aws: Add a new package to configure an AWS cognito endpoint

aws/aws.go

@@ -0,0 +1,25 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package aws provides constants for using OAuth2 to access aws services.
+package aws // import "golang.org/x/oauth2/aws"
+
+import (
+	"golang.org/x/oauth2"
+)
+
+// CognitoEndpoint returns a new oauth2.Endpoint for the supplied Cognito domain which is
+// linked to your Cognito User Pool.
+//
+// Example domain: https://testing.auth.us-east-1.amazoncognito.com
+//
+// For more information see:
+// https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-assign-domain.html
+// https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-userpools-server-contract-reference.html
+func CognitoEndpoint(domain string) oauth2.Endpoint {
+	return oauth2.Endpoint{
+		AuthURL:  domain + "/oauth2/authorize",
+		TokenURL: domain + "/oauth2/token",
+	}
+}