Update changelog for version 7.4.0

Merge pull request #1000 from filecage/master
Optional Refresh Tokens
2025-05-31 14:12:07 +05:30 · 2019-05-05 10:22:01 +01:00 · 2019-05-05 09:48:53 +01:00 · 2019-05-05 09:03:13 +01:00 · 2019-05-05 08:58:34 +01:00 · 2019-04-29 19:13:26 +02:00
42 changed files with 904 additions and 283 deletions
--- a/.styleci.yml
+++ b/.styleci.yml
@@ -4,6 +4,7 @@ enabled:
  - binary_operator_spaces
  - blank_line_before_return
  - concat_with_spaces
+  - fully_qualified_strict_types
  - function_typehint_space
  - hash_to_slash_comment
  - include
@@ -40,7 +41,6 @@ enabled:
  - print_to_echo
  - short_array_syntax
  - short_scalar_cast
-  - simplified_null_return
  - single_quote
  - spaces_cast
  - standardize_not_equal
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,6 +15,7 @@ php:
  - 7.0
  - 7.1
  - 7.2
+  - 7.3

 install:
  - composer update --no-interaction --prefer-dist $DEPENDENCIES
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,41 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.

 ## [Unreleased]

+## [7.4.0] - released 2019-05-05
+
+### Changed
+- RefreshTokenRepository can now return null, allowing refresh tokens to be optional. (PR #649)
+
+## [7.3.3] - released 2019-03-29
+
+### Added
+- Added `error_description` to the error payload to improve standards compliance. The contents of this are copied from the existing `message` value. (PR #1006)
+
+### Deprecated
+- Error payload will not issue `message` value in the next major release (PR #1006)
+
+## [7.3.2] - released 2018-11-21
+
+### Fixed
+- Revert setting keys on response type to be inside `getResponseType()` function instead of AuthorizationServer constructor (PR #969)
+
+## [7.3.1] - released 2018-11-15
+
+### Fixed
+- Fix issue with previous release where interface had changed for the AuthorizationServer. Reverted to the previous interface while maintaining functionality changes (PR #970)
+
+## [7.3.0] - released 2018-11-13
+
+### Changed
+- Moved  the `finalizeScopes()` call from `validateAuthorizationRequest` method to the `completeAuthorizationRequest` method so it is called just before the access token is issued (PR #923)
+
+### Added
+- Added a ScopeTrait to provide an implementation for jsonSerialize (PR #952)
+- Ability to nest exceptions (PR #965)
+
+### Fixed
+- Fix issue where AuthorizationServer is not stateless as ResponseType could store state of a previous request (PR #960)
+
 ## [7.2.0] - released 2018-06-23

 ### Changed
@@ -410,7 +445,12 @@ Version 5 is a complete code rewrite.

 - First major release

-[Unreleased]: https://github.com/thephpleague/oauth2-server/compare/7.2.0...HEAD
+[Unreleased]: https://github.com/thephpleague/oauth2-server/compare/7.4.0...HEAD
+[7.4.0]: https://github.com/thephpleague/oauth2-server/compare/7.3.3...7.4.0
+[7.3.3]: https://github.com/thephpleague/oauth2-server/compare/7.3.2...7.3.3
+[7.3.2]: https://github.com/thephpleague/oauth2-server/compare/7.3.1...7.3.2
+[7.3.1]: https://github.com/thephpleague/oauth2-server/compare/7.3.0...7.3.1
+[7.3.0]: https://github.com/thephpleague/oauth2-server/compare/7.2.0...7.3.0
 [7.2.0]: https://github.com/thephpleague/oauth2-server/compare/7.1.1...7.2.0
 [7.1.1]: https://github.com/thephpleague/oauth2-server/compare/7.1.0...7.1.1
 [7.1.0]: https://github.com/thephpleague/oauth2-server/compare/7.0.0...7.1.0
--- a/README.md
+++ b/README.md
@@ -34,6 +34,7 @@ The following versions of PHP are supported:
 * PHP 7.0
 * PHP 7.1
 * PHP 7.2
+* PHP 7.3

 The `openssl` extension is also required.

@@ -68,6 +69,8 @@ We use [Travis CI](https://travis-ci.org/), [Scrutinizer](https://scrutinizer-ci
 * [Drupal](https://www.drupal.org/project/simple_oauth)
 * [Laravel Passport](https://github.com/laravel/passport)
 * [OAuth 2 Server for CakePHP 3](https://github.com/uafrica/oauth-server)
+* [OAuth 2 Server for Expressive](https://github.com/zendframework/zend-expressive-authentication-oauth2)
+* [Trikoder OAuth 2 Bundle (Symfony)](https://github.com/trikoder/oauth2-bundle)

 ## Changelog

--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,8 @@
        "zendframework/zend-diactoros": "^1.3.2",
        "phpstan/phpstan": "^0.9.2",
        "phpstan/phpstan-phpunit": "^0.9.4",
-        "phpstan/phpstan-strict-rules": "^0.9.0"
+        "phpstan/phpstan-strict-rules": "^0.9.0",
+        "roave/security-advisories": "dev-master"
    },
    "repositories": [
        {
@@ -46,6 +47,12 @@
            "email": "hello@alexbilbie.com",
            "homepage": "http://www.alexbilbie.com",
            "role": "Developer"
+        },
+        {
+            "name": "Andy Millington",
+            "email": "andrew@noexceptions.io",
+            "homepage": "https://www.noexceptions.io",
+            "role": "Developer"
        }
    ],
    "replace": {
--- a/examples/composer.json
+++ b/examples/composer.json
@@ -1,14 +1,13 @@
 {
    "require": {
-        "slim/slim": "3.0.*"
+        "slim/slim": "^3.0.0"
    },
    "require-dev": {
        "league/event": "^2.1",
-        "lcobucci/jwt": "^3.1",
-        "paragonie/random_compat": "^2.0",
+        "lcobucci/jwt": "^3.2",
        "psr/http-message": "^1.0",
-        "defuse/php-encryption": "^2.1",
-        "zendframework/zend-diactoros": "^1.0"
+        "defuse/php-encryption": "^2.2",
+        "zendframework/zend-diactoros": "^2.0.0"
    },
    "autoload": {
        "psr-4": {
--- a/examples/composer.lock
+++ b/examples/composer.lock
@@ -4,7 +4,7 @@
        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
        "This file is @generated automatically"
    ],
-    "content-hash": "9813ed7c3b6dcf107f44df9392935b8f",
+    "content-hash": "97f2878428e37d1d8e5418cc85cbfa3d",
    "packages": [
        {
            "name": "container-interop/container-interop",
@@ -39,21 +39,24 @@
        },
        {
            "name": "nikic/fast-route",
-            "version": "v0.6.0",
+            "version": "v1.3.0",
            "source": {
                "type": "git",
                "url": "https://github.com/nikic/FastRoute.git",
-                "reference": "31fa86924556b80735f98b294a7ffdfb26789f22"
+                "reference": "181d480e08d9476e61381e04a71b34dc0432e812"
            },
            "dist": {
                "type": "zip",
-                "url": "https://api.github.com/repos/nikic/FastRoute/zipball/31fa86924556b80735f98b294a7ffdfb26789f22",
-                "reference": "31fa86924556b80735f98b294a7ffdfb26789f22",
+                "url": "https://api.github.com/repos/nikic/FastRoute/zipball/181d480e08d9476e61381e04a71b34dc0432e812",
+                "reference": "181d480e08d9476e61381e04a71b34dc0432e812",
                "shasum": ""
            },
            "require": {
                "php": ">=5.4.0"
            },
+            "require-dev": {
+                "phpunit/phpunit": "^4.8.35|~5.7"
+            },
            "type": "library",
            "autoload": {
                "psr-4": {
@@ -78,29 +81,33 @@
                "router",
                "routing"
            ],
-            "time": "2015-06-18T19:15:47+00:00"
+            "time": "2018-02-13T20:26:39+00:00"
        },
        {
            "name": "pimple/pimple",
-            "version": "v3.0.2",
+            "version": "v3.2.3",
            "source": {
                "type": "git",
                "url": "https://github.com/silexphp/Pimple.git",
-                "reference": "a30f7d6e57565a2e1a316e1baf2a483f788b258a"
+                "reference": "9e403941ef9d65d20cba7d54e29fe906db42cf32"
            },
            "dist": {
                "type": "zip",
-                "url": "https://api.github.com/repos/silexphp/Pimple/zipball/a30f7d6e57565a2e1a316e1baf2a483f788b258a",
-                "reference": "a30f7d6e57565a2e1a316e1baf2a483f788b258a",
+                "url": "https://api.github.com/repos/silexphp/Pimple/zipball/9e403941ef9d65d20cba7d54e29fe906db42cf32",
+                "reference": "9e403941ef9d65d20cba7d54e29fe906db42cf32",
                "shasum": ""
            },
            "require": {
-                "php": ">=5.3.0"
+                "php": ">=5.3.0",
+                "psr/container": "^1.0"
+            },
+            "require-dev": {
+                "symfony/phpunit-bridge": "^3.2"
            },
            "type": "library",
            "extra": {
                "branch-alias": {
-                    "dev-master": "3.0.x-dev"
+                    "dev-master": "3.2.x-dev"
                }
            },
            "autoload": {
@@ -124,7 +131,7 @@
                "container",
                "dependency injection"
            ],
-            "time": "2015-09-11T15:10:35+00:00"
+            "time": "2018-01-21T07:42:36+00:00"
        },
        {
            "name": "psr/container",
@@ -227,27 +234,32 @@
        },
        {
            "name": "slim/slim",
-            "version": "3.0.0",
+            "version": "3.11.0",
            "source": {
                "type": "git",
                "url": "https://github.com/slimphp/Slim.git",
-                "reference": "3b06f0f2d84dabbe81b6cea46ace46a3e883253e"
+                "reference": "d378e70431e78ee92ee32ddde61ecc72edf5dc0a"
            },
            "dist": {
                "type": "zip",
-                "url": "https://api.github.com/repos/slimphp/Slim/zipball/3b06f0f2d84dabbe81b6cea46ace46a3e883253e",
-                "reference": "3b06f0f2d84dabbe81b6cea46ace46a3e883253e",
+                "url": "https://api.github.com/repos/slimphp/Slim/zipball/d378e70431e78ee92ee32ddde61ecc72edf5dc0a",
+                "reference": "d378e70431e78ee92ee32ddde61ecc72edf5dc0a",
                "shasum": ""
            },
            "require": {
-                "container-interop/container-interop": "^1.1",
-                "nikic/fast-route": "^0.6",
+                "container-interop/container-interop": "^1.2",
+                "nikic/fast-route": "^1.0",
                "php": ">=5.5.0",
                "pimple/pimple": "^3.0",
+                "psr/container": "^1.0",
                "psr/http-message": "^1.0"
            },
+            "provide": {
+                "psr/http-message-implementation": "1.0"
+            },
            "require-dev": {
-                "phpunit/phpunit": "^4.0"
+                "phpunit/phpunit": "^4.0",
+                "squizlabs/php_codesniffer": "^2.5"
            },
            "type": "library",
            "autoload": {
@@ -282,38 +294,38 @@
                }
            ],
            "description": "Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs",
-            "homepage": "http://slimframework.com",
+            "homepage": "https://slimframework.com",
            "keywords": [
                "api",
                "framework",
                "micro",
                "router"
            ],
-            "time": "2015-12-07T14:11:09+00:00"
+            "time": "2018-09-16T10:54:21+00:00"
        }
    ],
    "packages-dev": [
        {
            "name": "defuse/php-encryption",
-            "version": "v2.1.0",
+            "version": "v2.2.1",
            "source": {
                "type": "git",
                "url": "https://github.com/defuse/php-encryption.git",
-                "reference": "5176f5abb38d3ea8a6e3ac6cd3bbb54d8185a689"
+                "reference": "0f407c43b953d571421e0020ba92082ed5fb7620"
            },
            "dist": {
                "type": "zip",
-                "url": "https://api.github.com/repos/defuse/php-encryption/zipball/5176f5abb38d3ea8a6e3ac6cd3bbb54d8185a689",
-                "reference": "5176f5abb38d3ea8a6e3ac6cd3bbb54d8185a689",
+                "url": "https://api.github.com/repos/defuse/php-encryption/zipball/0f407c43b953d571421e0020ba92082ed5fb7620",
+                "reference": "0f407c43b953d571421e0020ba92082ed5fb7620",
                "shasum": ""
            },
            "require": {
                "ext-openssl": "*",
-                "paragonie/random_compat": "~2.0",
+                "paragonie/random_compat": ">= 2",
                "php": ">=5.4.0"
            },
            "require-dev": {
-                "nikic/php-parser": "^2.0|^3.0",
+                "nikic/php-parser": "^2.0|^3.0|^4.0",
                "phpunit/phpunit": "^4|^5"
            },
            "bin": [
@@ -354,20 +366,20 @@
                "security",
                "symmetric key cryptography"
            ],
-            "time": "2017-05-18T21:28:48+00:00"
+            "time": "2018-07-24T23:27:56+00:00"
        },
        {
            "name": "lcobucci/jwt",
-            "version": "3.2.1",
+            "version": "3.2.4",
            "source": {
                "type": "git",
                "url": "https://github.com/lcobucci/jwt.git",
-                "reference": "ddce703826f9c5229781933b1a39069e38e6a0f3"
+                "reference": "c9704b751315d21735dc98d78d4f37bd73596da7"
            },
            "dist": {
                "type": "zip",
-                "url": "https://api.github.com/repos/lcobucci/jwt/zipball/ddce703826f9c5229781933b1a39069e38e6a0f3",
-                "reference": "ddce703826f9c5229781933b1a39069e38e6a0f3",
+                "url": "https://api.github.com/repos/lcobucci/jwt/zipball/c9704b751315d21735dc98d78d4f37bd73596da7",
+                "reference": "c9704b751315d21735dc98d78d4f37bd73596da7",
                "shasum": ""
            },
            "require": {
@@ -412,7 +424,7 @@
                "JWS",
                "jwt"
            ],
-            "time": "2016-10-31T20:09:32+00:00"
+            "time": "2018-08-03T11:23:50+00:00"
        },
        {
            "name": "league/event",
@@ -466,33 +478,29 @@
        },
        {
            "name": "paragonie/random_compat",
-            "version": "v2.0.10",
+            "version": "v9.99.99",
            "source": {
                "type": "git",
                "url": "https://github.com/paragonie/random_compat.git",
-                "reference": "634bae8e911eefa89c1abfbf1b66da679ac8f54d"
+                "reference": "84b4dfb120c6f9b4ff7b3685f9b8f1aa365a0c95"
            },
            "dist": {
                "type": "zip",
-                "url": "https://api.github.com/repos/paragonie/random_compat/zipball/634bae8e911eefa89c1abfbf1b66da679ac8f54d",
-                "reference": "634bae8e911eefa89c1abfbf1b66da679ac8f54d",
+                "url": "https://api.github.com/repos/paragonie/random_compat/zipball/84b4dfb120c6f9b4ff7b3685f9b8f1aa365a0c95",
+                "reference": "84b4dfb120c6f9b4ff7b3685f9b8f1aa365a0c95",
                "shasum": ""
            },
            "require": {
-                "php": ">=5.2.0"
+                "php": "^7"
            },
            "require-dev": {
-                "phpunit/phpunit": "4.*|5.*"
+                "phpunit/phpunit": "4.*|5.*",
+                "vimeo/psalm": "^1"
            },
            "suggest": {
                "ext-libsodium": "Provides a modern crypto API that can be used to generate random bytes."
            },
            "type": "library",
-            "autoload": {
-                "files": [
-                    "lib/random.php"
-                ]
-            },
            "notification-url": "https://packagist.org/downloads/",
            "license": [
                "MIT"
@@ -507,10 +515,129 @@
            "description": "PHP 5.x polyfill for random_bytes() and random_int() from PHP 7",
            "keywords": [
                "csprng",
+                "polyfill",
                "pseudorandom",
                "random"
            ],
-            "time": "2017-03-13T16:27:32+00:00"
+            "time": "2018-07-02T15:55:56+00:00"
+        },
+        {
+            "name": "psr/http-factory",
+            "version": "1.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-fig/http-factory.git",
+                "reference": "378bfe27931ecc54ff824a20d6f6bfc303bbd04c"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-fig/http-factory/zipball/378bfe27931ecc54ff824a20d6f6bfc303bbd04c",
+                "reference": "378bfe27931ecc54ff824a20d6f6bfc303bbd04c",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=7.0.0",
+                "psr/http-message": "^1.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.0.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Psr\\Http\\Message\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "PHP-FIG",
+                    "homepage": "http://www.php-fig.org/"
+                }
+            ],
+            "description": "Common interfaces for PSR-7 HTTP message factories",
+            "keywords": [
+                "factory",
+                "http",
+                "message",
+                "psr",
+                "psr-17",
+                "psr-7",
+                "request",
+                "response"
+            ],
+            "time": "2018-07-30T21:54:04+00:00"
+        },
+        {
+            "name": "zendframework/zend-diactoros",
+            "version": "2.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/zendframework/zend-diactoros.git",
+                "reference": "0bae78192e634774b5584f0210c1232da82cb1ff"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/zendframework/zend-diactoros/zipball/0bae78192e634774b5584f0210c1232da82cb1ff",
+                "reference": "0bae78192e634774b5584f0210c1232da82cb1ff",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.1",
+                "psr/http-factory": "^1.0",
+                "psr/http-message": "^1.0"
+            },
+            "provide": {
+                "psr/http-factory-implementation": "1.0",
+                "psr/http-message-implementation": "1.0"
+            },
+            "require-dev": {
+                "ext-dom": "*",
+                "ext-libxml": "*",
+                "http-interop/http-factory-tests": "^0.5.0",
+                "php-http/psr7-integration-tests": "dev-master",
+                "phpunit/phpunit": "^7.0.2",
+                "zendframework/zend-coding-standard": "~1.0.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.0.x-dev",
+                    "dev-develop": "2.1.x-dev",
+                    "dev-release-1.8": "1.8.x-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "src/functions/create_uploaded_file.php",
+                    "src/functions/marshal_headers_from_sapi.php",
+                    "src/functions/marshal_method_from_sapi.php",
+                    "src/functions/marshal_protocol_version_from_sapi.php",
+                    "src/functions/marshal_uri_from_sapi.php",
+                    "src/functions/normalize_server.php",
+                    "src/functions/normalize_uploaded_files.php",
+                    "src/functions/parse_cookie_header.php"
+                ],
+                "psr-4": {
+                    "Zend\\Diactoros\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "description": "PSR HTTP Message implementations",
+            "keywords": [
+                "http",
+                "psr",
+                "psr-7"
+            ],
+            "time": "2018-09-27T19:49:04+00:00"
        }
    ],
    "aliases": [],
--- a/examples/src/Entities/ScopeEntity.php
+++ b/examples/src/Entities/ScopeEntity.php
@@ -11,13 +11,9 @@ namespace OAuth2ServerExamples\Entities;

