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-rw-r--r--apps/encryption/lib/crypto/Encryption.php116
-rw-r--r--apps/encryption/lib/crypto/crypt.php355
2 files changed, 471 insertions, 0 deletions
diff --git a/apps/encryption/lib/crypto/Encryption.php b/apps/encryption/lib/crypto/Encryption.php
new file mode 100644
index 00000000000..123581b83ac
--- /dev/null
+++ b/apps/encryption/lib/crypto/Encryption.php
@@ -0,0 +1,116 @@
+<?php
+ /**
+ * @author Clark Tomlinson <fallen013@gmail.com>
+ * @since 3/6/15, 2:28 PM
+ * @link http:/www.clarkt.com
+ * @copyright Clark Tomlinson © 2015
+ *
+ */
+
+namespace OCA\Encryption\Crypto;
+
+
+use OCP\Encryption\IEncryptionModule;
+
+class Encryption extends Crypt implements IEncryptionModule {
+
+ /**
+ * @return string defining the technical unique id
+ */
+ public function getId() {
+ // TODO: Implement getId() method.
+ }
+
+ /**
+ * In comparison to getKey() this function returns a human readable (maybe translated) name
+ *
+ * @return string
+ */
+ public function getDisplayName() {
+ // TODO: Implement getDisplayName() method.
+ }
+
+ /**
+ * start receiving chunks from a file. This is the place where you can
+ * perform some initial step before starting encrypting/decrypting the
+ * chunks
+ *
+ * @param string $path to the file
+ * @param array $header contains the header data read from the file
+ * @param array $accessList who has access to the file contains the key 'users' and 'public'
+ *
+ * $return array $header contain data as key-value pairs which should be
+ * written to the header, in case of a write operation
+ * or if no additional data is needed return a empty array
+ */
+ public function begin($path, $header, $accessList) {
+ // TODO: Implement begin() method.
+ }
+
+ /**
+ * last chunk received. This is the place where you can perform some final
+ * operation and return some remaining data if something is left in your
+ * buffer.
+ *
+ * @param string $path to the file
+ * @return string remained data which should be written to the file in case
+ * of a write operation
+ */
+ public function end($path) {
+ // TODO: Implement end() method.
+ }
+
+ /**
+ * encrypt data
+ *
+ * @param string $data you want to encrypt
+ * @return mixed encrypted data
+ */
+ public function encrypt($data) {
+ // Todo: xxx Update Signature and usages
+ $this->symmetricEncryptFileContent($data);
+ }
+
+ /**
+ * decrypt data
+ *
+ * @param string $data you want to decrypt
+ * @param string $user decrypt as user (null for public access)
+ * @return mixed decrypted data
+ */
+ public function decrypt($data, $user) {
+ // Todo: xxx Update Usages?
+ $this->symmetricDecryptFileContent($data, $user);
+ }
+
+ /**
+ * update encrypted file, e.g. give additional users access to the file
+ *
+ * @param string $path path to the file which should be updated
+ * @param array $accessList who has access to the file contains the key 'users' and 'public'
+ * @return boolean
+ */
+ public function update($path, $accessList) {
+ // TODO: Implement update() method.
+ }
+
+ /**
+ * should the file be encrypted or not
+ *
+ * @param string $path
+ * @return boolean
+ */
+ public function shouldEncrypt($path) {
+ // TODO: Implement shouldEncrypt() method.
+ }
+
+ /**
+ * calculate unencrypted size
+ *
+ * @param string $path to file
+ * @return integer unencrypted size
+ */
+ public function calculateUnencryptedSize($path) {
+ // TODO: Implement calculateUnencryptedSize() method.
