264 lines
12 KiB
PHP
264 lines
12 KiB
PHP
<?php
|
||
/*
|
||
* GNU Social - a federating social network
|
||
* Copyright (C) 2015, Free Software Foundation, Inc.
|
||
*
|
||
* 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/>.
|
||
*/
|
||
|
||
if (!defined('GNUSOCIAL')) { exit(1); }
|
||
|
||
/**
|
||
* Diaspora federation protocol plugin for GNU Social
|
||
*
|
||
* Depends on:
|
||
* - OStatus plugin
|
||
* - WebFinger plugin
|
||
*
|
||
* @package ProtocolDiasporaPlugin
|
||
* @maintainer Mikael Nordfeldth <mmn@hethane.se>
|
||
*/
|
||
|
||
// Depends on OStatus of course.
|
||
addPlugin('OStatus');
|
||
|
||
class DiasporaPlugin extends Plugin
|
||
{
|
||
const PLUGIN_VERSION = '0.2.0';
|
||
|
||
const REL_SEED_LOCATION = 'http://joindiaspora.com/seed_location';
|
||
const REL_GUID = 'http://joindiaspora.com/guid';
|
||
const REL_PUBLIC_KEY = 'diaspora-public-key';
|
||
|
||
public function onEndAttachPubkeyToUserXRD(Magicsig $magicsig, XML_XRD $xrd, Profile $target)
|
||
{
|
||
// So far we've only handled RSA keys, but it can change in the future,
|
||
// so be prepared. And remember to change the statically assigned type attribute below!
|
||
assert($magicsig->publicKey instanceof \phpseclib\Crypt\RSA);
|
||
$xrd->links[] = new XML_XRD_Element_Link(self::REL_PUBLIC_KEY,
|
||
base64_encode($magicsig->exportPublicKey()), 'RSA');
|
||
|
||
// Instead of choosing a random string, we calculate our GUID from the public key
|
||
// by fingerprint through a sha256 hash.
|
||
$xrd->links[] = new XML_XRD_Element_Link(self::REL_GUID,
|
||
strtolower($magicsig->toFingerprint()));
|
||
}
|
||
|
||
public function onMagicsigPublicKeyFromXRD(XML_XRD $xrd, &$pubkey)
|
||
{
|
||
// See if we have a Diaspora public key in the XRD response
|
||
$link = $xrd->get(self::REL_PUBLIC_KEY, 'RSA');
|
||
if (!is_null($link)) {
|
||
// If we do, decode it so we have the PKCS1 format (starts with -----BEGIN PUBLIC KEY-----)
|
||
$pkcs1 = base64_decode($link->href);
|
||
$magicsig = new Magicsig(Magicsig::DEFAULT_SIGALG); // Diaspora uses RSA-SHA256 (we do too)
|
||
try {
|
||
// Try to load the public key so we can get it in the standard Magic signature format
|
||
$magicsig->loadPublicKeyPKCS1($pkcs1);
|
||
// We found it and will now store it in $pubkey in a proper format!
|
||
// This is how it would be found in a well implemented XRD according to the standard.
|
||
$pubkey = 'data:application/magic-public-key,'.$magicsig->toString();
|
||
common_debug('magic-public-key found in diaspora-public-key: '.$pubkey);
|
||
return false;
|
||
} catch (ServerException $e) {
|
||
common_log(LOG_WARNING, $e->getMessage());
|
||
}
|
||
}
|
||
return true;
|
||
}
|
||
|
||
public function onPluginVersion(array &$versions): bool
|
||
{
|
||
$versions[] = array('name' => 'Diaspora',
|
||
'version' => self::PLUGIN_VERSION,
|
||
'author' => 'Mikael Nordfeldth',
|
||
'homepage' => GNUSOCIAL_ENGINE_URL,
|
||
// TRANS: Plugin description.
|
||
'rawdescription' => _m('Follow people across social networks that implement '.
|
||
'the <a href="https://diasporafoundation.org/">Diaspora</a> federation protocol.'));
|
||
|
||
return true;
|
||
}
|
||
|
||
public function onStartMagicEnvelopeToXML(MagicEnvelope $magic_env, XMLStringer $xs, $flavour=null, Profile $target=null)
|
||
{
|
||
// Since Diaspora doesn't use a separate namespace for their "extended"
|
||
// salmon slap, we'll have to resort to this workaround hack.
