(Delphi DLL) Find Certificate by Email Address

See more Cert Store Examples

Demonstrates how to find a certificate having the specified email address either within the cert's subject email, or the RFC822 name.

In an X.509 certificate, an email address can typically be located in two places:

1. RFC822 Name (Subject Alternative Name extension) -
   • The certificate may include an email address in the Subject Alternative Name (SAN) extension under the RFC822 Name field. This is a modern and preferred method because it allows for flexibility and alignment with security best practices.
   • To find it, Chilkat inspects the SAN extension in the certificate details.
2. Subject (Common Name or Email Address attribute) -
   • Older certificates may store the email address directly in the Subject field, typically under the Email Address attribute ("emailAddress") or, less commonly, the Common Name (CN).
   • This method is less preferred in modern standards but can still be encountered in legacy implementations. Chilkat also searches here for the email address.

Note: Requires Chilkat v10.1.2 or later.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
certStore: HCkCertStore;
readOnly: Boolean;
success: Boolean;
json: HCkJsonObject;
email_address: PWideChar;
cert: HCkCert;

begin
certStore := CkCertStore_Create();

// This opens the Current User certificate store on Windows,
// On MacOS and iOS it opens the default Keychain.
readOnly := False;
success := CkCertStore_OpenCurrentUserStore(certStore,readOnly);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCertStore__lastErrorText(certStore));
    Exit;
  end;

// Find the certificate having the specified email address in either the RFC822 Name or in the Subject.
json := CkJsonObject_Create();
email_address := 'joe@example.com';
CkJsonObject_UpdateString(json,'email',email_address);

cert := CkCert_Create();
success := CkCertStore_FindCert(certStore,json,cert);
if (success = True) then
  begin
    // Show the full distinguished name of the certificate.
    Memo1.Lines.Add('Found: ' + CkCert__subjectDN(cert));
  end
else
  begin
    Memo1.Lines.Add('Not found.');
  end;

CkCertStore_Dispose(certStore);
CkJsonObject_Dispose(json);
CkCert_Dispose(cert);

end;