Issue 8714: Make redirects more secure

diff --git a/mod/redir.php b/mod/redir.php
index 56cb13a06b97bc24adaf9005ad27b9f50086592c..cb1ca20e0e0f8d2c9bef12f53fbd90882fdf4178 100644 (file)
--- a/mod/redir.php
+++ b/mod/redir.php
@@ -31,6 +31,9 @@ use Friendica\Util\Network;
 use Friendica\Util\Strings;
 
 function redir_init(App $a) {
+       if (!Session::isAuthenticated()) {
+               throw new \Friendica\Network\HTTPException\ForbiddenException(DI::l10n()->t('Access denied.'));
+       }
 
        $url = $_GET['url'] ?? '';
        $quiet = !empty($_GET['quiet']) ? '&quiet=1' : '';
@@ -44,102 +47,105 @@ function redir_init(App $a) {
        // Try magic auth before the legacy stuff
        redir_magic($a, $cid, $url);
 
-       if (!empty($cid)) {
-               $fields = ['id', 'uid', 'nurl', 'url', 'addr', 'name', 'network', 'poll', 'issued-id', 'dfrn-id', 'duplex', 'pending'];
-               $contact = DBA::selectFirst('contact', $fields, ['id' => $cid, 'uid' => [0, local_user()]]);
-               if (!DBA::isResult($contact)) {
-                       notice(DI::l10n()->t('Contact not found.'));
-                       DI::baseUrl()->redirect();
-               }
+       if (empty($cid)) {
+               throw new \Friendica\Network\HTTPException\NotFoundException(DI::l10n()->t('Contact not found.'));
+       }
 
-               $contact_url = $contact['url'];
+       $fields = ['id', 'uid', 'nurl', 'url', 'addr', 'name', 'network', 'poll', 'issued-id', 'dfrn-id', 'duplex', 'pending'];
+       $contact = DBA::selectFirst('contact', $fields, ['id' => $cid, 'uid' => [0, local_user()]]);
+       if (!DBA::isResult($contact)) {
+               throw new \Friendica\Network\HTTPException\NotFoundException(DI::l10n()->t('Contact not found.'));
+       }
+
+       $contact_url = $contact['url'];
 
-               if (!Session::isAuthenticated() // Visitors (not logged in or not remotes) can't authenticate.
-                       || (!empty($a->contact['id']) && $a->contact['id'] == $cid)) // Local user is already authenticated.
-               {
-                       $a->redirect($url ?: $contact_url);
+       if (!empty($a->contact['id']) && $a->contact['id'] == $cid) {
+               // Local user is already authenticated.
+               redir_check_url($contact_url, $url);
+               $a->redirect($url ?: $contact_url);
+       }
+
+       if ($contact['uid'] == 0 && local_user()) {
+               // Let's have a look if there is an established connection
+               // between the public contact we have found and the local user.
+               $contact = DBA::selectFirst('contact', $fields, ['nurl' => $contact['nurl'], 'uid' => local_user()]);
+
+               if (DBA::isResult($contact)) {
+                       $cid = $contact['id'];
                }
 
-               if ($contact['uid'] == 0 && local_user()) {
-                       // Let's have a look if there is an established connection
-                       // between the public contact we have found and the local user.
-                       $contact = DBA::selectFirst('contact', $fields, ['nurl' => $contact['nurl'], 'uid' => local_user()]);
-
-                       if (DBA::isResult($contact)) {
-                               $cid = $contact['id'];
-                       }
-
-                       if (!empty($a->contact['id']) && $a->contact['id'] == $cid) {
-                               // Local user is already authenticated.
-                               $target_url = $url ?: $contact_url;
-                               Logger::log($contact['name'] . " is already authenticated. Redirecting to " . $target_url, Logger::DEBUG);
-                               $a->redirect($target_url);
-                       }
+               if (!empty($a->contact['id']) && $a->contact['id'] == $cid) {
+                       // Local user is already authenticated.
+                       redir_check_url($contact_url, $url);
+                       $target_url = $url ?: $contact_url;
+                       Logger::log($contact['name'] . " is already authenticated. Redirecting to " . $target_url, Logger::DEBUG);
+                       $a->redirect($target_url);
                }
+       }
 
