Encrypt/Decrypt files using Carrierwave and storing in S3 (Rails)

Question

I need to be able to encrypt files before storing them on S3, and then decrypt them when accessing them. The files will be images, documents, PDF, etc.

I am using Carrierwave to handle the file upload and storage (this is with Ruby on Rails). I am storing them in Amazon S3.

Has anyone done this, or have any ideas how this would be achieved?

Thanks.

Answer 1

Amazon has now released functionality that lets you encrypt/decrypt files automatically in S3. The need to do this yourself is no longer there. Details are here http://docs.amazonwebservices.com/AmazonS3/latest/dev/index.html?UsingEncryption.html

Answer 2

To handle the encryption, you should look into implementing a processor. If you are using any other processors, you may have to look at extending the Carrierwave gem and adding a processor ordering mechanism so you can be sure encryption happens last.

For the decryption, you can either override the existing accessor to make the decryption transparent, or add a new method that returns the decrypted file and use that in place of the accessor. The latter approach is probably more resilient to upstream changes.

Answer 3

I know this post is a few months old, but if you're still looking for answers, check out the carrierwave_securefile gem I wrote. It's still new and probably a bit buggy on other setups, but it uses Crypt19 for Blowfish encryption on files prior to upload.

http://github.com/dougc84/carrierwave_securefile