* Using namespace(s): https://www.reddit.com/r/programming/comments/2gwqcr/multifactor_authentication_or_twofactor_auth_for/ckr9e1g

* Added simple "PSR-4" autoloader
* Classes and interfaces to separate files
* Updated README for namespaces

11 files changed, 420 insertions, 343 deletions

diff --git a/README.md b/README.md
index 334fd20..8dbba30 100644
--- a/README.md
+++ b/README.md
@@ -18,8 +18,7 @@ Here are some code snippets that should help you get started...
 
 ````php
 // Start by including the TwoFactorAuth.php file which contains all you need (for now)
-require_once 'src/TwoFactorAuth.php';
-$tfa = new TwoFactorAuth('My Company');
+$tfa = new RobThree\TwoFactorAuth\TwoFactorAuth('My Company');
 ````
 
 The TwoFactorAuth class constructor accepts 5 parameters (all optional):
@@ -109,11 +108,13 @@ The `getMimeType()` method should return the [MIME type](http://en.wikipedia.org
 
 All you need to do is return the QR-code as binary image data and you're done. All parts of the `$qrtext` have been escaped for you (but note: you *may* need to escape the entire `$qrtext` just once more when passing the data to another server as GET-parameter).
 
-Let's see if we can use [PHP QR Code](http://phpqrcode.sourceforge.net/) to implement our own, custom, no-3rd-parties-allowed-here, provider. We start with downloading the [required (single) file](https://github.com/t0k4rt/phpqrcode/blob/master/phpqrcode.php) and putting it in our `src/` directory where `TwoFactorAuth.php` is located as well. Now let's implement the provider: create another file named `myprovider.php` in the `src` directory and paste in this content:
+Let's see if we can use [PHP QR Code](http://phpqrcode.sourceforge.net/) to implement our own, custom, no-3rd-parties-allowed-here, provider. We start with downloading the [required (single) file](https://github.com/t0k4rt/phpqrcode/blob/master/phpqrcode.php) and putting it in the directory where `TwoFactorAuth.php` is located as well. Now let's implement the provider: create another file named `myprovider.php` in the `Providers` directory and paste in this content:
 
 ````php
 <?php
-require_once 'phpqrcode.php';                      // Yeah, we're gonna need that
+require_once '../phpqrcode.php';                   // Yeah, we're gonna need that
+
+namespace RobThree\TwoFactorAuth\Providers
 
 class MyProvider implements IQRCodeProvider {
   public function getMimeType() {
@@ -136,11 +137,8 @@ That's it. We're done! We've implemented our own provider (with help of PHP QR C
 
 ````php
 <?php
-require_once 'src/TwoFactorAuth.php';
-require_once 'src/myprovider.php';
-
-$mp = new MyProvider();
-$tfa = new TwoFactorAuth('My Company', 6, 30, 'sha1', $mp);
+$mp = new RobThree\TwoFactorAuth\TwoFactorAuth\Providers\MyProvider();
+$tfa = new RobThree\TwoFactorAuth\TwoFactorAuth\TwoFactorAuth('My Company', 6, 30, 'sha1', $mp);
 $secret = $tfa->createSecret();
 ?>
 <p><img src="<?php $tfa->getQRCodeImageAsDataUri('Bob Ross', $secret) ?>"></p>
diff --git a/RobThree/TwoFactorAuth/Providers/BaseHTTPQRCodeProvider.php b/RobThree/TwoFactorAuth/Providers/BaseHTTPQRCodeProvider.php
new file mode 100644
index 0000000..f29265d
--- /dev/null
+++ b/RobThree/TwoFactorAuth/Providers/BaseHTTPQRCodeProvider.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace RobThree\TwoFactorAuth\Providers;
+
+abstract class BaseHTTPQRCodeProvider implements IQRCodeProvider
+{
+    protected $verifyssl;
+
+	protected function getContent($url)
+    {
+        $ch = curl_init();
+        
+        curl_setopt_array($ch, array(
+			CURLOPT_URL => $url,
+			CURLOPT_FOLLOWLOCATION => true,
+			CURLOPT_MAXREDIRS => 3,
+			CURLOPT_RETURNTRANSFER => true,
+			CURLOPT_CONNECTTIMEOUT => 10,
+			CURLOPT_DNS_CACHE_TIMEOUT => 10,
+			CURLOPT_TIMEOUT => 10,
