yiisoft/yii — pull request #3413 by Jacques1 (2014-06-19 09:46:21+00:00)
Title: Added support for stream ciphers in CSecurityManager

Trying to encrypt data with a stream cipher like ARCFOUR triggers an exception with the message “Failed to initialize the mcrypt module.”.

The problem is that the class uses CBC as the default cipher mode and always tries to generate an initialization vector. However, stream ciphers require the “stream” mode and generally don't support an initialization vector.