Ystok-MD5 is a portable Common Lisp library including the implementation of the two algoritms.

  1. The MD5 Message-Digest Algorithm, as defined in RFC 1321 by R. Rivest published April 1992.
  2. The MD5 APR (Apache Portable Runtime) algorithm used for basic authorization by web servers Apache, Nginx, and others as well as by the htpasswd password encryption utility.

The Ystok-MD5 is based on Pierre R. Mai's MD5. On LispWorks, the library switches to a specialized code that uses a fast raw 32bit arithmetic introduced in LW 4.4. This version demonstrates speed increase of about two hundred times compared to a naive port.


Ystok-MD5 requires


The source code was tested on the following Lisp implementations:

Download and installation

Ystok-MD5 is available from
http://lisp.ystok.ru/ymd5/ymd5-1-0-001.zip or