Technical FAQ
PHP Manual
CSS2 Manual
HTML Manual
JS Guide
JS Reference
PhpDock Manual
Nu-Coder Manual
PhpExpress Manual
PHP Joomla
Learn PHP
Last updated: Tue, 19 Sep 2006


(PHP 4 >= 4.0.4, PHP 5)

openssl_verify -- Verify signature


int openssl_verify ( string data, string signature, mixed pub_key_id [, int signature_alg] )

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

openssl_verify() verifies that the signature is correct for the specified data using the public key associated with pub_key_id. This must be the public key corresponding to the private key used for signing.

Note: Optional 4th parameter signature_alg was added in version 5.2.0. Its default value is OPENSSL_ALGO_SHA1. For more information see the list of Signature Algorithms.

Example 1. openssl_verify() example

// $data and $signature are assumed to contain the data and the signature

// fetch public key from certificate and ready it
$fp = fopen("/src/openssl-0.9.6/demos/sign/cert.pem", "r");
$cert = fread($fp, 8192);
$pubkeyid = openssl_get_publickey($cert);

// state whether signature is okay or not
$ok = openssl_verify($data, $signature, $pubkeyid);
if ($ok == 1) {
    echo "good";
} elseif ($ok == 0) {
    echo "bad";
} else {
    echo "ugly, error checking signature";
// free the key from memory

See also openssl_sign().

Last updated: Tue, 19 Sep 2006