Mcrypt - libmcrypt bindings for Ruby

Mcrypt provides Ruby-language bindings for libmcrypt(3), a symmetric cryptography library. Libmcrypt supports lots of different ciphers and encryption modes.

You will need

• A working Ruby installation (>= 1.8.6 or 1.9)

• A working libmcrypt installation (2.5.x or 2.6.x, tested with 2.5.8)

• A sane build environment

Installation

Install the gem:

gem install ruby-mcrypt --test -- --with-mcrypt-dir=/path/to/mcrypt/prefix

If you’re installing on Ubuntu:

sudo apt-get install mcrypt libmcrypt-dev
gem install ruby-mcrypt

If you want to run the longer test suite, do this instead:

MCRYPT_TEST_BRUTE=1 \
gem install ruby-mcrypt --test -- --with-mcrypt-dir=/path/to/mcrypt/prefix

Put this in your code:

require 'rubygems'
require 'mcrypt'

Or in Rails’ environment.rb:

gem "ruby-mcrypt", :lib => "mcrypt"

Usage

crypto = Mcrypt.new(:twofish, :cbc, MY_KEY, MY_IV, :pkcs)

# encryption and decryption in one step
ciphertext = crypto.encrypt(plaintext)
plaintext  = crypto.decrypt(ciphertext)

# encrypt in smaller steps
while chunk = $stdin.read(4096)
  $stdout << crypto.encrypt_more(chunk)
end
$stdout << crypto.encrypt_finish

# or decrypt:
while chunk = $stdin.read(4096)
  $stdout << crypto.decrypt_more(chunk)
end
$stdout << crypto.decrypt_finish

Known Issues

• Test coverage is lacking.

If you find any bugs, please let the author know.

Wish List

• IO-like behavior, e.g. crypto.open($stdin) { |stream| … }

Author

• Philip Garrett <philgarr at gmail.com>

Copyright and License

Copyright © 2009-2013 Philip Garrett.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.