Check if Certificate Expired

How to check to see if a digital certificate is expired.

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATCERTIFICATELib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
cert: TChilkatCert;
success: Integer;
isExpired: Integer;

begin
cert := TChilkatCert.Create(Self);

//  The LoadByCommonName method searches the registry-based
//  Windows Current User Certificate Store and Local Machine Certificate
//  Store for a certificate whose common name (CN) matches
//  the argument:

success := cert.LoadByCommonName('Chilkat Software, Inc.');
if (success = 0) then
  begin
    ShowMessage('Failed to find certificate!');
  end
else
  begin

    //  Display the certificate's distinguished name:
    Memo1.Lines.Add(cert.SubjectDN);

    isExpired := cert.Expired;
    if (isExpired = 1) then
      begin
        Memo1.Lines.Add('Certificate is expired.');
      end
    else
      begin
        Memo1.Lines.Add('Certificate is NOT expired.');
      end;

  end;

//  Alternatively, load a Certificate from a .cer file.
//  (Certs may also be loaded from other types of files, such as PEM, DER, PFX, etc.)
success := cert.LoadFromFile('myCert.cer');
if (success = 0) then
  begin
    ShowMessage('Failed to load certificate!');
  end
else
  begin

    //  Display the certificate's distinguished name:
    Memo1.Lines.Add(cert.SubjectDN);

    isExpired := cert.Expired;
    if (isExpired = 1) then
      begin
        Memo1.Lines.Add('Certificate is expired.');
      end
    else
      begin
        Memo1.Lines.Add('Certificate is NOT expired.');
      end;

  end;

//  The Chilkat Certificate, Certificate Store, Private Key,
//  Public Key, and Key Container classes / objects are freeware.

//  They are used by and included with the Chilkat Email,
//  Crypt, S/MIME, and other commercial Chilkat components.

end;