openssl_verify
(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
openssl_verify — Verify signature
Description
string
$data,string
$signature,OpenSSLAsymmetricKey|OpenSSLCertificate|array|string
$public_key,string|int
$algorithm = OPENSSL_ALGO_SHA1): int|false
openssl_verify() verifies that the
signature is correct for the specified
data using the public key associated with
public_key. This must be the public key
corresponding to the private key used for signing.
Parameters
-
data -
The string of data used to generate the signature previously
-
signature -
A raw binary string, generated by openssl_sign() or similar means
-
public_key -
OpenSSLAsymmetricKey - a key, returned by openssl_get_publickey()
string - a PEM formatted key, example, "-----BEGIN PUBLIC KEY----- MIIBCgK..."
-
algorithm -
int - one of these Signature Algorithms.
string - a valid string returned by openssl_get_md_methods() example, "sha1WithRSAEncryption" or "sha512".
Return Values
Returns 1 if the signature is correct, 0 if it is incorrect, and
-1 or false on error.
Changelog
| Version | Description |
|---|---|
| 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_verify() example
<?php
// $data and $signature are assumed to contain the data and the signature
// fetch public key from certificate and ready it
$pubkeyid = openssl_pkey_get_public("file://src/openssl-0.9.6/demos/sign/cert.pem");
// 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);
?>
Example #2 openssl_verify() example
<?php
//data you want to sign
$data = 'my data';
//create new private and public key
$private_key_res = openssl_pkey_new(array(
"private_key_bits" => 2048,
"private_key_type" => OPENSSL_KEYTYPE_RSA,
));
$details = openssl_pkey_get_details($private_key_res);
$public_key_res = openssl_pkey_get_public($details['key']);
//create signature
openssl_sign($data, $signature, $private_key_res, "sha256WithRSAEncryption");
//verify signature
$ok = openssl_verify($data, $signature, $public_key_res, OPENSSL_ALGO_SHA256);
if ($ok == 1) {
echo "valid";
} elseif ($ok == 0) {
echo "invalid";
} else {
echo "error: ".openssl_error_string();
}
?>