+            CURLOPT_SSL_VERIFYPEER => $this->verifyssl,
+			CURLOPT_USERAGENT => 'TwoFactorAuth'
+        ));
+        $data = curl_exec($ch);
+        
+        curl_close($ch);
+        return $data;
+    }
+}
\ No newline at end of file
diff --git a/RobThree/TwoFactorAuth/Providers/GoogleQRCodeProvider.php b/RobThree/TwoFactorAuth/Providers/GoogleQRCodeProvider.php
new file mode 100644
index 0000000..5084bac
--- /dev/null
+++ b/RobThree/TwoFactorAuth/Providers/GoogleQRCodeProvider.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace RobThree\TwoFactorAuth\Providers;
+
+// https://developers.google.com/chart/infographics/docs/qr_codes
+class GoogleQRCodeProvider extends BaseHTTPQRCodeProvider 
+{
+    public $errorcorrectionlevel;
+    public $margin;
+
+    function __construct($verifyssl = false, $errorcorrectionlevel = 'L', $margin = 1) 
+    {
+        if (!is_bool($verifyssl))
+            throw new Exception('VerifySSL must be bool');
+
+        $this->verifyssl = $verifyssl;
+        
+        $this->errorcorrectionlevel = $errorcorrectionlevel;
+        $this->margin = $margin;
+    }
+    
+    public function getMimeType() 
+    {
+        return 'image/png';
+    }
+    
+    public function getQRCodeImage($qrtext, $size) 
+    {
+        return $this->getContent($this->getUrl($qrtext, $size));
+    }
+    
+    public function getUrl($qrtext, $size) 
+    {
+        return 'https://chart.googleapis.com/chart?cht=qr'
+            . '&chs=' . $size . 'x' . $size
+            . '&chld=' . $this->errorcorrectionlevel . '|' . $this->margin
+            . '&chl=' . rawurlencode($qrtext);
+    }
+}
\ No newline at end of file
diff --git a/RobThree/TwoFactorAuth/Providers/IQRCodeProvider.php b/RobThree/TwoFactorAuth/Providers/IQRCodeProvider.php
new file mode 100644
index 0000000..6aeb856
--- /dev/null
+++ b/RobThree/TwoFactorAuth/Providers/IQRCodeProvider.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace RobThree\TwoFactorAuth\Providers;
+
+interface IQRCodeProvider
+{
+	public function getQRCodeImage($qrtext, $size);
+    public function getMimeType();
+}
\ No newline at end of file
diff --git a/RobThree/TwoFactorAuth/Providers/QRServerProvider.php b/RobThree/TwoFactorAuth/Providers/QRServerProvider.php
new file mode 100644
index 0000000..d95260a
--- /dev/null
+++ b/RobThree/TwoFactorAuth/Providers/QRServerProvider.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace RobThree\TwoFactorAuth\Providers;
+
+// http://goqr.me/api/doc/create-qr-code/
+class QRServerProvider extends BaseHTTPQRCodeProvider 
+{
+    public $errorcorrectionlevel;
+    public $margin;
+    public $qzone;
+    public $bgcolor;
+    public $color;
+    public $format;
+
+    function __construct($verifyssl = false, $errorcorrectionlevel = 'L', $margin = 4, $qzone = 1, $bgcolor = 'ffffff', $color = '000000', $format = 'png') 
+    {
+        if (!is_bool($verifyssl))
+            throw new Exception('VerifySSL must be bool');
+
+        $this->verifyssl = $verifyssl;
+        
+        $this->errorcorrectionlevel = $errorcorrectionlevel;
+        $this->margin = $margin;
+        $this->qzone = $qzone;
+        $this->bgcolor = $bgcolor;
+        $this->color = $color;
+        $this->format = $format;
+    }
+    
+    public function getMimeType() 
+    {
+        switch (strtolower($this->format))
+        {
+        	case 'png':
+                return 'image/png';
+        	case 'gif':
+                return 'image/gif';
+        	case 'jpg':
+        	case 'jpeg':
+                return 'image/jpeg';
+        	case 'svg':
+                return 'image/svg+xml';
+        	case 'eps':
+                return 'application/postscript';
+        }
+    }
+    
+    public function getQRCodeImage($qrtext, $size) 
+    {
