Re: IntVal(float) Returns Different Values (Porting Delphi code to mix a block of data)

You probably want to use BC_MATH or that new-fangled thing like it if you want to deal in INT larger than 32 bit. Or you could buy 64-bit hardware. On Mon, March 20, 2006 9:13 am, Bruce wrote: > I am having trouble porting some code originally written in Borland > Delphi > to PHP. The Delphi code expects certain behavior on integer overflows > that I > can only duplicate on some PHP systems. For example: > > $BB = -2181087916; > $AA = (int)$BB; > $AA = intval($BB); > > On some systems, $AA will be (int)-2147483648, however, on most > systems, $AA > will be (int)2113879380, which is the same value truncated at 32 bits. > It is > this latter behavior that I need to properly port the Delphi code. > > Can someone suggest a way to do this that is consistent on all > platforms? > For reference, I am attaching the Delphi code and my PHP port. > > Thanks... > > --Bruce > > {quick (block) mixer routine} > procedure MixBlock(const Matrix : T128bit; var Block; Encrypt : > Boolean); > > const > CKeyBox : array [False..True, 0..3, 0..2] of LongInt = > > (((0, 3, 1), (2, 1, 3), (1, 0, 2), (3, 2, 0)), > ((3, 2, 0), (1, 0, 2), (2, 1, 3), (0, 3, 1))); > > var > Blocks : array [0..1] of LongInt absolute Block; > Work : LongInt; > Right : LongInt; > Left : LongInt; > > R : LongInt; > AA, BB : LongInt; > CC, DD : LongInt; > > begin > Right := Blocks[0]; > Left := Blocks[1]; > > for R := 0 to 3 do begin > {transform the right side} > AA := Right; > BB := Matrix[CKeyBox[Encrypt, R, 0]]; > > CC := Matrix[CKeyBox[Encrypt, R, 1]]; > DD := Matrix[CKeyBox[Encrypt, R, 2]]; > > AA := AA + DD; DD := DD + AA; AA := AA xor (AA shr 7); > BB := BB + AA; AA := AA + BB; BB := BB xor (BB shl 13); > > CC := CC + BB; BB := BB + CC; CC := CC xor (CC shr 17); > DD := DD + CC; CC := CC + DD; DD := DD xor (DD shl 9); > > AA := AA + DD; DD := DD + AA; AA := AA xor (AA shr 3); > BB := BB + AA; BB := BB xor (BB shl 7); > > CC := CC + BB; > CC := CC xor (DD shr 15); > DD := DD + CC; > DD := DD xor (DD shl 11); > > Work := Left xor DD; > Left := Right; > Right := Work; > end; > > Blocks[0] := Left; > > Blocks[1] := Right; > end; > > Here is my PHP port: > > <?php > function zeroFill($a, $b) > { > $z = hexdec(80000000); > if ($z & $a) > { > $a >>= 1; > $a &= (~ $z); > $a |= 0x40000000; > $a >>= ($b-1); > } > else > { > $a >>= $b; > } > return $a; > } > > function MixBlock($AKey, &$ACode, $Encrypt) > { > $CKeyBox = array(array(3, 2, 0), array(1, 0, 2), array( 2, 1, 3), > array(0 , > 3, 1)); > > $Right = $ACode[0]; > $Left = $ACode[1]; > > for ($R=0; $R<= 3; $R++) > { > $AA = $Right; > if ($Encrypt) > { > $BB = $AKey[$CKeyBox[ $R][0]]; > $CC = $AKey[$CKeyBox[ $R][1]]; > $DD = $AKey[$CKeyBox[ $R][2]]; > } > else > { > $BB = $AKey[$CKeyBox[ 3-$R][0]]; > $CC = $AKey[$CKeyBox[ 3-$R][1]]; > $DD = $AKey[$CKeyBox[ 3-$R][2]]; > } > > $AA = (int)$AA + (int)$DD; > $DD = (int)$DD + (int)$AA; > $AA = (int)$AA ^ zeroFill( $AA, 7); > $BB = (int)$BB + (int)$AA; > $AA = (int)$AA + (int)$BB; > > $BB = (int)$BB ^ ((int)$BB << 13); > $CC = (int)$CC + (int)$BB; $BB = (int)$BB + (int)$CC; > $CC = (int)$CC ^ zeroFill( $CC, 17); > $DD = (int)$DD + (int)$CC; $CC = (int)$CC + (int)$DD; > $DD = (int)$DD ^ ((int)$DD << 9); > > $AA = (int)$AA + (int)$DD; $DD = (int)$DD + (int)$AA; > $AA = (int)$AA ^ zeroFill( $AA, 3); > $BB = (int)$BB + (int)$AA; > $BB = (int)$BB ^ (int)((int)$BB << 7); > $CC = (int)$CC + (int)$BB; > $CC = (int)$CC ^ zeroFill( $DD, 15); > $DD = (int)$DD + (int)$CC; > $DD = (int)$DD ^ (int)((int)$DD << 11); > > $Work = $Left ^ $DD; > $Left = $Right; > $Right = $Work; > } > > $ACode[0] = $Left; > $ACode[1] = $Right; > } > ?> > -- Like Music? http://l-i-e.com/artists.htm