umwandlung von Delphi 7 in 2010 macht probs

[TheGame1492]

Ich verwende folgenden Ver-Entschlüsselungscode um strings in (IRC-taugliches)-Blowfish zu verschlüsseln.
(hatte das mal irgendwo im netz gefunden)

Delphi-Quellcode:

program Project1;

{$APPTYPE CONSOLE}

uses
  SysUtils,
  madcrypt;

const B64: ansistring = './0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';


function PCindex(w: ansistring): Cardinal;
begin
  Result:= Pos(w, B64);
  if Result > 0 then dec(Result);
end;

function PCsubstr(w: ansistring; i: Integer): ansichar;
var s: ansistring;
begin
  Result := #0;
  s:= Copy(w, i+1, 1);
  if (length(s) > 0) then
    Result:= s[1];
end;

function bytetoB64(ec: ansistring): ansistring;
var dc: ansistring;
    left, right: Cardinal;
    i, k : Integer;
begin
  dc := '';

  k := -1;

  while(k < (length(ec)-1)) do
  begin
    inc(k);
    left := (ord(PCsubstr(ec,k)) shl 24);
    inc(k);
    inc(left,(ord(PCsubstr(ec,k)) shl 16));
    inc(k);
    inc(left, (ord(PCsubstr(ec,k)) shl 8));
    inc(k);
    inc(left, ord(PCsubstr(ec,k)));

    inc(k);
    right := (ord(PCsubstr(ec,k)) shl 24);
    inc(k);
    inc(right,(ord(PCsubstr(ec,k)) shl 16));
    inc(k);
    inc(right,(ord(PCsubstr(ec,k)) shl 8));
    inc(k);
    inc(right, ord(PCsubstr(ec,k)));

    for i := 0 to 5 do
    begin
      dc := dc + PCsubstr(B64, right and $3F);
      right := right shr 6;
    end;

    for i := 0 to 5 do
    begin
      dc := dc + PCsubstr(B64, left and $3F);
      left := left shr 6;
    end;

  end;
  Result:= dc;
end;

function B64tobyte(ec: ansistring): ansistring;
var dc: ansistring;
    k: Integer;
    i, right, left: Cardinal;
begin
  dc:= '';
  k := -1;

  while(k < (length(ec)-1)) do
  begin
     right := 0;
     left := 0;

     for i := 0 to 5 do
     begin
       inc(k);
       right := right or (PCindex(PCsubstr(ec, k)) shl (i * 6));
     end;

     for i := 0 to 5 do
     begin
       inc(k);
       left := left or (PCindex(PCsubstr(ec, k)) shl (i * 6));
     end;

     for i := 0 to 3 do
     begin
       dc := dc + chr((left and ($FF shl ((3 - i) * 8))) shr ((3 - i) * 8));
     end;

     for i := 0 to 3 do
     begin
       dc := dc + chr((right and ($FF shl ((3 - i) * 8))) shr ((3 - i) * 8));
     end;

  end;

  Result:= dc;
end;


function set_key(key: ansistring): ansistring;
var i, keyLen: Integer;
    newkey: ansistring;
begin
  Result := key;
  if(length(key) < 8) then
  begin
    keyLen := length(key);
    i := 8 div keyLen;
    if (8 mod keyLen > 0) then inc(i);

    newkey := '';
    while (i > 0) do
    begin
      newkey := newkey + key;
      dec(i);
    end;
    Result := newkey;
  end;
end;

function EncryptIrcBlowfish(dText, key: ansistring): ansistring; stdcall;
var temp, eText: ansistring;
    i: Integer;
    mykey: ansistring;
begin
  eText := '';
  if(dText<>'') then
  begin
    temp := '';

    if (length(dText) mod 8 > 0) then
      for i:= 1 to 8 - (length(dText) mod 8) do
        dText:= dText+ #0;

    temp := '';

    mykey:= set_key(key);
    for i:= 1 to length(dText) div 8 do
    begin
      temp:= Copy(dText, 1+(i-1)*8,8);
      SetLength(temp, 8);
      madcrypt.Encrypt(PansiChar(temp), 8, mykey);
      eText := eText + bytetoB64(temp);
    end;
  end;
  Result:= eText;
end;


function DecryptIrcBlowfish(eText, key: ansistring): ansistring; stdcall;
var temp, dText: ansistring;
    i : Integer;
    mykey: ansistring;
begin
  mykey:= set_key(key);
  for i:= 1 to length(eText) div 12 do
  begin
     temp := B64tobyte(Copy(eText,1+(i-1)*12,12));
     SetLength(temp, 8);
     madcrypt.Decrypt(PansiChar(temp), 8, mykey);
     dText := dtext + temp;
  end;

  Result:= dText;
end;


var
  str, key, strEncrypted, strDecrypted: ansistring;
begin
  try
    str := 't2e3s4t5t6e7st';
    key := '123';
    writeln('----');
    strEncrypted := EncryptIrcBlowfish( str, key );
    writeln('Encrypted: '+strEncrypted);
    strDecrypted := DecryptIrcBlowfish( strEncrypted, key );
    writeln('DEcrypted: ' +strDecrypted);
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;

  readln;
end.

Unter Delphi 7 gibs keine Probs aba unter 2010 funktioniert das en- und de-crypten nur zu 50%, ich hab schon die strings durch ansistrings und pchar duch pansichar ersetzt.

Wo könnte da noch der Fehler drin liegen??