79 lines
1.5 KiB
ObjectPascal
79 lines
1.5 KiB
ObjectPascal
|
|
||
|
|
{******************************************}
|
||
|
|
{ }
|
||
|
|
{ FastReport FMX v2.0 }
|
||
|
|
{ RC4 crypto algorythm }
|
||
|
|
{ }
|
||
|
|
{******************************************}
|
||
|
|
|
||
|
|
unit FMX.frxRC4;
|
||
|
|
|
||
|
|
interface
|
||
|
|
|
||
|
|
{$I frx.inc}
|
||
|
|
|
||
|
|
uses
|
||
|
|
System.SysUtils, System.Classes;
|
||
|
|
|
||
|
|
type
|
||
|
|
PByte = ^Byte;
|
||
|
|
|
||
|
|
TfrxRC4 = class(TObject)
|
||
|
|
private
|
||
|
|
FKey: array[0..255] of byte;
|
||
|
|
procedure xchg(var byte1, byte2: Byte);
|
||
|
|
public
|
||
|
|
procedure Start(Key: Pointer; KeyLength: Integer);
|
||
|
|
procedure Crypt(Source, Target: Pointer; Length: Integer);
|
||
|
|
end;
|
||
|
|
|
||
|
|
implementation
|
||
|
|
|
||
|
|
procedure TfrxRC4.xchg(var byte1, byte2: Byte);
|
||
|
|
var
|
||
|
|
t: Byte;
|
||
|
|
begin
|
||
|
|
t := byte1;
|
||
|
|
byte1 := byte2;
|
||
|
|
byte2 := t;
|
||
|
|
end;
|
||
|
|
|
||
|
|
procedure TfrxRC4.Start(Key: Pointer; KeyLength: Integer);
|
||
|
|
var
|
||
|
|
i, j: integer;
|
||
|
|
k: array[0..255] of byte;
|
||
|
|
begin
|
||
|
|
if (KeyLength > 0) and (KeyLength <= 256) then
|
||
|
|
begin
|
||
|
|
for i := 0 to 255 do
|
||
|
|
begin
|
||
|
|
FKey[i] := i;
|
||
|
|
k[i] := PByte(NativeInt(Key) + (i mod KeyLength))^;
|
||
|
|
end;
|
||
|
|
j := 0;
|
||
|
|
for i := 0 to 255 do
|
||
|
|
begin
|
||
|
|
j := (j + FKey[i] + k[i]) and $FF;
|
||
|
|
xchg(FKey[i], FKey[j]);
|
||
|
|
end;
|
||
|
|
end;
|
||
|
|
end;
|
||
|
|
|
||
|
|
procedure TfrxRC4.Crypt(Source, Target: Pointer; Length: Integer);
|
||
|
|
var
|
||
|
|
i, j: byte;
|
||
|
|
k: integer;
|
||
|
|
begin
|
||
|
|
i := 0;
|
||
|
|
j := 0;
|
||
|
|
for k := 0 to Length - 1 do
|
||
|
|
begin
|
||
|
|
i := Byte(i + 1);
|
||
|
|
j := Byte(j + FKey[i]);
|
||
|
|
xchg(FKey[i], FKey[j]);
|
||
|
|
PByteArray(Target)[k] := PByteArray(Source)[k] xor FKey[Byte(FKey[i] + FKey[j])];
|
||
|
|
end;
|
||
|
|
end;
|
||
|
|
|
||
|
|
end.
|