 use League\OAuth2\Server\Entities\ScopeEntityInterface;
 use League\OAuth2\Server\Entities\Traits\EntityTrait;
+use League\OAuth2\Server\Entities\Traits\ScopeTrait;

 class ScopeEntity implements ScopeEntityInterface
 {
-    use EntityTrait;
-
-    public function jsonSerialize()
-    {
-        return $this->getIdentifier();
-    }
+    use EntityTrait, ScopeTrait;
 }
--- a/examples/src/Repositories/RefreshTokenRepository.php
+++ b/examples/src/Repositories/RefreshTokenRepository.php
@@ -18,7 +18,7 @@ class RefreshTokenRepository implements RefreshTokenRepositoryInterface
    /**
     * {@inheritdoc}
     */
-    public function persistNewRefreshToken(RefreshTokenEntityInterface $refreshTokenEntityInterface)
+    public function persistNewRefreshToken(RefreshTokenEntityInterface $refreshTokenEntity)
    {
        // Some logic to persist the refresh token in a database
    }
--- a/src/AuthorizationServer.php
+++ b/src/AuthorizationServer.php
@@ -9,6 +9,7 @@

 namespace League\OAuth2\Server;

+use DateInterval;
 use Defuse\Crypto\Key;
 use League\Event\EmitterAwareInterface;
 use League\Event\EmitterAwareTrait;
@@ -34,7 +35,7 @@ class AuthorizationServer implements EmitterAwareInterface
    protected $enabledGrantTypes = [];

    /**
-     * @var \DateInterval[]
+     * @var DateInterval[]
     */
    protected $grantTypeAccessTokenTTL = [];

@@ -49,7 +50,7 @@ class AuthorizationServer implements EmitterAwareInterface
    protected $publicKey;

    /**
-     * @var null|ResponseTypeInterface
+     * @var ResponseTypeInterface
     */
    protected $responseType;

@@ -103,8 +104,16 @@ class AuthorizationServer implements EmitterAwareInterface
        if ($privateKey instanceof CryptKey === false) {
            $privateKey = new CryptKey($privateKey);
        }
+
        $this->privateKey = $privateKey;
        $this->encryptionKey = $encryptionKey;
+
+        if ($responseType === null) {
+            $responseType = new BearerTokenResponse();
+        } else {
+            $responseType = clone $responseType;
+        }
+
        $this->responseType = $responseType;
    }

@@ -112,12 +121,12 @@ class AuthorizationServer implements EmitterAwareInterface
     * Enable a grant type on the server.
     *
     * @param GrantTypeInterface $grantType
-     * @param null|\DateInterval $accessTokenTTL
+     * @param null|DateInterval  $accessTokenTTL
     */
-    public function enableGrantType(GrantTypeInterface $grantType, \DateInterval $accessTokenTTL = null)
+    public function enableGrantType(GrantTypeInterface $grantType, DateInterval $accessTokenTTL = null)
    {
-        if ($accessTokenTTL instanceof \DateInterval === false) {
-            $accessTokenTTL = new \DateInterval('PT1H');
+        if ($accessTokenTTL instanceof DateInterval === false) {
+            $accessTokenTTL = new DateInterval('PT1H');
        }

        $grantType->setAccessTokenRepository($this->accessTokenRepository);
@@ -204,16 +213,15 @@ class AuthorizationServer implements EmitterAwareInterface
     */
    protected function getResponseType()
    {
-        if ($this->responseType instanceof ResponseTypeInterface === false) {
-            $this->responseType = new BearerTokenResponse();
+        $responseType = clone $this->responseType;
+
+        if ($responseType instanceof AbstractResponseType) {
+            $responseType->setPrivateKey($this->privateKey);
        }

-        if ($this->responseType instanceof AbstractResponseType === true) {
-            $this->responseType->setPrivateKey($this->privateKey);
-        }
-        $this->responseType->setEncryptionKey($this->encryptionKey);
+        $responseType->setEncryptionKey($this->encryptionKey);

-        return $this->responseType;
+        return $responseType;
    }

    /**
--- a/src/AuthorizationValidators/BearerTokenValidator.php
+++ b/src/AuthorizationValidators/BearerTokenValidator.php
@@ -9,6 +9,8 @@

 namespace League\OAuth2\Server\AuthorizationValidators;

+use BadMethodCallException;
+use InvalidArgumentException;
 use Lcobucci\JWT\Parser;
 use Lcobucci\JWT\Signer\Rsa\Sha256;
 use Lcobucci\JWT\ValidationData;
@@ -17,6 +19,7 @@ use League\OAuth2\Server\CryptTrait;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use League\OAuth2\Server\Repositories\AccessTokenRepositoryInterface;
 use Psr\Http\Message\ServerRequestInterface;
+use RuntimeException;

 class BearerTokenValidator implements AuthorizationValidatorInterface
 {
@@ -28,7 +31,7 @@ class BearerTokenValidator implements AuthorizationValidatorInterface
    private $accessTokenRepository;

