Add in support for late static binding, so that developers can extend and override variables / methods if they so require (#88)

Author: chappy84

Diff for: src/JWT.php

@@ -66,7 +66,7 @@ class JWT
      */
     public static function decode($jwt, $key, $allowed_algs = array())
     {
-        $timestamp = is_null(self::$timestamp) ? time() : self::$timestamp;
+        $timestamp = is_null(static::$timestamp) ? time() : static::$timestamp;
 
         if (empty($key)) {
             throw new InvalidArgumentException('Key may not be empty');
@@ -79,18 +79,18 @@ public static function decode($jwt, $key, $allowed_algs = array())
             throw new UnexpectedValueException('Wrong number of segments');
         }
         list($headb64, $bodyb64, $cryptob64) = $tks;
-        if (null === ($header = JWT::jsonDecode(JWT::urlsafeB64Decode($headb64)))) {
+        if (null === ($header = static::jsonDecode(static::urlsafeB64Decode($headb64)))) {
             throw new UnexpectedValueException('Invalid header encoding');
         }
-        if (null === $payload = JWT::jsonDecode(JWT::urlsafeB64Decode($bodyb64))) {
+        if (null === $payload = static::jsonDecode(static::urlsafeB64Decode($bodyb64))) {
             throw new UnexpectedValueException('Invalid claims encoding');
         }
-        $sig = JWT::urlsafeB64Decode($cryptob64);
+        $sig = static::urlsafeB64Decode($cryptob64);
 
         if (empty($header->alg)) {
             throw new UnexpectedValueException('Empty algorithm');
         }
-        if (empty(self::$supported_algs[$header->alg])) {
+        if (empty(static::$supported_algs[$header->alg])) {
             throw new UnexpectedValueException('Algorithm not supported');
         }
         if (!in_array($header->alg, $allowed_algs)) {
@@ -105,13 +105,13 @@ public static function decode($jwt, $key, $allowed_algs = array())
         }
 
         // Check the signature
-        if (!JWT::verify("$headb64.$bodyb64", $sig, $key, $header->alg)) {
+        if (!static::verify("$headb64.$bodyb64", $sig, $key, $header->alg)) {
             throw new SignatureInvalidException('Signature verification failed');
         }
 
         // Check if the nbf if it is defined. This is the time that the
         // token can actually be used. If it's not yet that time, abort.
-        if (isset($payload->nbf) && $payload->nbf > ($timestamp + self::$leeway)) {
+        if (isset($payload->nbf) && $payload->nbf > ($timestamp + static::$leeway)) {
             throw new BeforeValidException(
                 'Cannot handle token prior to ' . date(DateTime::ISO8601, $payload->nbf)
             );
@@ -120,14 +120,14 @@ public static function decode($jwt, $key, $allowed_algs = array())
         // Check that this token has been created before 'now'. This prevents
         // using tokens that have been created for later use (and haven't
         // correctly used the nbf claim).
-        if (isset($payload->iat) && $payload->iat > ($timestamp + self::$leeway)) {
+        if (isset($payload->iat) && $payload->iat > ($timestamp + static::$leeway)) {
             throw new BeforeValidException(
                 'Cannot handle token prior to ' . date(DateTime::ISO8601, $payload->iat)
             );
         }
 
         // Check if this token has expired.
-        if (isset($payload->exp) && ($timestamp - self::$leeway) >= $payload->exp) {
+        if (isset($payload->exp) && ($timestamp - static::$leeway) >= $payload->exp) {
             throw new ExpiredException('Expired token');
         }
 
@@ -160,12 +160,12 @@ public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $he
             $header = array_merge($head, $header);
         }
         $segments = array();
-        $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($header));
-        $segments[] = JWT::urlsafeB64Encode(JWT::jsonEncode($payload));
+        $segments[] = static::urlsafeB64Encode(static::jsonEncode($header));
+        $segments[] = static::urlsafeB64Encode(static::jsonEncode($payload));
         $signing_input = implode('.', $segments);
 
-        $signature = JWT::sign($signing_input, $key, $alg);
-        $segments[] = JWT::urlsafeB64Encode($signature);
+        $signature = static::sign($signing_input, $key, $alg);
+        $segments[] = static::urlsafeB64Encode($signature);
 
         return implode('.', $segments);
     }
@@ -184,10 +184,10 @@ public static function encode($payload, $key, $alg = 'HS256', $keyId = null, $he
      */
     public static function sign($msg, $key, $alg = 'HS256')
     {
-        if (empty(self::$supported_algs[$alg])) {
+        if (empty(static::$supported_algs[$alg])) {
             throw new DomainException('Algorithm not supported');
         }
-        list($function, $algorithm) = self::$supported_algs[$alg];
+        list($function, $algorithm) = static::$supported_algs[$alg];
         switch($function) {
             case 'hash_hmac':
                 return hash_hmac($algorithm, $msg, $key, true);
@@ -217,11 +217,11 @@ public static function sign($msg, $key, $alg = 'HS256')
      */
     private static function verify($msg, $signature, $key, $alg)
     {
-        if (empty(self::$supported_algs[$alg])) {
+        if (empty(static::$supported_algs[$alg])) {
             throw new DomainException('Algorithm not supported');
         }
 
-        list($function, $algorithm) = self::$supported_algs[$alg];
+        list($function, $algorithm) = static::$supported_algs[$alg];
         switch($function) {
             case 'openssl':
                 $success = openssl_verify($msg, $signature, $key, $algorithm);
@@ -236,13 +236,13 @@ private static function verify($msg, $signature, $key, $alg)
                 if (function_exists('hash_equals')) {
                     return hash_equals($signature, $hash);
                 }
-                $len = min(self::safeStrlen($signature), self::safeStrlen($hash));
+                $len = min(static::safeStrlen($signature), static::safeStrlen($hash));
 
                 $status = 0;
                 for ($i = 0; $i < $len; $i++) {
                     $status |= (ord($signature[$i]) ^ ord($hash[$i]));
                 }
-                $status |= (self::safeStrlen($signature) ^ self::safeStrlen($hash));
+                $status |= (static::safeStrlen($signature) ^ static::safeStrlen($hash));
 
                 return ($status === 0);
         }
@@ -276,7 +276,7 @@ public static function jsonDecode($input)
         }
 
         if (function_exists('json_last_error') && $errno = json_last_error()) {
-            JWT::handleJsonError($errno);
+            static::handleJsonError($errno);
         } elseif ($obj === null && $input !== 'null') {
             throw new DomainException('Null result with non-null input');
         }
@@ -296,7 +296,7 @@ public static function jsonEncode($input)
     {
         $json = json_encode($input);
         if (function_exists('json_last_error') && $errno = json_last_error()) {
-            JWT::handleJsonError($errno);
+            static::handleJsonError($errno);
         } elseif ($json === 'null' && $input !== null) {
             throw new DomainException('Null result with non-null input');
         }