Decrypt MIME with PFX

Download Chilkat MIME ActiveX

Demonstrates how to decrypt MIME using a PFX (containing a digital certificate with private key). The content-type of an encrypted MIME message looks like this:

Content-Type: application/x-pkcs7-mime;
	name="smime.p7m"

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
mime: CHILKATMIMELib_TLB.IChilkatMime;
success: Integer;
certStore: CHILKATCERTIFICATELib_TLB.IChilkatCertStore;
cert: CHILKATMIMELib_TLB.IChilkatCert;
privKey: CHILKATCERTIFICATELib_TLB.IPrivateKey;

begin
mime := CoChilkatMime.Create();

success := mime.UnlockComponent('Anything for 30-day trial');
if (success = 0) then
  begin
    ShowMessage('Failed to unlock component');
    Exit;
  end;

success := mime.LoadMimeFile('encryptedEmail.eml');
if (success <> 1) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

certStore := CoChilkatCertStore.Create();
success := certStore.LoadPfxFile('myPfx.pfx','myPfxPassword');
if (success <> 1) then
  begin
    Memo1.Lines.Add(certStore.LastErrorText);
    Exit;
  end;

//  Find the certificate by email address.  There are many
//  ways to find certificates within a Chilkat certificate store
//  object...

cert := certStore.FindCertBySubjectE('support@chilkatsoft.com') As CHILKATMIMELib_TLB.IChilkatCert;
if (cert = nil ) then
  begin
    Memo1.Lines.Add(certStore.LastErrorText);
    Exit;
  end;

privKey := cert.ExportPrivateKey() As CHILKATCERTIFICATELib_TLB.IPrivateKey;
if (privKey = nil ) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);

    Exit;
  end;

success := mime.Decrypt2(cert As CHILKATMIMELib_TLB.IChilkatCert,privKey);
if (success <> 1) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

//  Show the decrypted MIME:
Memo1.Lines.Add(mime.GetMime());


end;