diff --git a/src/Composer/Downloader/ArchiveDownloader.php b/src/Composer/Downloader/ArchiveDownloader.php
index 07d418bed..8e921a3e4 100644
--- a/src/Composer/Downloader/ArchiveDownloader.php
+++ b/src/Composer/Downloader/ArchiveDownloader.php
@@ -15,7 +15,6 @@ namespace Composer\Downloader;
 use Composer\IO\IOInterface;
 use Composer\Package\PackageInterface;
 use Composer\Util\Filesystem;
-use Composer\Util\RemoteFilesystem;
 
 /**
  * Base downloader for archives
diff --git a/src/Composer/Repository/Vcs/GitHubDriver.php b/src/Composer/Repository/Vcs/GitHubDriver.php
index 01371c1a2..95701ddd6 100644
--- a/src/Composer/Repository/Vcs/GitHubDriver.php
+++ b/src/Composer/Repository/Vcs/GitHubDriver.php
@@ -2,8 +2,11 @@
 
 namespace Composer\Repository\Vcs;
 
+use Composer\Downloader\TransportException;
 use Composer\Json\JsonFile;
 use Composer\IO\IOInterface;
+use Composer\Util\ProcessExecutor;
+use Composer\Util\RemoteFilesystem;
 
 /**
  * @author Jordi Boggiano <j.boggiano@seld.be>
@@ -16,14 +19,30 @@ class GitHubDriver extends VcsDriver
     protected $branches;
     protected $rootIdentifier;
     protected $infoCache = array();
+    protected $isPrivate = false;
 
-    public function __construct($url, IOInterface $io)
+    /**
+     * Git Driver
+     * 
+     * @var GitDriver
+     */
+    protected $gitDriver;
+
+    /**
+     * Constructor
+     * 
+     * @param string $url
+     * @param IOInterface $io
+     * @param ProcessExecutor $process
+     * @param RemoteFilesystem $remoteFilesystem
+     */
+    public function __construct($url, IOInterface $io, ProcessExecutor $process = null, RemoteFilesystem $remoteFilesystem = null)
     {
         preg_match('#^(?:https?|git)://github\.com/([^/]+)/(.+?)(?:\.git)?$#', $url, $match);
         $this->owner = $match[1];
         $this->repository = $match[2];
 
-        parent::__construct($url, $io);
+        parent::__construct($url, $io, $process, $remoteFilesystem);
     }
 
     /**
@@ -31,6 +50,7 @@ class GitHubDriver extends VcsDriver
      */
     public function initialize()
     {
+        $this->fetchRootIdentifier();
     }
 
     /**
@@ -38,11 +58,9 @@ class GitHubDriver extends VcsDriver
      */
     public function getRootIdentifier()
     {
-        if (null === $this->rootIdentifier) {
-            $repoData = JsonFile::parseJson($this->getContents($this->getScheme() . '://api.github.com/repos/'.$this->owner.'/'.$this->repository));
-            $this->rootIdentifier = $repoData['master_branch'] ?: 'master';
+        if ($this->gitDriver) {
+            return $this->gitDriver->getRootIdentifier();
         }
-
         return $this->rootIdentifier;
     }
 
@@ -51,6 +69,9 @@ class GitHubDriver extends VcsDriver
      */
     public function getUrl()
     {
+        if ($this->gitDriver) {
+            return $this->gitDriver->getUrl();
+        }
         return $this->url;
     }
 
@@ -59,9 +80,19 @@ class GitHubDriver extends VcsDriver
      */
     public function getSource($identifier)
     {
+        if ($this->gitDriver) {
+            return $this->gitDriver->getSource($identifier);
+        }
         $label = array_search($identifier, $this->getTags()) ?: $identifier;
+        if ($this->isPrivate) {
+            // Private GitHub repositories should be accessed using the
+            // SSH version of the URL.
+            $url = $this->generateSshUrl();
+        } else {
+            $url = $this->getUrl();
+        }
 
-        return array('type' => 'git', 'url' => $this->getUrl(), 'reference' => $label);
+        return array('type' => 'git', 'url' => $url, 'reference' => $label);
     }
 