    /**
-     * @var \League\OAuth2\Server\CryptKey
+     * @var CryptKey
     */
    protected $publicKey;

@@ -43,7 +46,7 @@ class BearerTokenValidator implements AuthorizationValidatorInterface
    /**
     * Set the public key
     *
-     * @param \League\OAuth2\Server\CryptKey $key
+     * @param CryptKey $key
     */
    public function setPublicKey(CryptKey $key)
    {
@@ -69,8 +72,8 @@ class BearerTokenValidator implements AuthorizationValidatorInterface
                if ($token->verify(new Sha256(), $this->publicKey->getKeyPath()) === false) {
                    throw OAuthServerException::accessDenied('Access token could not be verified');
                }
-            } catch (\BadMethodCallException $exception) {
-                throw OAuthServerException::accessDenied('Access token is not signed');
+            } catch (BadMethodCallException $exception) {
+                throw OAuthServerException::accessDenied('Access token is not signed', null, $exception);
            }

            // Ensure access token hasn't expired
@@ -92,12 +95,12 @@ class BearerTokenValidator implements AuthorizationValidatorInterface
                ->withAttribute('oauth_client_id', $token->getClaim('aud'))
                ->withAttribute('oauth_user_id', $token->getClaim('sub'))
                ->withAttribute('oauth_scopes', $token->getClaim('scopes'));
-        } catch (\InvalidArgumentException $exception) {
+        } catch (InvalidArgumentException $exception) {
            // JWT couldn't be parsed so return the request as is
-            throw OAuthServerException::accessDenied($exception->getMessage());
-        } catch (\RuntimeException $exception) {
+            throw OAuthServerException::accessDenied($exception->getMessage(), null, $exception);
+        } catch (RuntimeException $exception) {
            //JWR couldn't be parsed so return the request as is
-            throw OAuthServerException::accessDenied('Error while decoding to JSON');
+            throw OAuthServerException::accessDenied('Error while decoding to JSON', null, $exception);
        }
    }
 }
--- a/src/CryptKey.php
+++ b/src/CryptKey.php
@@ -11,6 +11,9 @@

 namespace League\OAuth2\Server;

+use LogicException;
+use RuntimeException;
+
 class CryptKey
 {
    const RSA_KEY_PATTERN =
@@ -42,7 +45,7 @@ class CryptKey
        }

        if (!file_exists($keyPath) || !is_readable($keyPath)) {
-            throw new \LogicException(sprintf('Key path "%s" does not exist or is not readable', $keyPath));
+            throw new LogicException(sprintf('Key path "%s" does not exist or is not readable', $keyPath));
        }

        if ($keyPermissionsCheck === true) {
@@ -64,7 +67,7 @@ class CryptKey
    /**
     * @param string $key
     *
-     * @throws \RuntimeException
+     * @throws RuntimeException
     *
     * @return string
     */
@@ -79,19 +82,19 @@ class CryptKey

        if (!touch($keyPath)) {
            // @codeCoverageIgnoreStart
-            throw new \RuntimeException(sprintf('"%s" key file could not be created', $keyPath));
+            throw new RuntimeException(sprintf('"%s" key file could not be created', $keyPath));
            // @codeCoverageIgnoreEnd
        }

        if (file_put_contents($keyPath, $key) === false) {
            // @codeCoverageIgnoreStart
-            throw new \RuntimeException(sprintf('Unable to write key file to temporary directory "%s"', $tmpDir));
+            throw new RuntimeException(sprintf('Unable to write key file to temporary directory "%s"', $tmpDir));
            // @codeCoverageIgnoreEnd
        }

        if (chmod($keyPath, 0600) === false) {
            // @codeCoverageIgnoreStart
-            throw new \RuntimeException(sprintf('The key file "%s" file mode could not be changed with chmod to 600', $keyPath));
+            throw new RuntimeException(sprintf('The key file "%s" file mode could not be changed with chmod to 600', $keyPath));
            // @codeCoverageIgnoreEnd
        }

--- a/src/CryptTrait.php
+++ b/src/CryptTrait.php
@@ -13,6 +13,8 @@ namespace League\OAuth2\Server;

 use Defuse\Crypto\Crypto;
 use Defuse\Crypto\Key;
+use Exception;
+use LogicException;

 trait CryptTrait
 {
@@ -26,7 +28,7 @@ trait CryptTrait
     *
     * @param string $unencryptedData
     *
-     * @throws \LogicException
+     * @throws LogicException
     *
     * @return string
     */
@@ -38,8 +40,8 @@ trait CryptTrait
            }

            return Crypto::encryptWithPassword($unencryptedData, $this->encryptionKey);
-        } catch (\Exception $e) {
-            throw new \LogicException($e->getMessage());
+        } catch (Exception $e) {
+            throw new LogicException($e->getMessage(), null, $e);
        }
    }

@@ -48,7 +50,7 @@ trait CryptTrait
     *
     * @param string $encryptedData
     *
-     * @throws \LogicException
+     * @throws LogicException
     *
     * @return string
     */
@@ -60,8 +62,8 @@ trait CryptTrait
            }

            return Crypto::decryptWithPassword($encryptedData, $this->encryptionKey);
-        } catch (\Exception $e) {
-            throw new \LogicException($e->getMessage());
+        } catch (Exception $e) {
+            throw new LogicException($e->getMessage(), null, $e);
        }
    }

--- a/src/Entities/RefreshTokenEntityInterface.php
+++ b/src/Entities/RefreshTokenEntityInterface.php
@@ -9,6 +9,8 @@

 namespace League\OAuth2\Server\Entities;

+use DateTime;
+
 interface RefreshTokenEntityInterface
 {
    /**
@@ -28,16 +30,16 @@ interface RefreshTokenEntityInterface
    /**
     * Get the token's expiry date time.
     *
-     * @return \DateTime
+     * @return DateTime
     */
    public function getExpiryDateTime();

    /**
     * Set the date time when the token expires.
     *
-     * @param \DateTime $dateTime
+     * @param DateTime $dateTime
     */
-    public function setExpiryDateTime(\DateTime $dateTime);
+    public function setExpiryDateTime(DateTime $dateTime);

    /**
     * Set the access token that the refresh token was associated with.
--- a/src/Entities/ScopeEntityInterface.php
+++ b/src/Entities/ScopeEntityInterface.php
@@ -9,7 +9,9 @@

 namespace League\OAuth2\Server\Entities;

-interface ScopeEntityInterface extends \JsonSerializable
+use JsonSerializable;
+
+interface ScopeEntityInterface extends JsonSerializable
 {
    /**
     * Get the scope's identifier.
--- a/src/Entities/TokenInterface.php
+++ b/src/Entities/TokenInterface.php
@@ -9,6 +9,8 @@

 namespace League\OAuth2\Server\Entities;

+use DateTime;
+
 interface TokenInterface
 {
    /**
@@ -28,16 +30,16 @@ interface TokenInterface
    /**
     * Get the token's expiry date time.
     *
-     * @return \DateTime
+     * @return DateTime
     */
    public function getExpiryDateTime();

    /**
     * Set the date time when the token expires.
     *
-     * @param \DateTime $dateTime
+     * @param DateTime $dateTime
     */
-    public function setExpiryDateTime(\DateTime $dateTime);
+    public function setExpiryDateTime(DateTime $dateTime);

    /**
     * Set the identifier of the user associated with the token.
--- a/src/Entities/Traits/AccessTokenTrait.php
+++ b/src/Entities/Traits/AccessTokenTrait.php
@@ -9,6 +9,7 @@

 namespace League\OAuth2\Server\Entities\Traits;

+use DateTime;
 use Lcobucci\JWT\Builder;
 use Lcobucci\JWT\Signer\Key;
 use Lcobucci\JWT\Signer\Rsa\Sha256;
@@ -46,7 +47,7 @@ trait AccessTokenTrait
    abstract public function getClient();

    /**
-     * @return \DateTime
+     * @return DateTime
     */
    abstract public function getExpiryDateTime();

--- a/src/Entities/Traits/RefreshTokenTrait.php
+++ b/src/Entities/Traits/RefreshTokenTrait.php
@@ -9,6 +9,7 @@

 namespace League\OAuth2\Server\Entities\Traits;

+use DateTime;
 use League\OAuth2\Server\Entities\AccessTokenEntityInterface;

 trait RefreshTokenTrait
@@ -19,7 +20,7 @@ trait RefreshTokenTrait
    protected $accessToken;

    /**
-     * @var \DateTime
+     * @var DateTime
     */
    protected $expiryDateTime;

@@ -42,7 +43,7 @@ trait RefreshTokenTrait
    /**
     * Get the token's expiry date time.
     *
-     * @return \DateTime
+     * @return DateTime
     */
    public function getExpiryDateTime()
    {
@@ -52,9 +53,9 @@ trait RefreshTokenTrait
    /**
     * Set the date time when the token expires.
     *
-     * @param \DateTime $dateTime
+     * @param DateTime $dateTime
     */
-    public function setExpiryDateTime(\DateTime $dateTime)
+    public function setExpiryDateTime(DateTime $dateTime)
    {
        $this->expiryDateTime = $dateTime;
    }
--- a/src/Entities/Traits/ScopeTrait.php
+++ b/src/Entities/Traits/ScopeTrait.php
@@ -0,0 +1,28 @@
+<?php
+/**
+ * @author    Andrew Millington <andrew@noexceptions.io>
+ * @copyright Copyright (c) Andrew Millington
+ * @license   http://mit-license.org
+ *
+ * @link      https://github.com/thephpleague/oauth2-server
+ */
+
+namespace League\OAuth2\Server\Entities\Traits;
+
+trait ScopeTrait
+{
+    /**
+     * Serialize the object to the scopes string identifier when using json_encode().
+     *
+     * @return string
+     */
+    public function jsonSerialize()
+    {
+        return $this->getIdentifier();
+    }
+
+    /**
+     * @return string
+     */
+    abstract public function getIdentifier();
+}
--- a/src/Entities/Traits/TokenEntityTrait.php
+++ b/src/Entities/Traits/TokenEntityTrait.php
@@ -9,6 +9,7 @@

 namespace League\OAuth2\Server\Entities\Traits;

+use DateTime;
 use League\OAuth2\Server\Entities\ClientEntityInterface;
 use League\OAuth2\Server\Entities\ScopeEntityInterface;

@@ -20,7 +21,7 @@ trait TokenEntityTrait
    protected $scopes = [];

    /**
-     * @var \DateTime
+     * @var DateTime
     */
    protected $expiryDateTime;

@@ -57,7 +58,7 @@ trait TokenEntityTrait
    /**
     * Get the token's expiry date time.
     *
-     * @return \DateTime
+     * @return DateTime
     */
    public function getExpiryDateTime()
    {
@@ -67,9 +68,9 @@ trait TokenEntityTrait
    /**
     * Set the date time when the token expires.
     *
-     * @param \DateTime $dateTime
+     * @param DateTime $dateTime
     */
-    public function setExpiryDateTime(\DateTime $dateTime)
+    public function setExpiryDateTime(DateTime $dateTime)
    {
        $this->expiryDateTime = $dateTime;
    }
--- a/src/Exception/OAuthServerException.php
+++ b/src/Exception/OAuthServerException.php
@@ -9,9 +9,11 @@

 namespace League\OAuth2\Server\Exception;

+use Exception;
 use Psr\Http\Message\ResponseInterface;
+use Throwable;

