feat: user without tokens is redirected to new page, when mfa is enforced

README.md

@@ -74,6 +74,11 @@ Add an instance of the auth proc filter with example configuration `authswitcher
           'preferred_filter' => 'privacyidea:PrivacyideaAuthProc',
           'max_user_capability_attr' => 'maxUserCapability',
           'max_auth' => 'https://id.muni.cz/profile/maxAuth',
+          'mfa_excluded_sps' => [
+                [1] => 'example_entity_id1',
+                [2] => 'example_entity_id2',
+          ],
+          'setup_mfa_redirect_url' => 'mfa.id.muni.cz',
           //'password_contexts' => array_merge(AuthSwitcher::PASSWORD_CONTEXTS, [
           //    'my-custom-authn-context-for-password',
           //    '/^my-regex-.*/',
@@ -127,6 +132,8 @@ Add an instance of the auth proc filter with example configuration `authswitcher
 
 You can override which AuthnContextClassRefs are treated as password authentication (`password_contexts`) and MFA authentication (`mfa_contexts`). It is recommended to keep the contexts supported by default, e.g. by merging arrays. If you set `contexts_regex` to `true` and a value in one of these options is a regular expression (wrapped in `/`), all contexts matching the expression are matched (but the regular expression is never used as a response).
 
+Use `setup_mfa_redirect_url` for redirecting user without MFA tokens to page, where he can register it. User is redirected when MFA is enforced and service is not excluded from this behaviour by `mfa_excluded_sps` configuration option.
+
 ## MFA tokens
 
 This module expects that there will be a user attribute (`$attributes` aka `$state['Attributes']`) with

dictionaries/mfa.definition.json

+{
+  "setup_mfa_text": {
+    "en": "To access service, you have to configure multi-factor authentication token.",
+    "cs": "K přístupu ke službě nejprve musíte nastavit token pro vícefázové ověření."
+  },
+  "manage_tokens_button": {
+    "en": "Continue",
+    "cs": "Pokračovat"
+  }
+}

lib/Auth/Process/SwitchAuth.php

@@ -9,17 +9,25 @@ use SimpleSAML\Auth\State;
 use SimpleSAML\Configuration;
 use SimpleSAML\Error\Exception;
 use SimpleSAML\Logger;
+use SimpleSAML\Module;
 use SimpleSAML\Module\authswitcher\AuthnContextHelper;
 use SimpleSAML\Module\authswitcher\AuthSwitcher;
 use SimpleSAML\Module\authswitcher\ContextSettings;
 use SimpleSAML\Module\authswitcher\ProxyHelper;
 use SimpleSAML\Module\authswitcher\Utils;
+use SimpleSAML\Utils\HTTP;
 
 class SwitchAuth extends \SimpleSAML\Auth\ProcessingFilter
 {
     /* constants */
     private const DEBUG_PREFIX = 'authswitcher:SwitchAuth: ';
 
+    private const SETUP_MFA_URL = 'authswitcher/setupMFA.php';
+
+    public const SETUP_MFA_TPL_URL = 'authswitcher/setup-mfa-tpl.php';
+
+    public const PARAM_MFA_REDIRECT_URL = 'mfa_redirect_url';
+
     private $type_filter_array = [
         'TOTP' => 'privacyidea:PrivacyideaAuthProc',
         'WebAuthn' => 'privacyidea:PrivacyideaAuthProc',
@@ -62,6 +70,10 @@ class SwitchAuth extends \SimpleSAML\Auth\ProcessingFilter
 
     private $entityID;
 
