<pre>

<?php

// this file to work out how to write the splitter

// I'm sure there are bugs that are caused by working with ascii test data and not hex data like a raw file would have

// but ascii test data means the decoded can be read easyly, maybe I should have use 0,1,2,3,4,5,6,7,8,9 but meh hind site

include 'functions.php';

$thebytes='that fox is quick as'. chr(4).chr(254); // bytes to scramble, this will be the compress file.

echo $thebytes.'<br>';

echo '<br>Orgional file size '.strlen($thebytes).'<br>';

$tb=str_split($thebytes); // convert input file into an array of bytes

// need to add for loop to cycle through split key (1-254) or just one key as this is the test area before working with compressed files.

$scramkey=102; // scramble key set

$skey=dec2bin($scramkey); // convert to binary

echo $skey[0].$skey[1].$skey[2].$skey[3].$skey[4].$skey[5].$skey[6].$skey[7].' scramble skey<br>';

$P0='';

$P1='';

foreach ($tb as $byte ) { // loop through file byte by byte

$bb= byte2bin($byte); // make chars binary

// $bb= dec2bin($byte); // make byte binary

// if key bit = 0 put bb bit in part 0 else put it into part 1

for ($i=0; $i<=7; $i++){ // process the byte bit by bit

if(($skey[$i]=='0')){

$P0.=$bb[$i];

} else {

$P1.=$bb[$i];

}

}

}

echo $P0.' p0<br>';

echo $P1.' p1<br>';

$p0len= strlen($P0); // mid point used to unscramble the file.

echo $p0len.' lenght of part 0 in hex<br>';

$nf=$P0.$P1; // nf is the new file in binary format

// convert to hex like a raw zip file would be

//echo binTohex($nf); // not needed really in the test file

// joint the two files and convet it back to decimal and

// add the 1st byte as the scramblekey followed by a long word 4 bytes (x00000000) of the size of part 0

$pa=''; // store decode file

$pac=0; // index into part a and b

$pbc=0;

$sizeofbin=strlen($nf);

for($ii=0;$ii<($sizeofbin/8);$ii++){ // cyctle through the whole file doing a byte at a time.

for ($i=0; $i<=7; $i++){ // process it the byte pulling it in bit by bit

if(($skey[$i]=='0')){

$pa.=$nf[$pba]; // pull bit for part 0 and out in part a

$pba++;

} else {

$pa.=$nf[$p0len+$pbc];

$pbc++;

}

}

}

echo '<br>decoded<br>';

echo $pa.' pa<br>'; // decoded bit file

// decode bin to acsii again

echo binTochr($pa);

?>

</pre>