-class OAuthServerException extends \Exception
+class OAuthServerException extends Exception
 {
    /**
     * @var int
@@ -47,17 +49,18 @@ class OAuthServerException extends \Exception
     * @param int         $httpStatusCode HTTP status code to send (default = 400)
     * @param null|string $hint           A helper hint
     * @param null|string $redirectUri    A HTTP URI to redirect the user back to
+     * @param Throwable   $previous       Previous exception
     */
-    public function __construct($message, $code, $errorType, $httpStatusCode = 400, $hint = null, $redirectUri = null)
+    public function __construct($message, $code, $errorType, $httpStatusCode = 400, $hint = null, $redirectUri = null, Throwable $previous = null)
    {
-        parent::__construct($message, $code);
+        parent::__construct($message, $code, $previous);
        $this->httpStatusCode = $httpStatusCode;
        $this->errorType = $errorType;
        $this->hint = $hint;
        $this->redirectUri = $redirectUri;
        $this->payload = [
-            'error'   => $errorType,
-            'message' => $message,
+            'error'             => $errorType,
+            'error_description' => $message,
        ];
        if ($hint !== null) {
            $this->payload['hint'] = $hint;
@@ -71,7 +74,15 @@ class OAuthServerException extends \Exception
     */
    public function getPayload()
    {
-        return $this->payload;
+        $payload = $this->payload;
+
+        // The "message" property is deprecated and replaced by "error_description"
+        // TODO: remove "message" property
+        if (isset($payload['error_description']) && !isset($payload['message'])) {
+            $payload['message'] = $payload['error_description'];
+        }
+
+        return $payload;
    }

    /**
@@ -102,16 +113,17 @@ class OAuthServerException extends \Exception
     *
     * @param string      $parameter The invalid parameter
     * @param null|string $hint
+     * @param Throwable   $previous  Previous exception
     *
     * @return static
     */
-    public static function invalidRequest($parameter, $hint = null)
+    public static function invalidRequest($parameter, $hint = null, Throwable $previous = null)
    {
        $errorMessage = 'The request is missing a required parameter, includes an invalid parameter value, ' .
            'includes a parameter more than once, or is otherwise malformed.';
        $hint = ($hint === null) ? sprintf('Check the `%s` parameter', $parameter) : $hint;

-        return new static($errorMessage, 3, 'invalid_request', 400, $hint);
+        return new static($errorMessage, 3, 'invalid_request', 400, $hint, null, $previous);
    }

    /**
@@ -163,20 +175,24 @@ class OAuthServerException extends \Exception
    /**
     * Server error.
     *
-     * @param string $hint
+     * @param string    $hint
+     * @param Throwable $previous
     *
     * @return static
     *
     * @codeCoverageIgnore
     */
-    public static function serverError($hint)
+    public static function serverError($hint, Throwable $previous = null)
    {
        return new static(
            'The authorization server encountered an unexpected condition which prevented it from fulfilling'
            . ' the request: ' . $hint,
            7,
            'server_error',
-            500
+            500,
+            null,
+            null,
+            $previous
        );
    }

@@ -184,12 +200,13 @@ class OAuthServerException extends \Exception
     * Invalid refresh token.
     *
     * @param null|string $hint
+     * @param Throwable   $previous
     *
     * @return static
     */
-    public static function invalidRefreshToken($hint = null)
+    public static function invalidRefreshToken($hint = null, Throwable $previous = null)
    {
-        return new static('The refresh token is invalid.', 8, 'invalid_request', 401, $hint);
+        return new static('The refresh token is invalid.', 8, 'invalid_request', 401, $hint, null, $previous);
    }

    /**
@@ -197,10 +214,11 @@ class OAuthServerException extends \Exception
     *
     * @param null|string $hint
     * @param null|string $redirectUri
+     * @param Throwable   $previous
     *
     * @return static
     */
-    public static function accessDenied($hint = null, $redirectUri = null)
+    public static function accessDenied($hint = null, $redirectUri = null, Throwable $previous = null)
    {
        return new static(
            'The resource owner or authorization server denied the request.',
@@ -208,7 +226,8 @@ class OAuthServerException extends \Exception
            'access_denied',
            401,
            $hint,
-            $redirectUri
+            $redirectUri,
+            $previous
        );
    }

--- a/src/Exception/UniqueTokenIdentifierConstraintViolationException.php
+++ b/src/Exception/UniqueTokenIdentifierConstraintViolationException.php
@@ -11,6 +11,9 @@ namespace League\OAuth2\Server\Exception;

 class UniqueTokenIdentifierConstraintViolationException extends OAuthServerException
 {
+    /**
+     * @return UniqueTokenIdentifierConstraintViolationException
+     */
    public static function create()
    {
        $errorMessage = 'Could not create unique access token identifier';
--- a/src/Grant/AbstractGrant.php
+++ b/src/Grant/AbstractGrant.php
@@ -10,6 +10,10 @@
 */
 namespace League\OAuth2\Server\Grant;

+use DateInterval;
+use DateTime;
+use Error;
+use Exception;
 use League\Event\EmitterAwareTrait;
 use League\OAuth2\Server\CryptKey;
 use League\OAuth2\Server\CryptTrait;
@@ -28,7 +32,9 @@ use League\OAuth2\Server\Repositories\ScopeRepositoryInterface;
 use League\OAuth2\Server\Repositories\UserRepositoryInterface;
 use League\OAuth2\Server\RequestEvent;
 use League\OAuth2\Server\RequestTypes\AuthorizationRequest;
+use LogicException;
 use Psr\Http\Message\ServerRequestInterface;
+use TypeError;

 /**
 * Abstract grant class.
@@ -72,12 +78,12 @@ abstract class AbstractGrant implements GrantTypeInterface
    protected $userRepository;

    /**
-     * @var \DateInterval
+     * @var DateInterval
     */
    protected $refreshTokenTTL;

    /**
-     * @var \League\OAuth2\Server\CryptKey
+     * @var CryptKey
     */
    protected $privateKey;

@@ -137,7 +143,7 @@ abstract class AbstractGrant implements GrantTypeInterface
    /**
     * {@inheritdoc}
     */
-    public function setRefreshTokenTTL(\DateInterval $refreshTokenTTL)
+    public function setRefreshTokenTTL(DateInterval $refreshTokenTTL)
    {
        $this->refreshTokenTTL = $refreshTokenTTL;
    }
@@ -145,7 +151,7 @@ abstract class AbstractGrant implements GrantTypeInterface
    /**
     * Set the private key
     *
-     * @param \League\OAuth2\Server\CryptKey $key
+     * @param CryptKey $key
     */
    public function setPrivateKey(CryptKey $key)
    {
@@ -174,7 +180,7 @@ abstract class AbstractGrant implements GrantTypeInterface
        list($basicAuthUser, $basicAuthPassword) = $this->getBasicAuthCredentials($request);

        $clientId = $this->getRequestParameter('client_id', $request, $basicAuthUser);
-        if (is_null($clientId)) {
+        if ($clientId === null) {
            throw OAuthServerException::invalidRequest('client_id');
        }

@@ -217,13 +223,13 @@ abstract class AbstractGrant implements GrantTypeInterface
        ClientEntityInterface $client,
        ServerRequestInterface $request
    ) {
-        if (is_string($client->getRedirectUri())
+        if (\is_string($client->getRedirectUri())
            && (strcmp($client->getRedirectUri(), $redirectUri) !== 0)
        ) {
            $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
            throw OAuthServerException::invalidClient();
-        } elseif (is_array($client->getRedirectUri())
-            && in_array($redirectUri, $client->getRedirectUri(), true) === false
+        } elseif (\is_array($client->getRedirectUri())
+            && \in_array($redirectUri, $client->getRedirectUri(), true) === false
        ) {
            $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
            throw OAuthServerException::invalidClient();
@@ -233,8 +239,8 @@ abstract class AbstractGrant implements GrantTypeInterface
    /**
     * Validate scopes in the request.
     *
-     * @param string $scopes
-     * @param string $redirectUri
+     * @param string|array $scopes
+     * @param string       $redirectUri
     *
     * @throws OAuthServerException
     *
@@ -242,13 +248,13 @@ abstract class AbstractGrant implements GrantTypeInterface
     */
    public function validateScopes($scopes, $redirectUri = null)
    {
-        $scopesList = array_filter(explode(self::SCOPE_DELIMITER_STRING, trim($scopes)), function ($scope) {
-            return !empty($scope);
-        });
+        if (!\is_array($scopes)) {
+            $scopes = $this->convertScopesQueryStringToArray($scopes);
+        }

        $validScopes = [];

-        foreach ($scopesList as $scopeItem) {
+        foreach ($scopes as $scopeItem) {
            $scope = $this->scopeRepository->getScopeEntityByIdentifier($scopeItem);

            if ($scope instanceof ScopeEntityInterface === false) {
@@ -261,6 +267,20 @@ abstract class AbstractGrant implements GrantTypeInterface
        return $validScopes;
    }

+    /**
+     * Converts a scopes query string to an array to easily iterate for validation.
+     *
+     * @param string $scopes
+     *
+     * @return array
+     */
+    private function convertScopesQueryStringToArray($scopes)
+    {
+        return array_filter(explode(self::SCOPE_DELIMITER_STRING, trim($scopes)), function ($scope) {
+            return !empty($scope);
+        });
+    }
+
    /**
     * Retrieve request parameter.
     *
@@ -274,7 +294,7 @@ abstract class AbstractGrant implements GrantTypeInterface
    {
        $requestParameters = (array) $request->getParsedBody();

-        return isset($requestParameters[$parameter]) ? $requestParameters[$parameter] : $default;
+        return $requestParameters[$parameter] ?? $default;
    }

    /**
@@ -355,7 +375,7 @@ abstract class AbstractGrant implements GrantTypeInterface
    /**
     * Issue an access token.
     *
-     * @param \DateInterval          $accessTokenTTL
+     * @param DateInterval           $accessTokenTTL
     * @param ClientEntityInterface  $client
     * @param string|null            $userIdentifier
     * @param ScopeEntityInterface[] $scopes
@@ -366,7 +386,7 @@ abstract class AbstractGrant implements GrantTypeInterface
     * @return AccessTokenEntityInterface
     */
    protected function issueAccessToken(
-        \DateInterval $accessTokenTTL,
+        DateInterval $accessTokenTTL,
        ClientEntityInterface $client,
        $userIdentifier,
        array $scopes = []
@@ -376,7 +396,7 @@ abstract class AbstractGrant implements GrantTypeInterface
        $accessToken = $this->accessTokenRepository->getNewToken($client, $scopes, $userIdentifier);
        $accessToken->setClient($client);
        $accessToken->setUserIdentifier($userIdentifier);
-        $accessToken->setExpiryDateTime((new \DateTime())->add($accessTokenTTL));
+        $accessToken->setExpiryDateTime((new DateTime())->add($accessTokenTTL));

        foreach ($scopes as $scope) {
            $accessToken->addScope($scope);
@@ -399,7 +419,7 @@ abstract class AbstractGrant implements GrantTypeInterface
    /**
     * Issue an auth code.
     *
-     * @param \DateInterval          $authCodeTTL
+     * @param DateInterval           $authCodeTTL
     * @param ClientEntityInterface  $client
     * @param string                 $userIdentifier
     * @param string|null            $redirectUri
@@ -411,7 +431,7 @@ abstract class AbstractGrant implements GrantTypeInterface
     * @return AuthCodeEntityInterface
     */
    protected function issueAuthCode(
-        \DateInterval $authCodeTTL,
+        DateInterval $authCodeTTL,
        ClientEntityInterface $client,
        $userIdentifier,
        $redirectUri,
@@ -420,7 +440,7 @@ abstract class AbstractGrant implements GrantTypeInterface
        $maxGenerationAttempts = self::MAX_RANDOM_TOKEN_GENERATION_ATTEMPTS;

        $authCode = $this->authCodeRepository->getNewAuthCode();
-        $authCode->setExpiryDateTime((new \DateTime())->add($authCodeTTL));
+        $authCode->setExpiryDateTime((new DateTime())->add($authCodeTTL));
        $authCode->setClient($client);
        $authCode->setUserIdentifier($userIdentifier);

