openssl_verify

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

openssl_verifyVerify signature

Description

openssl_verify(
    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 (e.g. -----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 ($ok == 0) {    echo "bad";} else {    echo "ugly, error checking signature";}// free the key from memoryopenssl_free_key($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 signatureopenssl_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();}?>

See Also