719 lines
No EOL
18 KiB
PHP
Executable file
719 lines
No EOL
18 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 'Crypt_Blowfish/Blowfish.php';
|
||
|
||
// Todo:
|
||
// - Add a setting "Don´t encrypt files larger than xx because of performance"
|
||
// - Don't use a password directly as encryption key. but a key which is
|
||
// stored on the server and encrypted with the user password. -> change pass
|
||
// faster
|
||
|
||
/**
|
||
* 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() {
|
||
|
||
$res = openssl_pkey_new(array('private_key_bits' => 4096));
|
||
|
||
// Get private key
|
||
openssl_pkey_export( $res, $privateKey );
|
||
|
||
// Get public key
|
||
$publicKey = openssl_pkey_get_details( $res );
|
||
|
||
$publicKey = $publicKey['key'];
|
||
|
||
return( array( 'publicKey' => $publicKey, 'privateKey' => $privateKey ) );
|
||
|
||
}
|
||
|
||
/**
|
||
* @brief Add arbitrary padding to encrypted data
|
||
* @param string $data data to be padded
|
||
* @return 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 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
|
||
* @return true / false
|
||
* @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( $metadata['encrypted'] ) and ( bool )$metadata['encrypted'];
|
||
|
||
}
|
||
|
||
/**
|
||
* @brief Check if a file is encrypted via legacy system
|
||
* @param string $relPath The path of the file, relative to user/data;
|
||
* e.g. filename or /Docs/filename, NOT admin/files/filename
|
||
* @return true / false
|
||
*/
|
||
public static function isLegacyEncryptedContent( $data, $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'] )
|
||
and $metadata['encrypted'] === true
|
||
and ! self::isCatfileContent( $data )
|
||
) {
|
||
|
||
return true;
|
||
|
||
} else {
|
||
|
||
return false;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
/**
|
||
* @brief Symmetrically encrypt a string
|
||
* @returns encrypted file
|
||
*/
|
||
public static function encrypt( $plainContent, $iv, $passphrase = '' ) {
|
||
|
||
if ( $encryptedContent = openssl_encrypt( $plainContent, 'AES-128-CFB', $passphrase, false, $iv ) ) {
|
||
|
||
return $encryptedContent;
|
||
|
||
} else {
|
||
|
||
\OC_Log::write( 'Encryption library', 'Encryption (symmetric) of content failed', \OC_Log::ERROR );
|
||
|
||
return false;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
/**
|
||
* @brief Symmetrically decrypt a string
|
||
* @returns decrypted file
|
||
*/
|
||
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' );
|
||
|
||
return false;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
/**
|
||
* @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 $plainContent content to be encrypted in keyfile
|
||
* @returns 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 ) {
|
||
|
||
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 {
|
||
|
||
\OC_Log::write( 'Encryption library', 'Encryption (symmetric) of keyfile content failed', \OC_Log::ERROR );
|
||
|
||
return false;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
|
||
/**
|
||
* @brief Symmetrically decrypts keyfile content
|
||
* @param string $source
|
||
* @param string $target
|
||
* @param string $key the decryption key
|
||
* @returns 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;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
/**
|
||
* @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 ) ) {
|
||
|
||
trigger_error( "Cannot mutliKeyEncrypt empty plain content" );
|
||
throw new \Exception( 'Cannot mutliKeyEncrypt empty plain content' );
|
||
|
||
}
|
||
|
||
// Set empty vars to be set by openssl by reference
|
||
$sealed = '';
|
||
$shareKeys = 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 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 {
|
||
|
||
\OC_Log::write( 'Encryption library', 'Decryption (asymmetric) of sealed content failed', \OC_Log::ERROR );
|
||
|
||
return false;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
/**
|
||
* @brief Asymetrically encrypt a string using a public key
|
||
* @returns 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
|
||
* @returns decrypted file
|
||
*/
|
||
public static function keyDecrypt( $encryptedContent, $privatekey ) {
|
||
|
||
$result = @openssl_private_decrypt( $encryptedContent, $plainContent, $privatekey );
|
||
|
||
if ( $result ) {
|
||
return $plainContent;
|