@@ -452,16 +472,21 @@ abstract class AbstractGrant implements GrantTypeInterface
     * @throws OAuthServerException
     * @throws UniqueTokenIdentifierConstraintViolationException
     *
-     * @return RefreshTokenEntityInterface
+     * @return RefreshTokenEntityInterface|null
     */
    protected function issueRefreshToken(AccessTokenEntityInterface $accessToken)
    {
-        $maxGenerationAttempts = self::MAX_RANDOM_TOKEN_GENERATION_ATTEMPTS;
-
        $refreshToken = $this->refreshTokenRepository->getNewRefreshToken();
-        $refreshToken->setExpiryDateTime((new \DateTime())->add($this->refreshTokenTTL));
+
+        if ($refreshToken === null) {
+            return null;
+        }
+
+        $refreshToken->setExpiryDateTime((new DateTime())->add($this->refreshTokenTTL));
        $refreshToken->setAccessToken($accessToken);

+        $maxGenerationAttempts = self::MAX_RANDOM_TOKEN_GENERATION_ATTEMPTS;
+
        while ($maxGenerationAttempts-- > 0) {
            $refreshToken->setIdentifier($this->generateUniqueIdentifier());
            try {
@@ -490,13 +515,13 @@ abstract class AbstractGrant implements GrantTypeInterface
        try {
            return bin2hex(random_bytes($length));
            // @codeCoverageIgnoreStart
-        } catch (\TypeError $e) {
-            throw OAuthServerException::serverError('An unexpected error has occurred');
-        } catch (\Error $e) {
-            throw OAuthServerException::serverError('An unexpected error has occurred');
-        } catch (\Exception $e) {
+        } catch (TypeError $e) {
+            throw OAuthServerException::serverError('An unexpected error has occurred', $e);
+        } catch (Error $e) {
+            throw OAuthServerException::serverError('An unexpected error has occurred', $e);
+        } catch (Exception $e) {
            // If you get this message, the CSPRNG failed hard.
-            throw OAuthServerException::serverError('Could not generate a random string');
+            throw OAuthServerException::serverError('Could not generate a random string', $e);
        }
        // @codeCoverageIgnoreEnd
    }
@@ -527,7 +552,7 @@ abstract class AbstractGrant implements GrantTypeInterface
     */
    public function validateAuthorizationRequest(ServerRequestInterface $request)
    {
-        throw new \LogicException('This grant cannot validate an authorization request');
+        throw new LogicException('This grant cannot validate an authorization request');
    }

    /**
@@ -535,6 +560,6 @@ abstract class AbstractGrant implements GrantTypeInterface
     */
    public function completeAuthorizationRequest(AuthorizationRequest $authorizationRequest)
    {
-        throw new \LogicException('This grant cannot complete an authorization request');
+        throw new LogicException('This grant cannot complete an authorization request');
    }
 }
--- a/src/Grant/AuthCodeGrant.php
+++ b/src/Grant/AuthCodeGrant.php
@@ -9,8 +9,10 @@

 namespace League\OAuth2\Server\Grant;

+use DateInterval;
+use DateTime;
+use Exception;
 use League\OAuth2\Server\Entities\ClientEntityInterface;
-use League\OAuth2\Server\Entities\ScopeEntityInterface;
 use League\OAuth2\Server\Entities\UserEntityInterface;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use League\OAuth2\Server\Repositories\AuthCodeRepositoryInterface;
@@ -19,12 +21,14 @@ use League\OAuth2\Server\RequestEvent;
 use League\OAuth2\Server\RequestTypes\AuthorizationRequest;
 use League\OAuth2\Server\ResponseTypes\RedirectResponse;
 use League\OAuth2\Server\ResponseTypes\ResponseTypeInterface;
+use LogicException;
 use Psr\Http\Message\ServerRequestInterface;
+use stdClass;

 class AuthCodeGrant extends AbstractAuthorizeGrant
 {
    /**
-     * @var \DateInterval
+     * @var DateInterval
     */
    private $authCodeTTL;

@@ -36,17 +40,19 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
    /**
     * @param AuthCodeRepositoryInterface     $authCodeRepository
     * @param RefreshTokenRepositoryInterface $refreshTokenRepository
-     * @param \DateInterval                   $authCodeTTL
+     * @param DateInterval                    $authCodeTTL
+     *
+     * @throws Exception
     */
    public function __construct(
        AuthCodeRepositoryInterface $authCodeRepository,
        RefreshTokenRepositoryInterface $refreshTokenRepository,
-        \DateInterval $authCodeTTL
+        DateInterval $authCodeTTL
    ) {
        $this->setAuthCodeRepository($authCodeRepository);
        $this->setRefreshTokenRepository($refreshTokenRepository);
        $this->authCodeTTL = $authCodeTTL;
-        $this->refreshTokenTTL = new \DateInterval('P1M');
+        $this->refreshTokenTTL = new DateInterval('P1M');
    }

    public function enableCodeExchangeProof()
@@ -59,7 +65,7 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
     *
     * @param ServerRequestInterface $request
     * @param ResponseTypeInterface  $responseType
-     * @param \DateInterval          $accessTokenTTL
+     * @param DateInterval           $accessTokenTTL
     *
     * @throws OAuthServerException
     *
@@ -68,7 +74,7 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
-        \DateInterval $accessTokenTTL
+        DateInterval $accessTokenTTL
    ) {
        // Validate request
        $client = $this->validateClient($request);
@@ -78,58 +84,25 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
            throw OAuthServerException::invalidRequest('code');
        }

-        // Validate the authorization code
        try {
            $authCodePayload = json_decode($this->decrypt($encryptedAuthCode));
-            if (time() > $authCodePayload->expire_time) {
-                throw OAuthServerException::invalidRequest('code', 'Authorization code has expired');
-            }

-            if ($this->authCodeRepository->isAuthCodeRevoked($authCodePayload->auth_code_id) === true) {
-                throw OAuthServerException::invalidRequest('code', 'Authorization code has been revoked');
-            }
+            $this->validateAuthorizationCode($authCodePayload, $client, $request);

-            if ($authCodePayload->client_id !== $client->getIdentifier()) {
-                throw OAuthServerException::invalidRequest('code', 'Authorization code was not issued to this client');
-            }
-
-            // The redirect URI is required in this request
-            $redirectUri = $this->getRequestParameter('redirect_uri', $request, null);
-            if (empty($authCodePayload->redirect_uri) === false && $redirectUri === null) {
-                throw OAuthServerException::invalidRequest('redirect_uri');
-            }
-
-            if ($authCodePayload->redirect_uri !== $redirectUri) {
-                throw OAuthServerException::invalidRequest('redirect_uri', 'Invalid redirect URI');
-            }
-
-            $scopes = [];
-            foreach ($authCodePayload->scopes as $scopeId) {
-                $scope = $this->scopeRepository->getScopeEntityByIdentifier($scopeId);
-
-                if ($scope instanceof ScopeEntityInterface === false) {
-                    // @codeCoverageIgnoreStart
-                    throw OAuthServerException::invalidScope($scopeId);
-                    // @codeCoverageIgnoreEnd
-                }
-
-                $scopes[] = $scope;
-            }
-
-            // Finalize the requested scopes
            $scopes = $this->scopeRepository->finalizeScopes(
-                $scopes,
+                $this->validateScopes($authCodePayload->scopes),
                $this->getIdentifier(),
                $client,
                $authCodePayload->user_id
            );
-        } catch (\LogicException  $e) {
-            throw OAuthServerException::invalidRequest('code', 'Cannot decrypt the authorization code');
+        } catch (LogicException $e) {
+            throw OAuthServerException::invalidRequest('code', 'Cannot decrypt the authorization code', $e);
        }

        // Validate code challenge
        if ($this->enableCodeExchangeProof === true) {
            $codeVerifier = $this->getRequestParameter('code_verifier', $request, null);
+
            if ($codeVerifier === null) {
                throw OAuthServerException::invalidRequest('code_verifier');
            }
@@ -172,17 +145,18 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
            }
        }

-        // Issue and persist access + refresh tokens
+        // Issue and persist new access token
        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, $authCodePayload->user_id, $scopes);
+        $this->getEmitter()->emit(new RequestEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request));
+        $responseType->setAccessToken($accessToken);
+
+        // Issue and persist new refresh token if given
        $refreshToken = $this->issueRefreshToken($accessToken);

-        // Send events to emitter
-        $this->getEmitter()->emit(new RequestEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request));
-        $this->getEmitter()->emit(new RequestEvent(RequestEvent::REFRESH_TOKEN_ISSUED, $request));
-
-        // Inject tokens into response type
-        $responseType->setAccessToken($accessToken);
-        $responseType->setRefreshToken($refreshToken);
+        if ($refreshToken !== null) {
+            $this->getEmitter()->emit(new RequestEvent(RequestEvent::REFRESH_TOKEN_ISSUED, $request));
+            $responseType->setRefreshToken($refreshToken);
+        }

        // Revoke used auth code
        $this->authCodeRepository->revokeAuthCode($authCodePayload->auth_code_id);
@@ -190,6 +164,41 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
        return $responseType;
    }

+    /**
+     * Validate the authorization code.
+     *
+     * @param stdClass               $authCodePayload
+     * @param ClientEntityInterface  $client
+     * @param ServerRequestInterface $request
+     */
+    private function validateAuthorizationCode(
+        $authCodePayload,
+        ClientEntityInterface $client,
+        ServerRequestInterface $request
+    ) {
+        if (time() > $authCodePayload->expire_time) {
+            throw OAuthServerException::invalidRequest('code', 'Authorization code has expired');
+        }
+
+        if ($this->authCodeRepository->isAuthCodeRevoked($authCodePayload->auth_code_id) === true) {
+            throw OAuthServerException::invalidRequest('code', 'Authorization code has been revoked');
+        }
+
+        if ($authCodePayload->client_id !== $client->getIdentifier()) {
+            throw OAuthServerException::invalidRequest('code', 'Authorization code was not issued to this client');
+        }
+
+        // The redirect URI is required in this request
+        $redirectUri = $this->getRequestParameter('redirect_uri', $request, null);
+        if (empty($authCodePayload->redirect_uri) === false && $redirectUri === null) {
+            throw OAuthServerException::invalidRequest('redirect_uri');
+        }
+
+        if ($authCodePayload->redirect_uri !== $redirectUri) {
+            throw OAuthServerException::invalidRequest('redirect_uri', 'Invalid redirect URI');
+        }
+    }
+
    /**
     * Return the grant identifier that can be used in matching up requests.
     *
@@ -223,7 +232,7 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
            $this->getServerParameter('PHP_AUTH_USER', $request)
        );

-        if (is_null($clientId)) {
+        if ($clientId === null) {
            throw OAuthServerException::invalidRequest('client_id');
        }

@@ -243,12 +252,12 @@ class AuthCodeGrant extends AbstractAuthorizeGrant

        if ($redirectUri !== null) {
            $this->validateRedirectUri($redirectUri, $client, $request);
-        } elseif (is_array($client->getRedirectUri()) && count($client->getRedirectUri()) !== 1
-            || empty($client->getRedirectUri())) {
+        } elseif (empty($client->getRedirectUri()) ||
+            (\is_array($client->getRedirectUri()) && \count($client->getRedirectUri()) !== 1)) {
            $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));
            throw OAuthServerException::invalidClient();
        } else {
-            $redirectUri = is_array($client->getRedirectUri())
+            $redirectUri = \is_array($client->getRedirectUri())
                ? $client->getRedirectUri()[0]
                : $client->getRedirectUri();
        }
@@ -279,7 +288,7 @@ class AuthCodeGrant extends AbstractAuthorizeGrant

            $codeChallengeMethod = $this->getQueryStringParameter('code_challenge_method', $request, 'plain');

