667 lines
16 KiB
PHP
Executable File
667 lines
16 KiB
PHP
Executable File
<?php
|
|
|
|
/**
|
|
* ownCloud
|
|
*
|
|
* @author Sam Tuke, Frank Karlitschek, Robin Appelman
|
|
* @copyright 2012 Sam Tuke samtuke@owncloud.com,
|
|
* Robin Appelman icewind@owncloud.com, Frank Karlitschek
|
|
* frank@owncloud.org
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
|
|
* License as published by the Free Software Foundation; either
|
|
* version 3 of the License, or any later version.
|
|
*
|
|
* This library 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 along with this library. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
*/
|
|
|
|
namespace OCA\Encryption;
|
|
|
|
//require_once '../3rdparty/Crypt_Blowfish/Blowfish.php';
|
|
require_once realpath(dirname(__FILE__) . '/../3rdparty/Crypt_Blowfish/Blowfish.php');
|
|
|
|
/**
|
|
* Class for common cryptography functionality
|
|
*/
|
|
|
|
class Crypt {
|
|
|
|
/**
|
|
* @brief return encryption mode client or server side encryption
|
|
* @param string $user name (use system wide setting if name=null)
|
|
* @return string 'client' or 'server'
|
|
*/
|
|
public static function mode($user = null) {
|
|
|
|
return 'server';
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Create a new encryption keypair
|
|
* @return array publicKey, privatekey
|
|
*/
|
|
public static function createKeypair() {
|
|
|
|
$return = false;
|
|
|
|
$res = openssl_pkey_new(array('private_key_bits' => 4096));
|
|
|
|
if ($res === false) {
|
|
\OCP\Util::writeLog('Encryption library', 'couldn\'t generate users key-pair for ' . \OCP\User::getUser(), \OCP\Util::ERROR);
|
|
} elseif (openssl_pkey_export($res, $privateKey)) {
|
|
// Get public key
|
|
$publicKey = openssl_pkey_get_details($res);
|
|
$publicKey = $publicKey['key'];
|
|
|
|
$return = array(
|
|
'publicKey' => $publicKey,
|
|
'privateKey' => $privateKey
|
|
);
|
|
} else {
|
|
\OCP\Util::writeLog('Encryption library', 'couldn\'t export users private key, please check your servers openSSL configuration.' . \OCP\User::getUser(), \OCP\Util::ERROR);
|
|
}
|
|
|
|
return $return;
|
|
}
|
|
|
|
/**
|
|
* @brief Add arbitrary padding to encrypted data
|
|
* @param string $data data to be padded
|
|
* @return string padded data
|
|
* @note In order to end up with data exactly 8192 bytes long we must
|
|
* add two letters. It is impossible to achieve exactly 8192 length
|
|
* blocks with encryption alone, hence padding is added to achieve the
|
|
* required length.
|
|
*/
|
|
public static function addPadding($data) {
|
|
|
|
$padded = $data . 'xx';
|
|
|
|
return $padded;
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Remove arbitrary padding to encrypted data
|
|
* @param string $padded padded data to remove padding from
|
|
* @return string unpadded data on success, false on error
|
|
*/
|
|
public static function removePadding($padded) {
|
|
|
|
if (substr($padded, -2) === 'xx') {
|
|
|
|
$data = substr($padded, 0, -2);
|
|
|
|
return $data;
|
|
|
|
} else {
|
|
|
|
// TODO: log the fact that unpadded data was submitted for removal of padding
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Check if a file's contents contains an IV and is symmetrically encrypted
|
|
* @param $content
|
|
* @return boolean
|
|
* @note see also OCA\Encryption\Util->isEncryptedPath()
|
|
*/
|
|
public static function isCatfileContent($content) {
|
|
|
|
if (!$content) {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
$noPadding = self::removePadding($content);
|
|
|
|
// Fetch encryption metadata from end of file
|
|
$meta = substr($noPadding, -22);
|
|
|
|
// Fetch IV from end of file
|
|
$iv = substr($meta, -16);
|
|
|
|
// Fetch identifier from start of metadata
|
|
$identifier = substr($meta, 0, 6);
|
|
|
|
if ($identifier === '00iv00') {
|
|
|
|
return true;
|
|
|
|
} else {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* Check if a file is encrypted according to database file cache
|
|
* @param string $path
|
|
* @return bool
|
|
*/
|
|
public static function isEncryptedMeta($path) {
|
|
|
|
// TODO: Use DI to get \OC\Files\Filesystem out of here
|
|
|
|
// Fetch all file metadata from DB
|
|
$metadata = \OC\Files\Filesystem::getFileInfo($path);
|
|
|
|
// Return encryption status
|
|
