3 * StatusNet - the distributed open-source microblogging tool
4 * Copyright (C) 2010, StatusNet, Inc.
6 * A sample module to show best practices for StatusNet plugins
10 * This program is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU Affero General Public License as published by
12 * the Free Software Foundation, either version 3 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU Affero General Public License for more details.
20 * You should have received a copy of the GNU Affero General Public License
21 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 * @author James Walker <james@status.net>
25 * @copyright 2010 StatusNet, Inc.
26 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
27 * @link http://status.net/
30 if (!defined('STATUSNET')) {
34 require_once 'Crypt/RSA.php';
36 class Magicsig extends Managed_DataObject
38 const PUBLICKEYREL = 'magic-public-key';
40 public $__table = 'magicsig';
43 * Key to user.id/profile.id for the local user whose key we're storing.
50 * Flattened string representation of the key pair; callers should
51 * usually use $this->publicKey and $this->privateKey directly,
52 * which hold live Crypt_RSA key objects.
59 * Crypto algorithm used for this key; currently only RSA-SHA256 is supported.
66 * Public RSA key; gets serialized in/out via $this->keypair string.
73 * PrivateRSA key; gets serialized in/out via $this->keypair string.
79 public function __construct($alg = 'RSA-SHA256')
85 * Fetch a Magicsig object from the cache or database on a field match.
91 static function getKV($k, $v=null)
93 $obj = parent::getKV($k, $v);
94 if ($obj instanceof Magicsig) {
95 // Please note we're replacing the $obj
96 // FIXME: There should be an import-key that modifies the fetched $obj
97 $obj = Magicsig::fromString($obj->keypair);
99 // Never allow less than 1024 bit keys.
100 // The only case these show up in would be imported or
101 // legacy very-old-StatusNet generated keypairs.
102 if (strlen($obj->publicKey->modulus->toBits()) < 1024) {
111 public static function schemaDef()
115 'user_id' => array('type' => 'int', 'not null' => true, 'description' => 'user id'),
116 'keypair' => array('type' => 'text', 'description' => 'keypair text representation'),
117 'alg' => array('type' => 'varchar', 'length' => 64, 'description' => 'algorithm'),
119 'primary key' => array('user_id'),
120 'foreign keys' => array(
121 'magicsig_user_id_fkey' => array('user', array('user_id' => 'id')),
127 * Save this keypair into the database.
129 * Overloads default insert behavior to encode the live key objects
130 * as a flat string for storage.
136 $this->keypair = $this->toString();
138 return parent::insert();
142 * Generate a new keypair for a local user and store in the database.
144 * Warning: this can be very slow on systems without the GMP module.
145 * Runtimes of 20-30 seconds are not unheard-of.
147 * @param int $user_id id of local user we're creating a key for
149 public function generate($user_id, $bits=1024)
151 $rsa = new Crypt_RSA();
153 $keypair = $rsa->createKey($bits);
155 $rsa->loadKey($keypair['privatekey']);
157 $this->privateKey = new Crypt_RSA();
158 $this->privateKey->loadKey($keypair['privatekey']);
160 $this->publicKey = new Crypt_RSA();
161 $this->publicKey->loadKey($keypair['publickey']);
163 $this->user_id = $user_id;
168 * Encode the keypair or public key as a string.
170 * @param boolean $full_pair set to false to leave out the private key.
173 public function toString($full_pair = true)
175 $mod = Magicsig::base64_url_encode($this->publicKey->modulus->toBytes());
176 $exp = Magicsig::base64_url_encode($this->publicKey->exponent->toBytes());
178 if ($full_pair && $this->privateKey->exponent->toBytes()) {
179 $private_exp = '.' . Magicsig::base64_url_encode($this->privateKey->exponent->toBytes());
182 return 'RSA.' . $mod . '.' . $exp . $private_exp;
186 * Decode a string representation of an RSA public key or keypair
187 * as a Magicsig object which can be used to sign or verify.
189 * @param string $text
192 public static function fromString($text)
194 $magic_sig = new Magicsig();
197 $text = preg_replace('/\s+/', '', $text);
200 if (!preg_match('/RSA\.([^\.]+)\.([^\.]+)(.([^\.]+))?/', $text, $matches)) {
201 common_debug('Magicsig error: RSA key not found in provided string.');
207 if (!empty($matches[4])) {
208 $private_exp = $matches[4];
210 $private_exp = false;
213 $magic_sig->loadKey($mod, $exp, 'public');
215 $magic_sig->loadKey($mod, $private_exp, 'private');
222 * Fill out $this->privateKey or $this->publicKey with a Crypt_RSA object
223 * representing the give key (as mod/exponent pair).
225 * @param string $mod base64-encoded
226 * @param string $exp base64-encoded exponent
227 * @param string $type one of 'public' or 'private'
229 public function loadKey($mod, $exp, $type = 'public')
231 common_log(LOG_DEBUG, "Adding ".$type." key: (".$mod .', '. $exp .")");
233 $rsa = new Crypt_RSA();
234 $rsa->signatureMode = CRYPT_RSA_SIGNATURE_PKCS1;
235 $rsa->setHash('sha256');
236 $rsa->modulus = new Math_BigInteger(Magicsig::base64_url_decode($mod), 256);
237 $rsa->k = strlen($rsa->modulus->toBytes());
238 $rsa->exponent = new Math_BigInteger(Magicsig::base64_url_decode($exp), 256);
240 if ($type == 'private') {
241 $this->privateKey = $rsa;
243 $this->publicKey = $rsa;
248 * Returns the name of the crypto algorithm used for this key.
252 public function getName()
258 * Returns the name of a hash function to use for signing with this key.
261 * @fixme is this used? doesn't seem to be called by name.
263 public function getHash()
265 switch ($this->alg) {
273 * Generate base64-encoded signature for the given byte string
274 * using our private key.
276 * @param string $bytes as raw byte string
277 * @return string base64-encoded signature
279 public function sign($bytes)
281 $sig = $this->privateKey->sign($bytes);
282 return Magicsig::base64_url_encode($sig);
287 * @param string $signed_bytes as raw byte string
288 * @param string $signature as base64
291 public function verify($signed_bytes, $signature)
293 $signature = Magicsig::base64_url_decode($signature);
294 return $this->publicKey->verify($signed_bytes, $signature);
298 * URL-encoding-friendly base64 variant encoding.
300 * @param string $input
303 public static function base64_url_encode($input)
305 return strtr(base64_encode($input), '+/', '-_');
309 * URL-encoding-friendly base64 variant decoding.
311 * @param string $input
314 public static function base64_url_decode($input)
316 return base64_decode(strtr($input, '-_', '+/'));