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 (e.g. -----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, $errstr, 30, STREAM_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";
}
}
?>

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