Requests_SSL::verify_certificate( string $host, array $cert )
Verify the certificate against common name and subject alternative names
Description
Unfortunately, PHP doesn’t check the certificate against the alternative names, leading things like ‘https://www.github.com/‘ to be invalid. Instead
See also
https://tools.ietf.org/html/rfc2818#section-3.1: RFC2818, Section 3.1
Parameters
- $host
-
(Required) Host name to verify against
- $cert
-
(Required) Certificate data from openssl_x509_parse()
Return
(bool)
Source
File: wp-includes/Requests/SSL.php
public static function verify_certificate($host, $cert) {
// Calculate the valid wildcard match if the host is not an IP address
$parts = explode('.', $host);
if (ip2long($host) === false) {
$parts[0] = '*';
}
$wildcard = implode('.', $parts);
$has_dns_alt = false;
// Check the subjectAltName
if (!empty($cert['extensions']) && !empty($cert['extensions']['subjectAltName'])) {
$altnames = explode(',', $cert['extensions']['subjectAltName']);
foreach ($altnames as $altname) {
$altname = trim($altname);
if (strpos($altname, 'DNS:') !== 0) {
continue;
}
$has_dns_alt = true;
// Strip the 'DNS:' prefix and trim whitespace
$altname = trim(substr($altname, 4));
// Check for a match
if (self::match_domain($host, $altname) === true) {
return true;
}
}
}
// Fall back to checking the common name if we didn't get any dNSName
// alt names, as per RFC2818
if (!$has_dns_alt && !empty($cert['subject']['CN'])) {
// Check for a match
if (self::match_domain($host, $cert['subject']['CN']) === true) {
return true;
}
}
return false;
}