<?php
declare(strict_types=1);
/*
* The MIT License (MIT)
*
* Copyright (c) 2014-2020 Spomky-Labs
*
* This software may be modified and distributed under the terms
* of the MIT license. See the LICENSE file for details.
*/
namespace Jose\Component\KeyManagement\KeyConverter;
use function array_key_exists;
use Base64Url\Base64Url;
use function count;
use function extension_loaded;
use InvalidArgumentException;
use function is_array;
use function is_string;
use RuntimeException;
use Throwable;
/**
* @internal
*/
class KeyConverter
{
/**
* @throws InvalidArgumentException if the certificate file cannot be read
*/
public static function loadKeyFromCertificateFile(string $file): array
{
if (!file_exists($file)) {
throw new InvalidArgumentException(sprintf('File "%s" does not exist.', $file));
}
$content = file_get_contents($file);
if (!is_string($content)) {
throw new InvalidArgumentException(sprintf('File "%s" cannot be read.', $file));
}
return self::loadKeyFromCertificate($content);
}
/**
* @throws InvalidArgumentException if the OpenSSL extension is not available
* @throws InvalidArgumentException if the certificate is invalid or cannot be loaded
*/
public static function loadKeyFromCertificate(string $certificate): array
{
if (!extension_loaded('openssl')) {
throw new RuntimeException('Please install the OpenSSL extension');
}
try {
$res = openssl_x509_read($certificate);
if (false === $res) {
throw new InvalidArgumentException('Unable to load the certificate.');
}
} catch (Throwable $e) {
$certificate = self::convertDerToPem($certificate);
$res = openssl_x509_read($certificate);
}
if (false === $res) {
throw new InvalidArgumentException('Unable to load the certificate.');
}
return self::loadKeyFromX509Resource($res);
}
/**
* @param resource $res
*
* @throws InvalidArgumentException if the OpenSSL extension is not available
* @throws InvalidArgumentException if the certificate is invalid or cannot be loaded
*/
public static function loadKeyFromX509Resource($res): array
{
if (!extension_loaded('openssl')) {
throw new RuntimeException('Please install the OpenSSL extension');
}
$key = openssl_get_publickey($res);
if (false === $key) {
throw new InvalidArgumentException('Unable to load the certificate.');
}
$details = openssl_pkey_get_details($key);
if (!is_array($details)) {
throw new InvalidArgumentException('Unable to load the certificate');
}
if (isset($details['key'])) {
$values = self::loadKeyFromPEM($details['key']);
openssl_x509_export($res, $out);
$x5c = preg_replace('#-.*-#', '', $out);
$x5c = preg_replace('~\R~', PHP_EOL, $x5c);
if (!is_string($x5c)) {
throw new InvalidArgumentException('Unable to load the certificate');
}
$x5c = trim($x5c);
$x5tsha1 = openssl_x509_fingerprint($res, 'sha1', true);
$x5tsha256 = openssl_x509_fingerprint($res, 'sha256', true);
if (!is_string($x5tsha1) || !is_string($x5tsha256)) {
throw new InvalidArgumentException('Unable to compute the certificate fingerprint');
}
$values['x5c'] = [$x5c];
$values['x5t'] = Base64Url::encode($x5tsha1);
$values['x5t#256'] = Base64Url::encode($x5tsha256);
return $values;
}
throw new InvalidArgumentException('Unable to load the certificate');
}
public static function loadFromKeyFile(string $file, ?string $password = null): array
{
$content = file_get_contents($file);
if (!is_string($content)) {
throw new InvalidArgumentException('Unable to load the key from the file.');
}
return self::loadFromKey($content, $password);
}
public static function loadFromKey(string $key, ?string $password = null): array
{
try {
return self::loadKeyFromDER($key, $password);
} catch (Throwable $e) {
return self::loadKeyFromPEM($key, $password);
}
}
/**
* Be careful! The certificate chain is loaded, but it is NOT VERIFIED by any mean!
* It is mandatory to verify the root CA or intermediate CA are trusted.
* If not done, it may lead to potential security issues.
