OPENSSL_VERIFY(3) 1 OPENSSL_VERIFY(3)
openssl_verify - Verify signature
SYNOPSIS
int openssl_verify (string $data, string $signature, mixed $pub_key_id, [mixed $signature_alg = OPENSSL_ALGO_SHA1])
DESCRIPTION
openssl_verify(3) 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
o $data
- The string of data used to generate the signature previously
o $signature
- A raw binary string, generated by openssl_sign(3) or similar means
o $pub_key_id
- resource - a key, returned by openssl_get_publickey(3) string - a PEM formatted key, example, "-----BEGIN PUBLIC KEY-----
MIIBCgK..."
o $signature_alg
- int - one of these Signature Algorithms. string - a valid string returned by openssl_get_md_methods(3) example, "sha1WithRSAEn-
cryption" or "sha512".
RETURN VALUES
Returns 1 if the signature is correct, 0 if it is incorrect, and -1 on error.
CHANGELOG
+--------+------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+------------------------------------------+
| 5.2.0 | |
| | |
| | The $signature_alg parameter was added. |
| | |
+--------+------------------------------------------+
EXAMPLES
Example #1
openssl_verify(3) 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(3) 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, "sha1WithRSAEncryption");
//verify signature
$ok = openssl_verify($data, $signature, $public_key_res, OPENSSL_ALGO_SHA1);
if ($ok == 1) {
echo "valid";
} elseif ($ok == 0) {
echo "invalid";
} else {
echo "error: ".openssl_error_string();
}
?>
SEE ALSO
openssl_sign(3).
PHP Documentation Group OPENSSL_VERIFY(3)