Considering AWS Auth

[KASHIHARAAkira]

AWS Authorization on frontend javascript
https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/config-web-identity-examples.html

User needs to integrate amazon, facebook or google account to aws on IAM.

[KASHIHARAAkira]

If we use AWS SDK, user need to make a setting about CROS on AWS console.
It is not good because it is complecated for user.

[KASHIHARAAkira]

We should use IAM user instead of access key.
https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_access-keys.html

[KASHIHARAAkira]

Authorization and file upload sample.
https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-post-example.html
https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-HTTPPOSTForms.html

I guess that I can rely on these website.