DCPCrypt HMAC / PBKDF1 / PBKDF2

uses
  dcpcrypt2, Math;

function RPad(x: string; c: Char; s: Integer): string;
var
  i: Integer;
begin
  Result := x;
  if Length(x)  blocksize then
    key := CalcDigest(key, hash)
  key := RPad(key, #0, blocksize);

  Result := CalcDigest(XorBlock(key, RPad('', #$36, blocksize)) + message, hash);
  Result := CalcDigest(XorBlock(key, RPad('', #$5c, blocksize)) + result, hash);
end;

function PBKDF1(pass, salt: ansistring; count: Integer; hash: TDCP_hashclass): ansistring;
var
  i: Integer;
begin
  Result := pass+salt;
  for i := 0 to count-1 do
    Result := CalcDigest(Result, hash);
end;

function PBKDF2(pass, salt: ansistring; count, kLen: Integer; hash: TDCP_hashclass): ansistring;

  function IntX(i: Integer): ansistring; inline;
  begin
    Result := Char(i shr 24) + Char(i shr 16) + Char(i shr 8) + Char(i);
  end;

var
  D, I, J: Integer;
  T, F, U: ansistring;
begin
  T := '';
  D := Ceil(kLen / (hash.GetHashSize div 8));
  for i := 1 to D do
  begin
    F := CalcHMAC(salt + IntX(i), pass, hash);
    U := F;
    for j := 2 to count do
    begin
      U := CalcHMAC(U, pass, hash);
      F := XorBlock(F, U);
    end;
    T := T + F;
  end;
  Result := Copy(T, 1, kLen);
end;