||
}
|
||
|
||
return $result;
|
||
|
||
}
|
||
|
||
/**
|
||
* @brief Symmetrically encrypt a file by combining encrypted component data blocks
|
||
*/
|
||
public static function symmetricBlockEncryptFileContent( $plainContent, $key ) {
|
||
|
||
$crypted = '';
|
||
|
||
$remaining = $plainContent;
|
||
|
||
$testarray = array();
|
||
|
||
while( strlen( $remaining ) ) {
|
||
|
||
//echo "\n\n\$block = ".substr( $remaining, 0, 6126 );
|
||
|
||
// Encrypt a chunk of unencrypted data and add it to the rest
|
||
$block = self::symmetricEncryptFileContent( substr( $remaining, 0, 6126 ), $key );
|
||
|
||
$padded = self::addPadding( $block );
|
||
|
||
$crypted .= $block;
|
||
|
||
$testarray[] = $block;
|
||
|
||
// Remove the data already encrypted from remaining unencrypted data
|
||
$remaining = substr( $remaining, 6126 );
|
||
|
||
}
|
||
|
||
//echo "hags ";
|
||
|
||
//echo "\n\n\n\$crypted = $crypted\n\n\n";
|
||
|
||
//print_r($testarray);
|
||
|
||
return $crypted;
|
||
|
||
}
|
||
|
||
|
||
/**
|
||
* @brief Symmetrically decrypt a file by combining encrypted component data blocks
|
||
*/
|
||
public static function symmetricBlockDecryptFileContent( $crypted, $key ) {
|
||
|
||
$decrypted = '';
|
||
|
||
$remaining = $crypted;
|
||
|
||
$testarray = array();
|
||
|
||
while( strlen( $remaining ) ) {
|
||
|
||
$testarray[] = substr( $remaining, 0, 8192 );
|
||
|
||
// Decrypt a chunk of unencrypted data and add it to the rest
|
||
$decrypted .= self::symmetricDecryptFileContent( $remaining, $key );
|
||
|
||
// Remove the data already encrypted from remaining unencrypted data
|
||
$remaining = substr( $remaining, 8192 );
|
||
|
||
}
|
||
|
||
//echo "\n\n\$testarray = "; print_r($testarray);
|
||
|
||
return $decrypted;
|
||
|
||
}
|
||
|
||
/**
|
||
* @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
|
||
\OC_Log::write( 'Encryption library', 'Insecure symmetric key was generated using openssl_random_pseudo_bytes()', \OC_Log::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;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
public static function changekeypasscode( $oldPassword, $newPassword ) {
|
||
|
||
if ( \OCP\User::isLoggedIn() ) {
|
||
|
||
$key = Keymanager::getPrivateKey( $user, $view );
|
||
|
||
if ( ( $key = Crypt::symmetricDecryptFileContent($key,$oldpasswd) ) ) {
|
||
|
||
if ( ( $key = Crypt::symmetricEncryptFileContent( $key, $newpasswd ) ) ) {
|
||
|
||
Keymanager::setPrivateKey( $key );
|
||
|
||
return true;
|
||
}
|
||
|
||
}
|
||
|
||
}
|
||
|
||
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;
|
||
|
||
}
|
||
|
||
}
|
||
|
||
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 $content the cleartext message you want to encrypt
|
||
* @param $key the encryption key (optional)
|
||
* @returns 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 $content the cleartext message you want to decrypt
|
||
* @param $key the encryption key (optional)
|
||
* @returns cleartext content
|
||
*
|
||
* This function decrypts an content
|
||
*/
|
||
public static function legacyDecrypt( $content, $passphrase = '' ) {
|
||
|
||
$bf = self::getBlowfish( $passphrase );
|
||
|
||
$decrypted = $bf->decrypt( $content );
|
||
|
||
$trimmed = rtrim( $decrypted, "\0" );
|
||
|
||
return $trimmed;
|
||
|
||
}
|
||
|
||
public static function legacyKeyRecryptKeyfile( $legacyEncryptedContent, $legacyPassphrase, $publicKeys, $newPassphrase, $path ) {
|
||
|
||
$decrypted = self::legacyDecrypt( $legacyEncryptedContent, $legacyPassphrase );
|
||
|
||
// Encrypt plain data, generate keyfile & encrypted file
|
||
$cryptedData = self::symmetricEncryptFileContentKeyfile( $decrypted );
|
||
|
||
// Encrypt plain keyfile to multiple sharefiles
|
||
$multiEncrypted = Crypt::multiKeyEncrypt( $cryptedData['key'], $publicKeys );
|
||
|
||
return array( 'data' => $cryptedData['encrypted'], 'filekey' => $multiEncrypted['data'], 'sharekeys' => $multiEncrypted['keys'] );
|
||
|
||
}
|
||
|
||
/**
|
||
* @brief Re-encryptes a legacy blowfish encrypted file using AES with integrated IV
|
||
* @param $legacyContent the legacy encrypted content to re-encrypt
|
||
* @returns cleartext content
|
||
*
|
||
* This function decrypts an content
|
||
*/
|
||
public static function legacyRecrypt( $legacyContent, $legacyPassphrase, $newPassphrase ) {
|
||
|
||
// TODO: write me
|
||
|
||
}
|
||
|
||
} |