friendica/mod/dfrn_confirm.php

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19 KiB
PHP

<?php
/**
* @copyright Copyright (C) 2020, Friendica
*
* @license GNU AGPL version 3 or any later version
*
* 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 <https://www.gnu.org/licenses/>.
*
* Friendship acceptance for DFRN contacts
*
* There are two possible entry points and three scenarios.
*
* 1. A form was submitted by our user approving a friendship that originated elsewhere.
* This may also be called from dfrn_request to automatically approve a friendship.
*
* 2. We may be the target or other side of the conversation to scenario 1, and will
* interact with that process on our own user's behalf.
*
* @see PDF with dfrn specs: https://github.com/friendica/friendica/blob/stable/spec/dfrn2.pdf
* You also find a graphic which describes the confirmation process at
* https://github.com/friendica/friendica/blob/stable/spec/dfrn2_contact_confirmation.png
*/
use Friendica\App;
use Friendica\Core\Logger;
use Friendica\Core\Protocol;
use Friendica\Core\System;
use Friendica\Database\DBA;
use Friendica\DI;
use Friendica\Model\Contact;
use Friendica\Model\Group;
use Friendica\Model\Notify\Type;
use Friendica\Model\User;
use Friendica\Protocol\Activity;
use Friendica\Util\Crypto;
use Friendica\Util\DateTimeFormat;
use Friendica\Util\Strings;
use Friendica\Util\XML;
function dfrn_confirm_post(App $a, $handsfree = null)
{
$node = null;
if (is_array($handsfree)) {
/*
* We were called directly from dfrn_request due to automatic friend acceptance.
* Any $_POST parameters we may require are supplied in the $handsfree array.
*
*/
$node = $handsfree['node'];
$a->interactive = false; // notice() becomes a no-op since nobody is there to see it
} elseif ($a->argc > 1) {
$node = $a->argv[1];
}
/*
* Main entry point. Scenario 1. Our user received a friend request notification (perhaps
* from another site) and clicked 'Approve'.
* $POST['source_url'] is not set. If it is, it indicates Scenario 2.
*
* We may also have been called directly from dfrn_request ($handsfree != null) due to
* this being a page type which supports automatic friend acceptance. That is also Scenario 1
* since we are operating on behalf of our registered user to approve a friendship.
*/
if (empty($_POST['source_url'])) {
$uid = ($handsfree['uid'] ?? 0) ?: local_user();
if (!$uid) {
notice(DI::l10n()->t('Permission denied.'));
return;
}
$user = DBA::selectFirst('user', [], ['uid' => $uid]);
if (!DBA::isResult($user)) {
notice(DI::l10n()->t('Profile not found.'));
return;
}
// These data elements may come from either the friend request notification form or $handsfree array.
if (is_array($handsfree)) {
Logger::log('Confirm in handsfree mode');
$dfrn_id = $handsfree['dfrn_id'];
$intro_id = $handsfree['intro_id'];
$duplex = $handsfree['duplex'];
$cid = 0;
$hidden = intval($handsfree['hidden'] ?? 0);
} else {
$dfrn_id = Strings::escapeTags(trim($_POST['dfrn_id'] ?? ''));
$intro_id = intval($_POST['intro_id'] ?? 0);
$duplex = intval($_POST['duplex'] ?? 0);
$cid = intval($_POST['contact_id'] ?? 0);
$hidden = intval($_POST['hidden'] ?? 0);
}
/*
* Ensure that dfrn_id has precedence when we go to find the contact record.
* We only want to search based on contact id if there is no dfrn_id,
* e.g. for OStatus network followers.
*/
if (strlen($dfrn_id)) {
$cid = 0;
}
Logger::log('Confirming request for dfrn_id (issued) ' . $dfrn_id);
if ($cid) {
Logger::log('Confirming follower with contact_id: ' . $cid);
}
/*
* The other person will have been issued an ID when they first requested friendship.
* Locate their record. At this time, their record will have both pending and blocked set to 1.
* There won't be any dfrn_id if this is a network follower, so use the contact_id instead.
*/
$r = q("SELECT *
FROM `contact`
WHERE (
(`issued-id` != '' AND `issued-id` = '%s')
OR
(`id` = %d AND `id` != 0)
)
AND `uid` = %d
AND `duplex` = 0
LIMIT 1",
DBA::escape($dfrn_id),
intval($cid),
intval($uid)
);
if (!DBA::isResult($r)) {
Logger::log('Contact not found in DB.');
notice(DI::l10n()->t('Contact not found.'));
notice(DI::l10n()->t('This may occasionally happen if contact was requested by both persons and it has already been approved.'));
return;
}
$contact = $r[0];
$contact_id = $contact['id'];
$relation = $contact['rel'];
$site_pubkey = $contact['site-pubkey'];
$dfrn_confirm = $contact['confirm'];
$aes_allow = $contact['aes_allow'];
$protocol = $contact['network'];
/*
* Generate a key pair for all further communications with this person.
