tools.pas

MISTY 加密算法 二进制兼容的加密算法,加密匙可到128位

unit Tools;

interface
uses
  Sysutils;

type
{$IFDEF VER120}
  dword= longword;
{$ELSE}
  dword= longint;
{$ENDIF}

function LRot16(X: word; c: integer): word; assembler;
function RRot16(X: word; c: integer): word; assembler;
function LRot32(X: dword; c: integer): dword; assembler;
function RRot32(X: dword; c: integer): dword; assembler;
procedure XorBlock(I1, I2, O1: PByteArray; Len: integer);
procedure IncBlock(P: PByteArray; Len: integer);

implementation

function LRot16(X: word; c: integer): word; assembler;
asm
  mov ecx,&c
  mov ax,&X
  rol ax,cl
  mov &Result,ax
end;

function RRot16(X: word; c: integer): word; assembler;
asm
  mov ecx,&c
  mov ax,&X
  ror ax,cl
  mov &Result,ax
end;

function LRot32(X: dword; c: integer): dword; assembler;
asm
  mov ecx,&c
  mov eax,&X
  rol eax,cl
  mov &Result,eax
end;

function RRot32(X: dword; c: integer): dword; assembler;
asm
  mov ecx,&c
  mov eax,&X
  ror eax,cl
  mov &Result,eax
end;

procedure XorBlock(I1, I2, O1: PByteArray; Len: integer);
var
  i: integer;
begin
  for i:= 0 to Len-1 do
    O1[i]:= I1[i] xor I2[i];
end;

procedure IncBlock(P: PByteArray; Len: integer);
begin
  Inc(P[Len-1]);
  if (P[Len-1]= 0) and (Len> 1) then
    IncBlock(P,Len-1);
end;

end.