<?php /** * StatusNet - the distributed open-source microblogging tool * Copyright (C) 2010, StatusNet, Inc. * * A sample module to show best practices for StatusNet plugins * * PHP version 5 * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * 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 * along with this program. If not, see <http://www.gnu.org/licenses/>. * * @package StatusNet * @author James Walker <james@status.net> * @copyright 2010 StatusNet, Inc. * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0 * @link http://status.net/ */ if (!defined('STATUSNET')) { exit(1); } require_once 'Crypt/RSA.php'; class Magicsig extends Memcached_DataObject { const PUBLICKEYREL = 'magic-public-key'; public $__table = 'magicsig'; /** * Key to user.id/profile.id for the local user whose key we're storing. * * @var int */ public $user_id; /** * Flattened string representation of the key pair; callers should * usually use $this->publicKey and $this->privateKey directly, * which hold live Crypt_RSA key objects. * * @var string */ public $keypair; /** * Crypto algorithm used for this key; currently only RSA-SHA256 is supported. * * @var string */ public $alg; /** * Public RSA key; gets serialized in/out via $this->keypair string. * * @var Crypt_RSA */ public $publicKey; /** * PrivateRSA key; gets serialized in/out via $this->keypair string. * * @var Crypt_RSA */ public $privateKey; public function __construct($alg = 'RSA-SHA256') { $this->alg = $alg; } /** * Fetch a Magicsig object from the cache or database on a field match. * * @param string $k * @param mixed $v * @return Magicsig */ public /*static*/ function staticGet($k, $v=null) { $obj = parent::staticGet(__CLASS__, $k, $v); if (!empty($obj)) { $obj = Magicsig::fromString($obj->keypair); // Double check keys: Crypt_RSA did not // consistently generate good keypairs. // We've also moved to 1024 bit keys. if (strlen($obj->publicKey->modulus->toBits()) != 1024) { $obj->delete(); return false; } } return $obj; } function table() { return array( 'user_id' => DB_DATAOBJECT_INT, 'keypair' => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL, 'alg' => DB_DATAOBJECT_STR ); } static function schemaDef() { return array(new ColumnDef('user_id', 'integer', null, false, 'PRI'), new ColumnDef('keypair', 'text', false, false), new ColumnDef('alg', 'varchar', 64, false)); } function keys() { return array_keys($this->keyTypes()); } function keyTypes() { return array('user_id' => 'K'); } function sequenceKey() { return array(false, false, false); } /** * Save this keypair into the database. * * Overloads default insert behavior to encode the live key objects * as a flat string for storage. * * @return mixed */ function insert() { $this->keypair = $this->toString(); return parent::insert(); } /** * Generate a new keypair for a local user and store in the database. * * Warning: this can be very slow on systems without the GMP module. * Runtimes of 20-30 seconds are not unheard-of. * * @param int $user_id id of local user we're creating a key for */ public function generate($user_id) { $rsa = new Crypt_RSA(); $keypair = $rsa->createKey(); $rsa->loadKey($keypair['privatekey']); $this->privateKey = new Crypt_RSA(); $this->privateKey->loadKey($keypair['privatekey']); $this->publicKey = new Crypt_RSA(); $this->publicKey->loadKey($keypair['publickey']); $this->user_id = $user_id; $this->insert(); } /** * Encode the keypair or public key as a string. * * @param boolean $full_pair set to false to leave out the private key. * @return string */ public function toString($full_pair = true) { $mod = Magicsig::base64_url_encode($this->publicKey->modulus->toBytes()); $exp = Magicsig::base64_url_encode($this->publicKey->exponent->toBytes()); $private_exp = ''; if ($full_pair && $this->privateKey->exponent->toBytes()) { $private_exp = '.' . Magicsig::base64_url_encode($this->privateKey->exponent->toBytes()); } return 'RSA.' . $mod . '.' . $exp . $private_exp; } /** * Decode a string representation of an RSA public key or keypair * as a Magicsig object which can be used to sign or verify. * * @param string $text * @return Magicsig */ public static function fromString($text) { $magic_sig = new Magicsig(); // remove whitespace $text = preg_replace('/\s+/', '', $text); // parse components if (!preg_match('/RSA\.([^\.]+)\.([^\.]+)(.([^\.]+))?/', $text, $matches)) { return false; } $mod = $matches[1]; $exp = $matches[2]; if (!empty($matches[4])) { $private_exp = $matches[4]; } else { $private_exp = false; } $magic_sig->loadKey($mod, $exp, 'public'); if ($private_exp) { $magic_sig->loadKey($mod, $private_exp, 'private'); } return $magic_sig; } /** * Fill out $this->privateKey or $this->publicKey with a Crypt_RSA object * representing the give key (as mod/exponent pair). * * @param string $mod base64-encoded * @param string $exp base64-encoded exponent * @param string $type one of 'public' or 'private' */ public function loadKey($mod, $exp, $type = 'public') { common_log(LOG_DEBUG, "Adding ".$type." key: (".$mod .', '. $exp .")"); $rsa = new Crypt_RSA(); $rsa->signatureMode = CRYPT_RSA_SIGNATURE_PKCS1; $rsa->setHash('sha256'); $rsa->modulus = new Math_BigInteger(Magicsig::base64_url_decode($mod), 256); $rsa->k = strlen($rsa->modulus->toBytes()); $rsa->exponent = new Math_BigInteger(Magicsig::base64_url_decode($exp), 256); if ($type == 'private') { $this->privateKey = $rsa; } else { $this->publicKey = $rsa; } } /** * Returns the name of the crypto algorithm used for this key. * * @return string */ public function getName() { return $this->alg; } /** * Returns the name of a hash function to use for signing with this key. * * @return string * @fixme is this used? doesn't seem to be called by name. */ public function getHash() { switch ($this->alg) { case 'RSA-SHA256': return 'sha256'; } } /** * Generate base64-encoded signature for the given byte string * using our private key. * * @param string $bytes as raw byte string * @return string base64-encoded signature */ public function sign($bytes) { $sig = $this->privateKey->sign($bytes); return Magicsig::base64_url_encode($sig); } /** * * @param string $signed_bytes as raw byte string * @param string $signature as base64 * @return boolean */ public function verify($signed_bytes, $signature) { $signature = Magicsig::base64_url_decode($signature); return $this->publicKey->verify($signed_bytes, $signature); } /** * URL-encoding-friendly base64 variant encoding. * * @param string $input * @return string */ public static function base64_url_encode($input) { return strtr(base64_encode($input), '+/', '-_'); } /** * URL-encoding-friendly base64 variant decoding. * * @param string $input * @return string */ public static function base64_url_decode($input) { return base64_decode(strtr($input, '-_', '+/')); } }