The source code under this directory is taken from the client for the
Tarsnap online backup system (and released under the 2-clause BSD license
with permission of the author); keeping this code in sync with the Tarsnap
code is highly desirable and explains why there is some functionality
included here which is not actually used by the scrypt file encryption
utility.

It has been modified to use PHP's internal memory functions and to report
more developer friendly error messages incase of invalid parameters.