PHP利用Socket获取网站的SSL证书与公钥

yskl

            通过 php curl 请求网页并不能获取到证书信息，此时需要使用 ssl socket 获取证书内容。下面来一起看看看详细的介绍：
示例代码：
// 创建 stream context
$context = stream_context_create([
'ssl' => [
  'capture_peer_cert' => true,
  'capture_peer_cert_chain' => true,
],
]);

$resource = stream_socket_client("ssl://$domainport", $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $context);
$cert = stream_context_get_params($resource);

$ssl = $cert['options']['ssl'];
$resource = $ssl['peer_certificate'];

// 网站证书中只有公钥，通过 openssl_pkey_get_details 导出公钥

$ret = [
'crt' => '',
'pub' => '',
];

$pkey = openssl_pkey_get_public($resource);
$ret['pub'] = openssl_pkey_get_details($pkey)['key'];

openssl_x509_export($resource, $pem);
$ret['crt'] = $pem;

foreach ($ssl['peer_certificate_chain'] as $resource)
{
openssl_x509_export($resource, $pem);
$ret['crt'] .= "\n" . $pem;
}

// 保存 $ret['crt'] 为 domain.crt
// 保存 $ret['pub'] 为 domain.pub

return $ret;