+ }
+}
diff --git a/apps/encryption/lib/crypto/crypt.php b/apps/encryption/lib/crypto/crypt.php
new file mode 100644
index 00000000000..8018f11a370
--- /dev/null
+++ b/apps/encryption/lib/crypto/crypt.php
@@ -0,0 +1,355 @@
+<?php
+/**
+ * @author Clark Tomlinson <clark@owncloud.com>
+ * @since 2/19/15, 1:42 PM
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Encryption\Crypto;
+
+
+use OC\Encryption\Exceptions\DecryptionFailedException;
+use OC\Encryption\Exceptions\EncryptionFailedException;
+use OC\Encryption\Exceptions\GenericEncryptionException;
+use OCP\IConfig;
+use OCP\ILogger;
+use OCP\IUser;
+use OCP\IUserSession;
+
+class Crypt {
+
+ const ENCRYPTION_UKNOWN_ERROR = -1;
+ const ENCRYPTION_NOT_INIALIZED_ERROR = 1;
+ const ENCRYPTIION_PRIVATE_KEY_NOT_VALID_ERROR = 2;
+ const ENCRYPTION_NO_SHARE_KEY_FOUND = 3;
+
+ const BLOCKSIZE = 8192;
+ const DEFAULT_CIPHER = 'AES-256-CFB';
+
+ const HEADERSTART = 'HBEGIN';
+ const HEADEREND = 'HEND';
+ /**
+ * @var ILogger
+ */
+ private $logger;
+ /**
+ * @var IUser
+ */
+ private $user;
+ /**
+ * @var IConfig
+ */
+ private $config;
+
+ /**
+ * @param ILogger $logger
+ * @param IUserSession $userSession
+ * @param IConfig $config
+ */
+ public function __construct(ILogger $logger, IUserSession $userSession, IConfig $config) {
+ $this->logger = $logger;
+ $this->user = $userSession && $userSession->isLoggedIn() ? $userSession->getUser() : false;
+ $this->config = $config;
+ }
+
+ /**
+ * @param null $user
+ * @return string
+ */
+ public function mode($user = null) {
+ return 'server';
+ }
+
+ /**
+ *
+ */
+ public function createKeyPair() {
+
+ $log = $this->logger;
+ $res = $this->getOpenSSLPKey();
+
+ if (!$res) {
+ $log->error("Encryption Library could'nt generate users key-pair for {$this->user->getUID()}", ['app' => 'encryption']);
+
+ if (openssl_error_string()) {
+ $log->error('Encryption library openssl_pkey_new() fails: ' . openssl_error_string(), ['app' => 'encryption']);
+ }
+ } elseif (openssl_pkey_export($res, $privateKey, null, $this->getOpenSSLConfig())) {
+ $keyDetails = openssl_pkey_get_details($res);
+ $publicKey = $keyDetails['key'];
+
+ return [
+ 'publicKey' => $publicKey,
+ 'privateKey' => $privateKey
+ ];
+ }
+ $log->error('Encryption library couldn\'t export users private key, please check your servers openSSL configuration.' . $user->getUID(), ['app' => 'encryption']);
+ if (openssl_error_string()) {
+ $log->error('Encryption Library:' . openssl_error_string(), ['app' => 'encryption']);
+ }
+
+ return false;
+ }
+
+ /**
+ * @return resource
+ */
+ public function getOpenSSLPKey() {
+ $config = $this->getOpenSSLConfig();
+ return openssl_pkey_new($config);
+ }
+
+ /**
+ * @return array
+ */
+ private function getOpenSSLConfig() {
+ $config = ['private_key_bits' => 4096];
+ $config = array_merge(\OC::$server->getConfig()->getSystemValue('openssl', []), $config);
+ return $config;
+ }
+
+ /**
+ * @param $plainContent
+ * @param $passphrase
+ * @return bool|string
+ * @throws GenericEncryptionException
+ */
+ public function symmetricEncryptFileContent($plainContent, $passphrase) {
+
+ if (!$plainContent) {
+ $this->logger->error('Encryption Library, symmetrical encryption failed no content given', ['app' => 'encryption']);
+ return false;
+ }
+
+ $iv = $this->generateIv();
+
+ try {
+ $encryptedContent = $this->encrypt($plainContent, $iv, $passphrase, $this->getCipher());
+ // combine content to encrypt the IV identifier and actual IV
+ $catFile = $this->concatIV($encryptedContent, $iv);
+ $padded = $this->addPadding($catFile);
+
+ return $padded;
+ } catch (EncryptionFailedException $e) {
+ $message = 'Could not encrypt file content (code: ' . $e->getCode() . '): ';
+ $this->logger->error('files_encryption' . $message . $e->getMessage(), ['app' => 'encryption']);
+ return false;
+ }
+
+ }
+
+ /**
+ * @param $plainContent
+ * @param $iv
+ * @param string $passphrase
+ * @param string $cipher
+ * @return string
+ * @throws EncryptionFailedException
+ */
+ private function encrypt($plainContent, $iv, $passphrase = '', $cipher = self::DEFAULT_CIPHER) {
+ $encryptedContent = openssl_encrypt($plainContent, $cipher, $passphrase, false, $iv);
+
+ if (!$encryptedContent) {
+ $error = 'Encryption (symmetric) of content failed';
+ $this->logger->error($error . openssl_error_string(), ['app' => 'encryption']);
+ throw new EncryptionFailedException($error);
+ }
+
+ return $encryptedContent;
+ }
+
+ /**
+ * @return mixed|string
+ */
+ public function getCipher() {