return isset($metadata['encrypted']) && ( bool )$metadata['encrypted'];
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Check if a file is encrypted via legacy system
|
|
* @param $data
|
|
* @param string $relPath The path of the file, relative to user/data;
|
|
* e.g. filename or /Docs/filename, NOT admin/files/filename
|
|
* @return boolean
|
|
*/
|
|
public static function isLegacyEncryptedContent($isCatFileContent, $relPath) {
|
|
|
|
// Fetch all file metadata from DB
|
|
$metadata = \OC\Files\Filesystem::getFileInfo($relPath, '');
|
|
|
|
// If a file is flagged with encryption in DB, but isn't a
|
|
// valid content + IV combination, it's probably using the
|
|
// legacy encryption system
|
|
if (isset($metadata['encrypted'])
|
|
&& $metadata['encrypted'] === true
|
|
&& $isCatFileContent === false
|
|
) {
|
|
|
|
return true;
|
|
|
|
} else {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Symmetrically encrypt a string
|
|
* @param $plainContent
|
|
* @param $iv
|
|
* @param string $passphrase
|
|
* @return string encrypted file content
|
|
*/
|
|
public static function encrypt($plainContent, $iv, $passphrase = '') {
|
|
|
|
if ($encryptedContent = openssl_encrypt($plainContent, 'AES-128-CFB', $passphrase, false, $iv)) {
|
|
|
|
return $encryptedContent;
|
|
|
|
} else {
|
|
|
|
\OCP\Util::writeLog('Encryption library', 'Encryption (symmetric) of content failed', \OCP\Util::ERROR);
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Symmetrically decrypt a string
|
|
* @param $encryptedContent
|
|
* @param $iv
|
|
* @param $passphrase
|
|
* @throws \Exception
|
|
* @return string decrypted file content
|
|
*/
|
|
public static function decrypt($encryptedContent, $iv, $passphrase) {
|
|
|
|
if ($plainContent = openssl_decrypt($encryptedContent, 'AES-128-CFB', $passphrase, false, $iv)) {
|
|
|
|
return $plainContent;
|
|
|
|
} else {
|
|
|
|
throw new \Exception('Encryption library: Decryption (symmetric) of content failed');
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Concatenate encrypted data with its IV and padding
|
|
* @param string $content content to be concatenated
|
|
* @param string $iv IV to be concatenated
|
|
* @returns string concatenated content
|
|
*/
|
|
public static function concatIv($content, $iv) {
|
|
|
|
$combined = $content . '00iv00' . $iv;
|
|
|
|
return $combined;
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Split concatenated data and IV into respective parts
|
|
* @param string $catFile concatenated data to be split
|
|
* @returns array keys: encrypted, iv
|
|
*/
|
|
public static function splitIv($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);
|
|
|
|
$split = array(
|
|
'encrypted' => $encrypted,
|
|
'iv' => $iv
|
|
);
|
|
|
|
return $split;
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Symmetrically encrypts a string and returns keyfile content
|
|
* @param string $plainContent content to be encrypted in keyfile
|
|
* @param string $passphrase
|
|
* @return bool|string
|
|
* @return string encrypted content combined with IV
|
|
* @note IV need not be specified, as it will be stored in the returned keyfile
|
|
* and remain accessible therein.
|
|
*/
|
|
public static function symmetricEncryptFileContent($plainContent, $passphrase = '') {
|
|
|
|
if (!$plainContent) {
|
|
\OCP\Util::writeLog('Encryption library', 'symmetrically encryption failed, no content given.', \OCP\Util::ERROR);
|
|
return false;
|
|
}
|
|
|
|
$iv = self::generateIv();
|
|
|
|
if ($encryptedContent = self::encrypt($plainContent, $iv, $passphrase)) {
|
|
// Combine content to encrypt with IV identifier and actual IV
|
|
$catfile = self::concatIv($encryptedContent, $iv);
|
|
$padded = self::addPadding($catfile);
|
|
|
|
return $padded;
|
|
|
|
} else {
|
|
\OCP\Util::writeLog('Encryption library', 'Encryption (symmetric) of keyfile content failed', \OCP\Util::ERROR);
|
|
return false;
|
|
}
|
|
|
|
}
|
|
|
|
|
|
/**
|
|
* @brief Symmetrically decrypts keyfile content
|
|
* @param $keyfileContent
|
|
* @param string $passphrase
|
|
* @throws \Exception
|
|
* @return bool|string
|
|
* @internal param string $source
|
|
* @internal param string $target
|
|
* @internal param string $key the decryption key
|
|
* @returns string decrypted content
