You can use OpenSSL to mimic the functionality of mencrypt. If you are decrypting PHP mcrypt encoded items, the key is null padded to max keysize returned by mcrypt_enc_get_key_size(). Below are “compatibility mode” examples. These can be passed back and forth between PHP and Ruby using the same key to decrypt/encrypt the data.
To encrypt:
require 'openssl'
cipher = OpenSSL::Cipher::Cipher.new("des-ede3-cbc")
cipher.encrypt
key = "my secret key"
_#TripleDES uses 26 character key_
key << "\0" until key.length == 26
cipher.key = key
cipher.iv = iv_to_use = cipher.random_iv
data_to_encode = "Encode me"
encoded_data = cipher.update(data_to_encode)
encoded_data << cipher.final
puts encoded_data
To decrypt:
require 'openssl'
cipher = OpenSSL::Cipher::Cipher.new("des-ede3-cbc")
cipher.decrypt
key = "my secret key"
_# TripleDES uses 26 character key_
key << "\0" until key.length == 26
cipher.key = key
cipher.iv = iv_to_use
decoded_output = cipher.update( data_to_decrypt )
decoded_output << cipher.final
puts decoded_output