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.
Parameters
$host
string|WpOrgRequestsStringablerequired- Host name to verify against
$cert
arrayrequired- Certificate data from openssl_x509_parse()
Source
public static function verify_certificate($host, $cert) {
if (InputValidator::is_string_or_stringable($host) === false) {
throw InvalidArgument::create(1, '$host', 'string|Stringable', gettype($host));
}
if (InputValidator::has_array_access($cert) === false) {
throw InvalidArgument::create(2, '$cert', 'array|ArrayAccess', gettype($cert));
}
$has_dns_alt = false;
// Check the subjectAltName
if (!empty($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, $altname) === true) {
return true;
}
}
if ($has_dns_alt === true) {
return false;
}
}
// Fall back to checking the common name if we didn't get any dNSName
// alt names, as per RFC2818
if (!empty($cert['subject']['CN'])) {
// Check for a match
return (self::match_domain($host, $cert['subject']['CN']) === true);
}
return false;
}
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