     /**
@@ -69,6 +100,9 @@ class GitHubDriver extends VcsDriver
      */
     public function getDist($identifier)
     {
+        if ($this->gitDriver) {
+            return $this->gitDriver->getDist($identifier);
+        }
         $label = array_search($identifier, $this->getTags()) ?: $identifier;
         $url = $this->getScheme() . '://github.com/'.$this->owner.'/'.$this->repository.'/zipball/'.$label;
 
@@ -80,6 +114,9 @@ class GitHubDriver extends VcsDriver
      */
     public function getComposerInformation($identifier)
     {
+        if ($this->gitDriver) {
+            return $this->gitDriver->getComposerInformation($identifier);
+        }
         if (!isset($this->infoCache[$identifier])) {
             $composer = $this->getContents($this->getScheme() . '://raw.github.com/'.$this->owner.'/'.$this->repository.'/'.$identifier.'/composer.json');
             if (!$composer) {
@@ -103,6 +140,9 @@ class GitHubDriver extends VcsDriver
      */
     public function getTags()
     {
+        if ($this->gitDriver) {
+            return $this->gitDriver->getTags();
+        }
         if (null === $this->tags) {
             $tagsData = JsonFile::parseJson($this->getContents($this->getScheme() . '://api.github.com/repos/'.$this->owner.'/'.$this->repository.'/tags'));
             $this->tags = array();
@@ -119,6 +159,9 @@ class GitHubDriver extends VcsDriver
      */
     public function getBranches()
     {
+        if ($this->gitDriver) {
+            return $this->gitDriver->getBranches();
+        }
         if (null === $this->branches) {
             $branchData = JsonFile::parseJson($this->getContents($this->getScheme() . '://api.github.com/repos/'.$this->owner.'/'.$this->repository.'/branches'));
             $this->branches = array();
@@ -137,4 +180,63 @@ class GitHubDriver extends VcsDriver
     {
         return extension_loaded('openssl') && preg_match('#^(?:https?|git)://github\.com/([^/]+)/(.+?)(?:\.git)?$#', $url);
     }
+
+    /**
+     * Generate an SSH URL
+     * 
+     * @return string
+     */
+    protected function generateSshUrl()
+    {
+        return 'git@github.com:'.$this->owner.'/'.$this->repository.'.git';
+    }
+
+    /**
+     * Fetch root identifier from GitHub
+     * 
+     * @throws TransportException
+     */
+    protected function fetchRootIdentifier()
+    {
+        $repoDataUrl = $this->getScheme() . '://api.github.com/repos/'.$this->owner.'/'.$this->repository;
+        $attemptCounter = 0;
+        while (null === $this->rootIdentifier) {
+            if (5 == $attemptCounter++) {
+                throw new \RuntimeException("Either you have entered invalid credentials or this GitHub repository does not exists (404)");
+            }
+            try {
+                $repoData = JsonFile::parseJson($this->getContents($repoDataUrl));
+                $this->rootIdentifier = $repoData['master_branch'] ?: 'master';
+            } catch (TransportException $e) {
+                switch($e->getCode()) {
+                    case 401:
+                    case 404:
+                        $this->isPrivate = true;
+                        if (!$this->io->isInteractive()) {
+                            // If this repository may be private (hard to say for sure,
+                            // GitHub returns 404 for private repositories) and we
+                            // cannot ask for authentication credentials (because we
+                            // are not interactive) then we fallback to GitDriver.
+                            $this->gitDriver = new GitDriver(
+                                $this->generateSshUrl(),
+                                $this->io,
+                                $this->process,
+                                $this->remoteFilesystem
+                            );
+                            $this->gitDriver->initialize();
+                            return;
+                        }
+                        $this->io->write('Authentication required (<info>'.$this->url.'</info>):');
+                        $username = $this->io->ask('Username: ');
+                        $password = $this->io->askAndHideAnswer('Password: ');
+                        $this->io->setAuthorization($this->url, $username, $password);
+                        break;
+
+                    default:
+                        throw $e;
+                        break;
+                }
+            }
+        }
+    }
 }
diff --git a/src/Composer/Repository/Vcs/VcsDriver.php b/src/Composer/Repository/Vcs/VcsDriver.php
index a20e959fd..99c705c50 100644
--- a/src/Composer/Repository/Vcs/VcsDriver.php
+++ b/src/Composer/Repository/Vcs/VcsDriver.php
@@ -27,6 +27,7 @@ abstract class VcsDriver implements VcsDriverInterface
     protected $url;
     protected $io;
     protected $process;
+    protected $remoteFilesystem;
 
