const
 Codes64 = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/';

 function Encode64(S: string): string;
 var
 i: Integer;
 a: Integer;
 x: Integer;
 b: Integer;
 begin
 Result := '';
 a := 0;
 b := 0;
 for i := 1 to Length(s) do
 begin
 x := Ord(s[i]);
 b := b * 256 + x;
 a := a + 8;
 while a >= 6 do
 begin
 a := a - 6;
 x := b div (1 shl a);
 b := b mod (1 shl a);
 Result := Result + Codes64[x + 1];
 end;
 end;
 if a > 0 then
 begin
 x := b shl (6 - a);
 Result := Result + Codes64[x + 1];
 end;
 end;

 function Decode64(S: string): string;
 var
 i: Integer;
 a: Integer;
 x: Integer;
 b: Integer;
 begin
 Result := '';
 a := 0;
 b := 0;
 for i := 1 to Length(s) do
 begin
 x := Pos(s[i], codes64) - 1;
 if x >= 0 then
 begin
 b := b * 64 + x;
 a := a + 6;
 if a >= 8 then
 begin
 a := a - 8;
 x := b shr a;
 b := b mod (1 shl a);
 x := x mod 256;
 Result := Result + chr(x);
 end;
 end
 else
 Exit;
 end;
 end;