer for your API.

How do I write a Lambda authorizer?

Now, let’s start the real work!

1. Create a Lambda function as the authorizer. Set up a Lambda function, which will work as the authorizer.
2. Create a Lambda function as the end service. The API you want to secure will call some web service.
3. Create the API using API Gateway.
4. Configure API Gateway with your custom authorizer.

How do I test my authorizer?

For the REQUEST authorizer, type the valid request parameters corresponding to the specified identity sources and then choose Test. In addition to using the API Gateway console, you can use AWS CLI or an AWS SDK for API Gateway to test invoking an authorizer. To do so using the AWS CLI, see test-invoke-authorizer.

How does the Lambda authorizer work in AWS?

The Lambda authorizer executes the authorization logic and creates an identity management policy. API Gateway evaluates the identity management policy against the API Gateway resource that the user requested and either allows or denies the request. If allowed, API Gateway forwards the user request to the API Gateway resource.

What does the context object do in AWS Lambda?

AWS Lambda context object in Node.js. When Lambda runs your function, it passes a context object to the handler . This object provides methods and properties that provide information about the invocation, function, and execution environment.

How does API gateway work in AWS Lambda?

API Gateway evaluates the identity management policy against the API Gateway resource that the user requested and either allows or denies the request. If allowed, API Gateway forwards the user request to the API Gateway resource.

How to pass principalid from custom authorizer to Lambda?

Using the passthrough option, principalId should be available in event.context [‘authorizer-principal-id’]. This is the default behavior when you create an endpoint. In addition to Alexis answer, principalId – is currently the only param which can be passed from custom authorizer to a Lambda (as of today).