     /**
      * Constructor.
@@ -34,12 +35,14 @@ abstract class VcsDriver implements VcsDriverInterface
      * @param string      $url The URL
      * @param IOInterface $io  The IO instance
      * @param ProcessExecutor $process  Process instance, injectable for mocking
+     * @param callable $remoteFilesystem Remote Filesystem, injectable for mocking
      */
-    public function __construct($url, IOInterface $io, ProcessExecutor $process = null)
+    public function __construct($url, IOInterface $io, ProcessExecutor $process = null, $remoteFilesystem = null)
     {
         $this->url = $url;
         $this->io = $io;
         $this->process = $process ?: new ProcessExecutor;
+        $this->remoteFilesystem = $remoteFilesystem ?: new RemoteFilesystem($io);
     }
 
     /**
@@ -80,8 +83,7 @@ abstract class VcsDriver implements VcsDriverInterface
      */
     protected function getContents($url)
     {
-        $rfs = new RemoteFilesystem($this->io);
-        return $rfs->getContents($this->url, $url, false);
+        return $this->remoteFilesystem->getContents($this->url, $url, false);
     }
 
     protected static function isLocalUrl($url)
diff --git a/src/Composer/Util/RemoteFilesystem.php b/src/Composer/Util/RemoteFilesystem.php
index 57719cbf4..e14201a13 100644
--- a/src/Composer/Util/RemoteFilesystem.php
+++ b/src/Composer/Util/RemoteFilesystem.php
@@ -80,13 +80,11 @@ class RemoteFilesystem
      * @param string  $fileUrl   The file URL
      * @param string  $fileName  the local filename
      * @param boolean $progress  Display the progression
-     * @param boolean $firstCall Whether this is the first attempt at fetching this resource
      *
      * @throws TransportException When the file could not be downloaded
      */
-    protected function get($originUrl, $fileUrl, $fileName = null, $progress = true, $firstCall = true)
+    protected function get($originUrl, $fileUrl, $fileName = null, $progress = true)
     {
-        $this->firstCall = $firstCall;
         $this->bytesMax = 0;
         $this->result = null;
         $this->originUrl = $originUrl;
@@ -139,20 +137,12 @@ class RemoteFilesystem
     protected function callbackGet($notificationCode, $severity, $message, $messageCode, $bytesTransferred, $bytesMax)
     {
         switch ($notificationCode) {
-            case STREAM_NOTIFY_AUTH_REQUIRED:
             case STREAM_NOTIFY_FAILURE:
-                if (404 === $messageCode && !$this->firstCall) {
-                    throw new TransportException("The '" . $this->fileUrl . "' URL not found", 404);
-                }
+                throw new TransportException(trim($message), $messageCode);
+                break;
 
-                // for private repository returning 404 error when the authorization is incorrect
-                $auth = $this->io->getAuthorization($this->originUrl);
-                $attemptAuthentication = $this->firstCall && 404 === $messageCode && null === $auth['username'];
-
-                $this->firstCall = false;
-
-                // get authorization informations
-                if (401 === $messageCode || $attemptAuthentication) {
+            case STREAM_NOTIFY_AUTH_REQUIRED:
+                if (401 === $messageCode) {
                     if (!$this->io->isInteractive()) {
                         $message = "The '" . $this->fileUrl . "' URL required authentication.\nYou must be using the interactive console";
 