-               if (remote_user()) {
-                       $host = substr(DI::baseUrl()->getUrlPath() . (DI::baseUrl()->getUrlPath() ? '/' . DI::baseUrl()->getUrlPath() : ''), strpos(DI::baseUrl()->getUrlPath(), '://') + 3);
-                       $remotehost = substr($contact['addr'], strpos($contact['addr'], '@') + 1);
-
-                       // On a local instance we have to check if the local user has already authenticated
-                       // with the local contact. Otherwise the local user would ask the local contact
-                       // for authentification everytime he/she is visiting a profile page of the local
-                       // contact.
-                       if (($host == $remotehost) && (Session::getRemoteContactID(Session::get('visitor_visiting')) == Session::get('visitor_id'))) {
-                               // Remote user is already authenticated.
-                               $target_url = $url ?: $contact_url;
-                               Logger::log($contact['name'] . " is already authenticated. Redirecting to " . $target_url, Logger::DEBUG);
-                               $a->redirect($target_url);
-                       }
+       if (remote_user()) {
+               $host = substr(DI::baseUrl()->getUrlPath() . (DI::baseUrl()->getUrlPath() ? '/' . DI::baseUrl()->getUrlPath() : ''), strpos(DI::baseUrl()->getUrlPath(), '://') + 3);
+               $remotehost = substr($contact['addr'], strpos($contact['addr'], '@') + 1);
+
+               // On a local instance we have to check if the local user has already authenticated
+               // with the local contact. Otherwise the local user would ask the local contact
+               // for authentification everytime he/she is visiting a profile page of the local
+               // contact.
+               if (($host == $remotehost) && (Session::getRemoteContactID(Session::get('visitor_visiting')) == Session::get('visitor_id'))) {
+                       // Remote user is already authenticated.
+                       redir_check_url($contact_url, $url);
+                       $target_url = $url ?: $contact_url;
+                       Logger::log($contact['name'] . " is already authenticated. Redirecting to " . $target_url, Logger::DEBUG);
+                       $a->redirect($target_url);
                }
+       }
 
-               // Doing remote auth with dfrn.
-               if (local_user() && (!empty($contact['dfrn-id']) || !empty($contact['issued-id'])) && empty($contact['pending'])) {
-                       $dfrn_id = $orig_id = (($contact['issued-id']) ? $contact['issued-id'] : $contact['dfrn-id']);
+       // Doing remote auth with dfrn.
+       if (local_user() && (!empty($contact['dfrn-id']) || !empty($contact['issued-id'])) && empty($contact['pending'])) {
+               $dfrn_id = $orig_id = (($contact['issued-id']) ? $contact['issued-id'] : $contact['dfrn-id']);
 
-                       if ($contact['duplex'] && $contact['issued-id']) {
-                               $orig_id = $contact['issued-id'];
-                               $dfrn_id = '1:' . $orig_id;
-                       }
-                       if ($contact['duplex'] && $contact['dfrn-id']) {
-                               $orig_id = $contact['dfrn-id'];
-                               $dfrn_id = '0:' . $orig_id;
-                       }
+               if ($contact['duplex'] && $contact['issued-id']) {
+                       $orig_id = $contact['issued-id'];
+                       $dfrn_id = '1:' . $orig_id;
+               }
+               if ($contact['duplex'] && $contact['dfrn-id']) {
+                       $orig_id = $contact['dfrn-id'];
+                       $dfrn_id = '0:' . $orig_id;
+               }
 
-                       $sec = Strings::getRandomHex();
+               $sec = Strings::getRandomHex();
 
