Make OIDC discovery url configurable

Add docker test case for Microsoft Azure OIDC

README.md

@@ -162,10 +162,16 @@ Not all configuration options from `authoauth2:OAuth2` are supported in `OpenIDC
               'clientSecret' => '36aefb235314bad5df075363b79cbbcd',
 
               // Most Optional settings for OAuth2 above can be used
-              // *** New Optional ***
+              // *** Optional ***
               // Customize post logout redirect, if you don't want to use the standard /module.php/authoauth2/loggedout.php
               'postLogoutRedirectUri' => 'https://myapp.example.com/loggedout'
 
+              // Set a specific discovery url. Default is $issuer/.well-known/openid-configuration
+              'discoveryUrl' => 'https://login.microsoftonline.com/common/.well-known/openid-configuration',
+              // Check if the issuer in the ID token matches the one from discovery. Default true. For some multi-tenant
+              // applications (for example cross tenant Azure logins) the token issuer varies with tenant
+              'validateIssuer' => false,
+
               // Earlier version OpenIDConnect authsource doesn't support using `scopes` for overriding scope
               //'urlAuthorizeOptions' => [
               //    'scope' => 'openid'
@@ -177,7 +183,7 @@ If your OP supports front channel single logout, you can configure `https://host
 
 ## Provider Specific Usage
 
-There are numerous [Offical](http://oauth2-client.thephpleague.com/providers/league/) and [Third-Party](http://oauth2-client.thephpleague.com/providers/thirdparty/) providers
+There are numerous [Official](http://oauth2-client.thephpleague.com/providers/league/) and [Third-Party](http://oauth2-client.thephpleague.com/providers/thirdparty/) providers
 that you can use instead of the generic OAuth2 provider. Using one of those providers can simplify the configurations.
 
 To use a provider you must first install it `composer require league/oauth2-some-provider`

docker/config/authsources.php

@@ -16,6 +16,13 @@ $config = array(
          */
     ],
 
+    'templateMicrosoft' => [
+        'authoauth2:OAuth2',
+        'template' => 'MicrosoftGraphV1',
+        'clientId' => 'f579dc6e-58f5-41a8-8bbf-96d54eacfe8d',
+        'clientSecret' => 'GXc8Q~mgI7kTBllrvpBthUEioeARdjrRYORSyda4',
+    ],
+
     /** Test using Google OIDC but with config explicitly define rather than pulled from .well-know */
     'templateGoogle' => [
         'authoauth2:OAuth2',
@@ -38,6 +45,18 @@ $config = array(
          */
     ],
 
+    /** Using the OIDC authsource for MS logins */
+    'microsoftOIDCSource' => [
+        'authoauth2:OpenIDConnect',
+        'issuer' => 'https://sts.windows.net/{tenantid}/',
+        // When using the 'common' discovery endpoint it allows any Azure user to authenticate, however
+        // the token issuer is tenant specific and will not match what is in the common discovery document.
+        'validateIssuer' => false,  // issuer is just used to confirm correct discovery endpoint loaded
+        'discoveryUrl' => 'https://login.microsoftonline.com/common/.well-known/openid-configuration',
+        'clientId' => 'f579dc6e-58f5-41a8-8bbf-96d54eacfe8d',
+        'clientSecret' => 'GXc8Q~mgI7kTBllrvpBthUEioeARdjrRYORSyda4',
+    ],
+
 
     // This is a authentication source which handles admin authentication.
     'admin' => array(

lib/Providers/OpenIDConnectProvider.php

@@ -24,6 +24,8 @@ class OpenIDConnectProvider extends AbstractProvider
      */
     protected string $issuer;
 
+    protected string $discoveryUrl;
+
     /**
      * @var ?Configuration
      */
@@ -39,13 +41,20 @@ class OpenIDConnectProvider extends AbstractProvider
      */
     private array $defaultScopes = [];
 
+    protected bool $validateIssuer = false;
+
     public function __construct(array $options = [], array $collaborators = [])
     {
         parent::__construct($options, $collaborators);
 
         $optionsConfig = Configuration::loadFromArray($options);
         $this->issuer = $optionsConfig->getString('issuer');
+        $this->discoveryUrl = $optionsConfig->getOptionalString(
+            'discoveryUrl',
+            rtrim($this->issuer, '/') . self::CONFIGURATION_PATH
+        );
         $this->defaultScopes = $optionsConfig->getOptionalArray('scopes', ['openid', 'profile']);
+        $this->validateIssuer = $optionsConfig->getOptionalBoolean('validateIssuer', true);
     }
 
     /**
@@ -95,8 +104,13 @@ class OpenIDConnectProvider extends AbstractProvider
             if (!in_array($this->clientId, $aud)) {
                 throw new IdentityProviderException("ID token has incorrect audience", 0, $claims->aud);
             }
-            if ($claims->iss !== $this->issuer) {
-                throw new IdentityProviderException("ID token has incorrect issuer", 0, $claims->iss);
+            // When working with Azure the issuer is tenant specific, but the discovery metadata can be for all tenants
+            if ($this->validateIssuer && $claims->iss !== $this->issuer) {
+                throw new IdentityProviderException(
+                    "ID token has incorrect issuer. Expected '{$this->issuer}' recieved '{$claims->iss}'",
+                    0,
+                    $claims->iss
+                );
             }
         } catch (\UnexpectedValueException $e) {
             throw new IdentityProviderException("ID token validation failed", 0, $e->getMessage());
@@ -114,13 +128,18 @@ class OpenIDConnectProvider extends AbstractProvider
         return $result;
     }
 
+    public function getDiscoveryUrl(): string
+    {
+        return $this->discoveryUrl;
+    }
+
     protected function getOpenIDConfiguration(): Configuration
     {
         if (isset($this->openIdConfiguration)) {
             return $this->openIdConfiguration;
         }
 
-        $req = $this->getRequest('GET', rtrim($this->issuer, '/') . self::CONFIGURATION_PATH);
+        $req = $this->getRequest('GET', $this->getDiscoveryUrl());
         /** @var array $config */
         $config = $this->getParsedResponse($req);
         $requiredEndPoints = [ "authorization_endpoint", "token_endpoint", "jwks_uri", "issuer", "userinfo_endpoint" ];

tests/lib/Providers/OpenIDConnectProviderTest.php

@@ -74,4 +74,26 @@ class OpenIDConnectProviderTest extends TestCase
         $request = Request::create($url);
         $this->assertEquals('openid', $request->query->get('scope'));
     }
+
+    public function testConfiguringDiscoveryUrl(): void
+    {
+        $provider = new OpenIDConnectProvider(
+            ['issuer' => 'https://accounts.example.com']
+        );
+        $this->assertEquals(
+            'https://accounts.example.com/.well-known/openid-configuration',
+            $provider->getDiscoveryUrl()
+        );
+
+        $provider = new OpenIDConnectProvider(
+            [
+                'issuer' => 'https://accounts.example.com',
+                'discoveryUrl' => 'https://otherhost.example.com/path/path2/.well-known/openid-configuration'
+            ]
+        );
+        $this->assertEquals(
+            'https://otherhost.example.com/path/path2/.well-known/openid-configuration',
+            $provider->getDiscoveryUrl()
+        );
+    }
 }