diff --git a/core/lib/Drupal/Core/Config/Entity/Condition.php b/core/lib/Drupal/Core/Config/Entity/Condition.php
new file mode 100644
index 0000000..0d30585
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/Entity/Condition.php
@@ -0,0 +1,95 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Config\Query\ConditionSql.
+ */
+
+namespace Drupal\Core\Config\Entity;
+
+use Drupal\Core\Entity\Query\ConditionBase;
+use Symfony\Component\Yaml\Escaper;
+use Drupal\Core\Entity\Query\ConditionInterface;
+
+class Condition extends ConditionBase {
+
+  /**
+   * Implements Drupal\Core\Entity\Query\ConditionInterface::compile().
+   */
+  public function compile($query) {
+    $commands = array();
+    $info = entity_get_info($query->entityType);
+    $config_prefix = $info['config_prefix'];
+    // -H forces grep to print the filenames.
+    $options = '-H';
+    $postfix = " $query->directory/$config_prefix.*.yml";
+
+    // The general idea is to build a list of grep commands via pipes to apply multiple search conditions.
+    foreach ($this->conditions as $condition) {
+      $field = '^ *' . $condition['field'];
+      // \Drupal\Core\Config\Config::castValue() casts to string.
+      $value = (string) $condition['value'];
+      // \Symfony\Component\Yaml\Inline::dump() does this.
+      $quote = ctype_digit($value) ? "'" : '';
+      if (Escaper::requiresDoubleQuoting($value)) {
+        throw new \InvalidArgumentException('Invalid character in value.');
+      }
+      elseif (Escaper::requiresSingleQuoting($value)) {
+        $value = str_replace("'", "''", $value);
+        $quote = "'";
+      }
+      switch ($condition['operator']) {
+        case NULL:
+        case '=':
+          $value = "$quote$value$quote$";
+          break;
+
+        case 'CONTAINS':
+          $value = ".*$value";
+          break;
+
+        case 'STARTS_WITH':
+          $value = "$quote$value";
+          break;
+
+        case 'ENDS_WITH':
+          $value = ".*$value$quote$";
+          break;
+      }
+      $subject = escapeshellarg("$field: $value");
+      $commands[] = "grep $options $subject $postfix";
+      $options = '';
+    }
+    if (!empty($commands)) {
+      $command = implode('|', $commands);
+    }
+    else {
+      // @todo Find a better way to get all files matching a certain config_prefix.
+      $options .= ' -L';
+      $command = "grep $options $postfix";
+    }
+    exec($command, $output);
+
+    // Get the actual entity IDs out of the filename using a regular expression.
+    $cut_length = strlen($query->directory) + strlen($config_prefix) + 2;
+    $ids = array();
+    foreach ($output as $line) {
+      preg_match('/^([^.]+)\./', substr($line, $cut_length), $matches);
+      $ids[] = $matches[1];
+    }
+    return $ids;
+  }
+
+  /**
+   * Implements Drupal\Core\Entity\Query\ConditionInterface::exists().
+   */
+  public function exists($field, $langcode = NULL) {
+  }
+
+  /**
+   * Implements Drupal\Core\Entity\Query\ConditionInterface::notExists().
+   */
+  public function notExists($field, $langcode = NULL) {
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php b/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
index 6d0a3f4..8187dfc 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
@@ -428,6 +428,6 @@ protected function invokeHook($hook, EntityInterface $entity) {
    * Implements Drupal\Core\Entity\EntityStorageControllerInterface::getQueryServicename().
    */
   public function getQueryServicename() {
-    throw new \LogicException('Querying configuration entities is not supported.');
+    return 'entity.query.config';
   }
 }
diff --git a/core/lib/Drupal/Core/Config/Entity/Query.php b/core/lib/Drupal/Core/Config/Entity/Query.php
new file mode 100644
index 0000000..617d596
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/Entity/Query.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace Drupal\Core\Config\Entity;
+
+use Drupal\Core\Entity\Query\QueryBase;
+
+class Query extends QueryBase {
+
+  /**
+   * Stores the directory to search for config entities.
+   *
+   * @var string
+   */
+  protected $directory;
+
+  /**
+   * @param string $entity_type
+   *   The entity type.
+   * @param string $conjunction
+   *   - AND: all of the conditions on the query need to match.
+   *   - OR: at least one of the conditions on the query need to match.
+   * @param string $directory
+   */
+  public function __construct($entity_type, $conjunction, $directory) {
+    parent::__construct($entity_type, $conjunction);
+    $this->directory = $directory;
+  }
+
+  /**
+   * Implements Drupal\Core\Entity\Query\QueryInterface::conditionGroupFactory().
+   */
+  public function conditionGroupFactory($conjunction = 'AND') {
+    return new Condition($conjunction);
+  }
+
+  /**
+   * Implements Drupal\Core\Entity\Query\QueryInterface::execute().
+   */
+  public function execute() {
+    $query = new \stdClass;
+    $query->directory = $this->directory;
+    $query->entityType = $this->entityType;
+    return drupal_map_assoc($this->condition->compile($query));
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Config/Entity/QueryFactory.php b/core/lib/Drupal/Core/Config/Entity/QueryFactory.php
new file mode 100644
index 0000000..bea2b27
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/Entity/QueryFactory.php
@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Config\Entity\QueryFactory.
+ */
+
+namespace Drupal\Core\Config\Entity;
+
+/**
+ * Factory class creating entity query objects for the SQL backend.