+        return $this->getContent($this->getUrl($qrtext, $size));
+    }
+    
+    private function decodeColor($value) 
+    {
+        return vsprintf('%d-%d-%d', sscanf($value, "%02x%02x%02x"));
+    }
+    
+    public function getUrl($qrtext, $size) 
+    {
+        return 'https://api.qrserver.com/v1/create-qr-code/'
+            . '?size=' . $size . 'x' . $size
+            . '&ecc=' . strtoupper($this->errorcorrectionlevel)
+            . '&margin=' . $this->margin
+            . '&qzone=' . $this->qzone
+            . '&bgcolor=' . $this->decodeColor($this->bgcolor)
+            . '&color=' . $this->decodeColor($this->color)
+            . '&format=' . strtolower($this->format)
+            . '&data=' . rawurlencode($qrtext);
+    }
+}
\ No newline at end of file
diff --git a/RobThree/TwoFactorAuth/Providers/QRicketProvider.php b/RobThree/TwoFactorAuth/Providers/QRicketProvider.php
new file mode 100644
index 0000000..2356235
--- /dev/null
+++ b/RobThree/TwoFactorAuth/Providers/QRicketProvider.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace RobThree\TwoFactorAuth\Providers;
+
+// http://qrickit.com/qrickit_apps/qrickit_api.php
+class QRicketProvider extends BaseHTTPQRCodeProvider 
+{
+    public $errorcorrectionlevel;
+    public $margin;
+    public $qzone;
+    public $bgcolor;
+    public $color;
+    public $format;
+
+    function __construct($errorcorrectionlevel = 'L', $bgcolor = 'ffffff', $color = '000000', $format = 'p') 
+    {
+        $this->verifyssl = false;
+        
+        $this->errorcorrectionlevel = $errorcorrectionlevel;
+        $this->bgcolor = $bgcolor;
+        $this->color = $color;
+        $this->format = $format;
+    }
+    
+    public function getMimeType() 
+    {
+        switch (strtolower($this->format))
+        {
+        	case 'p':
+                return 'image/png';
+        	case 'g':
+                return 'image/gif';
+        	case 'j':
+                return 'image/jpeg';
+        }
+    }
+    
+    public function getQRCodeImage($qrtext, $size) 
+    {
+        return $this->getContent($this->getUrl($qrtext, $size));
+    }
+    
+    public function getUrl($qrtext, $size) 
+    {
+        return 'http://qrickit.com/api/qr'
+            . '?qrsize=' . $size
+            . '&e=' . strtolower($this->errorcorrectionlevel)
+            . '&bgdcolor=' . $this->bgcolor
+            . '&fgdcolor=' . $this->color
+            . '&t=' . strtolower($this->format)
+            . '&d=' . rawurlencode($qrtext);
+    }
+}
\ No newline at end of file
diff --git a/RobThree/TwoFactorAuth/TwoFactorAuth.php b/RobThree/TwoFactorAuth/TwoFactorAuth.php
new file mode 100644
index 0000000..a825d46
--- /dev/null
+++ b/RobThree/TwoFactorAuth/TwoFactorAuth.php
@@ -0,0 +1,147 @@
+<?php
+
+namespace RobThree\TwoFactorAuth;
+
+// Based on / inspired by: https://github.com/PHPGangsta/GoogleAuthenticator
+// Algorithms, digits, period etc. explained: https://code.google.com/p/google-authenticator/wiki/KeyUriFormat
+class TwoFactorAuth 
+{
+    private $algorithm;
+    private $period;
+    private $digits;
+    private $issuer;
+    private $qrcodeprovider;
+    private static $_base32;
+    private static $_base32lookup = array();
+    private static $_supportedalgos = array('sha1', 'sha256', 'sha512', 'md5');
+    
+    function __construct($issuer = null, $digits = 6, $period = 30, $algorithm = 'sha1', $qrcodeprovider = null) 
+    {
+        $this->issuer = $issuer;
+
+        if (!is_int($digits) || $digits <= 0)
+            throw new Exception('Digits must be int > 0');
+        $this->digits = $digits;
+        
+        if (!is_int($period) || $period <= 0)
+            throw new Exception('Period must be int > 0');
+        $this->period = $period;
+        
+        $algorithm = strtolower(trim($algorithm));