-                       $fields = ['uid' => local_user(), 'cid' => $cid, 'dfrn_id' => $dfrn_id,
-                               'sec' => $sec, 'expire' => time() + 45];
-                       DBA::insert('profile_check', $fields);
+               $fields = ['uid' => local_user(), 'cid' => $cid, 'dfrn_id' => $dfrn_id,
+                       'sec' => $sec, 'expire' => time() + 45];
+               DBA::insert('profile_check', $fields);
 
-                       Logger::log('mod_redir: ' . $contact['name'] . ' ' . $sec, Logger::DEBUG);
+               Logger::log('mod_redir: ' . $contact['name'] . ' ' . $sec, Logger::DEBUG);
 
-                       $dest = (!empty($url) ? '&destination_url=' . $url : '');
+               $dest = (!empty($url) ? '&destination_url=' . $url : '');
 
-                       System::externalRedirect($contact['poll'] . '?dfrn_id=' . $dfrn_id
-                               . '&dfrn_version=' . DFRN_PROTOCOL_VERSION . '&type=profile&sec=' . $sec . $dest . $quiet);
-               }
+               System::externalRedirect($contact['poll'] . '?dfrn_id=' . $dfrn_id
+                       . '&dfrn_version=' . DFRN_PROTOCOL_VERSION . '&type=profile&sec=' . $sec . $dest . $quiet);
 
+               redir_check_url($contact_url, $url);
                $url = $url ?: $contact_url;
        }
 
+       if (empty($url)) {
+               throw new \Friendica\Network\HTTPException\NotFoundException(DI::l10n()->t('Contact not found.'));
+       }
+
        // If we don't have a connected contact, redirect with
        // the 'zrl' parameter.
-       if (!empty($url)) {
-               $my_profile = Profile::getMyURL();
+       $my_profile = Profile::getMyURL();
 
-               if (!empty($my_profile) && !Strings::compareLink($my_profile, $url)) {
-                       $separator = strpos($url, '?') ? '&' : '?';
+       if (!empty($my_profile) && !Strings::compareLink($my_profile, $url)) {
+               $separator = strpos($url, '?') ? '&' : '?';
 
-                       $url .= $separator . 'zrl=' . urlencode($my_profile);
-               }
-
-               Logger::log('redirecting to ' . $url, Logger::DEBUG);
-               $a->redirect($url);
+               $url .= $separator . 'zrl=' . urlencode($my_profile);
        }
 
-       notice(DI::l10n()->t('Contact not found.'));
-       DI::baseUrl()->redirect();
+       Logger::log('redirecting to ' . $url, Logger::DEBUG);
+       $a->redirect($url);
 }
 
 function redir_magic($a, $cid, $url)
@@ -152,15 +158,10 @@ function redir_magic($a, $cid, $url)
        $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid]);
        if (!DBA::isResult($contact)) {
                Logger::info('Contact not found', ['id' => $cid]);
-               // Shouldn't happen under normal conditions
-               notice(DI::l10n()->t('Contact not found.'));
-               if (!empty($url)) {
-                       System::externalRedirect($url);
-               } else {
-                       DI::baseUrl()->redirect();
-               }
+               throw new \Friendica\Network\HTTPException\NotFoundException(DI::l10n()->t('Contact not found.'));
        } else {
                $contact_url = $contact['url'];
+               redir_check_url($contact_url, $url);
                $target_url = $url ?: $contact_url;
        }
 
@@ -184,3 +185,20 @@ function redir_magic($a, $cid, $url)
                Logger::info('No magic for contact', ['contact' => $contact_url]);
        }
 }
+
+function redir_check_url(string $contact_url, string $url)
+{
+       if (empty($contact_url) || empty($url)) {
+               return;
+       }
+
+       $url_host = parse_url($url, PHP_URL_HOST);
+       $contact_url_host = parse_url($contact_url, PHP_URL_HOST);
+
+       if ($url_host == $contact_url_host) {
+               return;
+       }
+
+       Logger::error('URL check host mismatch', ['contact' => $contact_url, 'url' => $url]);
+       throw new \Friendica\Network\HTTPException\ForbiddenException(DI::l10n()->t('Access denied.'));
+}
\ No newline at end of file