|
|
*
|
|
* This function decrypts a file
|
|
*/
|
|
public static function symmetricDecryptFileContent($keyfileContent, $passphrase = '') {
|
|
|
|
if (!$keyfileContent) {
|
|
|
|
throw new \Exception('Encryption library: no data provided for decryption');
|
|
|
|
}
|
|
|
|
// Remove padding
|
|
$noPadding = self::removePadding($keyfileContent);
|
|
|
|
// Split into enc data and catfile
|
|
$catfile = self::splitIv($noPadding);
|
|
|
|
if ($plainContent = self::decrypt($catfile['encrypted'], $catfile['iv'], $passphrase)) {
|
|
|
|
return $plainContent;
|
|
|
|
} else {
|
|
return false;
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Decrypt private key and check if the result is a valid keyfile
|
|
* @param string $encryptedKey encrypted keyfile
|
|
* @param string $passphrase to decrypt keyfile
|
|
* @returns encrypted private key or false
|
|
*
|
|
* This function decrypts a file
|
|
*/
|
|
public static function decryptPrivateKey($encryptedKey, $passphrase) {
|
|
|
|
$plainKey = self::symmetricDecryptFileContent($encryptedKey, $passphrase);
|
|
|
|
// check if this a valid private key
|
|
$res = openssl_pkey_get_private($plainKey);
|
|
if (is_resource($res)) {
|
|
$sslInfo = openssl_pkey_get_details($res);
|
|
if (!isset($sslInfo['key'])) {
|
|
$plainKey = false;
|
|
}
|
|
} else {
|
|
$plainKey = false;
|
|
}
|
|
|
|
return $plainKey;
|
|
|
|
}
|
|
|
|
|
|
/**
|
|
* @brief Creates symmetric keyfile content using a generated key
|
|
* @param string $plainContent content to be encrypted
|
|
* @returns array keys: key, encrypted
|
|
* @note symmetricDecryptFileContent() can be used to decrypt files created using this method
|
|
*
|
|
* This function decrypts a file
|
|
*/
|
|
public static function symmetricEncryptFileContentKeyfile($plainContent) {
|
|
|
|
$key = self::generateKey();
|
|
|
|
if ($encryptedContent = self::symmetricEncryptFileContent($plainContent, $key)) {
|
|
|
|
return array(
|
|
'key' => $key,
|
|
'encrypted' => $encryptedContent
|
|
);
|
|
|
|
} else {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Create asymmetrically encrypted keyfile content using a generated key
|
|
* @param string $plainContent content to be encrypted
|
|
* @param array $publicKeys array keys must be the userId of corresponding user
|
|
* @returns array keys: keys (array, key = userId), data
|
|
* @note symmetricDecryptFileContent() can decrypt files created using this method
|
|
*/
|
|
public static function multiKeyEncrypt($plainContent, array $publicKeys) {
|
|
|
|
// openssl_seal returns false without errors if $plainContent
|
|
// is empty, so trigger our own error
|
|
if (empty($plainContent)) {
|
|
|
|
throw new \Exception('Cannot mutliKeyEncrypt empty plain content');
|
|
|
|
}
|
|
|
|
// Set empty vars to be set by openssl by reference
|
|
$sealed = '';
|
|
$shareKeys = array();
|
|
$mappedShareKeys = array();
|
|
|
|
if (openssl_seal($plainContent, $sealed, $shareKeys, $publicKeys)) {
|
|
|
|
$i = 0;
|
|
|
|
// Ensure each shareKey is labelled with its
|
|
// corresponding userId
|
|
foreach ($publicKeys as $userId => $publicKey) {
|
|
|
|
$mappedShareKeys[$userId] = $shareKeys[$i];
|
|
$i++;
|
|
|
|
}
|
|
|
|
return array(
|
|
'keys' => $mappedShareKeys,
|
|
'data' => $sealed
|
|
);
|
|
|
|
} else {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Asymmetrically encrypt a file using multiple public keys
|
|
* @param $encryptedContent
|
|
* @param $shareKey
|
|
* @param $privateKey
|
|
* @return bool
|
|
* @internal param string $plainContent content to be encrypted
|
|
* @returns string $plainContent decrypted string
|
|
* @note symmetricDecryptFileContent() can be used to decrypt files created using this method
|
|
*
|
|
* This function decrypts a file
|
|
*/
|
|
public static function multiKeyDecrypt($encryptedContent, $shareKey, $privateKey) {
|
|
|
|
if (!$encryptedContent) {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
if (openssl_open($encryptedContent, $plainContent, $shareKey, $privateKey)) {
|
|
|
|
return $plainContent;
|
|
|
|
} else {
|
|
|
|
\OCP\Util::writeLog('Encryption library', 'Decryption (asymmetric) of sealed content with share-key "'.$shareKey.'" failed', \OCP\Util::ERROR);
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Asymetrically encrypt a string using a public key
