This Dart library signs Amazon Web Services (AWS) URLs with the given credentials in contrast to signing the header entries. This is particularly helpful to connect to Amazon WebSocket API Gateway secured with IAM authorizer.
I created this work mainly because Amazon Amplify does not provide any easy mechanism to sign the URLs to be able to connect to secured WebSocket endpoints, unfortunately. I spent over a week between searching and reading the source codes of different projects to be able to connect my Flutter App to my AWS secured WebSocket API Gateway backend.
Now, after I got this working, I am glad to share this work, maybe it can save someone's day.
Pull Requests are welcome.
Credits further readings
Skimming this code file also helped me to replace some critical python parts with their Dart equivalents.
A look on the official documentation Signing AWS Requests V4 from Amazon will help to understand the logic behind the code.