[Security] Fix http digest authentication entry point

src/Symfony/Component/Security/Http/EntryPoint/DigestAuthenticationEntryPoint.php

@@ -57,7 +57,7 @@ class DigestAuthenticationEntryPoint implements AuthenticationEntryPointInterfac
 
         $response = new Response();
         $response->headers->set('WWW-Authenticate', $authenticateHeader);
-        $response->setStatusCode(401, $authException->getMessage());
+        $response->setStatusCode(401, $authException ? $authException->getMessage() : null);
 
         return $response;
     }

tests/Symfony/Tests/Component/Security/Http/EntryPoint/DigestAuthenticationEntryPointTest.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Symfony\Tests\Component\Security\Http\EntryPoint;
+
+use Symfony\Component\Security\Http\EntryPoint\DigestAuthenticationEntryPoint;
+use Symfony\Component\Security\Core\Exception\AuthenticationException;
+use Symfony\Component\Security\Core\Exception\NonceExpiredException;
+
+class DigestAuthenticationEntryPointTest extends \PHPUnit_Framework_TestCase
+{
+    public function testStart()
+    {
+        $request = $this->getMock('Symfony\Component\HttpFoundation\Request');
+
+        $authenticationException = new AuthenticationException('TheAuthenticationExceptionMessage');
+
+        $entryPoint = new DigestAuthenticationEntryPoint('TheRealmName', 'TheKey');
+        $response = $entryPoint->start($request, $authenticationException);
+
+        $this->assertEquals(401, $response->getStatusCode());
+        $this->assertAttributeEquals('TheAuthenticationExceptionMessage', 'statusText', $response);
+        $this->assertRegExp('/^Digest realm="TheRealmName", qop="auth", nonce="[a-zA-Z0-9\/+]+={0,2}"$/', $response->headers->get('WWW-Authenticate'));
+    }
+
+    public function testStartWithNoException()
+    {
+        $request = $this->getMock('Symfony\Component\HttpFoundation\Request');
+
+        $entryPoint = new DigestAuthenticationEntryPoint('TheRealmName', 'TheKey');
+        $response = $entryPoint->start($request);
+
+        $this->assertEquals(401, $response->getStatusCode());
+        $this->assertAttributeEquals('Unauthorized', 'statusText', $response);
+        $this->assertRegExp('/^Digest realm="TheRealmName", qop="auth", nonce="[a-zA-Z0-9\/+]+={0,2}"$/', $response->headers->get('WWW-Authenticate'));
+    }
+
+    public function testStartWithNonceExpiredException()
+    {
+        $request = $this->getMock('Symfony\Component\HttpFoundation\Request');
+
+        $nonceExpiredException = new NonceExpiredException('TheNonceExpiredExceptionMessage');
+
+        $entryPoint = new DigestAuthenticationEntryPoint('TheRealmName', 'TheKey');
+        $response = $entryPoint->start($request, $nonceExpiredException);
+
+        $this->assertEquals(401, $response->getStatusCode());
+        $this->assertAttributeEquals('TheNonceExpiredExceptionMessage', 'statusText', $response);
+        $this->assertRegExp('/^Digest realm="TheRealmName", qop="auth", nonce="[a-zA-Z0-9\/+]+={0,2}", stale="true"$/', $response->headers->get('WWW-Authenticate'));
+    }
+}