+ $cipher = $this->config->getSystemValue('cipher', self::DEFAULT_CIPHER);
+ if ($cipher !== 'AES-256-CFB' || $cipher !== 'AES-128-CFB') {
+ $this->logger->warning('Wrong cipher defined in config.php only AES-128-CFB and AES-256-CFB are supported. Fall back' . self::DEFAULT_CIPHER, ['app' => 'encryption']);
+ $cipher = self::DEFAULT_CIPHER;
+ }
+
+ return $cipher;
+ }
+
+ /**
+ * @param $encryptedContent
+ * @param $iv
+ * @return string
+ */
+ private function concatIV($encryptedContent, $iv) {
+ return $encryptedContent . '00iv00' . $iv;
+ }
+
+ /**
+ * @param $data
+ * @return string
+ */
+ private function addPadding($data) {
+ return $data . 'xx';
+ }
+
+ /**
+ * @param $recoveryKey
+ * @param $password
+ * @return bool|string
+ */
+ public function decryptPrivateKey($recoveryKey, $password) {
+
+ $header = $this->parseHeader($recoveryKey);
+ $cipher = $this->getCipher($header);
+
+ // If we found a header we need to remove it from the key we want to decrypt
+ if (!empty($header)) {
+ $recoveryKey = substr($recoveryKey, strpos($recoveryKey, self::HEADEREND) + strlen(self::HEADERSTART));
+ }
+
+ $plainKey = $this->symmetricDecryptFileContent($recoveryKey, $password, $cipher);
+
+ // Check if this is a valid private key
+ $res = openssl_get_privatekey($plainKey);
+ if (is_resource($res)) {
+ $sslInfo = openssl_pkey_get_details($res);
+ if (!isset($sslInfo['key'])) {
+ return false;
+ }
+ } else {
+ return false;
+ }
+
+ return $plainKey;
+ }
+
+ /**
+ * @param $keyFileContents
+ * @param string $passphrase
+ * @param string $cipher
+ * @return bool|string
+ * @throws DecryptionFailedException
+ */
+ public function symmetricDecryptFileContent($keyFileContents, $passphrase = '', $cipher = self::DEFAULT_CIPHER) {
+ // Remove Padding
+ $noPadding = $this->removePadding($keyFileContents);
+
+ $catFile = $this->splitIv($noPadding);
+
+ $plainContent = $this->decrypt($catFile['encrypted'], $catFile['iv'], $passphrase, $cipher);
+
+ if ($plainContent) {
+ return $plainContent;
+ }
+
+ return false;
+ }
+
+ /**
+ * @param $padded
+ * @return bool|string
+ */
+ private function removePadding($padded) {
+ if (substr($padded, -2) === 'xx') {
+ return substr($padded, 0, -2);
+ }
+ return false;
+ }
+
+ /**
+ * @param $catFile
+ * @return array
+ */
+ private function splitIv($catFile) {
+ // Fetch encryption metadata from end of file
+ $meta = substr($catFile, -22);
+
+ // Fetch IV from end of file
+ $iv = substr($meta, -16);
+
+ // Remove IV and IV Identifier text to expose encrypted content
+
+ $encrypted = substr($catFile, 0, -22);
+
+ return [
+ 'encrypted' => $encrypted,
+ 'iv' => $iv
+ ];
+ }
+
+ /**
+ * @param $encryptedContent
+ * @param $iv
+ * @param string $passphrase
+ * @param string $cipher
+ * @return string
+ * @throws DecryptionFailedException
+ */
+ private function decrypt($encryptedContent, $iv, $passphrase = '', $cipher = self::DEFAULT_CIPHER) {
+ $plainContent = openssl_decrypt($encryptedContent, $cipher, $passphrase, false, $iv);
+
+ if ($plainContent) {
+ return $plainContent;
+ } else {
+ throw new DecryptionFailedException('Encryption library: Decryption (symmetric) of content failed');
+ }
+ }
+
+ /**
+ * @param $data
+ * @return array
+ */
+ private function parseHeader($data) {
+ $result = [];
+
+ if (substr($data, 0, strlen(self::HEADERSTART)) === self::HEADERSTART) {
+ $endAt = strpos($data, self::HEADEREND);
+ $header = substr($data, 0, $endAt + strlen(self::HEADEREND));
+
+ // +1 not to start with an ':' which would result in empty element at the beginning
+ $exploded = explode(':', substr($header, strlen(self::HEADERSTART) + 1));
+
+ $element = array_shift($exploded);
+
+ while ($element != self::HEADEREND) {
+ $result[$element] = array_shift($exploded);
+ $element = array_shift($exploded);
+ }
+ }
+
+ return $result;
+ }
+
+ /**
+ * @return string
+ * @throws GenericEncryptionException
+ */
+ private function generateIv() {
+ $random = openssl_random_pseudo_bytes(12, $strong);
+ if ($random) {
+ if (!$strong) {
+ // If OpenSSL indicates randomness is insecure log error
+ $this->logger->error('Encryption Library: Insecure symmetric key was generated using openssl_random_psudo_bytes()', ['app' => 'encryption']);
+ }
+
+ /*
+ * We encode the iv purely for string manipulation
+ * purposes -it gets decoded before use
+ */
+ return base64_encode($random);
+ }
+ // If we ever get here we've failed anyway no need for an else
+ throw new GenericEncryptionException('Generating IV Failed');
+ }
+}
+
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