Get crypt() Blowfish results in PHP 5.3 identical to those generated by PHP 5.2

Question

Is there a way in PHP 5.3 to get crypt() blowfish (salt starting with $2a$) results identical to those generated by PHP 5.2? In 5.3, Zend implements all encryption algorithms internally, thus producing different results. Also, in 5.3, blowfish needs a cost parameter.

Basically, is there a way to call whatever system mechanisms were used for encryption in PHP 5.2 using a command line program?

Note: The server is on Linux, must be distro portable.

Answer 1

Perhaps via mcrypt?

Answer 2

No matter which PHP version you using the crypt(); function will produce the same result. Because its a AES implementation

Answer 3

The internal implementations are supposed to be completely compatible with the external OS implementations.

Presumably the OS implementation (libxcrypt?) has a default value for the cost parameter if none is supplied - you'll just have to track down what that is!