John Davidson

Message:

Is there a simple way using OpenSSL to extract the serial number of a certificate using PHP?

I've tried converting the .pfx file to a .pem file using an openssl command, but I'm wondering if it's possible purely inside PHP.

I'm currently able to read the serial number from a .pem/.crt file, but not from a .pfx file.

Thank you for any help given

---

My Answer:
You can extract the serial number from a .pfx file using PHP by using the `openssl_pkcs12_read` function. Here's an example code snippet to achieve this:

php
$pfxFile = 'path/to/your/file.pfx';
$pfxPassword = 'password';

$certs = [];
if (openssl_pkcs12_read(file_get_contents($pfxFile), $certs, $pfxPassword)) {
$cert = $certs['cert'];
$x509 = openssl_x509_read($cert);
$certInfo = openssl_x509_parse($x509);

$serialNumber = $certInfo['serialNumber'];

echo "Serial Number: $serialNumber";
} else {
echo "Failed to read .pfx file";
}


Make sure to replace `path/to/your/file.pfx` with the actual path to your .pfx file and `password` with the password used to protect the .pfx file. This code snippet will read the .pfx file, extract the certificate information, and then retrieve the serial number from it.