Delphi DLL

Example: Mime.GetDecryptCertInfo method

Demonstrates the GetDecryptCertInfo method. Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Mime, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
mime: HCkMime;
json: HCkJsonObject;
serial: PWideChar;
issuerCN: PWideChar;
i: Integer;
count: Integer;

begin
success := False;

mime := CkMime_Create();

// 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 := CkMime_LoadMimeFile(mime,'qa_data/mime/enveloped_data.eml');
if (success = False) then
  begin
    Memo1.Lines.Add(CkMime__lastErrorText(mime));
    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 := CkJsonObject_Create();
success := CkMime_GetDecryptCertInfo(mime,json);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMime__lastErrorText(mime));
    Exit;
  end;

CkJsonObject_putEmitCompact(json,False);
Memo1.Lines.Add(CkJsonObject__emit(json));

// Sample output:

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

// Get each certificate's information like this:

i := 0;
count := CkJsonObject_SizeOfArray(json,'recipientInfo');
while i < count do
  begin
    CkJsonObject_putI(json,i);
    serial := CkJsonObject__stringOf(json,'recipientInfo[i].serial');
    issuerCN := CkJsonObject__stringOf(json,'recipientInfo[i].issuerCN');
    i := i + 1;
  end;

CkMime_Dispose(mime);
CkJsonObject_Dispose(json);

end;