(Delphi ActiveX) RSA Sign with PKCS8 Encrypted Key

See more RSA Examples

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature.

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
pkey: TPrivateKey;
success: Integer;
pkeyXml: WideString;
rsa: TChilkatRsa;
strData: WideString;
hexSig: WideString;

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

pkey := TPrivateKey.Create(Self);

// Load the private key from an RSA PEM file:
success := pkey.LoadPkcs8EncryptedFile('privateKey.key','myPassword');

// Get the private key in XML format:
pkeyXml := pkey.GetXml();

rsa := TChilkatRsa.Create(Self);

// Import the private key into the RSA object:
success := rsa.ImportPrivateKey(pkeyXml);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

// Return the signature in hex
rsa.EncodingMode := 'hex';

strData := 'This is the string to be signed.';

// Sign the string using the sha-1 hash algorithm.
// Other valid choices are "md2", "sha256", "sha384", "sha512",  and "md5".
hexSig := rsa.SignStringENC(strData,'sha-1');

Memo1.Lines.Add(hexSig);
end;