+        if (!in_array($algorithm, self::$_supportedalgos))
+            throw new Exception('Unsupported algorithm: ' . $algorithm);
+        $this->algorithm = $algorithm;
+        
+        if ($qrcodeprovider==null)
+            $qrcodeprovider = new Providers\GoogleQRCodeProvider();
+        
+        if (!($qrcodeprovider instanceof Providers\IQRCodeProvider))
+            throw new Exception('QRCodeProvider must implement IQRCodeProvider');
+        
+        $this->qrcodeprovider = $qrcodeprovider;
+        
+        self::$_base32 = str_split('ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=');
+        self::$_base32lookup = array_flip(self::$_base32);
+    }
+    
+    /**
+     * Create a new secret
+     */
+    public function createSecret($bits = 80) 
+    {
+        $secret = '';
+        $bytes = ceil($bits / 5);   //We use 5 bits of each byte
+        $rnd = openssl_random_pseudo_bytes($bytes);
+        for ($i = 0; $i < $bytes; $i++)
+            $secret .= self::$_base32[ord($rnd[$i]) & 31];  //Mask out left 3 bits for 0-31 values
+        return $secret;
+    }
+    
+    /**
+     * Calculate the code with given secret and point in time
+     */
+    public function getCode($secret, $time = null)
+    {
+        $secretkey = $this->base32Decode($secret);
+        
+        $ts = "\0\0\0\0" . pack('N*', $this->getTimeSlice($this->getTime($time)));  // Pack time into binary string
+        $hm = hash_hmac($this->algorithm, $ts, $secretkey, true);                   // Hash it with users secret key
+        $hashpart = substr($hm, ord(substr($hm, -1)) & 0x0F, 4);                    // Use last nibble of result as index/offset and grab 4 bytes of the result
+        $value = unpack('N', $hashpart);                                            // Unpack binary value
+        $value = $value[1] & 0x7FFFFFFF;                                            // Drop MSB, keep only 31 bits
+        
+        return str_pad($value % pow(10, $this->digits), $this->digits, '0', STR_PAD_LEFT);
+    }
+    
+    /**
+     * Check if the code is correct. This will accept codes starting from ($discrepancy * $period) sec ago to ($discrepancy * period) sec from now
+     */
+    public function verifyCode($secret, $code, $discrepancy = 1, $time = null)
+    {
+        $t = $this->getTime($time);
+        for ($i = -$discrepancy; $i <= $discrepancy; $i++) 
+        {
+            if (strcmp($this->getCode($secret, $t + ($i * $this->period)), $code) === 0)
+                return true;
+        }
+        
+        return false;
+    }
+    
+    /**
+     * Get data-uri of QRCode
+     */
+    public function getQRCodeImageAsDataUri($label, $secret, $size = 200) 
+    {
+        if (!is_int($size) || $size < 0)
+            throw new  Exception('Size must be int > 0');
+        
+        return 'data:'
+            . $this->qrcodeprovider->getMimeType()
+            . ';base64,'
+            . base64_encode($this->qrcodeprovider->getQRCodeImage($this->getQRText($label, $secret), $size));
+    }
+    
+    private function getTime($time) 
+    {
+        return ($time === null) ? time() : $time;
+    }
+    
+    private function getTimeSlice($time = null, $offset = 0) 
+    {
+        return (int)floor($time / $this->period) + ($offset * $this->period);
+    }
+    
+    /**
+     * Builds a string to be encoded in a QR code
+     */
+    private function getQRText($label, $secret) 
+    {
+        return 'otpauth://totp/' . rawurlencode($label)
+            . '?secret=' . rawurlencode($secret)
+            . '&issuer=' . rawurlencode($this->issuer)
+            . '&period=' . intval($this->period)
+            . '&algorithm=' . rawurlencode(strtoupper($this->algorithm))
+            . '&digits=' . intval($this->digits);
