The test enviornment for the API Gateway..... Cognito Authorizer.
What value is it expecting ?
I tried to use accessKeyId returned from CognitoIdentityCredentials and it did not work.
Identity Flow
'Testing the accessKeyId gives Error
I also tried _identityId and that did not work as well.
The error for both is "Unauthorized request"
I think your API endpoints are protected by AWS_IAM authorization method. you can confirm it from the Method Execution section of your API endpoint.
If you are using AWS_IAM method, the api end points excepts a signature to be generated using your aws credentials and pass it in the request under the Authorization header.
You can use postman app to test the endpoint, follow these steps
create a new request with the correct http method and the url
under Authroization tab, select AWS Signature
Enter the values for AccessKey, Secret Key
under the Advanced section, enter your region and Session Token
Postman application is very handy to test rest api endpoints. it's even handy to test the api gateway endpoints protected by AWS_IAM authorization method. The postman app generates the signatures required using your AWS credentials and include the generated signature part of http headers of the request.
Note: Also make sure your identity pool's Authenticated role has permission to invoke the api endpoint.
Reference:
https://docs.aws.amazon.com/apigateway/latest/developerguide/how-to-use-postman-to-call-api.html
you can download postman application if you dont have - https://www.getpostman.com/downloads/
Related
I've managed to setup a third party google login by integrating it with Cognito user pools. On successful sign-on, I am able to access an id_token as a query parameter in the redirect url.
I'm trying to sign REST calls to API gateway using this id_token. I have an authorizer configured on that particular API using Cognito user pools. When I try to test this on the Authorizer UI by setting the Authorization(header) field to this id_token which I received as a query parameter, I keep getting an Unauthorized request error.
Also, I have configured an IAM policy for my user according to this doc: https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-user-pool-authorizer-permissions.html
Can someone help me with what I'm doing wrong?
Thanks
Turns out you have to pass the access_token that Cognito returns as part of the authorization header. You can try if your access token works by testing it in the UI offered by the Authorizor interface of API Gateway.
When using a AWS Cognito attribute from a JWT token in a lambda, do I need to verify the JWT? The Lambda is only triggered by an API Gateway which already verifies the token.
Adding details:
- I'm using Cognito Authorizer in the API Gateway to verify the token.
- The lambda is connected to the API Gateway as proxy.
No you don't need to verify the JWT in backend lambda if protected by a custom lambda authorizer by API Gateway. I would suggest you to use REQUEST based lambda authorizer and attach attributes in the response. So your backend lambda will be able to access attributes in event.requestContext.authorizer['your_attribue'].
This will also enable you to test your Lambda in isolation without needing to get attribute from JWT. You can always mock the event object for unit testing.
I ran into the same conundrum, and was trying to find documented confirmation that, within the Lambda, I wouldn't have to do any validation on my own, and that I can safely rely on the the token / claims being genuine. Unfortunately, nothing in the AWS documentation or the forum posts that I've seen so far has explicitly confirmed this.
But I did find something similar for GCP, and how the API Gateway there validates the JWT. From the GCP documentation:
To authenticate a user, a client application must send a JSON Web
Token (JWT) in the authorization header of the HTTP request to your
backend API. API Gateway validates the token on behalf of your API, so
you don't have to add any code in your API to process the
authentication. However, you do need to configure the API config for
your gateway to support your chosen authentication methods.
API Gateway validates a JWT in a performant way by using the JWT
issuer's JSON Web Key Set (JWKS). The location of the JWKS is
specified in the x-google-jwks_uri field of the gateway's API config.
API Gateway caches the JWKS for five minutes and refreshes it every
five minutes.
So, it seems that within GCP at least, we don't have to do anything, and the API Gateway will handle everything. Even though this is not a confirmation that this is how it works in AWS as well, but the fact that this is how it works in GCP, it gives me some more confidence in assuming that it must be so in AWS too.
My objective is for my user to sign-in using Cognito and get a temporary IAM role that allows them HTTP access to specific methods in API Gateway.
