Programming Amazon Web Services

Mediated Access to S3 with JetS3t

The S3 service can be a very effective platform for sharing information, when its simple access control mechanisms meet your needs; but the level of control possible with the service’s ACL settings may not always be sufficient. Some scenarios are difficult or impossible to achieve with ACL settings alone, such as if you wish to make your S3 storage available to your customers or colleagues to use when they do not have their own AWS account. In such cases you may need to provide your own intermediate service to mediate access to your S3 storage.

In this section we will demonstrate how to use tools available in the JetS3t Java library to mediate third-party access to your S3 storage. These tools include a client-side application, for interacting with S3 to upload and download files, and a server-side Gatekeeper component that decides whether the client, or user, should be authorized to perform these operations.

Note

Disclaimer: The JetS3t project was created by the author of this book.

There are a number of ways you could share your S3 storage with others. Let us take a look at a few of the options to see why we think the JetS3t tools are worth considering.

Public write permission via an ACL

The simplest way to allow third parties to upload files to your S3 buckets is to grant write permission to the general public. If you apply this ACL setting, anyone with S3 client software can upload files into the bucket and replace or delete existing objects. This ...