* We have a keypair for every contact, and a site key for unknown people.
* This provides a means to carry on relationships with other people if
* any single key is compromised. It is a robust key. We're much more
* worried about key leakage than anybody cracking it.
*/
$res = Crypto::newKeypair(4096);
$private_key = $res['prvkey'];
$public_key = $res['pubkey'];
// Save the private key. Send them the public key.
$fields = ['prvkey' => $private_key, 'protocol' => Protocol::DFRN];
DBA::update('contact', $fields, ['id' => $contact_id]);
$params = [];
/*
* Per the DFRN protocol, we will verify both ends by encrypting the dfrn_id with our
* site private key (person on the other end can decrypt it with our site public key).
* Then encrypt our profile URL with the other person's site public key. They can decrypt
* it with their site private key. If the decryption on the other end fails for either
* item, it indicates tampering or key failure on at least one site and we will not be
* able to provide a secure communication pathway.
*
* If other site is willing to accept full encryption, (aes_allow is 1 AND we have php5.3
* or later) then we encrypt the personal public key we send them using AES-256-CBC and a
* random key which is encrypted with their site public key.
*/
$src_aes_key = openssl_random_pseudo_bytes(64);
$result = '';
openssl_private_encrypt($dfrn_id, $result, $user['prvkey']);
$params['dfrn_id'] = bin2hex($result);
$params['public_key'] = $public_key;
$my_url = DI::baseUrl() . '/profile/' . $user['nickname'];
openssl_public_encrypt($my_url, $params['source_url'], $site_pubkey);
$params['source_url'] = bin2hex($params['source_url']);
if ($aes_allow && function_exists('openssl_encrypt')) {
openssl_public_encrypt($src_aes_key, $params['aes_key'], $site_pubkey);
$params['aes_key'] = bin2hex($params['aes_key']);
$params['public_key'] = bin2hex(openssl_encrypt($public_key, 'AES-256-CBC', $src_aes_key));
}
$params['dfrn_version'] = DFRN_PROTOCOL_VERSION;
if ($duplex == 1) {
$params['duplex'] = 1;
}
if ($user['page-flags'] == User::PAGE_FLAGS_COMMUNITY) {
$params['page'] = 1;
}
if ($user['page-flags'] == User::PAGE_FLAGS_PRVGROUP) {
$params['page'] = 2;
}
Logger::debug('Confirm: posting data', ['confirm' => $dfrn_confirm, 'parameter' => $params]);
/*
*
* POST all this stuff to the other site.
* Temporarily raise the network timeout to 120 seconds because the default 60
* doesn't always give the other side quite enough time to decrypt everything.
*
*/
$res = DI::httpRequest()->post($dfrn_confirm, $params, [], 120)->getBody();
Logger::log(' Confirm: received data: ' . $res, Logger::DATA);
// Now figure out what they responded. Try to be robust if the remote site is
// having difficulty and throwing up errors of some kind.
$leading_junk = substr($res, 0, strpos($res, '<?xml'));
$res = substr($res, strpos($res, '<?xml'));
if (!strlen($res)) {
// No XML at all, this exchange is messed up really bad.
// We shouldn't proceed, because the xml parser might choke,
// and $status is going to be zero, which indicates success.
// We can hardly call this a success.
notice(DI::l10n()->t('Response from remote site was not understood.'));
return;
}
if (strlen($leading_junk) && DI::config()->get('system', 'debugging')) {
// This might be more common. Mixed error text and some XML.
// If we're configured for debugging, show the text. Proceed in either case.
notice(DI::l10n()->t('Unexpected response from remote site: ') . $leading_junk);
}
if (stristr($res, "<status") === false) {
// wrong xml! stop here!
Logger::log('Unexpected response posting to ' . $dfrn_confirm);
notice(DI::l10n()->t('Unexpected response from remote site: ') . EOL . htmlspecialchars($res));
return;
}
$xml = XML::parseString($res);
$status = (int) $xml->status;
$message = XML::unescape($xml->message); // human readable text of what may have gone wrong.
switch ($status) {
case 0:
info(DI::l10n()->t("Confirmation completed successfully."));
break;
case 1:
// birthday paradox - generate new dfrn-id and fall through.
