Developer
<?php
declare(strict_types=1);
namespace Lcobucci\JWT\Signer;
use Lcobucci\JWT\Signer;
use OpenSSLAsymmetricKey;
use function array_key_exists;
use function assert;
use function is_array;
use function is_bool;
use function is_string;
use function openssl_error_string;
use function openssl_free_key;
use function openssl_pkey_get_details;
use function openssl_pkey_get_private;
use function openssl_pkey_get_public;
use function openssl_sign;
use function openssl_verify;
abstract class OpenSSL implements Signer
{
/**
* @throws CannotSignPayload
* @throws InvalidKeyProvided
*/
final protected function createSignature(
string $pem,
string $passphrase,
string $payload
): string {
$key = $this->getPrivateKey($pem, $passphrase);
try {
$signature = '';
if (! openssl_sign($payload, $signature, $key, $this->algorithm())) {
$error = openssl_error_string();
assert(is_string($error));
throw CannotSignPayload::errorHappened($error);
}
return $signature;
} finally {
$this->freeKey($key);
}
}
/**
* @return resource|OpenSSLAsymmetricKey
*
* @throws CannotSignPayload
*/
private function getPrivateKey(string $pem, string $passphrase)
{
$privateKey = openssl_pkey_get_private($pem, $passphrase);
$this->validateKey($privateKey);
return $privateKey;
}
/** @throws InvalidKeyProvided */
final protected function verifySignature(
string $expected,
string $payload,
string $pem
): bool {
$key = $this->getPublicKey($pem);
$result = openssl_verify($payload, $expected, $key, $this->algorithm());
$this->freeKey($key);
return $result === 1;
}
/**
* @return resource|OpenSSLAsymmetricKey
*
* @throws InvalidKeyProvided
*/
private function getPublicKey(string $pem)
{
$publicKey = openssl_pkey_get_public($pem);
$this->validateKey($publicKey);
return $publicKey;
}
/**
* Raises an exception when the key type is not the expected type
*
* @param resource|OpenSSLAsymmetricKey|bool $key
*
* @throws InvalidKeyProvided
*/
private function validateKey($key): void
{
if (is_bool($key)) {
$error = openssl_error_string();
assert(is_string($error));
throw InvalidKeyProvided::cannotBeParsed($error);
}
$details = openssl_pkey_get_details($key);
assert(is_array($details));
if (! array_key_exists('key', $details) || $details['type'] !== $this->keyType()) {
throw InvalidKeyProvided::incompatibleKey();
}
}
/** @param resource|OpenSSLAsymmetricKey $key */
private function freeKey($key): void
{
if ($key instanceof OpenSSLAsymmetricKey) {
return;
}
openssl_free_key($key); // Deprecated and no longer necessary as of PHP >= 8.0
}
/**
* Returns the type of key to be used to create/verify the signature (using OpenSSL constants)
*
* @internal
*/
abstract public function keyType(): int;
/**
* Returns which algorithm to be used to create/verify the signature (using OpenSSL constants)
*
* @internal
*/
abstract public function algorithm(): int;
}
Developer
To ensure a smooth integration process and optimal performance, follow these best practices: