Zweifische

Ruby binding for C implementation of twofish from @drewcsillag

Installation

Add this line to your application's Gemfile:

gem "zweifische"

or

gem "zweifsiche", git: "https://github.com/fudanchii/zweifische"

And then execute:

$ bundle

Usage

All key length (256, 192, and 128 bit) is supported. Each respective class can be used directly.

• ECB mode with 128 bit key: Zweifische::Cipher128ecb
• ECB mode with 192 bit key: Zweifische::Cipher192ecb
• ECB mode with 256 bit key: Zweifische::Cipher256ecb
• CBC mode with 128 bit key: Zweifische::Cipher128cbc
• CBC mode with 192 bit key: Zweifische::Cipher192cbc
• CBC mode with 256 bit key: Zweifische::Cipher256cbc

to use:

require "zweifische"

# ecb mode

# for 128 bit key (16 bytes)
key="0123456789123456"
tf = Zweifische::Cipher128ecb.new(key)
crypted_text = tf.encrypt("plain text to encrypt here", pad: Zweifische::ZeroPadding)
plain_text = tf.decrypt(crypted_text, pad: Zweifische::ZeroPadding)

to encrypt stream use encrypt_update for each chunks, then encrypt_final at the end of the stream.

Notice that padding is specified explicitly above, by default encryption and decryption wont expect any padding in exchange of user should explicitly set the data length to be encrypted/decrypted to be a multiple of 16 bytes.

So for example, this will raise RuntimeError:

key="0123456789123456"
tf = Zweifische::Cipher128ecb.new(key)
crypted_text = tf.encrypt("plain text to encrypt here")

Available padding scheme:

• ANSI X.923 Zweifische::AnsiX923Padding
• ISO/IEC 7816-4 Zweifische::ISOIEC78164Padding
• PKCS7 Zweifische::PKC7Padding
• Zero bytes Zweifische::ZeroPadding

Just be aware that padding is not bullet-proof, for example using zero bytes padding for data which may contain zero bytes trailer may cause all the trailer to be removed at decryption.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/fudanchii/zweifische.