(Delphi ActiveX) PKCS7 Sign Text using RSA 2048, SHA256, Base64 Output

Demonstrates how to sign text using 2048-bit RSA with SHA256, producing PKCS#7 output in Base64. The certificate w/ private key used for signing is loaded from a .p12/.pfx file.

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
cert: TChilkatCert;
success: Integer;
crypt: TChilkatCrypt2;
textToSign: WideString;
sigBase64: WideString;

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

cert := TChilkatCert.Create(Self);

// Load the cert and private key.  Whatever the private key happens to be,
// such as RSA or ECC, then Chilkat will use it.  If the private key is 
// a 2048-bit RSA key, then that's what will be used..
success := cert.LoadPfxFile('qa_data/pfx/myCertAndKey.p12','password');
if (success <> 1) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

crypt := TChilkatCrypt2.Create(Self);

success := crypt.SetSigningCert(cert.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

// Use SHA-256
crypt.HashAlgorithm := 'sha256';

// Hash the utf-8 byte representation of the string
crypt.Charset := 'utf-8';

// Return the result in base64
crypt.EncodingMode := 'base64';

// Sign some text..
textToSign := 'This is the text to be hashed and signed.';
sigBase64 := crypt.OpaqueSignStringENC(textToSign);
if (crypt.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add(sigBase64);

// The result:
// MIIS2wYJKoZIhvcNAQc ... zGeeY4Oxg==
end;