-            if (in_array($codeChallengeMethod, ['plain', 'S256'], true) === false) {
+            if (\in_array($codeChallengeMethod, ['plain', 'S256'], true) === false) {
                throw OAuthServerException::invalidRequest(
                    'code_challenge_method',
                    'Code challenge method must be `plain` or `S256`'
@@ -308,14 +317,11 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
    public function completeAuthorizationRequest(AuthorizationRequest $authorizationRequest)
    {
        if ($authorizationRequest->getUser() instanceof UserEntityInterface === false) {
-            throw new \LogicException('An instance of UserEntityInterface should be set on the AuthorizationRequest');
+            throw new LogicException('An instance of UserEntityInterface should be set on the AuthorizationRequest');
        }

-        $finalRedirectUri = ($authorizationRequest->getRedirectUri() === null)
-            ? is_array($authorizationRequest->getClient()->getRedirectUri())
-                ? $authorizationRequest->getClient()->getRedirectUri()[0]
-                : $authorizationRequest->getClient()->getRedirectUri()
-            : $authorizationRequest->getRedirectUri();
+        $finalRedirectUri = $authorizationRequest->getRedirectUri()
+                          ?? $this->getClientRedirectUri($authorizationRequest);

        // The user approved the client, redirect them back with an auth code
        if ($authorizationRequest->isAuthorizationApproved() === true) {
@@ -333,7 +339,7 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
                'auth_code_id'          => $authCode->getIdentifier(),
                'scopes'                => $authCode->getScopes(),
                'user_id'               => $authCode->getUserIdentifier(),
-                'expire_time'           => (new \DateTime())->add($this->authCodeTTL)->format('U'),
+                'expire_time'           => (new DateTime())->add($this->authCodeTTL)->format('U'),
                'code_challenge'        => $authorizationRequest->getCodeChallenge(),
                'code_challenge_method' => $authorizationRequest->getCodeChallengeMethod(),
            ];
@@ -367,4 +373,18 @@ class AuthCodeGrant extends AbstractAuthorizeGrant
            )
        );
    }
+
+    /**
+     * Get the client redirect URI if not set in the request.
+     *
+     * @param AuthorizationRequest $authorizationRequest
+     *
+     * @return string
+     */
+    private function getClientRedirectUri(AuthorizationRequest $authorizationRequest)
+    {
+        return \is_array($authorizationRequest->getClient()->getRedirectUri())
+                ? $authorizationRequest->getClient()->getRedirectUri()[0]
+                : $authorizationRequest->getClient()->getRedirectUri();
+    }
 }
--- a/src/Grant/ClientCredentialsGrant.php
+++ b/src/Grant/ClientCredentialsGrant.php
@@ -11,6 +11,7 @@

 namespace League\OAuth2\Server\Grant;

+use DateInterval;
 use League\OAuth2\Server\RequestEvent;
 use League\OAuth2\Server\ResponseTypes\ResponseTypeInterface;
 use Psr\Http\Message\ServerRequestInterface;
@@ -26,7 +27,7 @@ class ClientCredentialsGrant extends AbstractGrant
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
-        \DateInterval $accessTokenTTL
+        DateInterval $accessTokenTTL
    ) {
        // Validate request
        $client = $this->validateClient($request);
--- a/src/Grant/GrantTypeInterface.php
+++ b/src/Grant/GrantTypeInterface.php
@@ -11,6 +11,7 @@

 namespace League\OAuth2\Server\Grant;

+use DateInterval;
 use Defuse\Crypto\Key;
 use League\Event\EmitterAwareInterface;
 use League\OAuth2\Server\CryptKey;
@@ -29,9 +30,9 @@ interface GrantTypeInterface extends EmitterAwareInterface
    /**
     * Set refresh token TTL.
     *
-     * @param \DateInterval $refreshTokenTTL
+     * @param DateInterval $refreshTokenTTL
     */
-    public function setRefreshTokenTTL(\DateInterval $refreshTokenTTL);
+    public function setRefreshTokenTTL(DateInterval $refreshTokenTTL);

    /**
     * Return the grant identifier that can be used in matching up requests.
@@ -45,14 +46,14 @@ interface GrantTypeInterface extends EmitterAwareInterface
     *
     * @param ServerRequestInterface $request
     * @param ResponseTypeInterface  $responseType
-     * @param \DateInterval          $accessTokenTTL
+     * @param DateInterval           $accessTokenTTL
     *
     * @return ResponseTypeInterface
     */
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
-        \DateInterval $accessTokenTTL
+        DateInterval $accessTokenTTL
    );

    /**
--- a/src/Grant/ImplicitGrant.php
+++ b/src/Grant/ImplicitGrant.php
@@ -9,6 +9,8 @@

 namespace League\OAuth2\Server\Grant;

+use DateInterval;
+use DateTime;
 use League\OAuth2\Server\Entities\ClientEntityInterface;
 use League\OAuth2\Server\Entities\UserEntityInterface;
 use League\OAuth2\Server\Exception\OAuthServerException;
@@ -17,12 +19,13 @@ use League\OAuth2\Server\RequestEvent;
 use League\OAuth2\Server\RequestTypes\AuthorizationRequest;
 use League\OAuth2\Server\ResponseTypes\RedirectResponse;
 use League\OAuth2\Server\ResponseTypes\ResponseTypeInterface;
+use LogicException;
 use Psr\Http\Message\ServerRequestInterface;

 class ImplicitGrant extends AbstractAuthorizeGrant
 {
    /**
-     * @var \DateInterval
+     * @var DateInterval
     */
    private $accessTokenTTL;

@@ -32,33 +35,33 @@ class ImplicitGrant extends AbstractAuthorizeGrant
    private $queryDelimiter;

    /**
-     * @param \DateInterval $accessTokenTTL
-     * @param string        $queryDelimiter
+     * @param DateInterval $accessTokenTTL
+     * @param string       $queryDelimiter
     */
-    public function __construct(\DateInterval $accessTokenTTL, $queryDelimiter = '#')
+    public function __construct(DateInterval $accessTokenTTL, $queryDelimiter = '#')
    {
        $this->accessTokenTTL = $accessTokenTTL;
        $this->queryDelimiter = $queryDelimiter;
    }

    /**
-     * @param \DateInterval $refreshTokenTTL
+     * @param DateInterval $refreshTokenTTL
     *
-     * @throw \LogicException
+     * @throw LogicException
     */
-    public function setRefreshTokenTTL(\DateInterval $refreshTokenTTL)
+    public function setRefreshTokenTTL(DateInterval $refreshTokenTTL)
    {
-        throw new \LogicException('The Implicit Grant does not return refresh tokens');
+        throw new LogicException('The Implicit Grant does not return refresh tokens');
    }

    /**
     * @param RefreshTokenRepositoryInterface $refreshTokenRepository
     *
-     * @throw \LogicException
+     * @throw LogicException
     */
    public function setRefreshTokenRepository(RefreshTokenRepositoryInterface $refreshTokenRepository)
    {
-        throw new \LogicException('The Implicit Grant does not return refresh tokens');
+        throw new LogicException('The Implicit Grant does not return refresh tokens');
    }

    /**
@@ -84,16 +87,16 @@ class ImplicitGrant extends AbstractAuthorizeGrant
     *
     * @param ServerRequestInterface $request
     * @param ResponseTypeInterface  $responseType
-     * @param \DateInterval          $accessTokenTTL
+     * @param DateInterval           $accessTokenTTL
     *
     * @return ResponseTypeInterface
     */
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
-        \DateInterval $accessTokenTTL
+        DateInterval $accessTokenTTL
    ) {
-        throw new \LogicException('This grant does not used this method');
+        throw new LogicException('This grant does not used this method');
    }

    /**
@@ -154,13 +157,6 @@ class ImplicitGrant extends AbstractAuthorizeGrant
            $redirectUri
        );

-        // Finalize the requested scopes
-        $finalizedScopes = $this->scopeRepository->finalizeScopes(
-            $scopes,
-            $this->getIdentifier(),
-            $client
-        );
-
        $stateParameter = $this->getQueryStringParameter('state', $request);

        $authorizationRequest = new AuthorizationRequest();
@@ -172,7 +168,7 @@ class ImplicitGrant extends AbstractAuthorizeGrant
            $authorizationRequest->setState($stateParameter);
        }

-        $authorizationRequest->setScopes($finalizedScopes);
+        $authorizationRequest->setScopes($scopes);

        return $authorizationRequest;
    }
@@ -183,7 +179,7 @@ class ImplicitGrant extends AbstractAuthorizeGrant
    public function completeAuthorizationRequest(AuthorizationRequest $authorizationRequest)
    {
        if ($authorizationRequest->getUser() instanceof UserEntityInterface === false) {
-            throw new \LogicException('An instance of UserEntityInterface should be set on the AuthorizationRequest');
+            throw new LogicException('An instance of UserEntityInterface should be set on the AuthorizationRequest');
        }

        $finalRedirectUri = ($authorizationRequest->getRedirectUri() === null)
@@ -194,11 +190,19 @@ class ImplicitGrant extends AbstractAuthorizeGrant

        // The user approved the client, redirect them back with an access token
        if ($authorizationRequest->isAuthorizationApproved() === true) {
+            // Finalize the requested scopes
+            $finalizedScopes = $this->scopeRepository->finalizeScopes(
+                $authorizationRequest->getScopes(),
+                $this->getIdentifier(),
+                $authorizationRequest->getClient(),
+                $authorizationRequest->getUser()->getIdentifier()
+            );
+
            $accessToken = $this->issueAccessToken(
                $this->accessTokenTTL,
                $authorizationRequest->getClient(),
                $authorizationRequest->getUser()->getIdentifier(),
-                $authorizationRequest->getScopes()
+                $finalizedScopes
            );

            $response = new RedirectResponse();
@@ -208,7 +212,7 @@ class ImplicitGrant extends AbstractAuthorizeGrant
                    [
                        'access_token' => (string) $accessToken->convertToJWT($this->privateKey),
                        'token_type'   => 'Bearer',
-                        'expires_in'   => $accessToken->getExpiryDateTime()->getTimestamp() - (new \DateTime())->getTimestamp(),
+                        'expires_in'   => $accessToken->getExpiryDateTime()->getTimestamp() - (new DateTime())->getTimestamp(),
                        'state'        => $authorizationRequest->getState(),
                    ],
                    $this->queryDelimiter
--- a/src/Grant/PasswordGrant.php
+++ b/src/Grant/PasswordGrant.php
@@ -11,6 +11,7 @@

 namespace League\OAuth2\Server\Grant;

+use DateInterval;
 use League\OAuth2\Server\Entities\ClientEntityInterface;
 use League\OAuth2\Server\Entities\UserEntityInterface;
 use League\OAuth2\Server\Exception\OAuthServerException;
@@ -36,7 +37,7 @@ class PasswordGrant extends AbstractGrant
        $this->setUserRepository($userRepository);
        $this->setRefreshTokenRepository($refreshTokenRepository);

-        $this->refreshTokenTTL = new \DateInterval('P1M');
+        $this->refreshTokenTTL = new DateInterval('P1M');
    }

    /**
@@ -45,7 +46,7 @@ class PasswordGrant extends AbstractGrant
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
-        \DateInterval $accessTokenTTL
+        DateInterval $accessTokenTTL
    ) {
        // Validate request
        $client = $this->validateClient($request);
@@ -55,17 +56,18 @@ class PasswordGrant extends AbstractGrant
        // Finalize the requested scopes
        $finalizedScopes = $this->scopeRepository->finalizeScopes($scopes, $this->getIdentifier(), $client, $user->getIdentifier());

-        // Issue and persist new tokens
+        // Issue and persist new access token
        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, $user->getIdentifier(), $finalizedScopes);
+        $this->getEmitter()->emit(new RequestEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request));
+        $responseType->setAccessToken($accessToken);
+
+        // Issue and persist new refresh token if given
        $refreshToken = $this->issueRefreshToken($accessToken);