+ */
+class QueryFactory {
+
+  function __construct($directory) {
+    $this->directory = $directory;
+  }
+
+  function get($entity_type, $conjunction = 'AND') {
+    return new Query($entity_type, $conjunction, $this->directory);
+  }
+}
diff --git a/core/lib/Drupal/Core/CoreBundle.php b/core/lib/Drupal/Core/CoreBundle.php
index e1147ac..51d2caa 100644
--- a/core/lib/Drupal/Core/CoreBundle.php
+++ b/core/lib/Drupal/Core/CoreBundle.php
@@ -127,6 +127,9 @@ public function build(ContainerBuilder $container) {
     // Add the entity query factory.
     $container->register('entity.query', 'Drupal\Core\Entity\Query\QueryFactory')
       ->addArgument(new Reference('service_container'));
+    // @todo: replace with active config storage refernece once it is in CoreBundle.
+    $container->register('entity.query.config', 'Drupal\Core\Config\Entity\QueryFactory')
+      ->addArgument(config_get_config_directory(CONFIG_ACTIVE_DIRECTORY));
 
     $container->register('router.dumper', 'Drupal\Core\Routing\MatcherDumper')
       ->addArgument(new Reference('database'));
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigEntityQueryTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigEntityQueryTest.php
new file mode 100644
index 0000000..a54738d
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigEntityQueryTest.php
@@ -0,0 +1,165 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config\Tests\ConfigEntityQueryTest.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\simpletest\DrupalUnitTestBase;
+use Drupal\Core\Config\Entity\QueryFactory;
+
+/**
+ * Tests the config entity query.
+ *
+ * @see \Drupal\Core\Config\Entity\Query
+ */
+class ConfigEntityQueryTest extends DrupalUnitTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('config_test');
+
+  /**
+   * @var array
+   */
+  protected $queryResults;
+
+  /**
+   * @var \Drupal\Core\Config\Entity\QueryFactory
+   */
+  protected $factory;
+
+  /**
+   * All config entities created for that test.
+   *
+   * @var array
+   */
+  protected $entities;
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Config Entity Query',
+      'description' => 'Tests Config Entity Query functionality.',
+      'group' => 'Configuration',
+    );
+  }
+
+  protected function setUp() {
+    parent::setUp();
+
+    $entity = entity_create('config_test', array(
+        'label' => $this->randomName(),
+        'id' => 1,
+      )
+    );
+    $this->entities[] = $entity;
+    $entity->enforceIsNew();
+    $entity->save();
+
+    $entity = entity_create('config_test', array(
+        'label' => $this->randomName(),
+        'id' => 2,
+      )
+    );
+    $this->entities[] = $entity;
+    $entity->enforceIsNew();
+    $entity->save();
+
+    $entity = entity_create('config_test', array(
+        'label' => 'test_prefix_' . $this->randomName(),
+        'id' => 3,
+      )
+    );
+    $this->entities[] = $entity;
+    $entity->enforceIsNew();
+    $entity->save();
+
+    $entity = entity_create('config_test', array(
+        'label' => $this->randomName() . '_test_suffix',
+        'id' => 4,
+      )
+    );
+    $this->entities[] = $entity;
+    $entity->enforceIsNew();
+    $entity->save();
+
+    $entity = entity_create('config_test', array(
+        'label' => $this->randomName() . '_test_contains_' . $this->randomName(),
+        'id' => 5,
+      )
+    );
+    $this->entities[] = $entity;
+    $entity->enforceIsNew();
+    $entity->save();
+
+    // @todo This should be from the container.
+    $this->factory = new QueryFactory(config_get_config_directory(CONFIG_ACTIVE_DIRECTORY));
+  }
+
+
+  /**
+   * Test basic functionality.
+   */
+  public function testConfigEntityQuery() {
+    //d Run a test without any condition.
+    $this->queryResults = $this->factory->get('config_test')
+      ->execute();
+
+    $this->assertEqual(count($this->queryResults), count($this->entities));
+
+    // Filter by ID with equality.
+    $this->queryResults = $this->factory->get('config_test')
+      ->condition('id', 3)
+      ->execute();
+
+    $this->assertEqual(count($this->queryResults), 1);
+
+    // Filter by label with a known prefix.
+    $this->queryResults = $this->factory->get('config_test')
+      ->condition('label', 'test_prefix', 'STARTS_WITH')
+      ->execute();
+
+    $this->assertEqual(count($this->queryResults), 1);
+    $this->assertEqual($this->queryResults[3], '3');
+
+    // Filter by label with a known suffix.
+    $this->queryResults = $this->factory->get('config_test')
+      ->condition('label', 'test_suffix', 'ENDS_WITH')
+      ->execute();
+
+    $this->assertEqual(count($this->queryResults), 1);
+    $this->assertEqual($this->queryResults[4], 4);
+
+    // Filter by label with a known containing word.
+    $this->queryResults = $this->factory->get('config_test')
+      ->condition('label', 'test_contains', 'CONTAINS')
+      ->execute();
+
+    $this->assertEqual(count($this->queryResults), 1);
+    $this->assertEqual($this->queryResults[5], 5);
+
+    // Filter with an OR condition group.
+    $this->queryResults = $this->factory->get('config_test', 'OR')
+      ->condition('id', 1)
+      ->condition('id', 2)
+      ->execute();
+    $this->assertEqual(count($this->queryResults), 2);
+  }
+
+  /**
+   * Test entity count query.
+   */
+  protected function testCount() {
+    $this->queryResults = $this->factory->get('config_test')
+      ->count()
+      ->execute();
+
+    $this->assertEqual(count($this->queryResults), 5);
+  }
+
+}