AWS API GW - HTTP API - Authorization Header

Question

We are using AWS API Gateway for hosting our HTTP APIs which are supported by ECS Farget backend . 
1. In API GW we receive externa token in "Authorization" header from caller 
2. Validate that  token in "Authorization" header using Lambda Authorizer and determine user context
3. We intend to create a new internal "Authorization" token and send it to ECS backend 
4. However , we are not able to set "Authorization" header as part parameter mapping with new token as it appears to be reserved header https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-parameter-mapping.html#http-api-mapping-reserved-headers
Has anyone faced similar issue and what is suggested workaround ?

Thanks and Kind Regards,
VJ

Giovanni Lauria · Accepted Answer

You can try to validate the external token in the "Authorization" header using a Lambda Authorizer.

Then a batch of operations you can run are the following:

* Generate the internal authorization token within the Lambda function.
* Return the internal token as part of the authorization context or in a custom header from the Lambda Authorizer.
* Use a custom header (e.g., "X-Internal-Authorization") to map and pass the internal token to the ECS backend in API Gateway's Integration Request settings.

AWS API GW - HTTP API - Authorization Header

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