|
||
if ($flavour !== 'diaspora') {
|
||
return true;
|
||
}
|
||
|
||
// WARNING: This changes the $magic_env contents! Be aware of it.
|
||
|
||
/**
|
||
* https://wiki.diasporafoundation.org/Federation_protocol_overview
|
||
* http://www.rubydoc.info/github/Raven24/diaspora-federation/master/DiasporaFederation/Salmon/EncryptedSlap
|
||
*
|
||
* Constructing the encryption header
|
||
*/
|
||
|
||
// For some reason diaspora wants the salmon slap in a <diaspora> header.
|
||
$xs->elementStart('diaspora', array('xmlns'=>'https://joindiaspora.com/protocol'));
|
||
|
||
/**
|
||
* Choose an AES key and initialization vector, suitable for the
|
||
* aes-256-cbc cipher. I shall refer to this as the “inner key”
|
||
* and the “inner initialization vector (iv)”.
|
||
*/
|
||
$inner_key = new \phpseclib\Crypt\AES(\phpseclib\Crypt\AES::MODE_CBC);
|
||
$inner_key->setKeyLength(256); // set length to 256 bits (could be calculated, but let's be sure)
|
||
$inner_key->setKey(common_random_rawstr(32)); // 32 bytes from a (pseudo) random source
|
||
$inner_key->setIV(common_random_rawstr(16)); // 16 bytes is the block length
|
||
|
||
/**
|
||
* Construct the following XML snippet:
|
||
* <decrypted_header>
|
||
* <iv>((base64-encoded inner iv))</iv>
|
||
* <aes_key>((base64-encoded inner key))</aes_key>
|
||
* <author>
|
||
* <name>Alice Exampleman</name>
|
||
* <uri>acct:user@sender.example</uri>
|
||
* </author>
|
||
* </decrypted_header>
|
||
*/
|
||
$decrypted_header = sprintf('<decrypted_header><iv>%1$s</iv><aes_key>%2$s</aes_key><author_id>%3$s</author_id></decrypted_header>',
|
||
base64_encode($inner_key->iv),
|
||
base64_encode($inner_key->key),
|
||
$magic_env->getActor()->getAcctUri());
|
||
|
||
/**
|
||
* Construct another AES key and initialization vector suitable
|
||
* for the aes-256-cbc cipher. I shall refer to this as the
|
||
* “outer key” and the “outer initialization vector (iv)”.
|
||
*/
|
||
$outer_key = new \phpseclib\Crypt\AES(\phpseclib\Crypt\AES::MODE_CBC);
|
||
$outer_key->setKeyLength(256); // set length to 256 bits (could be calculated, but let's be sure)
|
||
$outer_key->setKey(common_random_rawstr(32)); // 32 bytes from a (pseudo) random source
|
||
$outer_key->setIV(common_random_rawstr(16)); // 16 bytes is the block length
|
||
|
||
/**
|
||
* Encrypt your <decrypted_header> XML snippet using the “outer key”
|
||
* and “outer iv” (using the aes-256-cbc cipher). This encrypted
|
||
* blob shall be referred to as “the ciphertext”.
|
||
*/
|
||
$ciphertext = $outer_key->encrypt($decrypted_header, \phpseclib\Crypt\RSA::PADDING_PKCS1);
|
||
|
||
/**
|
||
* Construct the following JSON object, which shall be referred to
|
||
* as “the outer aes key bundle”:
|
||
* {
|
||
* "iv": ((base64-encoded AES outer iv)),
|
||
* "key": ((base64-encoded AES outer key))
|
||
* }
|
||
*/
|
||
$outer_bundle = json_encode(array(
|
||
'iv' => base64_encode($outer_key->iv),
|
||
'key' => base64_encode($outer_key->key),
|
||
));
|
||
/**
|
||
* Encrypt the “outer aes key bundle” with Bob’s RSA public key.
|
||
* I shall refer to this as the “encrypted outer aes key bundle”.
