RHMASK(8)

NAME
       rhmask - generates and recovers file masks

SYNOPSIS
       rhmask <infile> <maskfile>
       rhmask -d <infile> <outfile> <maskfile>

DESCRIPTION
       rhmask  is  intended to allow the distribution of files as
       masks against other files. This lets new versions of soft-
       ware  be freely distributed on public internet servers but
       limits their usefulness to those who already have  a  copy
       of  the  package. It uses a simple XOR scheme for creating
       the file mask and uses file size and md5  sums  to  ensure
       the integrity of the result.

       There  are three files involved in this process. The first
       is the file which both parties much had, which is referred
       to  as  the infile.  The file which the user would like to
       end up with is the outfile and the mask generated  between
       the two is the maskfile.

OPTIONS
       There are two ways of running rhmask. Most users will only
       use it to recover the original file by giving the path  to
       the  infile  as the first argument and the maskfile as the
       second argument. The outfile will be generated in the cur-
       rent directory and checked for correctness.

       To  generate  the  masks, the other form of rhmask must be
       used instead.  The first parameter, -d indicates that  you
       are  generating  a delta. The next parameter is the infile
       which is followed by the outfile.  The final parameter  is
       the  file  name to store the maskfile in. If the operation
       is successful, no output is produced.

SEE ALSO
       md5sum(1) 

AUTHOR
       Erik Troan lt;ewt@redhat.com