@@ -164,7 +154,7 @@ class RemoteFilesystem
                     $password = $this->io->askAndHideAnswer('      Password: ');
                     $this->io->setAuthorization($this->originUrl, $username, $password);
 
-                    $this->get($this->originUrl, $this->fileUrl, $this->fileName, $this->progress, false);
+                    $this->get($this->originUrl, $this->fileUrl, $this->fileName, $this->progress);
                 }
                 break;
 
diff --git a/tests/Composer/Test/Repository/Vcs/GitHubDriverTest.php b/tests/Composer/Test/Repository/Vcs/GitHubDriverTest.php
new file mode 100644
index 000000000..c410b5ab5
--- /dev/null
+++ b/tests/Composer/Test/Repository/Vcs/GitHubDriverTest.php
@@ -0,0 +1,223 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Test\Repository\Vcs;
+
+use Composer\Downloader\TransportException;
+use Composer\Repository\Vcs\GitHubDriver;
+
+/**
+ * @author Beau Simensen <beau@dflydev.com>
+ */
+class GitHubDriverTest extends \PHPUnit_Framework_TestCase
+{
+    public function testPrivateRepository()
+    {
+        $repoUrl = 'http://github.com/composer/packagist';
+        $repoApiUrl = 'https://api.github.com/repos/composer/packagist';
+        $repoSshUrl = 'git@github.com:composer/packagist.git';
+        $identifier = 'v0.0.0';
+        $sha = 'SOMESHA';
+
+        $io = $this->getMock('Composer\IO\IOInterface');
+        $io->expects($this->any())
+            ->method('isInteractive')
+            ->will($this->returnValue(true));
+
+        $remoteFilesystem = $this->getMockBuilder('Composer\Util\RemoteFilesystem')
+            ->setConstructorArgs(array($io))
+            ->getMock();
+
+        $remoteFilesystem->expects($this->at(0))
+            ->method('getContents')
+            ->with($this->equalTo($repoUrl), $this->equalTo($repoApiUrl), $this->equalTo(false))
+            ->will($this->throwException(new TransportException('HTTP/1.1 404 Not Found', 404)));
+
+        $io->expects($this->once())
+            ->method('ask')
+            ->with($this->equalTo('Username: '))
+            ->will($this->returnValue('someuser'));
+
+        $io->expects($this->once())
+            ->method('askAndHideAnswer')
+            ->with($this->equalTo('Password: '))
+            ->will($this->returnValue('somepassword'));
+
+        $io->expects($this->once())
+            ->method('setAuthorization')
+            ->with($this->equalTo($repoUrl), 'someuser', 'somepassword');
+
+        $remoteFilesystem->expects($this->at(1))
+            ->method('getContents')
+            ->with($this->equalTo($repoUrl), $this->equalTo($repoApiUrl), $this->equalTo(false))
+            ->will($this->returnValue('{"master_branch": "test_master"}'));
+
+        $gitHubDriver = new GitHubDriver($repoUrl, $io, null, $remoteFilesystem);
+        $gitHubDriver->initialize();
+        $this->setAttribute($gitHubDriver, 'tags', array($identifier => $sha));
+
+        $this->assertEquals('test_master', $gitHubDriver->getRootIdentifier());
+
+        $dist = $gitHubDriver->getDist($identifier);
+        $this->assertEquals('zip', $dist['type']);
+        $this->assertEquals('https://github.com/composer/packagist/zipball/v0.0.0', $dist['url']);
+        $this->assertEquals('v0.0.0', $dist['reference']);
+
+        $source = $gitHubDriver->getSource($identifier);
+        $this->assertEquals('git', $source['type']);
+        $this->assertEquals($repoSshUrl, $source['url']);
+        $this->assertEquals('v0.0.0', $source['reference']);
+
+        $dist = $gitHubDriver->getDist($sha);
+        $this->assertEquals('zip', $dist['type']);
+        $this->assertEquals('https://github.com/composer/packagist/zipball/v0.0.0', $dist['url']);
+        $this->assertEquals('v0.0.0', $dist['reference']);
+
+        $source = $gitHubDriver->getSource($sha);
+        $this->assertEquals('git', $source['type']);
+        $this->assertEquals($repoSshUrl, $source['url']);
+        $this->assertEquals('v0.0.0', $source['reference']);
+    }
+
+    public function testPublicRepository()
+    {
+        $repoUrl = 'http://github.com/composer/packagist';
+        $repoApiUrl = 'https://api.github.com/repos/composer/packagist';
+        $identifier = 'v0.0.0';
+        $sha = 'SOMESHA';
+
+        $io = $this->getMock('Composer\IO\IOInterface');
+        $io->expects($this->any())
+            ->method('isInteractive')
+            ->will($this->returnValue(true));
+
+        $remoteFilesystem = $this->getMockBuilder('Composer\Util\RemoteFilesystem')
+            ->setConstructorArgs(array($io))
+            ->getMock();
+
+        $remoteFilesystem->expects($this->at(0))
+            ->method('getContents')
+            ->with($this->equalTo($repoUrl), $this->equalTo($repoApiUrl), $this->equalTo(false))
+            ->will($this->returnValue('{"master_branch": "test_master"}'));
+
+        $gitHubDriver = new GitHubDriver($repoUrl, $io, null, $remoteFilesystem);
+        $gitHubDriver->initialize();