|
||
*/
|
||
common_debug('Diaspora creating "outer aes key bundle", will require magic-public-key');
|
||
$key_fetcher = new MagicEnvelope();
|
||
$remote_keys = $key_fetcher->getKeyPair($target, true); // actually just gets the public key
|
||
$enc_outer = $remote_keys->publicKey->encrypt($outer_bundle, \phpseclib\Crypt\RSA::PADDING_PKCS1);
|
||
|
||
/**
|
||
* Construct the following JSON object, which I shall refer to as
|
||
* the “encrypted header json object”:
|
||
* {
|
||
* "aes_key": ((base64-encoded encrypted outer aes key bundle)),
|
||
* "ciphertext": ((base64-encoded ciphertextm from above))
|
||
* }
|
||
*/
|
||
$enc_header = json_encode(array(
|
||
'aes_key' => base64_encode($enc_outer),
|
||
'ciphertext' => base64_encode($ciphertext),
|
||
));
|
||
|
||
/**
|
||
* Construct the xml snippet:
|
||
* <encrypted_header>((base64-encoded encrypted header json object))</encrypted_header>
|
||
*/
|
||
$xs->element('encrypted_header', null, base64_encode($enc_header));
|
||
|
||
/**
|
||
* In order to prepare the payload message for inclusion in your
|
||
* salmon slap, you will:
|
||
*
|
||
* 1. Encrypt the payload message using the aes-256-cbc cipher and
|
||
* the “inner encryption key” and “inner encryption iv” you
|
||
* chose earlier.
|
||
* 2. Base64-encode the encrypted payload message.
|
||
*/
|
||
$payload = $inner_key->encrypt($magic_env->getData(), \phpseclib\Crypt\RSA::PADDING_PKCS1);
|
||
//FIXME: This means we don't actually put an <atom:entry> in the payload,
|
||
// since Diaspora has its own update method! Silly me. Read up on:
|
||
// https://wiki.diasporafoundation.org/Federation_Message_Semantics
|
||
$magic_env->signMessage(base64_encode($payload), 'application/xml');
|
||
|
||
|
||
// Since we have to change the content of me:data we'll just write the
|
||
// whole thing from scratch. We _could_ otherwise have just manipulated
|
||
// that element and added the encrypted_header in the EndMagicEnvelopeToXML event.
|
||
$xs->elementStart('me:env', array('xmlns:me' => MagicEnvelope::NS));
|
||
$xs->element('me:data', array('type' => $magic_env->getDataType()), $magic_env->getData());
|
||
$xs->element('me:encoding', null, $magic_env->getEncoding());
|
||
$xs->element('me:alg', null, $magic_env->getSignatureAlgorithm());
|
||
$xs->element('me:sig', null, $magic_env->getSignature());
|
||
$xs->elementEnd('me:env');
|
||
|
||
$xs->elementEnd('entry');
|
||
|
||
return false;
|
||
}
|
||
|
||
public function onSalmonSlap($endpoint_uri, MagicEnvelope $magic_env, Profile $target=null)
|
||
{
|
||
try {
|
||
$envxml = $magic_env->toXML($target, 'diaspora');
|
||
} catch (Exception $e) {
|
||
common_log(LOG_ERR, sprintf('Could not generate Magic Envelope XML (diaspora flavour) for profile id=='.$target->getID().': '.$e->getMessage()));
|
||
return false;
|
||
}
|
||
|
||
// Diaspora wants another POST format (base64url-encoded POST variable 'xml')
|
||
$headers = array('Content-Type: application/x-www-form-urlencoded');
|
||
|
||
// Another way to distinguish Diaspora from GNU social is that a POST with
|
||
// $headers=array('Content-Type: application/magic-envelope+xml') would return
|
||
// HTTP status code 422 Unprocessable Entity, at least as of 2015-10-04.
|
||
try {
|
||
$client = new HTTPClient();
|
||
$client->setBody('xml=' . Magicsig::base64_url_encode($envxml));
|
||
$response = $client->post($endpoint_uri, $headers);
|
||
} catch (Exception $e) {
|
||
common_log(LOG_ERR, "Diaspora-flavoured Salmon post to $endpoint_uri failed: " . $e->getMessage());
|
||
return false;
|
||
}
|
||
|
||
// 200 OK is the best response
|
||
// 202 Accepted is what we get from Diaspora for example
|
||
if (!in_array($response->getStatus(), array(200, 202))) {
|
||
common_log(LOG_ERR, sprintf('Salmon (from profile %d) endpoint %s returned status %s: %s',
|
||
$magic_env->getActor()->getID(), $endpoint_uri, $response->getStatus(), $response->getBody()));
|
||
return true;
|
||
}
|
||
|
||
// Success!
|
||
return false;
|
||
}
|
||
}
|