In Amazan S3 and many open source CDN servers like Minio there is a feature called presigned URL to let users without credential information to download/upload files. but there is a small problem in uploading file. the General scenario is:
- we pass presigned URL to client
- client upload files to Amazon s3
- client inform the server that file has been uploaded.
But after that, client can upload files and overwrite them until expiration time of presigned URL. So we can not trust any file in the S3 server until URL got expired. It's not desirable!
How to solve this problem?