+        $this->setAttribute($gitHubDriver, 'tags', array($identifier => $sha));
+
+        $this->assertEquals('test_master', $gitHubDriver->getRootIdentifier());
+
+        $dist = $gitHubDriver->getDist($identifier);
+        $this->assertEquals('zip', $dist['type']);
+        $this->assertEquals('https://github.com/composer/packagist/zipball/v0.0.0', $dist['url']);
+        $this->assertEquals($identifier, $dist['reference']);
+
+        $source = $gitHubDriver->getSource($identifier);
+        $this->assertEquals('git', $source['type']);
+        $this->assertEquals($repoUrl, $source['url']);
+        $this->assertEquals($identifier, $source['reference']);
+
+        $dist = $gitHubDriver->getDist($sha);
+        $this->assertEquals('zip', $dist['type']);
+        $this->assertEquals('https://github.com/composer/packagist/zipball/v0.0.0', $dist['url']);
+        $this->assertEquals($identifier, $dist['reference']);
+
+        $source = $gitHubDriver->getSource($sha);
+        $this->assertEquals('git', $source['type']);
+        $this->assertEquals($repoUrl, $source['url']);
+        $this->assertEquals($identifier, $source['reference']);
+    }
+
+    public function testPrivateRepositoryNoInteraction()
+    {
+        $repoUrl = 'http://github.com/composer/packagist';
+        $repoApiUrl = 'https://api.github.com/repos/composer/packagist';
+        $repoSshUrl = 'git@github.com:composer/packagist.git';
+        $identifier = 'v0.0.0';
+        $sha = 'SOMESHA';
+
+        $process = $this->getMockBuilder('Composer\Util\ProcessExecutor')
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $io = $this->getMock('Composer\IO\IOInterface');
+        $io->expects($this->any())
+            ->method('isInteractive')
+            ->will($this->returnValue(false));
+
+        $remoteFilesystem = $this->getMockBuilder('Composer\Util\RemoteFilesystem')
+            ->setConstructorArgs(array($io))
+            ->getMock();
+
+        $remoteFilesystem->expects($this->at(0))
+            ->method('getContents')
+            ->with($this->equalTo($repoUrl), $this->equalTo($repoApiUrl), $this->equalTo(false))
+            ->will($this->throwException(new TransportException('HTTP/1.1 404 Not Found', 404)));
+
+        $process->expects($this->at(0))
+            ->method('execute')
+            ->with($this->stringContains('git fetch origin'));
+
+        $process->expects($this->at(1))
+            ->method('execute')
+            ->with($this->stringContains('git tag'));
+
+        $process->expects($this->at(2))
+            ->method('splitLines')
+            ->will($this->returnValue(array($identifier)));
+
+        $process->expects($this->at(3))
+            ->method('execute')
+            ->with($this->stringContains('git branch'));
+
+        $process->expects($this->at(4))
+            ->method('splitLines')
+            ->will($this->returnValue(array('  test_master                              edf93f1fccaebd8764383dc12016d0a1a9672d89 Fix test & behavior')));
+
+        $process->expects($this->at(5))
+            ->method('execute')
+            ->with($this->stringContains('git branch'));
+
+        $process->expects($this->at(6))
+            ->method('splitLines')
+            ->will($this->returnValue(array('  upstream/HEAD -> upstream/test_master')));
+
+        $gitHubDriver = new GitHubDriver($repoUrl, $io, $process, $remoteFilesystem);
+        $gitHubDriver->initialize();
+
+        $this->assertEquals('test_master', $gitHubDriver->getRootIdentifier());
+
+        // Dist is not available for GitDriver
+        $dist = $gitHubDriver->getDist($identifier);
+        $this->assertNull($dist);
+
+        $source = $gitHubDriver->getSource($identifier);
+        $this->assertEquals('git', $source['type']);
+        $this->assertEquals($repoSshUrl, $source['url']);
+        $this->assertEquals($identifier, $source['reference']);
+
+        // Dist is not available for GitDriver
+        $dist = $gitHubDriver->getDist($sha);
+        $this->assertNull($dist);
+
+        $source = $gitHubDriver->getSource($sha);
+        $this->assertEquals('git', $source['type']);
+        $this->assertEquals($repoSshUrl, $source['url']);
+        $this->assertEquals($sha, $source['reference']);
+    }
+
+    protected function setAttribute($object, $attribute, $value)
+    {
+        $attr = new \ReflectionProperty($object, $attribute);
+        $attr->setAccessible(true);
+        $attr->setValue($object, $value);
+    }
+}
diff --git a/tests/Composer/Test/Util/RemoteFilesystemTest.php b/tests/Composer/Test/Util/RemoteFilesystemTest.php
index bee389941..97e50b848 100644
--- a/tests/Composer/Test/Util/RemoteFilesystemTest.php
+++ b/tests/Composer/Test/Util/RemoteFilesystemTest.php
@@ -105,41 +105,14 @@ class RemoteFilesystemTest extends \PHPUnit_Framework_TestCase
     public function testCallbackGetNotifyFailure404()
     {
         $fs = new RemoteFilesystem($this->getMock('Composer\IO\IOInterface'));
-        $this->setAttribute($fs, 'firstCall', false);
 