+    private $mfa_excluded_sps;
+
+    private $setup_mfa_redirect_url;
+
     /**
      * @override
      *
@@ -95,6 +107,8 @@ class SwitchAuth extends \SimpleSAML\Auth\ProcessingFilter
         $this->sfa_len_attr = $config->getString('sfa_len_attr', $this->sfa_len_attr);
         $this->check_entropy = $config->getBoolean('check_entropy', $this->check_entropy);
         $this->entityID = $config->getValue('entityID', null);
+        $this->mfa_excluded_sps = $config->getArray('mfa_excluded_sps', []);
+        $this->setup_mfa_redirect_url = $config->getString('setup_mfa_redirect_url', "");
 
         list($this->password_contexts, $this->mfa_contexts, $password_contexts_patterns, $mfa_contexts_patterns)
             = ContextSettings::parseConfig($config);
@@ -120,6 +134,16 @@ class SwitchAuth extends \SimpleSAML\Auth\ProcessingFilter
 
         $usersCapabilities = $this->getMFAForUid($state);
 
+        if (
+            $mfaEnforced && empty($state['Attributes'][AuthSwitcher::MFA_TOKENS]) &&
+            !in_array($this->entityID, $this->mfa_excluded_sps) && !empty($this->setup_mfa_redirect_url)
+        ) {
+            $url = Module::getModuleURL(self::SETUP_MFA_URL);
+            $params = [];
+            $params[self::PARAM_MFA_REDIRECT_URL] = $this->setup_mfa_redirect_url;
+            HTTP::redirectTrustedURL($url, $params);
+        }
+
         self::info('user capabilities: ' . json_encode($usersCapabilities));
 
         self::setErrorHandling($state);
@@ -143,8 +167,8 @@ class SwitchAuth extends \SimpleSAML\Auth\ProcessingFilter
         self::info('supported requested contexts: ' . json_encode($this->supported_requested_contexts));
 
         $shouldPerformMFA = !$this->authnContextHelper->MFAin([
-            $upstreamContext,
-        ]) && ($mfaEnforced || $this->authnContextHelper->isMFAprefered($this->supported_requested_contexts));
+                $upstreamContext,
+            ]) && ($mfaEnforced || $this->authnContextHelper->isMFAprefered($this->supported_requested_contexts));
 
         if (
             $this->mfa_preferred_privacyidea_fail
@@ -160,7 +184,7 @@ class SwitchAuth extends \SimpleSAML\Auth\ProcessingFilter
         $maxUserCapability = '';
         if (
             in_array(AuthSwitcher::REFEDS_MFA, $usersCapabilities, true) || $this->authnContextHelper->MFAin([
-            $upstreamContext,
+                $upstreamContext,
             ])
         ) {
             $maxUserCapability = AuthSwitcher::REFEDS_MFA;

templates/setup-mfa-tpl.php

+<?php
+
+declare(strict_types=1);
+
+use SimpleSAML\Module\authswitcher\Auth\Process\SwitchAuth;
+
+$this->includeAtTemplateBase('includes/header.php');
+?>
+
+<div class="row">
+  <div>
+      <p><?php echo $this->t('{authswitcher:mfa:setup_mfa_text}'); ?></p>
+      <?php if (!empty($this->data[SwitchAuth::PARAM_MFA_REDIRECT_URL])) { ?>
+        <a class="btn btn-lg btn-block btn-primary"
+           href="<?php echo $this->data[SwitchAuth::PARAM_MFA_REDIRECT_URL]; ?>">
+            <?php echo $this->t('{authswitcher:mfa:manage_tokens_button}'); ?>
+        </a>
+      <?php } ?>
+
+  </div>
+</div>
+
+<?php
+$this->includeAtTemplateBase('includes/footer.php');
+?>

www/setupMFA.php

+<?php
+
+declare(strict_types=1);
+
+use SimpleSAML\Configuration;
+use SimpleSAML\Module\authswitcher\Auth\Process\SwitchAuth;
+use SimpleSAML\XHTML\Template;
+
+$config = Configuration::getInstance();
+$t = new Template($config, SwitchAuth::SETUP_MFA_TPL_URL);
+$t->data[SwitchAuth::PARAM_MFA_REDIRECT_URL] = $_REQUEST[SwitchAuth::PARAM_MFA_REDIRECT_URL];
+
+$t->show();