README

Password-Manager

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Password managers emerged to address the problem that users require secure passwords both for their own systems and for numerous user accounts across various online services. Using identical usernames and passwords for different services poses a significant security risk, as a single stolen password would grant access to all of those services. Consequently, a multitude of distinct passwords is required. Secure passwords are lengthy and consist of combinations of letters, numbers, and special characters that are difficult to memorize (see "Choosing Secure Passwords"). Password managers enable users to safeguard a large number of distinct and secure passwords against unauthorized access while still allowing for their convenient use.

In my opinion, a password manager does not need to be versatile or visually appealing, but rather practical and secure. The more practical and simple a program is designed, the more commonly it is used in everyday life.

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Data encryption does not take place in main memory, but rather on a dynamically recreated memo component, ensuring that external programs cannot intercept the operations occurring in memory.

Encryption

Nine encryption methods are available, featuring various algorithms both password-protected and unprotected. With this feature, the security key for existing account entries can also be edited something that was not possible with the old version.

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Modern ciphers are more secure than classical ciphers and are designed to withstand a wide range of attacks. An attacker should not be able to find the key used in a modern cipher, even if they know any specifics about the plaintext and its corresponding ciphertext.

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RC4 Decryption problem

If the RC4 encryption method is used, an EEncodingError is raised in debugger mode when entering the security key; this error can be ignored.

Message:

"In project Project1.exe, an exception of class EEncodingError occurred
  with the message 'No mapping exists for the Unicode character in the
  target multibyte code page"

The Delphi EEncodingError exception (typically raised as "No mapping for the Unicode character exists in the target multi-byte code page") occurs when you try to convert a modern Unicode string into an older, restricted encoding (like ANSI or ASCII) that doesn't support the specific character you are using.

The exception error is triggered in this part of the code, but it is irrelevant, as the text to be decrypted resides in a dynamic component that is discarded immediately after encryption.

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function RC4DecryptString(const AHexText, AKey: string): string;
var
  SBox: array[0..255] of Byte;
  KeyBytes, TextBytes, ResultBytes: TBytes;
  I, J, T, KeyLen, TextLen: Integer;
  Temp: Byte;
  HexChar: string;
begin
  Result := '';
  if (AHexText = '') or (AKey = '') then Exit;

  // Convert a hex string back into a byte array
  TextLen := Length(AHexText) div 2;
  SetLength(TextBytes, TextLen);
  for I := 0 to TextLen - 1 do
  begin
    HexChar := Copy(AHexText, (I * 2) + 1, 2);
    TextBytes[I] := StrToInt('$' + HexChar);
  end;

  KeyBytes := TEncoding.UTF8.GetBytes(AKey);
  KeyLen := Length(KeyBytes);
  SetLength(ResultBytes, TextLen);

  // 1. Initializing the S-Box
  for I := 0 to 255 do
    SBox[I] := I;

  J := 0;
  for I := 0 to 255 do
  begin
    J := (J + SBox[I] + KeyBytes[I mod KeyLen]) mod 256;
    Temp := SBox[I];
    SBox[I] := SBox[J];
    SBox[J] := Temp;
  end;

  // 2. Decryption
  I := 0;
  J := 0;
  for T := 0 to TextLen - 1 do
  begin
    I := (I + 1) mod 256;
    J := (J + SBox[I]) mod 256;

    Temp := SBox[I];
    SBox[I] := SBox[J];
    SBox[J] := Temp;

    ResultBytes[T] := TextBytes[T] xor SBox[(SBox[I] + SBox[J]) mod 256];
  end;

  // Convert UTF-8 bytes back into a Delphi Unicode string
  Result := TEncoding.UTF8.GetString(ResultBytes);
end;

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History

The first password manager software designed to securely store passwords was Password Safe created by Bruce Schneier, which was released as a free utility on September 5, 1997. Designed for Microsoft Windows 95, Password Safe used Schneier's Blowfish algorithm to encrypt passwords and other sensitive data. Although Password Safe was released as a free utility, due to export restrictions on cryptography from the United States, only U.S. and Canadian citizens and permanent residents were initially allowed to download it.

As of October 2024, the built-in Google Password Manager in Google Chrome has become the most used password manager.

List of password managers: https://en.wikipedia.org/wiki/List_of_password_managers

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Password Generator

A random password generator is a software program or hardware device that takes input from a random or pseudo-random number generator and automatically generates a password.

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// Example Code
procedure TForm1.Button1Click(Sender: TObject);
  var
    Result,str,str1,str2,str3,str4:String;
    PLen:Integer;
  begin
    Randomize;
    str:='';
    str1:='19283746504378192560';
    str2:='abcdefghijklmnopqastuvwxyz';
    str3:='ABCDEFGHIJKLMNOPQASTUVWXYZ';
    str4:='!@#$%^&*()_+|\=-<>.,/?''; :"][}{';
    Result:='';
    PLen:=SpinEdit1.Value;
      if (CheckBox1.Checked=True) then str:=str+str1;
      if (CheckBox2.Checked=True) then str:=str+str2;
      if (CheckBox3.Checked=True) then str:=str+str3;
      if (CheckBox4.Checked=true) then str:=str+str4;
      if  (CheckBox1.Checked=False)
      and (CheckBox2.Checked=False)
      and (CheckBox3.Checked=False)
      and (CheckBox4.Checked=False)
      then
        MessageDlg('You must select a category to generate a password.!',mtInformation,[mbOK],0)
      else
        repeat
          Result:= Result+str[Random(Length(str))+1];
        until (Length(Result)=PLen);
          Edit2.Text:=Result;
   StatusBar1.SetFocus;
end;