$new_dfrn_id = Strings::getRandomHex();
q("UPDATE contact SET `issued-id` = '%s' WHERE `id` = %d AND `uid` = %d",
DBA::escape($new_dfrn_id),
intval($contact_id),
intval($uid)
);
case 2:
notice(DI::l10n()->t("Temporary failure. Please wait and try again."));
break;
case 3:
notice(DI::l10n()->t("Introduction failed or was revoked."));
break;
}
if (strlen($message)) {
notice(DI::l10n()->t('Remote site reported: ') . $message);
}
if (($status == 0) && $intro_id) {
$intro = DBA::selectFirst('intro', ['note'], ['id' => $intro_id]);
if (DBA::isResult($intro)) {
DBA::update('contact', ['reason' => $intro['note']], ['id' => $contact_id]);
}
// Success. Delete the notification.
DBA::delete('intro', ['id' => $intro_id]);
}
if ($status != 0) {
return;
}
/*
* We have now established a relationship with the other site.
* Let's make our own personal copy of their profile photo so we don't have
* to always load it from their site.
*
* We will also update the contact record with the nature and scope of the relationship.
*/
Contact::updateAvatar($contact_id, $contact['photo']);
Logger::log('dfrn_confirm: confirm - imported photos');
$new_relation = Contact::FOLLOWER;
if (($relation == Contact::SHARING) || ($duplex)) {
$new_relation = Contact::FRIEND;
}
if (($relation == Contact::SHARING) && ($duplex)) {
$duplex = 0;
}
$r = q("UPDATE `contact` SET `rel` = %d,
`name-date` = '%s',
`uri-date` = '%s',
`blocked` = 0,
`pending` = 0,
`duplex` = %d,
`hidden` = %d,
`network` = '%s' WHERE `id` = %d
",
intval($new_relation),
DBA::escape(DateTimeFormat::utcNow()),
DBA::escape(DateTimeFormat::utcNow()),
intval($duplex),
intval($hidden),
DBA::escape(Protocol::DFRN),
intval($contact_id)
);
// reload contact info
$contact = DBA::selectFirst('contact', [], ['id' => $contact_id]);
Group::addMember(User::getDefaultGroup($uid, $contact["network"]), $contact['id']);
// Let's send our user to the contact editor in case they want to
// do anything special with this new friend.
if ($handsfree === null) {
DI::baseUrl()->redirect('contact/' . intval($contact_id));
} else {
return;
}
//NOTREACHED
}
/*
* End of Scenario 1. [Local confirmation of remote friend request].
*
* Begin Scenario 2. This is the remote response to the above scenario.
* This will take place on the site that originally initiated the friend request.
* In the section above where the confirming party makes a POST and
* retrieves xml status information, they are communicating with the following code.
*/
if (!empty($_POST['source_url'])) {
// We are processing an external confirmation to an introduction created by our user.
$public_key = $_POST['public_key'] ?? '';
$dfrn_id = hex2bin($_POST['dfrn_id'] ?? '');
$source_url = hex2bin($_POST['source_url'] ?? '');
$aes_key = $_POST['aes_key'] ?? '';
$duplex = intval($_POST['duplex'] ?? 0);
$page = intval($_POST['page'] ?? 0);
$forum = (($page == 1) ? 1 : 0);
$prv = (($page == 2) ? 1 : 0);
Logger::notice('requestee contacted', ['node' => $node]);
Logger::debug('request', ['POST' => $_POST]);
// If $aes_key is set, both of these items require unpacking from the hex transport encoding.
if (!empty($aes_key)) {
$aes_key = hex2bin($aes_key);
$public_key = hex2bin($public_key);
}
// Find our user's account
$user = DBA::selectFirst('user', [], ['nickname' => $node]);
if (!DBA::isResult($user)) {
$message = DI::l10n()->t('No user record found for \'%s\' ', $node);
System::xmlExit(3, $message); // failure
// NOTREACHED
}
$my_prvkey = $user['prvkey'];
$local_uid = $user['uid'];
if (!strstr($my_prvkey, 'PRIVATE KEY')) {
$message = DI::l10n()->t('Our site encryption key is apparently messed up.');
System::xmlExit(3, $message);
}
// verify everything
$decrypted_source_url = "";
openssl_private_decrypt($source_url, $decrypted_source_url, $my_prvkey);
if (!strlen($decrypted_source_url)) {
$message = DI::l10n()->t('Empty site URL was provided or URL could not be decrypted by us.');
System::xmlExit(3, $message);
// NOTREACHED
}
$contact = DBA::selectFirst('contact', [], ['url' => $decrypted_source_url, 'uid' => $local_uid]);
if (!DBA::isResult($contact)) {
if (strstr($decrypted_source_url, 'http:')) {
$newurl = str_replace('http:', 'https:', $decrypted_source_url);
} else {
$newurl = str_replace('https:', 'http:', $decrypted_source_url);
}
$contact = DBA::selectFirst('contact', [], ['url' => $newurl, 'uid' => $local_uid]);
if (!DBA::isResult($contact)) {
// this is either a bogus confirmation (?) or we deleted the original introduction.