What I have done so far:
set up my user pool
set up my identity pool
set up IAM roles for authenticated and unauthenticated users
set up a group with an IAM role allowing access to POST to (at
present) all API gateway methods.
put my user into the group
set up my API Gateway method to use IAM authorization
I can sign-in via Cognito in my browser using a front end created via Amplify.
When I check in the browsers local storage I can see I have the following:
idToken
accessToken
refreshToken
When I have done this using a COGNITO authorizer on the API Gateway all I had to do in Postman was add a Authorization header and paste in the idToken. This gave me access to the API.
How can I test my API using Postman with IAM authorization?
I am still given the tokens, but now pasting them in to the Authorization header gives me an error message:
Authorization header requires 'Credential' parameter. Authorization header requires 'Signature' parameter. Authorization header requires 'SignedHeaders' parameter. Authorization header requires existence of either a 'X-Amz-Date' or a 'Date' header.
I have read that I need to sign requests but I am unsure how I would do this from my web browser based application.
Even if I can do that how can I test in Postman, or is this no longer possible?
Ok, the requests can still be made via Postman but they must be in Amazon's Sigv4 format.
The solution is as follows.
Get the accessKey, secretKey and sessionToken returned from the sign-in process*.
In Postman, for the request, select the Authorization tab and for type choose AWS Signature.
Enter the accessKey, secretKey and sessionToken retrieved from step 1 into the corresponding fields in Postman.
You also need to set the AWS Region e.g. eu-central-1.
Press SEND.
Postman will create the appropriate Sigv4 request to call your API. You can see the result of this in Postman's Headers tab for the request where it will have automatically created the required headers.
*I added temporary code into my React/Amplify application to do this.
I'm trying to setup security on an API using Cognito user pools. I'm getting back 401 Unauthorized.
The API and User Pools are existing, and I've been using the user pool to log into an application. I'm now trying to secure the API calls.
I created an authorizer on the API,
Then I added the authorizer to one GET method in the API
Then finally I tried to test the API in Postman. I'm using the AWS Signature authorization.
Calling the method returns 401. The method functioned before with no security, and turning off the authorizer makes it work again (without security).
Any ideas what step I'm missing?
The AWS Signature authorization is different than a Custom Authorizer.
The AWS Signature authorization (Postman) requests an AWS AccessKey and SecretKey to authenticate requests. This corresponds to IAM Authentication in API Gateway. The AccessKey and SecretKey are received through IAM.
A Custom Authorizer takes a JWT called #id_token that is issued by your specified Cognito User Pool. To test the validity of the token, go to your custom authorizer and click test, and then copy and paste the token into the text area.
The way to perform the Custom Authorizer authentication is this:
obtain an #id_token from the your user pool by following AWS Configuration
Configure API gateway with a Cognito custom Authorizer with your user pool as the source (Seems that you have done correctly)
Use OAuth 2.0 as Authorization in postman, with your #id_token as the Access Token, Or add the header: Authorization with the value Bearer and the #id_token
Drop a comment if you want me to add the AWS Signature Auth Flow.
For authorization using Postman when using Cognito user pools, chose No Auth. Then add a header Authorization (the value in token source field of your authorizer) and copy the id_token into that header value. I did not have to add anything else besides that to make it work (i.e. no bearer).
How do I call API gateway with postman with cognito?
Tried to use AWS Signature in postman and this did not work.
https://docs.aws.amazon.com/apigateway/latest/developerguide/how-to-use-postman-to-call-api.html
I am using hosted UI in cognito if that makes a difference. I see that there is an Oauth 2.0 option in postman but dont know how to fill out the fields.
So my api works when I pass Authorization in the header with the id_token. Without the id_token is there any other way?
thanks
If you are using a Cognito user pool and have your API Gateway authorizer set to user pool, then you need to pass either the id or access token in the Authorization header.
If you are using a Cognito identity pool and have your API Gateway authorizer set to AWS_IAM you need to use AWS signatures