(Delphi ActiveX) POP3 Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

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

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
success: Integer;
mailman: TChilkatMailMan;
stUidls: TChilkatStringTable;
email: TChilkatEmail;
cert: TChilkatCert;
count: Integer;
i: Integer;

begin
success := 0;

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

mailman := TChilkatMailMan.Create(Self);

// Set the POP3 server's hostname
mailman.MailHost := 'pop.example.com';

// Set the POP3 login/password.
mailman.PopUsername := 'myLogin';
mailman.PopPassword := 'myPassword';

stUidls := TChilkatStringTable.Create(Self);
success := mailman.FetchUidls(stUidls.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(mailman.LastErrorText);
    Exit;
  end;

email := TChilkatEmail.Create(Self);
cert := TChilkatCert.Create(Self);

count := stUidls.Count;
i := 0;
while i < count do
  begin
    // Download the full email.
    success := mailman.FetchByUidl(stUidls.StringAt(i),0,0,email.ControlInterface);
    if (success = 0) then
      begin
        Memo1.Lines.Add(mailman.LastErrorText);
        Exit;
      end;

    Memo1.Lines.Add(IntToStr(i));
    Memo1.Lines.Add('From: ' + email.From);
    Memo1.Lines.Add('Subject: ' + email.Subject);

    // The security layers of signed and/or encrypted emails
    // are automatically "unwrapped" when loaded into
    // a Chilkat email object.
    // An application only needs to check to see if an email
    // was received signed or encrypted, and then examine
    // the success/failure.  For example:
    if (email.ReceivedSigned = 1) then
      begin

        Memo1.Lines.Add('This email was signed.');

        // Check to see if the signatures were verified.
        if (email.SignaturesValid = 1) then
          begin
            Memo1.Lines.Add('Digital signature(s) verified.');
            Memo1.Lines.Add('Signer: ' + email.SignedBy);

            success := email.LastSignerCert(0,cert.ControlInterface);
            if (success = 0) then
              begin
                Memo1.Lines.Add(email.LastErrorText);
                Exit;
              end;

            Memo1.Lines.Add('Signing cert: ' + cert.SubjectCN);
          end;

      end
    else
      begin
        Memo1.Lines.Add('Digital signature verification failed.');
      end;

    i := i + 1;
  end;

mailman.Pop3EndSession();
end;