(Delphi DLL) AES OFB Output Feedback Mode Encryption

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

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: HCkCrypt2;
ivHex: PWideChar;
keyHex: PWideChar;
encStr: PWideChar;
decrypt: HCkCrypt2;
decStr: PWideChar;

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

crypt := CkCrypt2_Create();

CkCrypt2_putCryptAlgorithm(crypt,'aes');
// Set the cipher mode to Output Feedback
CkCrypt2_putCipherMode(crypt,'ofb');
CkCrypt2_putKeyLength(crypt,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.
CkCrypt2_putEncodingMode(crypt,'hex');

ivHex := '000102030405060708090A0B0C0D0E0F';
CkCrypt2_SetEncodedIV(crypt,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';
CkCrypt2_SetEncodedKey(crypt,keyHex,'hex');

// Encrypt a string...
encStr := CkCrypt2__encryptStringENC(crypt,'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 := CkCrypt2_Create();
CkCrypt2_putCryptAlgorithm(decrypt,'aes');
CkCrypt2_putCipherMode(decrypt,'ofb');
CkCrypt2_putKeyLength(decrypt,256);
CkCrypt2_putEncodingMode(decrypt,'hex');
CkCrypt2_SetEncodedIV(decrypt,ivHex,'hex');
CkCrypt2_SetEncodedKey(decrypt,keyHex,'hex');

// Now decrypt:
decStr := CkCrypt2__decryptStringENC(decrypt,encStr);
Memo1.Lines.Add(decStr);

CkCrypt2_Dispose(crypt);
CkCrypt2_Dispose(decrypt);

end;