|
|
* @param $plainContent
|
|
* @param $publicKey
|
|
* @return string encrypted file
|
|
*/
|
|
public static function keyEncrypt($plainContent, $publicKey) {
|
|
|
|
openssl_public_encrypt($plainContent, $encryptedContent, $publicKey);
|
|
|
|
return $encryptedContent;
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Asymetrically decrypt a file using a private key
|
|
* @param $encryptedContent
|
|
* @param $privatekey
|
|
* @return string decrypted file
|
|
*/
|
|
public static function keyDecrypt($encryptedContent, $privatekey) {
|
|
|
|
$result = @openssl_private_decrypt($encryptedContent, $plainContent, $privatekey);
|
|
|
|
if ($result) {
|
|
return $plainContent;
|
|
}
|
|
|
|
return $result;
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Generates a pseudo random initialisation vector
|
|
* @return String $iv generated IV
|
|
*/
|
|
public static function generateIv() {
|
|
|
|
if ($random = openssl_random_pseudo_bytes(12, $strong)) {
|
|
|
|
if (!$strong) {
|
|
|
|
// If OpenSSL indicates randomness is insecure, log error
|
|
\OCP\Util::writeLog('Encryption library', 'Insecure symmetric key was generated using openssl_random_pseudo_bytes()', \OCP\Util::WARN);
|
|
|
|
}
|
|
|
|
// We encode the iv purely for string manipulation
|
|
// purposes - it gets decoded before use
|
|
$iv = base64_encode($random);
|
|
|
|
return $iv;
|
|
|
|
} else {
|
|
|
|
throw new \Exception('Generating IV failed');
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Generate a pseudo random 1024kb ASCII key
|
|
* @returns $key Generated key
|
|
*/
|
|
public static function generateKey() {
|
|
|
|
// Generate key
|
|
if ($key = base64_encode(openssl_random_pseudo_bytes(183, $strong))) {
|
|
|
|
if (!$strong) {
|
|
|
|
// If OpenSSL indicates randomness is insecure, log error
|
|
throw new \Exception('Encryption library, Insecure symmetric key was generated using openssl_random_pseudo_bytes()');
|
|
|
|
}
|
|
|
|
return $key;
|
|
|
|
} else {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief Get the blowfish encryption handeler for a key
|
|
* @param $key string (optional)
|
|
* @return \Crypt_Blowfish blowfish object
|
|
*
|
|
* if the key is left out, the default handeler will be used
|
|
*/
|
|
public static function getBlowfish($key = '') {
|
|
|
|
if ($key) {
|
|
|
|
return new \Crypt_Blowfish($key);
|
|
|
|
} else {
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* @param $passphrase
|
|
* @return mixed
|
|
*/
|
|
public static function legacyCreateKey($passphrase) {
|
|
|
|
// Generate a random integer
|
|
$key = mt_rand(10000, 99999) . mt_rand(10000, 99999) . mt_rand(10000, 99999) . mt_rand(10000, 99999);
|
|
|
|
// Encrypt the key with the passphrase
|
|
$legacyEncKey = self::legacyEncrypt($key, $passphrase);
|
|
|
|
return $legacyEncKey;
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief encrypts content using legacy blowfish system
|
|
* @param string $content the cleartext message you want to encrypt
|
|
* @param string $passphrase
|
|
* @returns string encrypted content
|
|
*
|
|
* This function encrypts an content
|
|
*/
|
|
public static function legacyEncrypt($content, $passphrase = '') {
|
|
|
|
$bf = self::getBlowfish($passphrase);
|
|
|
|
return $bf->encrypt($content);
|
|
|
|
}
|
|
|
|
/**
|
|
* @brief decrypts content using legacy blowfish system
|
|
* @param string $content the cleartext message you want to decrypt
|
|
* @param string $passphrase
|
|
* @return string cleartext content
|
|
*
|
|
* This function decrypts an content
|
|
*/
|
|
public static function legacyDecrypt($content, $passphrase = '') {
|
|
|
|
$bf = self::getBlowfish($passphrase);
|
|
|
|
$decrypted = $bf->decrypt($content);
|
|
|
|
return $decrypted;
|
|
}
|
|
|
|
/**
|
|
* @param $data
|
|
* @param string $key
|
|
* @param int $maxLength
|
|
* @return string
|
|
*/
|
|
public static function legacyBlockDecrypt($data, $key = '', $maxLength = 0) {
|
|
|
|
$result = '';
|
|
while (strlen($data)) {
|
|
$result .= self::legacyDecrypt(substr($data, 0, 8192), $key);
|
|
$data = substr($data, 8192);
|
|
}
|
|
if ($maxLength > 0) {
|
|
return substr($result, 0, $maxLength);
|
|
} else {
|
|
return rtrim($result, "\0");
|
|
}
|
|
}
|
|
|
|
} |