(Delphi ActiveX) AES OFB Output Feedback Mode Encryption

Demonstrates how to encrypt using AES OFB (Output Feedback) mode.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: TChilkatCrypt2;
ivHex: WideString;
keyHex: WideString;
encStr: WideString;
decrypt: TChilkatCrypt2;
decStr: WideString;

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

crypt := TChilkatCrypt2.Create(Self);

crypt.CryptAlgorithm := 'aes';
// Set the cipher mode to Output Feedback
crypt.CipherMode := 'ofb';
crypt.KeyLength := 256;

// EncodingMode specifies the encoding of the output for
// encryption, and the input for decryption.
// It may be "hex", "url", "base64", "quoted-printable", or many other choices.
crypt.EncodingMode := 'hex';

ivHex := '000102030405060708090A0B0C0D0E0F';
crypt.SetEncodedIV(ivHex,'hex');

// The secret key must equal the size of the key.  For
// 256-bit encryption, the binary secret key is 32 bytes.
keyHex := '603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4';
crypt.SetEncodedKey(keyHex,'hex');

// Encrypt a string...
encStr := crypt.EncryptStringENC('Popular opinions, on subjects not palpable to sense, are often true, but seldom or never the whole truth. -- John Stuart Mill');
Memo1.Lines.Add(encStr);

decrypt := TChilkatCrypt2.Create(Self);
decrypt.CryptAlgorithm := 'aes';
decrypt.CipherMode := 'ofb';
decrypt.KeyLength := 256;
decrypt.EncodingMode := 'hex';
decrypt.SetEncodedIV(ivHex,'hex');
decrypt.SetEncodedKey(keyHex,'hex');

// Now decrypt:
decStr := decrypt.DecryptStringENC(encStr);
Memo1.Lines.Add(decStr);
end;