By taking the lowest 7 bits of each  of  the  first  eight
       characters  of  the  key,  a 56-bit key is obtained.  This
       56-bit key is used to encrypt repeatedly a constant string
       (usually  a string consisting of all zeros).  The returned
       value points to the encrypted password,  a  series  of  13
       printable  ASCII characters (the first two characters rep-
       resent the salt  itself).   The  return  value  points  to
       static data whose content is overwritten by each call.