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(PHP 4 >= 4.0.4, PHP 5)
openssl_verify — Verify signature
$data
, string $signature
, mixed $pub_key_id
[, mixed $signature_alg
= OPENSSL_ALGO_SHA1
] )
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.
data
The string of data used to generate the signature previously
signature
A raw binary string, generated by openssl_sign() or similar means
pub_key_id
resource - a key, returned by openssl_get_publickey()
string - a PEM formatted key, example, "-----BEGIN PUBLIC KEY----- MIIBCgK..."
signature_alg
int - one of these Signature Algorithms.
string - a valid string returned by openssl_get_md_methods() example, "sha1WithRSAEncryption" or "sha512".
Returns 1 if the signature is correct, 0 if it is incorrect, and -1 on error.
Version | Description |
---|---|
5.2.0 |
The signature_alg parameter was added.
|
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, "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();
}
?>