OoxmlDecrypt

A Ruby library and script for decrypting password-protected Microsoft Office XML files (.docx, .xlsx, etc.), which use the OOXML format. There are many tools available for working with OOXML files without Office, but a password-protected document typically requires an Office installation to decrypt. This pure-Ruby, standalone library and script can decrypt Office files without an Office installation.

At present, this only supports documents encrypted (i.e. password-protected) by Office 2010 or later. Office 2007 also uses XML, but the encryption settings are a bit different.

Add this line to your application's Gemfile:

gem 'ooxml_decrypt'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ooxml_decrypt

If you installed the gem using Bundler, execute:

$ bundle exec ooxml_decrypt --source <path> --destination <path> --password <password>

otherwise use:

$ ooxml_decrypt --source <path> --destination <path> --password <password>

To decrypt a file programatically:

require 'ooxml_decrypt'

encrypted_path = ...
decrypted_path = ...
# Ensure password is a binary representation of a UTF-16LE string
binary_password = password.encode("utf-16le")
                          .bytes.pack("c*")
                          .encode("binary")

OoxmlDecrypt::EncryptedFile.decrypt_to_file(encrypted_path, binary_password, decrypted_path)

After checking out the repo, run bin/setup to install dependencies. Then, run bundle exec rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Pull requests welcome! Once you've forked and cloned the project, you can bundle install to take care of the dependencies; after that, you're ready to code.

You can also create issues for any bugs or feature requests, but they may take longer to get done, of course.

• Support for Office 2007 documents
• Do verification (i.e. detect when password is incorrect)

• Microsoft MS-OFFCRYPTO
• http://www.lyquidity.com/devblog/?p=35
• http://www.lyquidity.com/devblog/?p=85