*
* @throws InvalidArgumentException if the certificate chain is empty
* @throws InvalidArgumentException if the OpenSSL extension is not available
*/
public static function loadFromX5C(array $x5c): array
{
if (0 === count($x5c)) {
throw new InvalidArgumentException('The certificate chain is empty');
}
foreach ($x5c as $id => $cert) {
$x5c[$id] = '-----BEGIN CERTIFICATE-----'.PHP_EOL.chunk_split($cert, 64, PHP_EOL).'-----END CERTIFICATE-----';
$x509 = openssl_x509_read($x5c[$id]);
if (false === $x509) {
throw new InvalidArgumentException('Unable to load the certificate chain');
}
$parsed = openssl_x509_parse($x509);
if (false === $parsed) {
throw new InvalidArgumentException('Unable to load the certificate chain');
}
}
return self::loadKeyFromCertificate(reset($x5c));
}
private static function loadKeyFromDER(string $der, ?string $password = null): array
{
$pem = self::convertDerToPem($der);
return self::loadKeyFromPEM($pem, $password);
}
/**
* @throws InvalidArgumentException if the OpenSSL extension is not available
* @throws InvalidArgumentException if the key cannot be loaded
*/
private static function loadKeyFromPEM(string $pem, ?string $password = null): array
{
if (1 === preg_match('#DEK-Info: (.+),(.+)#', $pem, $matches)) {
$pem = self::decodePem($pem, $matches, $password);
}
if (!extension_loaded('openssl')) {
throw new RuntimeException('Please install the OpenSSL extension');
}
self::sanitizePEM($pem);
$res = openssl_pkey_get_private($pem);
if (false === $res) {
$res = openssl_pkey_get_public($pem);
}
if (false === $res) {
throw new InvalidArgumentException('Unable to load the key.');
}
$details = openssl_pkey_get_details($res);
if (!is_array($details) || !array_key_exists('type', $details)) {
throw new InvalidArgumentException('Unable to get details of the key');
}
switch ($details['type']) {
case OPENSSL_KEYTYPE_EC:
$ec_key = ECKey::createFromPEM($pem);
return $ec_key->toArray();
case OPENSSL_KEYTYPE_RSA:
$rsa_key = RSAKey::createFromPEM($pem);
return $rsa_key->toArray();
default:
throw new InvalidArgumentException('Unsupported key type');
}
}
/**
* This method modifies the PEM to get 64 char lines and fix bug with old OpenSSL versions.
*/
private static function sanitizePEM(string &$pem): void
{
preg_match_all('#(-.*-)#', $pem, $matches, PREG_PATTERN_ORDER);
$ciphertext = preg_replace('#-.*-|\r|\n| #', '', $pem);
$pem = $matches[0][0].PHP_EOL;
$pem .= chunk_split($ciphertext, 64, PHP_EOL);
$pem .= $matches[0][1].PHP_EOL;
}
/**
* @param string[] $matches
*
* @throws InvalidArgumentException if the password to decrypt the key is not provided
* @throws InvalidArgumentException if the key cannot be loaded
*/
private static function decodePem(string $pem, array $matches, ?string $password = null): string
{
if (null === $password) {
throw new InvalidArgumentException('Password required for encrypted keys.');
}
$iv = pack('H*', trim($matches[2]));
$iv_sub = mb_substr($iv, 0, 8, '8bit');
$symkey = pack('H*', md5($password.$iv_sub));
$symkey .= pack('H*', md5($symkey.$password.$iv_sub));
$key = preg_replace('#^(?:Proc-Type|DEK-Info): .*#m', '', $pem);
$ciphertext = base64_decode(preg_replace('#-.*-|\r|\n#', '', $key), true);
if (!is_string($ciphertext)) {
throw new InvalidArgumentException('Unable to encode the data.');
}
$decoded = openssl_decrypt($ciphertext, mb_strtolower($matches[1]), $symkey, OPENSSL_RAW_DATA, $iv);
if (false === $decoded) {
throw new RuntimeException('Unable to decrypt the key');
}
$number = preg_match_all('#-{5}.*-{5}#', $pem, $result);
if (2 !== $number) {
throw new InvalidArgumentException('Unable to load the key');
}
$pem = $result[0][0].PHP_EOL;
$pem .= chunk_split(base64_encode($decoded), 64);
$pem .= $result[0][1].PHP_EOL;
return $pem;
}
private static function convertDerToPem(string $der_data): string
{
$pem = chunk_split(base64_encode($der_data), 64, PHP_EOL);
return '-----BEGIN CERTIFICATE-----'.PHP_EOL.$pem.'-----END CERTIFICATE-----'.PHP_EOL;
}
}