-        // Send events to emitter
-        $this->getEmitter()->emit(new RequestEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request));
-        $this->getEmitter()->emit(new RequestEvent(RequestEvent::REFRESH_TOKEN_ISSUED, $request));
-
-        // Inject tokens into response
-        $responseType->setAccessToken($accessToken);
-        $responseType->setRefreshToken($refreshToken);
+        if ($refreshToken !== null) {
+            $this->getEmitter()->emit(new RequestEvent(RequestEvent::REFRESH_TOKEN_ISSUED, $request));
+            $responseType->setRefreshToken($refreshToken);
+        }

        return $responseType;
    }
--- a/src/Grant/RefreshTokenGrant.php
+++ b/src/Grant/RefreshTokenGrant.php
@@ -11,6 +11,8 @@

 namespace League\OAuth2\Server\Grant;

+use DateInterval;
+use Exception;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use League\OAuth2\Server\Repositories\RefreshTokenRepositoryInterface;
 use League\OAuth2\Server\RequestEvent;
@@ -29,7 +31,7 @@ class RefreshTokenGrant extends AbstractGrant
    {
        $this->setRefreshTokenRepository($refreshTokenRepository);

-        $this->refreshTokenTTL = new \DateInterval('P1M');
+        $this->refreshTokenTTL = new DateInterval('P1M');
    }

    /**
@@ -38,7 +40,7 @@ class RefreshTokenGrant extends AbstractGrant
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
-        \DateInterval $accessTokenTTL
+        DateInterval $accessTokenTTL
    ) {
        // Validate request
        $client = $this->validateClient($request);
@@ -61,17 +63,18 @@ class RefreshTokenGrant extends AbstractGrant
        $this->accessTokenRepository->revokeAccessToken($oldRefreshToken['access_token_id']);
        $this->refreshTokenRepository->revokeRefreshToken($oldRefreshToken['refresh_token_id']);

-        // Issue and persist new tokens
+        // Issue and persist new access token
        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, $oldRefreshToken['user_id'], $scopes);
+        $this->getEmitter()->emit(new RequestEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request));
+        $responseType->setAccessToken($accessToken);
+
+        // Issue and persist new refresh token if given
        $refreshToken = $this->issueRefreshToken($accessToken);

-        // Send events to emitter
-        $this->getEmitter()->emit(new RequestEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request));
-        $this->getEmitter()->emit(new RequestEvent(RequestEvent::REFRESH_TOKEN_ISSUED, $request));
-
-        // Inject tokens into response
-        $responseType->setAccessToken($accessToken);
-        $responseType->setRefreshToken($refreshToken);
+        if ($refreshToken !== null) {
+            $this->getEmitter()->emit(new RequestEvent(RequestEvent::REFRESH_TOKEN_ISSUED, $request));
+            $responseType->setRefreshToken($refreshToken);
+        }

        return $responseType;
    }
@@ -94,8 +97,8 @@ class RefreshTokenGrant extends AbstractGrant
        // Validate refresh token
        try {
            $refreshToken = $this->decrypt($encryptedRefreshToken);
-        } catch (\Exception $e) {
-            throw OAuthServerException::invalidRefreshToken('Cannot decrypt the refresh token');
+        } catch (Exception $e) {
+            throw OAuthServerException::invalidRefreshToken('Cannot decrypt the refresh token', $e);
        }

        $refreshTokenData = json_decode($refreshToken, true);
--- a/src/Middleware/AuthorizationServerMiddleware.php
+++ b/src/Middleware/AuthorizationServerMiddleware.php
@@ -9,6 +9,7 @@

 namespace League\OAuth2\Server\Middleware;

+use Exception;
 use League\OAuth2\Server\AuthorizationServer;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use Psr\Http\Message\ResponseInterface;
@@ -43,7 +44,7 @@ class AuthorizationServerMiddleware
        } catch (OAuthServerException $exception) {
            return $exception->generateHttpResponse($response);
            // @codeCoverageIgnoreStart
-        } catch (\Exception $exception) {
+        } catch (Exception $exception) {
            return (new OAuthServerException($exception->getMessage(), 0, 'unknown_error', 500))
                ->generateHttpResponse($response);
            // @codeCoverageIgnoreEnd
--- a/src/Middleware/ResourceServerMiddleware.php
+++ b/src/Middleware/ResourceServerMiddleware.php
@@ -9,6 +9,7 @@

 namespace League\OAuth2\Server\Middleware;

+use Exception;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use League\OAuth2\Server\ResourceServer;
 use Psr\Http\Message\ResponseInterface;
@@ -34,7 +35,7 @@ class ResourceServerMiddleware
     * @param ResponseInterface      $response
     * @param callable               $next
     *
-     * @return \Psr\Http\Message\ResponseInterface
+     * @return ResponseInterface
     */
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, callable $next)
    {
@@ -43,7 +44,7 @@ class ResourceServerMiddleware
        } catch (OAuthServerException $exception) {
            return $exception->generateHttpResponse($response);
            // @codeCoverageIgnoreStart
-        } catch (\Exception $exception) {
+        } catch (Exception $exception) {
            return (new OAuthServerException($exception->getMessage(), 0, 'unknown_error', 500))
                ->generateHttpResponse($response);
            // @codeCoverageIgnoreEnd
--- a/src/Repositories/RefreshTokenRepositoryInterface.php
+++ b/src/Repositories/RefreshTokenRepositoryInterface.php
@@ -20,7 +20,7 @@ interface RefreshTokenRepositoryInterface extends RepositoryInterface
    /**
     * Creates a new refresh token
     *
-     * @return RefreshTokenEntityInterface
+     * @return RefreshTokenEntityInterface|null
     */
    public function getNewRefreshToken();

--- a/src/ResponseTypes/AbstractResponseType.php
+++ b/src/ResponseTypes/AbstractResponseType.php
@@ -54,7 +54,7 @@ abstract class AbstractResponseType implements ResponseTypeInterface
    /**
     * Set the private key
     *
-     * @param \League\OAuth2\Server\CryptKey $key
+     * @param CryptKey $key
     */
    public function setPrivateKey(CryptKey $key)
    {
--- a/src/ResponseTypes/BearerTokenResponse.php
+++ b/src/ResponseTypes/BearerTokenResponse.php
@@ -11,6 +11,7 @@

 namespace League\OAuth2\Server\ResponseTypes;

+use DateTime;
 use League\OAuth2\Server\Entities\AccessTokenEntityInterface;
 use League\OAuth2\Server\Entities\RefreshTokenEntityInterface;
 use Psr\Http\Message\ResponseInterface;
@@ -28,7 +29,7 @@ class BearerTokenResponse extends AbstractResponseType

        $responseParams = [
            'token_type'   => 'Bearer',
-            'expires_in'   => $expireDateTime - (new \DateTime())->getTimestamp(),
+            'expires_in'   => $expireDateTime - (new DateTime())->getTimestamp(),
            'access_token' => (string) $jwtAccessToken,
        ];

--- a/tests/AuthorizationServerTest.php
+++ b/tests/AuthorizationServerTest.php
@@ -3,6 +3,7 @@
 namespace LeagueTests;

 use League\OAuth2\Server\AuthorizationServer;
+use League\OAuth2\Server\CryptKey;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use League\OAuth2\Server\Grant\AuthCodeGrant;
 use League\OAuth2\Server\Grant\ClientCredentialsGrant;
@@ -109,6 +110,95 @@ class AuthorizationServerTest extends TestCase
        $this->assertInstanceOf(BearerTokenResponse::class, $method->invoke($server));
    }

+    public function testGetResponseTypeExtended()
+    {
+        $clientRepository = $this->getMockBuilder(ClientRepositoryInterface::class)->getMock();
+        $privateKey = 'file://' . __DIR__ . '/Stubs/private.key';
+        $encryptionKey = 'file://' . __DIR__ . '/Stubs/public.key';
+
+        $server = new class($clientRepository, $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock(), $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock(), $privateKey, $encryptionKey) extends AuthorizationServer {
+            protected function getResponseType()
+            {
+                $this->responseType = new class extends BearerTokenResponse {
+                    /* @return null|CryptKey */
+                    public function getPrivateKey()
+                    {
+                        return $this->privateKey;
+                    }
+
+                    public function getEncryptionKey()
+                    {
+                        return $this->encryptionKey;
+                    }
+                };
+
+                return parent::getResponseType();
+            }
+        };
+
+        $abstractGrantReflection = new \ReflectionClass($server);
+        $method = $abstractGrantReflection->getMethod('getResponseType');
+        $method->setAccessible(true);
+        $responseType = $method->invoke($server);
+
+        $this->assertInstanceOf(BearerTokenResponse::class, $responseType);
+        // generated instances should have keys setup
+        $this->assertSame($privateKey, $responseType->getPrivateKey()->getKeyPath());
+        $this->assertSame($encryptionKey, $responseType->getEncryptionKey());
+    }
+
+    public function testMultipleRequestsGetDifferentResponseTypeInstances()
+    {
+        $privateKey = 'file://' . __DIR__ . '/Stubs/private.key';
+        $encryptionKey = 'file://' . __DIR__ . '/Stubs/public.key';
+
+        $responseTypePrototype = new class extends BearerTokenResponse {
+            /* @return null|CryptKey */
+            public function getPrivateKey()
+            {
+                return $this->privateKey;
+            }
+
+            public function getEncryptionKey()
+            {
+                return $this->encryptionKey;
+            }
+        };
+
+        $clientRepository = $this->getMockBuilder(ClientRepositoryInterface::class)->getMock();
+
+        $server = new AuthorizationServer(
+            $clientRepository,
+            $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock(),
+            $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock(),
+            $privateKey,
+            $encryptionKey,
+            $responseTypePrototype
+        );
+
+        $abstractGrantReflection = new \ReflectionClass($server);
+        $method = $abstractGrantReflection->getMethod('getResponseType');
+        $method->setAccessible(true);
+
+        $responseTypeA = $method->invoke($server);
+        $responseTypeB = $method->invoke($server);
+
+        // prototype should not get changed
+        $this->assertNull($responseTypePrototype->getPrivateKey());
+        $this->assertNull($responseTypePrototype->getEncryptionKey());
+
+        // generated instances should have keys setup
+        $this->assertSame($privateKey, $responseTypeA->getPrivateKey()->getKeyPath());
+        $this->assertSame($encryptionKey, $responseTypeA->getEncryptionKey());
+
+        // all instances should be different but based on the same prototype
+        $this->assertSame(get_class($responseTypePrototype), get_class($responseTypeA));
+        $this->assertSame(get_class($responseTypePrototype), get_class($responseTypeB));
+        $this->assertNotSame($responseTypePrototype, $responseTypeA);
+        $this->assertNotSame($responseTypePrototype, $responseTypeB);
+        $this->assertNotSame($responseTypeA, $responseTypeB);
+    }
+
    public function testCompleteAuthorizationRequest()
    {
        $clientRepository = $this->getMockBuilder(ClientRepositoryInterface::class)->getMock();
--- a/tests/Exception/OAuthServerExceptionTest.php
+++ b/tests/Exception/OAuthServerExceptionTest.php
@@ -2,6 +2,7 @@

 namespace LeagueTests\Exception;

+use Exception;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use PHPUnit\Framework\TestCase;

@@ -20,4 +21,19 @@ class OAuthServerExceptionTest extends TestCase

        $this->assertFalse($exceptionWithoutRedirect->hasRedirect());
    }
+
+    public function testHasPrevious()
+    {
+        $previous = new Exception('This is the previous');
+        $exceptionWithPrevious = OAuthServerException::accessDenied(null, null, $previous);
+
+        $this->assertSame('This is the previous', $exceptionWithPrevious->getPrevious()->getMessage());
+    }
+
+    public function testDoesNotHavePrevious()
+    {
+        $exceptionWithoutPrevious = OAuthServerException::accessDenied();
+
+        $this->assertNull($exceptionWithoutPrevious->getPrevious());
+    }
 }
--- a/tests/Grant/AbstractGrantTest.php
+++ b/tests/Grant/AbstractGrantTest.php
@@ -346,6 +346,27 @@ class AbstractGrantTest extends TestCase
        $this->assertEquals($accessToken, $refreshToken->getAccessToken());
    }

