(PHP Extension) 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 PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

include("chilkat.php");
// Use "chilkat_9_5_0.php" for versions of Chilkat < 10.0.0

$certStore = new CkCertStore();

// This opens the Current User certificate store on Windows,
// On MacOS and iOS it opens the default Keychain.
$readOnly = false;
$success = $certStore->OpenCurrentUserStore($readOnly);
if ($success == false) {
    print $certStore->lastErrorText() . "\n";
    exit;
}

// Find the certificate having the specified email address in either the RFC822 Name or in the Subject.
$json = new CkJsonObject();
$email_address = 'joe@example.com';
$json->UpdateString('email',$email_address);

$cert = new CkCert();
$success = $certStore->FindCert($json,$cert);
if ($success == true) {
    // Show the full distinguished name of the certificate.
    print 'Found: ' . $cert->subjectDN() . "\n";
}
else {
    print 'Not found.' . "\n";
}


?>