Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

libmcrypt is a powerful encryption library that is very popular with PHP-based applications. However, most Linux distributions do not include it. This causes problems for many users that need to download and compile it separately.

I am guessing that the reason it is not shipped is related to encryption or patent issues. However, the source code for library itself is hosted and available on

I have been searching unsuccessfully for a document of authoritative post that explains the exact issues why this extension is not bundled with mainstream distributions. Can anyone provide a pointer to such material or provide an explanation?

share|improve this question
up vote 4 down vote accepted

I guess you missed it. It's available in Debian, OpenSUSE and Fedora repositories, so that accounts for most of the mainstream distributions if you include the hundreds of their derivatives like Ubuntu and Mandriva. There aren't very many "mainstream" distros that aren't a derivative of the ones above.

If a package isn't in a specific distribution's repositories, it's probably because someone didn't get around to it yet. You may want to roll up your sleeves volunteer to add it yourself, or ask for someone to do it for you.

share|improve this answer
You are right, it is available on those platforms. I checked RHEL, CentOS, SLES and Ubuntu, and they don't by default (are third-party repositories) so I wrongly assumed it was related to encryption issues. Thanks! – Daniel Lopez Mar 15 '11 at 13:33

My guess is that if it isn't a dependency in the base installation package, it wouldn't be included, but is available through repos for many of the popular distributions.

Why install it by default if nothing by default uses it?

share|improve this answer

The US bans its software companies and distributors from exporting strong encryption - even if the software is already available or even developed outside the US.

AFAIK there are no patent restrictions on mcrypt - but the man page does suggest you check with the relevant algorithm developers.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.