+    }
+    
+    private function base32Decode($value)
+    {
+        if (strlen($value)==0) return '';
+        
+        $s = '';
+        foreach (str_split($value) as $c) 
+        {
+            if ($c !== '=')
+                $s .= str_pad(decbin(self::$_base32lookup[$c]), 5, 0, STR_PAD_LEFT);
+        }
+        $l = strlen($s);
+        $r = trim(chunk_split(substr($s, 0, $l - ($l % 8)), 8, ' '));
+        
+		$o = '';
+		foreach (explode(' ', $r) as $b)
+            $o .= chr(bindec(str_pad($b, 8, 0, STR_PAD_RIGHT)));
+
+		return $o;
+    }
+}
\ No newline at end of file
diff --git a/TwoFactorAuth.phpproj b/TwoFactorAuth.phpproj
index 9d36825..ca8028e 100644
--- a/TwoFactorAuth.phpproj
+++ b/TwoFactorAuth.phpproj
@@ -23,12 +23,20 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="demo.php" />
-    <Compile Include="src\TwoFactorAuth.php" />
+    <Compile Include="loader.php" />
+    <Compile Include="RobThree\TwoFactorAuth\Providers\BaseHTTPQRCodeProvider.php" />
+    <Compile Include="RobThree\TwoFactorAuth\Providers\GoogleQRCodeProvider.php" />
+    <Compile Include="RobThree\TwoFactorAuth\Providers\IQRCodeProvider.php" />
+    <Compile Include="RobThree\TwoFactorAuth\Providers\QRicketProvider.php" />
+    <Compile Include="RobThree\TwoFactorAuth\Providers\QRServerProvider.php" />
+    <Compile Include="RobThree\TwoFactorAuth\TwoFactorAuth.php" />
     <Compile Include=".gitignore" />
     <Compile Include="README.md" />
   </ItemGroup>
   <ItemGroup>
-    <Folder Include="src\" />
+    <Folder Include="RobThree\" />
+    <Folder Include="RobThree\TwoFactorAuth\" />
+    <Folder Include="RobThree\TwoFactorAuth\Providers\" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="LICENSE" />
diff --git a/demo.php b/demo.php
index ba64627..e8c74cf 100644
--- a/demo.php
+++ b/demo.php
@@ -7,9 +7,12 @@
     <ol>
         <?php
         error_reporting(-1);
-        require_once 'src/TwoFactorAuth.php';
-
-        $tfa = new TwoFactorAuth('MyApp');
+        require_once 'loader.php';
+        Loader::register('RobThree','RobThree');
+        
+        use RobThree\TwoFactorAuth;
+        
+        $tfa = new TwoFactorAuth\TwoFactorAuth('MyApp', 6, 30, 'sha1', new TwoFactorAuth\Providers\QRicketProvider());
 
         echo '<li>First create a secret and associate it with a user';
         $secret = $tfa->createSecret();
diff --git a/loader.php b/loader.php
new file mode 100644
index 0000000..208f24d
--- /dev/null
+++ b/loader.php
@@ -0,0 +1,50 @@
+<?php
+
+//http://www.leaseweblabs.com/2014/04/psr-0-psr-4-autoloading-classes-php/
+class Loader
+{
+    protected static $parentPath = null;
+    protected static $paths = null;
+    protected static $files = null;
+    protected static $nsChar = '\\';
+    protected static $initialized = false;
+    
+    protected static function initialize()
+    {
+        if (static::$initialized) return;
+        static::$initialized = true;
+        static::$parentPath = __FILE__;
+        for ($i=substr_count(get_class(), static::$nsChar);$i>=0;$i--) {
+            static::$parentPath = dirname(static::$parentPath);
+        }
+        static::$paths = array();
+        static::$files = array(__FILE__);
+    }
+    
+    public static function register($path,$namespace) {
+        if (!static::$initialized) static::initialize();
+        static::$paths[$namespace] = trim($path,DIRECTORY_SEPARATOR);
+    }
+    
+    public static function load($class) {
+        if (class_exists($class,false)) return;
+        if (!static::$initialized) static::initialize();
+        
+        foreach (static::$paths as $namespace => $path) {
+            if (!$namespace || $namespace.static::$nsChar === substr($class, 0, strlen($namespace.static::$nsChar))) {
+                
