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 $obj->importKeys(); // Loads Crypt_RSA objects etc.
97 // Throw out a big fat warning for keys of less than 1024 bits. (
98 // The only case these show up in would be imported or
99 // legacy very-old-StatusNet generated keypairs.
100 if (strlen($obj->publicKey->modulus->toBits()) < 1024) {
101 common_log(LOG_WARNING, sprintf('Salmon key with <1024 bits (%d) belongs to profile with id==%d',
102 strlen($obj->publicKey->modulus->toBits()),
110 public static function schemaDef()
114 'user_id' => array('type' => 'int', 'not null' => true, 'description' => 'user id'),
115 'keypair' => array('type' => 'text', 'description' => 'keypair text representation'),
116 'alg' => array('type' => 'varchar', 'length' => 64, 'description' => 'algorithm'),
118 'primary key' => array('user_id'),
119 'foreign keys' => array(
120 'magicsig_user_id_fkey' => array('profile', array('user_id' => 'id')),
126 * Save this keypair into the database.
128 * Overloads default insert behavior to encode the live key objects
129 * as a flat string for storage.
135 $this->keypair = $this->toString();
137 return parent::insert();
141 * Generate a new keypair for a local user and store in the database.
143 * Warning: this can be very slow on systems without the GMP module.
144 * Runtimes of 20-30 seconds are not unheard-of.
146 * @param int $user_id id of local user we're creating a key for
148 public function generate($user_id, $bits=1024)
150 $rsa = new Crypt_RSA();
152 $keypair = $rsa->createKey($bits);
154 $this->privateKey = new Crypt_RSA();
155 $this->privateKey->loadKey($keypair['privatekey']);
157 $this->publicKey = new Crypt_RSA();
158 $this->publicKey->loadKey($keypair['publickey']);
160 $this->user_id = $user_id;
165 * Encode the keypair or public key as a string.
167 * @param boolean $full_pair set to false to leave out the private key.
170 public function toString($full_pair = true)
172 $mod = Magicsig::base64_url_encode($this->publicKey->modulus->toBytes());
173 $exp = Magicsig::base64_url_encode($this->publicKey->exponent->toBytes());
175 if ($full_pair && $this->privateKey->exponent->toBytes()) {
176 $private_exp = '.' . Magicsig::base64_url_encode($this->privateKey->exponent->toBytes());
179 return 'RSA.' . $mod . '.' . $exp . $private_exp;
183 * Decode a string representation of an RSA public key or keypair
184 * as a Magicsig object which can be used to sign or verify.
186 * @param string $text
189 public static function fromString($text)
191 $magic_sig = new Magicsig();
194 $text = preg_replace('/\s+/', '', $text);
195 $magic_sig->importKeys($text);
197 // Please note this object will be missing the user_id field
202 * importKeys will load the object's keypair string, which initiates
203 * loadKey() and configures Crypt_RSA objects.
205 * @param string $keypair optional, otherwise the object's "keypair" property will be used
207 public function importKeys($keypair=null)
209 $keypair = $keypair ?: $this->keypair;
212 if (!preg_match('/RSA\.([^\.]+)\.([^\.]+)(\.([^\.]+))?/', $keypair, $matches)) {
213 common_debug('Magicsig error: RSA key not found in provided string.');
214 throw new ServerException('RSA key not found in keypair string.');
219 if (!empty($matches[4])) {
220 $private_exp = $matches[4];
222 $private_exp = false;
225 $this->loadKey($mod, $exp, 'public');
227 $this->loadKey($mod, $private_exp, 'private');
232 * Fill out $this->privateKey or $this->publicKey with a Crypt_RSA object
233 * representing the give key (as mod/exponent pair).
235 * @param string $mod base64-encoded
236 * @param string $exp base64-encoded exponent
237 * @param string $type one of 'public' or 'private'
239 public function loadKey($mod, $exp, $type = 'public')
241 common_log(LOG_DEBUG, "Adding ".$type." key: (".$mod .', '. $exp .")");
243 $rsa = new Crypt_RSA();
244 $rsa->signatureMode = CRYPT_RSA_SIGNATURE_PKCS1;
245 $rsa->setHash($this->getHash());
246 $rsa->modulus = new Math_BigInteger(Magicsig::base64_url_decode($mod), 256);
247 $rsa->k = strlen($rsa->modulus->toBytes());
248 $rsa->exponent = new Math_BigInteger(Magicsig::base64_url_decode($exp), 256);
250 if ($type == 'private') {
251 $this->privateKey = $rsa;
253 $this->publicKey = $rsa;
258 * Returns the name of the crypto algorithm used for this key.
262 public function getName()
268 * Returns the name of a hash function to use for signing with this key.
272 public function getHash()
274 switch ($this->alg) {
278 throw new ServerException('Unknown or unsupported hash algorithm for Salmon');
282 * Generate base64-encoded signature for the given byte string
283 * using our private key.
285 * @param string $bytes as raw byte string
286 * @return string base64url-encoded signature
288 public function sign($bytes)
290 $sig = $this->privateKey->sign($bytes);
291 if ($sig === false) {
292 throw new ServerException('Could not sign data');
294 return Magicsig::base64_url_encode($sig);
299 * @param string $signed_bytes as raw byte string
300 * @param string $signature as base64url encoded
303 public function verify($signed_bytes, $signature)
305 $signature = self::base64_url_decode($signature);
306 return $this->publicKey->verify($signed_bytes, $signature);
310 * URL-encoding-friendly base64 variant encoding.
312 * @param string $input
315 public static function base64_url_encode($input)
317 return strtr(base64_encode($input), '+/', '-_');
321 * URL-encoding-friendly base64 variant decoding.
323 * @param string $input
326 public static function base64_url_decode($input)
328 return base64_decode(strtr($input, '-_', '+/'));