Carrierwave Encrypter Decrypter

A Rubygem to secure the file uploaded by encrypting the file later on decrypting when needed. Completely secure and depends on Ruby 2.0.0 OpenSSL::Cipher and OpenSSL::PKCS5

You can find a Sample application with usage here.

OpenSSL::Cipher

Provides symmetric algorithms for encryption and decryption.

OpenSSL::PKCS5

Provides password-based encryption functionality based on PKCS#5.

Add the gem to the Gemfile:

gem 'carrierwave_encrypter_decrypter'

bundle install

Start off by trigerring the installer

rails g ced:install

This will create a initializer carrierwave_encrypter_decrypter

create config/initializers/carrierwave_encrypter_decrypter.rb

and a carrierwave_encrypter_decrypter.yml

create  config/carrierwave_encrypter_decrypter.yml

the above will be used when you have the encryption_type as pkcs5.

The Gem support 2 ways OpenSSL::Cipher and OpenSSL::PKCS5

if you want to go with standard encryption in your config/initializers/carrierwave_encrypter_decrypter.rb select

Carrierwave::EncrypterDecrypter.configure  do |config|
  config.encryption_type = :aes
  config.key_size = 256
end

if you want to go with password based encrption (pkcs5) in your config/initializers/carrierwave_encrypter_decrypter.rb select

Carrierwave::EncrypterDecrypter.configure  do |config|
    config.encryption_type = :pkcs5
    config.key_size = 256
	end

Note: Make sure you have the password set in config/carrierwave_encrypter_decrypter.yml

Now in your Uploader for eg app/uploaders/avatar_uploader.rb add the after store callback

class AvatarUploader < CarrierWave::Uploader::Base
	after :store, :encrypt_file

	def encrypt_file(file)
	  Carrierwave::EncrypterDecrypter::Uploader.encrypt(self)
	end
end

Now create the migration on the model on which your uploader is mounted

rails g migration add_iv_and_key_to_users iv:binary key:binary
rake db:migrate

File Encryption

The File encryption will happen with Carrierwave::EncrypterDecrypter::Uploader.encrypt(self) once the file is uploaded you will find it with a extendion of .enc

File Decryption

The File Decryption will happen with

Carrierwave::EncrypterDecrypter::Downloader.decrypt(model,mounted_as: :avatar)

Where Model is the model on which the uploader is mounted. The Encrypted file will be decrypted in the same folder.

Eg Controller

def download
  #This will decrpyt the file first

  Carrierwave::EncrypterDecrypter::Downloader.decrypt(@user, mounted_as: :avatar)

  file_path = @user.avatar.path
    File.open(file_path, 'r') do |f|
      send_data f.read, type: MIME::Types.type_for(file_path).first.content_type,disposition: :inline,:filename => File.basename(file_path)
  end
    #This is to remove the decrypted file after transfer
    File.unlink(file_path)
end

The gem itself is released under the MIT license

🙏