+                $fileName = substr($class,strlen($namespace.static::$nsChar)-1);
+                $fileName = str_replace(static::$nsChar, DIRECTORY_SEPARATOR, ltrim($fileName,static::$nsChar));
+                $fileName = static::$parentPath.DIRECTORY_SEPARATOR.$path.DIRECTORY_SEPARATOR.$fileName.'.php';
+                
+                if (file_exists($fileName)) {
+                    include $fileName;
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+}
+
+spl_autoload_register(array('Loader', 'load'));
\ No newline at end of file
diff --git a/src/TwoFactorAuth.php b/src/TwoFactorAuth.php
deleted file mode 100644
index 6cffa6d..0000000
--- a/src/TwoFactorAuth.php
+++ /dev/null
@@ -1,329 +0,0 @@
-<?php
-// Based on / inspired by: https://github.com/PHPGangsta/GoogleAuthenticator
-// Algorithms, digits, period etc. explained: https://code.google.com/p/google-authenticator/wiki/KeyUriFormat
-class TwoFactorAuth 
-{
-    private $algorithm;
-    private $period;
-    private $digits;
-    private $issuer;
-    private $qrcodeprovider;
-    private static $_base32;
-    private static $_base32lookup = array();
-    private static $_supportedalgos = array('sha1', 'sha256', 'sha512', 'md5');
-    
-    function __construct($issuer = null, $digits = 6, $period = 30, $algorithm = 'sha1', $qrcodeprovider = null) 
-    {
-        $this->issuer = $issuer;
-
-        if (!is_int($digits) || $digits <= 0)
-            throw new Exception('Digits must be int > 0');
-        $this->digits = $digits;
-        
-        if (!is_int($period) || $period <= 0)
-            throw new Exception('Period must be int > 0');
-        $this->period = $period;
-        
-        $algorithm = strtolower(trim($algorithm));
-        if (!in_array($algorithm, self::$_supportedalgos))
-            throw new Exception('Unsupported algorithm: ' . $algorithm);
-        $this->algorithm = $algorithm;
-        
-        if ($qrcodeprovider==null)
-            $qrcodeprovider = new GoogleQRCodeProvider();
-        
-        if (!($qrcodeprovider instanceof IQRCodeProvider))
-            throw new Exception('QRCodeProvider must implement IQRCodeProvider');
-        
-        $this->qrcodeprovider = $qrcodeprovider;
-        
-        self::$_base32 = str_split('ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=');
-        self::$_base32lookup = array_flip(self::$_base32);
-    }
-    
-    /**
-     * Create a new secret
-     */
-    public function createSecret($bits = 80) 
-    {
-        $secret = '';
-        $bytes = ceil($bits / 5);   //We use 5 bits of each byte
-        $rnd = openssl_random_pseudo_bytes($bytes);
-        for ($i = 0; $i < $bytes; $i++)
-            $secret .= self::$_base32[ord($rnd[$i]) & 31];  //Mask out left 3 bits for 0-31 values
-        return $secret;
-    }
-    
-    /**
-     * Calculate the code with given secret and point in time
-     */
-    public function getCode($secret, $time = null)
-    {
-        $secretkey = $this->base32Decode($secret);
-        
-        $ts = "\0\0\0\0" . pack('N*', $this->getTimeSlice($this->getTime($time)));  // Pack time into binary string
-        $hm = hash_hmac($this->algorithm, $ts, $secretkey, true);                   // Hash it with users secret key
-        $hashpart = substr($hm, ord(substr($hm, -1)) & 0x0F, 4);                    // Use last nibble of result as index/offset and grab 4 bytes of the result
-        $value = unpack('N', $hashpart);                                            // Unpack binary value
-        $value = $value[1] & 0x7FFFFFFF;                                            // Drop MSB, keep only 31 bits
-        
-        return str_pad($value % pow(10, $this->digits), $this->digits, '0', STR_PAD_LEFT);
-    }
-    
-    /**
