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';
39 const DIASPORA_PUBLICKEYREL = 'diaspora-public-key';
41 const DEFAULT_KEYLEN = 1024;
42 const DEFAULT_SIGALG = 'RSA-SHA256';
44 public $__table = 'magicsig';
47 * Key to user.id/profile.id for the local user whose key we're storing.
54 * Flattened string representation of the key pair; callers should
55 * usually use $this->publicKey and $this->privateKey directly,
56 * which hold live Crypt_RSA key objects.
63 * Crypto algorithm used for this key; currently only RSA-SHA256 is supported.
70 * Public RSA key; gets serialized in/out via $this->keypair string.
77 * PrivateRSA key; gets serialized in/out via $this->keypair string.
83 public function __construct($alg=self::DEFAULT_SIGALG)
89 * Fetch a Magicsig object from the cache or database on a field match.
95 static function getKV($k, $v=null)
97 $obj = parent::getKV($k, $v);
98 if ($obj instanceof Magicsig) {
99 $obj->importKeys(); // Loads Crypt_RSA objects etc.
101 // Throw out a big fat warning for keys of less than 1024 bits. (
102 // The only case these show up in would be imported or
103 // legacy very-old-StatusNet generated keypairs.
104 if (strlen($obj->publicKey->modulus->toBits()) < 1024) {
105 common_log(LOG_WARNING, sprintf('Salmon key with <1024 bits (%d) belongs to profile with id==%d',
106 strlen($obj->publicKey->modulus->toBits()),
114 public static function schemaDef()
118 'user_id' => array('type' => 'int', 'not null' => true, 'description' => 'user id'),
119 'keypair' => array('type' => 'text', 'description' => 'keypair text representation'),
120 'alg' => array('type' => 'varchar', 'length' => 64, 'description' => 'algorithm'),
122 'primary key' => array('user_id'),
123 'foreign keys' => array(
124 'magicsig_user_id_fkey' => array('profile', array('user_id' => 'id')),
130 * Save this keypair into the database.
132 * Overloads default insert behavior to encode the live key objects
133 * as a flat string for storage.
139 $this->keypair = $this->toString(true);
141 return parent::insert();
145 * Generate a new keypair for a local user and store in the database.
147 * Warning: this can be very slow on systems without the GMP module.
148 * Runtimes of 20-30 seconds are not unheard-of.
150 * FIXME: More than 1024 bits please. But StatusNet _discards_ non-1024 bits,
151 * so we'll have to wait the last mohican out before switching defaults.
153 * @param User $user the local user (since we don't have remote private keys)
155 public static function generate(User $user, $bits=self::DEFAULT_KEYLEN, $alg=self::DEFAULT_SIGALG)
157 $magicsig = new Magicsig($alg);
158 $magicsig->user_id = $user->id;
160 $rsa = new Crypt_RSA();
162 $keypair = $rsa->createKey($bits);
164 $magicsig->privateKey = new Crypt_RSA();
165 $magicsig->privateKey->loadKey($keypair['privatekey']);
167 $magicsig->publicKey = new Crypt_RSA();
168 $magicsig->publicKey->loadKey($keypair['publickey']);
170 $magicsig->insert(); // will do $this->keypair = $this->toString(true);
171 $magicsig->importKeys(); // seems it's necessary to re-read keys from text keypair
177 * Encode the keypair or public key as a string.
179 * @param boolean $full_pair set to true to include the private key.
182 public function toString($full_pair=false)
184 $mod = Magicsig::base64_url_encode($this->publicKey->modulus->toBytes());
185 $exp = Magicsig::base64_url_encode($this->publicKey->exponent->toBytes());
187 if ($full_pair && $this->privateKey instanceof Crypt_RSA && $this->privateKey->exponent->toBytes()) {
188 $private_exp = '.' . Magicsig::base64_url_encode($this->privateKey->exponent->toBytes());
191 return 'RSA.' . $mod . '.' . $exp . $private_exp;
194 public function exportPublicKey($format=CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
196 $this->publicKey->setPublicKey();
197 return $this->publicKey->getPublicKey($format);
201 * importKeys will load the object's keypair string, which initiates
202 * loadKey() and configures Crypt_RSA objects.
204 * @param string $keypair optional, otherwise the object's "keypair" property will be used
206 public function importKeys($keypair=null)
208 $this->keypair = $keypair===null ? $this->keypair : preg_replace('/\s+/', '', $keypair);
211 if (!preg_match('/RSA\.([^\.]+)\.([^\.]+)(\.([^\.]+))?/', $this->keypair, $matches)) {
212 common_debug('Magicsig error: RSA key not found in provided string.');
213 throw new ServerException('RSA key not found in keypair string.');
218 if (!empty($matches[4])) {
219 $private_exp = $matches[4];
221 $private_exp = false;
224 $this->loadKey($mod, $exp, 'public');
226 $this->loadKey($mod, $private_exp, 'private');
231 * Fill out $this->privateKey or $this->publicKey with a Crypt_RSA object
232 * representing the give key (as mod/exponent pair).
234 * @param string $mod base64-encoded
235 * @param string $exp base64-encoded exponent
236 * @param string $type one of 'public' or 'private'
238 public function loadKey($mod, $exp, $type = 'public')
240 $rsa = new Crypt_RSA();
241 $rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
242 $rsa->setHash($this->getHash());
243 $rsa->modulus = new Math_BigInteger(Magicsig::base64_url_decode($mod), 256);
244 $rsa->k = strlen($rsa->modulus->toBytes());
245 $rsa->exponent = new Math_BigInteger(Magicsig::base64_url_decode($exp), 256);
247 if ($type == 'private') {
248 $this->privateKey = $rsa;
250 $this->publicKey = $rsa;
255 * Returns the name of the crypto algorithm used for this key.
259 public function getName()
265 * Returns the name of a hash function to use for signing with this key.
269 public function getHash()
271 switch ($this->alg) {
275 throw new ServerException('Unknown or unsupported hash algorithm for Salmon');
279 * Generate base64-encoded signature for the given byte string
280 * using our private key.
282 * @param string $bytes as raw byte string
283 * @return string base64url-encoded signature
285 public function sign($bytes)
287 $sig = $this->privateKey->sign($bytes);
288 if ($sig === false) {
289 throw new ServerException('Could not sign data');
291 return Magicsig::base64_url_encode($sig);
296 * @param string $signed_bytes as raw byte string
297 * @param string $signature as base64url encoded
300 public function verify($signed_bytes, $signature)
302 $signature = self::base64_url_decode($signature);
303 return $this->publicKey->verify($signed_bytes, $signature);
307 * URL-encoding-friendly base64 variant encoding.
309 * @param string $input
312 public static function base64_url_encode($input)
314 return strtr(base64_encode($input), '+/', '-_');
318 * URL-encoding-friendly base64 variant decoding.
320 * @param string $input
323 public static function base64_url_decode($input)
325 return base64_decode(strtr($input, '-_', '+/'));