(Delphi ActiveX) Example: Mime.GetDecryptCertInfo method

Demonstrates the GetDecryptCertInfo method.

Note: This example requires Chilkat v11.4.0 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;
mime: TChilkatMime;
json: TChilkatJsonObject;
serial: WideString;
issuerCN: WideString;
i: Integer;
count: Integer;

begin
success := 0;

mime := TChilkatMime.Create(Self);

// Load MIME that is has Content-Type like this:
// Content-Type: application/pkcs7-mime; smime-type="enveloped-data"; name="smime.p7m"; smime-type="enveloped-data"
success := mime.LoadMimeFile('qa_data/mime/enveloped_data.eml');
if (success = 0) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

// Get information about the certificate that would be needed to decrypt.
// An enveloped-data can potentially be decrypted by multiple certificates if it was encrypted in a way that allows it,
// but in most cases, only a single certificate with associated private key (that of the message recipient) is possible.
json := TChilkatJsonObject.Create(Self);
success := mime.GetDecryptCertInfo(json.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

json.EmitCompact := 0;
Memo1.Lines.Add(json.Emit());

// Sample output:

// {
//   "recipientInfo": [
//     {
//       "serial": "****",
//       "issuerCN": "****"
//     }
//   ]
// }

// Get each certificate's information like this:

i := 0;
count := json.SizeOfArray('recipientInfo');
while i < count do
  begin
    json.I := i;
    serial := json.StringOf('recipientInfo[i].serial');
    issuerCN := json.StringOf('recipientInfo[i].issuerCN');
    i := i + 1;
  end;
end;