(Delphi DLL) RSA OAEP Padding

Demonstrates how to use OAEP padding with the RSA encryption algorithm. More information about OAEP Padding.

Note: This example requires Chilkat v11.0.0 or greater.

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, PublicKey, Rsa;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
rsa: HCkRsa;
pubKeyXml: PWideChar;
pubKey: HCkPublicKey;
plainText: PWideChar;
usePrivateKey: Boolean;
encryptedStr: PWideChar;

begin
success := False;

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

rsa := CkRsa_Create();

// RSA public key in XML format:
pubKeyXml := '<RSAPublicKey><Modulus>of3im3mRgd2NLXIGoK6uYLg6jj0Ug2b42rnqa5Tbwz2ieFqMJqt+++x2oqLYGurlz49nt+7/785g3XYWqoka4u9c9zul6YubIjnBM72dQy7rEkEfbUxgjcxqXyjZFx+FpaxFUecLu688XEu+9UA42VKiCgcl+E7TrqnfeeYpNXc=</Modulus><Exponent>AQAB</Exponent></RSAPublicKey>';

pubKey := CkPublicKey_Create();
success := CkPublicKey_LoadFromString(pubKey,pubKeyXml);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubKey));
    Exit;
  end;

success := CkRsa_UsePublicKey(rsa,pubKey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

// To use Optimal Asymmetric Encryption Padding (OAEP) padding,
// simply set the PkcsPadding property to False
CkRsa_putPkcsPadding(rsa,False);

// Encrypt a string and return the encrypted data base64-encoded:
CkRsa_putEncodingMode(rsa,'base64');

plainText := 'RSA Encryption should be easy.';

usePrivateKey := False;
encryptedStr := CkRsa__encryptStringENC(rsa,plainText,usePrivateKey);
Memo1.Lines.Add(encryptedStr);

CkRsa_Dispose(rsa);
CkPublicKey_Dispose(pubKey);

end;