[saml] $_SESSION['user_id'] is empty, leads to redirect loop

[pminkler]

It seems my issue is met at:

\var\www\html\owncloud\apps\user_saml\appinfo\app.php line 54
OCP\User::isLoggedIn() is false, because in...
\var\www\html\owncloud\lib\private\user.php line 372
\OC::$server->getSession()->get('user_id') !== null
is null. My $_SESSION at the time is:

$_SESSION['SID_CREATED'] = (int) 1458312636
$_SESSION['LAST_ACTIVITY'] = (int) 1458314546
$_SESSION['OC_Version_Timestamp'] = (int) 1450706342
$_SESSION['OC_Version'] = array[4]
    $_SESSION['OC_Version'][0] = (int) 8
    $_SESSION['OC_Version'][1] = (int) 1
    $_SESSION['OC_Version'][2] = (int) 5
    $_SESSION['OC_Version'][3] = (int) 2
$_SESSION['OC_VersionString'] = (string) 8.1.5
$_SESSION['OC_Build'] = (string) 2015-12-21T13:58:19+00:00 47a2c3738cff363a477fcef011a838f3f05fec2e
$_SESSION['OC_Channel'] = (string) stable
$_SESSION['checkServer_succeeded'] = (bool) 1
$_SESSION['requesttoken'] = (string) qPfclVuxmt0Cma3lyq/RD3sZNzWus0

I don't know if it matters, but my $_REQUEST seems to say that I'm authenticated.
$_REQUEST['user_saml_logged_in'] = (string) 1
$_REQUEST['ochdifsb1rd4'] = (string) r78OgK48Q5V6cdSaPBAb7MCTqP6
$_REQUEST['PHPSESSID'] = (string) lDV962524CvnT595vEzCKeeCCy2
$_REQUEST['__utma'] = (string) 58122552.1425340076.1456513695.1456513695.1456513695.1
$_REQUEST['__utmc'] = (string) 58122552
$_REQUEST['__utmz'] = (string) 58122552.1456513695.1.1.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=(not provided)
$_REQUEST['XDEBUG_SESSION'] = (string) XDEBUG_SUBLIME
$_REQUEST['SimpleSAMLSessionID'] = (string) ba94d64fa6b0d0e2af5766297a3550ac
$_REQUEST['SimpleSAMLAuthToken'] = (string) _52a5c98a41e774bac024c5051fa07e210ade73fe70

I am using SQL for my simplesaml sessions. What is supposed to set $_SESSION['user_id']? What user is it the ID for, as the code hasn't even gotten to creating the Owncloud user that corresponds to my SAML user.

On a side note, I am confused by the line:
if (!OC_User::login('', '')) {
$error = true;
OC_Log::write('saml','Error trying to authenticate the user', OC_Log::DEBUG);
}

In \var\www\html\owncloud\apps\user_saml\appinfo\app.php. Are we attempting to login with an unkown user, just to create a failed login log?

Affected apps

user_saml

Expected behaviour

After SAML authentication, I am logged in

Actual behaviour

I am not logged in and am taken through a redirect loop.

Steps to reproduce

1. Forced login through SAML
2. Login with SAML
3. Get redirected back to /owncloud/index.php/apps/files/
4. See error of redirect loops

Server configuration

Operating system: Amazon EC2

Web server:

Database: mySQL

PHP version: 5.5.5

ownCloud version: 8.1

Client configuration

Browser: Chrome

Operating system: Windows 7

Logs

Web server error log

none

ownCloud log (data/owncloud.log)

none

Browser log

Just a bunch of attempts to load the same URL over and over again in Live HTTP Headers

[pminkler]

If setAttributes in lib/hooks.php sets the user_id, I never get there since post_login is never called.