-     * Check if the code is correct. This will accept codes starting from ($discrepancy * $period) sec ago to ($discrepancy * period) sec from now
-     */
-    public function verifyCode($secret, $code, $discrepancy = 1, $time = null)
-    {
-        $t = $this->getTime($time);
-        for ($i = -$discrepancy; $i <= $discrepancy; $i++) 
-        {
-            if (strcmp($this->getCode($secret, $t + ($i * $this->period)), $code) === 0)
-                return true;
-        }
-        
-        return false;
-    }
-    
-    /**
-     * Get data-uri of QRCode
-     */
-    public function getQRCodeImageAsDataUri($label, $secret, $size = 200) 
-    {
-        if (!is_int($size) || $size < 0)
-            throw new  Exception('Size must be int > 0');
-        
-        return 'data:'
-            . $this->qrcodeprovider->getMimeType()
-            . ';base64,'
-            . base64_encode($this->qrcodeprovider->getQRCodeImage($this->getQRText($label, $secret), $size));
-    }
-    
-    private function getTime($time) 
-    {
-        return ($time === null) ? time() : $time;
-    }
-    
-    private function getTimeSlice($time = null, $offset = 0) 
-    {
-        return (int)floor($time / $this->period) + ($offset * $this->period);
-    }
-    
-    /**
-     * Builds a string to be encoded in a QR code
-     */
-    private function getQRText($label, $secret) 
-    {
-        return 'otpauth://totp/' . rawurlencode($label)
-            . '?secret=' . rawurlencode($secret)
-            . '&issuer=' . rawurlencode($this->issuer)
-            . '&period=' . intval($this->period)
-            . '&algorithm=' . rawurlencode(strtoupper($this->algorithm))
-            . '&digits=' . intval($this->digits);
-    }
-    
-    private function base32Decode($value)
-    {
-        if (strlen($value)==0) return '';
-        
-        $s = '';
-        foreach (str_split($value) as $c) 
-        {
-            if ($c !== '=')
-                $s .= str_pad(decbin(self::$_base32lookup[$c]), 5, 0, STR_PAD_LEFT);
-        }
-        $l = strlen($s);
-        $r = trim(chunk_split(substr($s, 0, $l - ($l % 8)), 8, ' '));
-        
-		$o = '';
-		foreach (explode(' ', $r) as $b)
-            $o .= chr(bindec(str_pad($b, 8, 0, STR_PAD_RIGHT)));
-
-		return $o;
-    }
-}
-
-interface IQRCodeProvider
-{
-	public function getQRCodeImage($qrtext, $size);
-    public function getMimeType();
-}
-
-abstract class BaseHTTPQRCodeProvider implements IQRCodeProvider
-{
-    protected $verifyssl;
-
-	protected function getContent($url)
-    {
-        $ch = curl_init();
-        
-        curl_setopt_array($ch, array(
-			CURLOPT_URL => $url,
-			CURLOPT_FOLLOWLOCATION => true,
-			CURLOPT_MAXREDIRS => 3,
-			CURLOPT_RETURNTRANSFER => true,
-			CURLOPT_CONNECTTIMEOUT => 10,
-			CURLOPT_DNS_CACHE_TIMEOUT => 10,
-			CURLOPT_TIMEOUT => 10,
-            CURLOPT_SSL_VERIFYPEER => $this->verifyssl,
-			CURLOPT_USERAGENT => 'TwoFactorAuth'
-        ));
-        $data = curl_exec($ch);
-        
-        curl_close($ch);
-        return $data;
-    }
-}
-
-// https://developers.google.com/chart/infographics/docs/qr_codes
-class GoogleQRCodeProvider extends BaseHTTPQRCodeProvider 
-{
-    public $errorcorrectionlevel;
-    public $margin;
-
-    function __construct($verifyssl = false, $errorcorrectionlevel = 'L', $margin = 1) 
-    {
-        if (!is_bool($verifyssl))
-            throw new Exception('VerifySSL must be bool');
-
-        $this->verifyssl = $verifyssl;
-        
-        $this->errorcorrectionlevel = $errorcorrectionlevel;
-        $this->margin = $margin;
-    }
-    
-    public function getMimeType() 
-    {
-        return 'image/png';
-    }
-    
-    public function getQRCodeImage($qrtext, $size) 
-    {
-        return $this->getContent($this->getUrl($qrtext, $size));
-    }
-    
