RAR & ZIP archivez management

   RARLIB.INC and ZIPLIB.INC provides similar interface part to work with
RAR and ZIP archives.

   Available operations are:
   - scan archives (i.e. read headers & filenames) file by file;
   - modify file information (name,time,crc,...) for any file;
   - add new file to archive (with 'storing' method)

   Archive  infection method: find first .EXE file, add dropper with same
name  to  the end of archive, then rename .EXE file to '.EX_'. Archive is
'alredy infected' if .EX_ file present with special datetime signature.

   Each  include  file has ONLY ONE public subroutine called process_xxx;
all  other  functions  uses variables defined on the process_xxx's stack,
i.e. they're internal.
   To  use  these  functions  in your allpication, move rar_data/zip_data
structures into udata section and remove [ebp] addressing from code.

==========================================================================
FUNCTIONs      INPUT REGISTERS        DESCRIPTION
==========================================================================
process_rar    EDX=archive name       open archive;
process_zip    ESI=file data          skip sfx part if present;
               ECX=file size          find first .EXE file;
                                      add new file with the same name;
                                      rename .EXE file to .ZMB
                                      Returns CF=0 if archive changed
==========================================================================
internal functions:
==========================================================================
rar_open       EDX=archive name       open file;
zip_open                              skip sfx part;
                                      read main archive headers/other info;
--------------------------------------------------------------------------
rar_findnext   none                   read current header(s)/file name
zip_findnext                          (rar_fh/zip_fh structures);
                                        calculate offset of next header;
--------------------------------------------------------------------------
rar_update     none                   write current header(s)/file name
zip_update                            (rar_fh/zip_fh, rar_fname/zip_fname)
--------------------------------------------------------------------------
rar_add        EDX=file data          add new file to archive;
zip_add        ECX=file size          if ESI and/or EBX = 0, name/time will
               ESI=fname (0=default)  be taken from current file header
               EBX=ftime (0=default)  (rar_fh/zip_fh);
--------------------------------------------------------------------------
rar_close      none                   close file
zip_close
==========================================================================