private function rsa($public_or_private_key, $padding_mode)
{
if ($public_or_private_key instanceof JOSE_JWK) {
$rsa = $public_or_private_key->toKey();
} else {
if ($public_or_private_key instanceof RSA) {
$rsa = $public_or_private_key;
} else {
$rsa = new RSA();
$rsa->loadKey($public_or_private_key);
}
}
$rsa->setHash($this->digest());
$rsa->setMGFHash($this->digest());
$rsa->setSignatureMode($padding_mode);
return $rsa;
}
private function rsa($public_or_private_key, $padding_mode)
{
if ($public_or_private_key instanceof JOSE_JWK) {
$rsa = $public_or_private_key->toKey();
} else {
if ($public_or_private_key instanceof RSA) {
$rsa = $public_or_private_key;
} else {
$rsa = new RSA();
$rsa->loadKey($public_or_private_key);
}
}
$rsa->setHash($this->digest());
$rsa->setMGFHash($this->digest());
$rsa->setSaltLength(false);
# NOTE: https://github.com/phpseclib/phpseclib/issues/768
$rsa->setSignatureMode($padding_mode);
return $rsa;
}
/**
* Verifies the signature for the specified path.
*
* @param string $signaturePath
* @param string $basePath
* @param string $certificateCN
* @return array
* @throws InvalidSignatureException
* @throws \Exception
*/
private function verify($signaturePath, $basePath, $certificateCN)
{
if (!$this->isCodeCheckEnforced()) {
return [];
}
$signatureData = json_decode($this->fileAccessHelper->file_get_contents($signaturePath), true);
if (!is_array($signatureData)) {
throw new InvalidSignatureException('Signature data not found.');
}
$expectedHashes = $signatureData['hashes'];
ksort($expectedHashes);
$signature = base64_decode($signatureData['signature']);
$certificate = $signatureData['certificate'];
// Check if certificate is signed by ownCloud Root Authority
$x509 = new \phpseclib\File\X509();
$rootCertificatePublicKey = $this->fileAccessHelper->file_get_contents($this->environmentHelper->getServerRoot() . '/resources/codesigning/root.crt');
$x509->loadCA($rootCertificatePublicKey);
$x509->loadX509($certificate);
if (!$x509->validateSignature()) {
throw new InvalidSignatureException('Certificate is not valid.');
}
// Verify if certificate has proper CN. "core" CN is always trusted.
if ($x509->getDN(X509::DN_OPENSSL)['CN'] !== $certificateCN && $x509->getDN(X509::DN_OPENSSL)['CN'] !== 'core') {
throw new InvalidSignatureException(sprintf('Certificate is not valid for required scope. (Requested: %s, current: %s)', $certificateCN, $x509->getDN(true)));
}
// Check if the signature of the files is valid
$rsa = new \phpseclib\Crypt\RSA();
$rsa->loadKey($x509->currentCert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey']);
$rsa->setSignatureMode(RSA::SIGNATURE_PSS);
$rsa->setMGFHash('sha512');
if (!$rsa->verify(json_encode($expectedHashes), $signature)) {
throw new InvalidSignatureException('Signature could not get verified.');
}
// Compare the list of files which are not identical
$currentInstanceHashes = $this->generateHashes($this->getFolderIterator($basePath), $basePath);
$differencesA = array_diff($expectedHashes, $currentInstanceHashes);
$differencesB = array_diff($currentInstanceHashes, $expectedHashes);
$differences = array_unique(array_merge($differencesA, $differencesB));
$differenceArray = [];
foreach ($differences as $filename => $hash) {
// Check if file should not exist in the new signature table
if (!array_key_exists($filename, $expectedHashes)) {
$differenceArray['EXTRA_FILE'][$filename]['expected'] = '';
$differenceArray['EXTRA_FILE'][$filename]['current'] = $hash;
continue;
}
// Check if file is missing
if (!array_key_exists($filename, $currentInstanceHashes)) {
$differenceArray['FILE_MISSING'][$filename]['expected'] = $expectedHashes[$filename];
$differenceArray['FILE_MISSING'][$filename]['current'] = '';
continue;
}
// Check if hash does mismatch
if ($expectedHashes[$filename] !== $currentInstanceHashes[$filename]) {
$differenceArray['INVALID_HASH'][$filename]['expected'] = $expectedHashes[$filename];
$differenceArray['INVALID_HASH'][$filename]['current'] = $currentInstanceHashes[$filename];
continue;
}
// Should never happen.
throw new \Exception('Invalid behaviour in file hash comparison experienced. Please report this error to the developers.');
}
return $differenceArray;
}
/**
* Creates the signature data
*
* @param array $hashes
* @param X509 $certificate
* @param RSA $privateKey
* @return string
*/
private function createSignatureData(array $hashes, X509 $certificate, RSA $privateKey)
{
ksort($hashes);
$privateKey->setSignatureMode(RSA::SIGNATURE_PSS);
$privateKey->setMGFHash('sha512');
$signature = $privateKey->sign(json_encode($hashes));
return ['hashes' => $hashes, 'signature' => base64_encode($signature), 'certificate' => $certificate->saveX509($certificate->currentCert)];
}
/**
* Decrypt with RSAES-OAEP + MGF1+SHA256
*
* @param string $ciphertext
* @param PrivateKey $rsaPrivateKey
* @return string
* @throws InvalidCiphertextException
*/
protected static function rsaDecrypt($ciphertext, PrivateKey $rsaPrivateKey)
{
static $rsa = null;
if (!$rsa) {
$rsa = new RSA();
$rsa->setEncryptionMode(RSA::ENCRYPTION_OAEP);
$rsa->setMGFHash('sha256');
}
$rsa->loadKey($rsaPrivateKey->getKey());
$return = @$rsa->decrypt($ciphertext);
if ($return === false) {
throw new InvalidCiphertextException('Decryption failed');
}
return $return;
}