         try {
-            $this->callCallbackGet($fs, STREAM_NOTIFY_FAILURE, 0, '', 404, 0, 0);
+            $this->callCallbackGet($fs, STREAM_NOTIFY_FAILURE, 0, 'HTTP/1.1 404 Not Found', 404, 0, 0);
             $this->fail();
         } catch (\Exception $e) {
             $this->assertInstanceOf('Composer\Downloader\TransportException', $e);
-            $this->assertContains('URL not found', $e->getMessage());
-        }
-    }
-
-    public function testCallbackGetNotifyFailure404FirstCall()
-    {
-        $io = $this->getMock('Composer\IO\IOInterface');
-        $io
-            ->expects($this->once())
-            ->method('getAuthorization')
-            ->will($this->returnValue(array('username' => null)))
-        ;
-        $io
-            ->expects($this->once())
-            ->method('isInteractive')
-            ->will($this->returnValue(false))
-        ;
-
-        $fs = new RemoteFilesystem($io);
-        $this->setAttribute($fs, 'firstCall', true);
-
-        try {
-            $this->callCallbackGet($fs, STREAM_NOTIFY_FAILURE, 0, '', 404, 0, 0);
-            $this->fail();
-        } catch (\Exception $e) {
-            $this->assertInstanceOf('Composer\Downloader\TransportException', $e);
-            $this->assertContains('URL required authentication', $e->getMessage());
-            $this->assertAttributeEquals(false, 'firstCall', $fs);
+            $this->assertEquals(404, $e->getCode());
+            $this->assertContains('HTTP/1.1 404 Not Found', $e->getMessage());
         }
     }