openssl_x509_verify

(PHP 7 >= 7.4.0, PHP 8)

openssl_x509_verifyVerifies digital signature of x509 certificate against a public key

Description

openssl_x509_verify(OpenSSLCertificate|string $certificate, OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $public_key): int

openssl_x509_verify() verifies that the certificate certificate was signed by the private key corresponding to public key public_key.

Parameters

x509

See Key/Certificate parameters for a list of valid values.

public_key

OpenSSLAsymmetricKey - a key, returned by openssl_get_publickey()

string - a PEM formatted key, example, "-----BEGIN PUBLIC KEY----- MIIBCgK..."

Return Values

Returns 1 if the signature is correct, 0 if it is incorrect, and -1 on error.

Changelog

Version Description
8.0.0 certificate accepts an OpenSSLCertificate instance now; previously, a resource of type OpenSSL X.509 was accepted.
8.0.0 public_key accepts an OpenSSLAsymmetricKey or OpenSSLCertificate instance now; previously, a resource of type OpenSSL key or OpenSSL X.509 was accepted.

Examples

Example #1 openssl_x509_verify() example

<?php
$hostname 
"news.php.net";
$ssloptions = array(
    
"capture_peer_cert" => true
    
"capture_peer_cert_chain" => true
    
"allow_self_signed"=> false
    
"CN_match" => $hostname,
    
"verify_peer" => true,
    
"SNI_enabled" => true,
    
"SNI_server_name" => $hostname,
);
 
$ctx stream_context_create( array("ssl" => $ssloptions) );
$result stream_socket_client("ssl://$hostname:443"$errno$errstr30STREAM_CLIENT_CONNECT$ctx);
$cont stream_context_get_params($result);
$x509 $cont["options"]["ssl"]["peer_certificate"];
$certparsed openssl_x509_parse($x509);

foreach(
$cont["options"]["ssl"]["peer_certificate_chain"] as $chaincert)
{
    
$chainparsed openssl_x509_parse($chaincert);
    
$chain_public_key openssl_get_publickey($chaincert);
    
$r openssl_x509_verify($x509$chain_public_key);   
    if (
$r==1)
    {
        echo 
$certparsed['subject']['CN'];
        echo 
" was digitally signed by ";
        echo 
$chainparsed['subject']['CN']."\n";
    }
}
?>

See Also