# openssl_verify

(PHP 4 >= 4.0.4, PHP 5)

openssl_verify — Verify signature

### Description

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

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.

### Parameters

`data`

`signature`

`pub_key_id`

`signature_alg`

  Defaults to `OPENSSL_ALGO_SHA1`. For more information see the list of Signature Algorithms.

### Return Values

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

### ChangeLog

Version | Description
--- | ---
5.0.0 | The `signature_alg` parameter was added.

### Examples

Example#1 openssl_verify() example

`<?php
// $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);
fclose($fp);
$pubkeyid = openssl_get_publickey($cert);
// state whether signature is okay or not
$ok = openssl_verify($data, $signature, $pubkeyid);
if ($ok == 1) {
echo "good";
} elseif ($ok == 0) {
echo "bad";
} else {
echo "ugly, error checking signature";
}
// free the key from memory
openssl_free_key($pubkeyid);
?>`

### See Also

- openssl_sign()