-    public function getUrl($qrtext, $size) 
-    {
-        return 'https://chart.googleapis.com/chart?cht=qr'
-            . '&chs=' . $size . 'x' . $size
-            . '&chld=' . $this->errorcorrectionlevel . '|' . $this->margin
-            . '&chl=' . rawurlencode($qrtext);
-    }
-}
-
-// http://goqr.me/api/doc/create-qr-code/
-class QRServerProvider extends BaseHTTPQRCodeProvider 
-{
-    public $errorcorrectionlevel;
-    public $margin;
-    public $qzone;
-    public $bgcolor;
-    public $color;
-    public $format;
-
-    function __construct($verifyssl = false, $errorcorrectionlevel = 'L', $margin = 4, $qzone = 1, $bgcolor = 'ffffff', $color = '000000', $format = 'png') 
-    {
-        if (!is_bool($verifyssl))
-            throw new Exception('VerifySSL must be bool');
-
-        $this->verifyssl = $verifyssl;
-        
-        $this->errorcorrectionlevel = $errorcorrectionlevel;
-        $this->margin = $margin;
-        $this->qzone = $qzone;
-        $this->bgcolor = $bgcolor;
-        $this->color = $color;
-        $this->format = $format;
-    }
-    
-    public function getMimeType() 
-    {
-        switch (strtolower($this->format))
-        {
-        	case 'png':
-                return 'image/png';
-        	case 'gif':
-                return 'image/gif';
-        	case 'jpg':
-        	case 'jpeg':
-                return 'image/jpeg';
-        	case 'svg':
-                return 'image/svg+xml';
-        	case 'eps':
-                return 'application/postscript';
-        }
-    }
-    
-    public function getQRCodeImage($qrtext, $size) 
-    {
-        return $this->getContent($this->getUrl($qrtext, $size));
-    }
-    
-    private function decodeColor($value) 
-    {
-        return vsprintf('%d-%d-%d', sscanf($value, "%02x%02x%02x"));
-    }
-    
-    public function getUrl($qrtext, $size) 
-    {
-        return 'https://api.qrserver.com/v1/create-qr-code/'
-            . '?size=' . $size . 'x' . $size
-            . '&ecc=' . strtoupper($this->errorcorrectionlevel)
-            . '&margin=' . $this->margin
-            . '&qzone=' . $this->qzone
-            . '&bgcolor=' . $this->decodeColor($this->bgcolor)
-            . '&color=' . $this->decodeColor($this->color)
-            . '&format=' . strtolower($this->format)
-            . '&data=' . rawurlencode($qrtext);
-    }
-}
-
-// http://qrickit.com/qrickit_apps/qrickit_api.php
-class QRicketProvider extends BaseHTTPQRCodeProvider 
-{
-    public $errorcorrectionlevel;
-    public $margin;
-    public $qzone;
-    public $bgcolor;
-    public $color;
-    public $format;
-
-    function __construct($errorcorrectionlevel = 'L', $bgcolor = 'ffffff', $color = '000000', $format = 'p') 
-    {
-        $this->verifyssl = false;
-        
-        $this->errorcorrectionlevel = $errorcorrectionlevel;
-        $this->bgcolor = $bgcolor;
-        $this->color = $color;
-        $this->format = $format;
-    }
-    
-    public function getMimeType() 
-    {
-        switch (strtolower($this->format))
-        {
-        	case 'p':
-                return 'image/png';
-        	case 'g':
-                return 'image/gif';
-        	case 'j':
-                return 'image/jpeg';
-        }
-    }
-    
-    public function getQRCodeImage($qrtext, $size) 
-    {
-        return $this->getContent($this->getUrl($qrtext, $size));
-    }
-    
-    public function getUrl($qrtext, $size) 
-    {
-        return 'http://qrickit.com/api/qr'
-            . '?qrsize=' . $size
-            . '&e=' . strtolower($this->errorcorrectionlevel)
-            . '&bgdcolor=' . $this->bgcolor
-            . '&fgdcolor=' . $this->color
-            . '&t=' . strtolower($this->format)
-            . '&d=' . rawurlencode($qrtext);
-    }
-}
\ No newline at end of file