Delphi DLL

DNS Query CAA Records

See more DNS Examples

Shows how to perform a DNS query to retrieve CAA records.

Note: This example requires Chilkat v9.5.0.96 or later.

Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
dns: HCkDns;
json: HCkJsonObject;
name: PWideChar;
ttl: Integer;
flags: Integer;
tag: PWideChar;
value: PWideChar;
i: Integer;
count_i: Integer;

begin
success := False;

dns := CkDns_Create();

json := CkJsonObject_Create();
CkJsonObject_putEmitCompact(json,False);

success := CkDns_Query(dns,'CAA','zoom.us',json);
if (success = False) then
  begin
    Memo1.Lines.Add(CkDns__lastErrorText(dns));
    Exit;
  end;

Memo1.Lines.Add(CkJsonObject__emit(json));

// Sample response.
// Parsing code below..

// {
//   "answer": {
//     "caa": [
//       {
//         "name": "zoom.us",
//         "ttl": 300,
//         "flags": 0,
//         "tag": "iodef",
//         "value": "mailto:security@zoom.us"
//       },
//       {
//         "name": "zoom.us",
//         "ttl": 300,
//         "flags": 0,
//         "tag": "issue",
//         "value": "amazon.com"
//       },
//       {
//         "name": "zoom.us",
//         "ttl": 300,
//         "flags": 0,
//         "tag": "issue",
//         "value": "digicert.com"
//       },
//       {
//         "name": "zoom.us",
//         "ttl": 300,
//         "flags": 0,
//         "tag": "issue",
//         "value": "godaddy.com"
//       },
//       {
//         "name": "zoom.us",
//         "ttl": 300,
//         "flags": 0,
//         "tag": "issue",
//         "value": "letsencrypt.org"
//       },
//       {
//         "name": "zoom.us",
//         "ttl": 300,
//         "flags": 0,
//         "tag": "issue",
//         "value": "pki.goog"
//       },
//       {
//         "name": "zoom.us",
//         "ttl": 300,
//         "flags": 0,
//         "tag": "issue",
//         "value": "sectigo.com"
//       }
//     ]
//   }
// }

// Use this online tool to generate parsing code from sample JSON: 
// Generate Parsing Code from JSON

i := 0;
count_i := CkJsonObject_SizeOfArray(json,'answer.caa');
while i < count_i do
  begin
    CkJsonObject_putI(json,i);
    name := CkJsonObject__stringOf(json,'answer.caa[i].name');
    ttl := CkJsonObject_IntOf(json,'answer.caa[i].ttl');
    flags := CkJsonObject_IntOf(json,'answer.caa[i].flags');
    tag := CkJsonObject__stringOf(json,'answer.caa[i].tag');
    value := CkJsonObject__stringOf(json,'answer.caa[i].value');
    i := i + 1;
  end;

CkDns_Dispose(dns);
CkJsonObject_Dispose(json);

end;