$message = DI::l10n()->t('Contact record was not found for you on our site.');
System::xmlExit(3, $message);
return; // NOTREACHED
}
}
$relation = $contact['rel'];
// Decrypt all this stuff we just received
$foreign_pubkey = $contact['site-pubkey'];
$dfrn_record = $contact['id'];
if (!$foreign_pubkey) {
$message = DI::l10n()->t('Site public key not available in contact record for URL %s.', $decrypted_source_url);
System::xmlExit(3, $message);
}
$decrypted_dfrn_id = "";
openssl_public_decrypt($dfrn_id, $decrypted_dfrn_id, $foreign_pubkey);
if (strlen($aes_key)) {
$decrypted_aes_key = "";
openssl_private_decrypt($aes_key, $decrypted_aes_key, $my_prvkey);
$dfrn_pubkey = openssl_decrypt($public_key, 'AES-256-CBC', $decrypted_aes_key);
} else {
$dfrn_pubkey = $public_key;
}
if (DBA::exists('contact', ['dfrn-id' => $decrypted_dfrn_id])) {
$message = DI::l10n()->t('The ID provided by your system is a duplicate on our system. It should work if you try again.');
System::xmlExit(1, $message); // Birthday paradox - duplicate dfrn-id
// NOTREACHED
}
$r = q("UPDATE `contact` SET `dfrn-id` = '%s', `pubkey` = '%s' WHERE `id` = %d",
DBA::escape($decrypted_dfrn_id),
DBA::escape($dfrn_pubkey),
intval($dfrn_record)
);
if (!DBA::isResult($r)) {
$message = DI::l10n()->t('Unable to set your contact credentials on our system.');
System::xmlExit(3, $message);
}
// It's possible that the other person also requested friendship.
// If it is a duplex relationship, ditch the issued-id if one exists.
if ($duplex) {
q("UPDATE `contact` SET `issued-id` = '' WHERE `id` = %d",
intval($dfrn_record)
);
}
// We're good but now we have to scrape the profile photo and send notifications.
$contact = DBA::selectFirst('contact', ['photo'], ['id' => $dfrn_record]);
if (DBA::isResult($contact)) {
$photo = $contact['photo'];
} else {
$photo = DI::baseUrl() . '/images/person-300.jpg';
}
Contact::updateAvatar($dfrn_record, $photo);
Logger::log('dfrn_confirm: request - photos imported');
$new_relation = Contact::SHARING;
if (($relation == Contact::FOLLOWER) || ($duplex)) {
$new_relation = Contact::FRIEND;
}
if (($relation == Contact::FOLLOWER) && ($duplex)) {
$duplex = 0;
}
$r = q("UPDATE `contact` SET
`rel` = %d,
`name-date` = '%s',
`uri-date` = '%s',
`blocked` = 0,
`pending` = 0,
`duplex` = %d,
`forum` = %d,
`prv` = %d,
`network` = '%s' WHERE `id` = %d
",
intval($new_relation),
DBA::escape(DateTimeFormat::utcNow()),
DBA::escape(DateTimeFormat::utcNow()),
intval($duplex),
intval($forum),
intval($prv),
DBA::escape(Protocol::DFRN),
intval($dfrn_record)
);
if (!DBA::isResult($r)) { // indicates schema is messed up or total db failure
$message = DI::l10n()->t('Unable to update your contact profile details on our system');
System::xmlExit(3, $message);
}
// Otherwise everything seems to have worked and we are almost done. Yay!
// Send an email notification
Logger::log('dfrn_confirm: request: info updated');
$combined = null;
$r = q("SELECT `contact`.*, `user`.*
FROM `contact`
LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
WHERE `contact`.`id` = %d
LIMIT 1",
intval($dfrn_record)
);
if (DBA::isResult($r)) {
$combined = $r[0];
if ($combined['notify-flags'] & Type::CONFIRM) {
$mutual = ($new_relation == Contact::FRIEND);
notification([
'type' => Type::CONFIRM,
'notify_flags' => $combined['notify-flags'],
'language' => $combined['language'],
'to_name' => $combined['username'],
'to_email' => $combined['email'],
'uid' => $combined['uid'],
'link' => DI::baseUrl() . '/contact/' . $dfrn_record,
'source_name' => ((strlen(stripslashes($combined['name']))) ? stripslashes($combined['name']) : DI::l10n()->t('[Name Withheld]')),
'source_link' => $combined['url'],
'source_photo' => $combined['photo'],
'verb' => ($mutual ? Activity::FRIEND : Activity::FOLLOW),
'otype' => 'intro'
]);
}
}
System::xmlExit(0); // Success
return; // NOTREACHED
////////////////////// End of this scenario ///////////////////////////////////////////////
}
// somebody arrived here by mistake or they are fishing. Send them to the homepage.
DI::baseUrl()->redirect();
// NOTREACHED
}