+    public function testIssueNullRefreshToken()
+    {
+        $refreshTokenRepoMock = $this->getMockBuilder(RefreshTokenRepositoryInterface::class)->getMock();
+        $refreshTokenRepoMock
+            ->expects($this->once())
+            ->method('getNewRefreshToken')
+            ->willReturn(null);
+
+        /** @var AbstractGrant $grantMock */
+        $grantMock = $this->getMockForAbstractClass(AbstractGrant::class);
+        $grantMock->setRefreshTokenTTL(new \DateInterval('PT1M'));
+        $grantMock->setRefreshTokenRepository($refreshTokenRepoMock);
+
+        $abstractGrantReflection = new \ReflectionClass($grantMock);
+        $issueRefreshTokenMethod = $abstractGrantReflection->getMethod('issueRefreshToken');
+        $issueRefreshTokenMethod->setAccessible(true);
+
+        $accessToken = new AccessTokenEntity();
+        $this->assertNull($issueRefreshTokenMethod->invoke($grantMock, $accessToken));
+    }
+
    public function testIssueAccessToken()
    {
        $accessTokenRepoMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
--- a/tests/Grant/AuthCodeGrantTest.php
+++ b/tests/Grant/AuthCodeGrantTest.php
@@ -644,6 +644,73 @@ class AuthCodeGrantTest extends TestCase
        $this->assertInstanceOf(RefreshTokenEntityInterface::class, $response->getRefreshToken());
    }

+    public function testRespondToAccessTokenRequestNullRefreshToken()
+    {
+        $client = new ClientEntity();
+        $client->setIdentifier('foo');
+        $client->setRedirectUri('http://foo/bar');
+        $clientRepositoryMock = $this->getMockBuilder(ClientRepositoryInterface::class)->getMock();
+        $clientRepositoryMock->method('getClientEntity')->willReturn($client);
+
+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeEntity = new ScopeEntity();
+        $scopeRepositoryMock->method('getScopeEntityByIdentifier')->willReturn($scopeEntity);
+        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);
+
+        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
+        $accessTokenRepositoryMock->method('getNewToken')->willReturn(new AccessTokenEntity());
+        $accessTokenRepositoryMock->method('persistNewAccessToken')->willReturnSelf();
+
+        $refreshTokenRepositoryMock = $this->getMockBuilder(RefreshTokenRepositoryInterface::class)->getMock();
+        $refreshTokenRepositoryMock->method('persistNewRefreshToken')->willReturnSelf();
+        $refreshTokenRepositoryMock->method('getNewRefreshToken')->willReturn(null);
+
+        $grant = new AuthCodeGrant(
+            $this->getMockBuilder(AuthCodeRepositoryInterface::class)->getMock(),
+            $refreshTokenRepositoryMock,
+            new \DateInterval('PT10M')
+        );
+
+        $grant->setClientRepository($clientRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);
+        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setEncryptionKey($this->cryptStub->getKey());
+
+        $request = new ServerRequest(
+            [],
+            [],
+            null,
+            'POST',
+            'php://input',
+            [],
+            [],
+            [],
+            [
+                'grant_type'   => 'authorization_code',
+                'client_id'    => 'foo',
+                'redirect_uri' => 'http://foo/bar',
+                'code'         => $this->cryptStub->doEncrypt(
+                    json_encode(
+                        [
+                            'auth_code_id' => uniqid(),
+                            'expire_time'  => time() + 3600,
+                            'client_id'    => 'foo',
+                            'user_id'      => 123,
+                            'scopes'       => ['foo'],
+                            'redirect_uri' => 'http://foo/bar',
+                        ]
+                    )
+                ),
+            ]
+        );
+
+        /** @var StubResponseType $response */
+        $response = $grant->respondToAccessTokenRequest($request, new StubResponseType(), new \DateInterval('PT10M'));
+
+        $this->assertInstanceOf(AccessTokenEntityInterface::class, $response->getAccessToken());
+        $this->assertNull($response->getRefreshToken());
+    }
+
    public function testRespondToAccessTokenRequestCodeChallengePlain()
    {
        $client = new ClientEntity();
--- a/tests/Grant/ImplicitGrantTest.php
+++ b/tests/Grant/ImplicitGrantTest.php
@@ -94,7 +94,6 @@ class ImplicitGrantTest extends TestCase
        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
        $scopeEntity = new ScopeEntity();
        $scopeRepositoryMock->method('getScopeEntityByIdentifier')->willReturn($scopeEntity);
-        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);

        $grant = new ImplicitGrant(new \DateInterval('PT10M'));
        $grant->setClientRepository($clientRepositoryMock);
@@ -129,7 +128,6 @@ class ImplicitGrantTest extends TestCase
        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
        $scopeEntity = new ScopeEntity();
        $scopeRepositoryMock->method('getScopeEntityByIdentifier')->willReturn($scopeEntity);
-        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);

        $grant = new ImplicitGrant(new \DateInterval('PT10M'));
        $grant->setClientRepository($clientRepositoryMock);
@@ -286,9 +284,13 @@ class ImplicitGrantTest extends TestCase
        $accessTokenRepositoryMock->method('getNewToken')->willReturn(new AccessTokenEntity());
        $accessTokenRepositoryMock->method('persistNewAccessToken')->willReturnSelf();

+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);
+
        $grant = new ImplicitGrant(new \DateInterval('PT10M'));
        $grant->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);

        $this->assertInstanceOf(RedirectResponse::class, $grant->completeAuthorizationRequest($authRequest));
    }
@@ -309,9 +311,13 @@ class ImplicitGrantTest extends TestCase
        $accessTokenRepositoryMock->method('getNewToken')->willReturn(new AccessTokenEntity());
        $accessTokenRepositoryMock->method('persistNewAccessToken')->willReturnSelf();

+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);
+
        $grant = new ImplicitGrant(new \DateInterval('PT10M'));
        $grant->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);

        $grant->completeAuthorizationRequest($authRequest);
    }
@@ -330,9 +336,13 @@ class ImplicitGrantTest extends TestCase
        $accessTokenRepositoryMock->expects($this->at(0))->method('persistNewAccessToken')->willThrowException(UniqueTokenIdentifierConstraintViolationException::create());
        $accessTokenRepositoryMock->expects($this->at(1))->method('persistNewAccessToken')->willReturnSelf();

+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);
+
        $grant = new ImplicitGrant(new \DateInterval('PT10M'));
        $grant->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);

        $this->assertInstanceOf(RedirectResponse::class, $grant->completeAuthorizationRequest($authRequest));
    }
@@ -354,9 +364,13 @@ class ImplicitGrantTest extends TestCase
        $accessTokenRepositoryMock->method('getNewToken')->willReturn(new AccessTokenEntity());
        $accessTokenRepositoryMock->method('persistNewAccessToken')->willThrowException(OAuthServerException::serverError('something bad happened'));

+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);
+
        $grant = new ImplicitGrant(new \DateInterval('PT10M'));
        $grant->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);

        $grant->completeAuthorizationRequest($authRequest);
    }
@@ -378,9 +392,13 @@ class ImplicitGrantTest extends TestCase
        $accessTokenRepositoryMock->method('getNewToken')->willReturn(new AccessTokenEntity());
        $accessTokenRepositoryMock->method('persistNewAccessToken')->willThrowException(UniqueTokenIdentifierConstraintViolationException::create());

+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);
+
        $grant = new ImplicitGrant(new \DateInterval('PT10M'));
        $grant->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);

        $grant->completeAuthorizationRequest($authRequest);
    }
--- a/tests/Grant/PasswordGrantTest.php
+++ b/tests/Grant/PasswordGrantTest.php
@@ -78,6 +78,51 @@ class PasswordGrantTest extends TestCase
        $this->assertInstanceOf(RefreshTokenEntityInterface::class, $responseType->getRefreshToken());
    }

+    public function testRespondToRequestNullRefreshToken()
+    {
+        $client = new ClientEntity();
+        $clientRepositoryMock = $this->getMockBuilder(ClientRepositoryInterface::class)->getMock();
+        $clientRepositoryMock->method('getClientEntity')->willReturn($client);
+
+        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
+        $accessTokenRepositoryMock->method('getNewToken')->willReturn(new AccessTokenEntity());
+        $accessTokenRepositoryMock->method('persistNewAccessToken')->willReturnSelf();
+
+        $userRepositoryMock = $this->getMockBuilder(UserRepositoryInterface::class)->getMock();
+        $userEntity = new UserEntity();
+        $userRepositoryMock->method('getUserEntityByUserCredentials')->willReturn($userEntity);
+
+        $scope = new ScopeEntity();
+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeRepositoryMock->method('getScopeEntityByIdentifier')->willReturn($scope);
+        $scopeRepositoryMock->method('finalizeScopes')->willReturnArgument(0);
+
+        $refreshTokenRepositoryMock = $this->getMockBuilder(RefreshTokenRepositoryInterface::class)->getMock();
+        $refreshTokenRepositoryMock->method('getNewRefreshToken')->willReturn(null);
+
+        $grant = new PasswordGrant($userRepositoryMock, $refreshTokenRepositoryMock);
+        $grant->setClientRepository($clientRepositoryMock);
+        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);
+        $grant->setDefaultScope(self::DEFAULT_SCOPE);
+
+        $serverRequest = new ServerRequest();
+        $serverRequest = $serverRequest->withParsedBody(
+            [
+                'client_id'     => 'foo',
+                'client_secret' => 'bar',
+                'username'      => 'foo',
+                'password'      => 'bar',
+            ]
+        );
+
+        $responseType = new StubResponseType();
+        $grant->respondToAccessTokenRequest($serverRequest, $responseType, new \DateInterval('PT5M'));
+
+        $this->assertInstanceOf(AccessTokenEntityInterface::class, $responseType->getAccessToken());
+        $this->assertNull($responseType->getRefreshToken());
+    }
+
    /**
     * @expectedException \League\OAuth2\Server\Exception\OAuthServerException
     */
--- a/tests/Grant/RefreshTokenGrantTest.php
+++ b/tests/Grant/RefreshTokenGrantTest.php
@@ -94,6 +94,63 @@ class RefreshTokenGrantTest extends TestCase
        $this->assertInstanceOf(RefreshTokenEntityInterface::class, $responseType->getRefreshToken());
    }

+    public function testRespondToRequestNullRefreshToken()
+    {
+        $client = new ClientEntity();
+        $client->setIdentifier('foo');
+
+        $clientRepositoryMock = $this->getMockBuilder(ClientRepositoryInterface::class)->getMock();
+        $clientRepositoryMock->method('getClientEntity')->willReturn($client);
+
+        $scopeEntity = new ScopeEntity();
+        $scopeEntity->setIdentifier('foo');
+
+        $scopeRepositoryMock = $this->getMockBuilder(ScopeRepositoryInterface::class)->getMock();
+        $scopeRepositoryMock->method('getScopeEntityByIdentifier')->willReturn($scopeEntity);
+
+        $accessTokenRepositoryMock = $this->getMockBuilder(AccessTokenRepositoryInterface::class)->getMock();
+        $accessTokenRepositoryMock->method('getNewToken')->willReturn(new AccessTokenEntity());
+        $accessTokenRepositoryMock->expects($this->once())->method('persistNewAccessToken')->willReturnSelf();
+
+        $refreshTokenRepositoryMock = $this->getMockBuilder(RefreshTokenRepositoryInterface::class)->getMock();
+        $refreshTokenRepositoryMock->method('getNewRefreshToken')->willReturn(null);
+        $refreshTokenRepositoryMock->expects($this->never())->method('persistNewRefreshToken');
+
+        $grant = new RefreshTokenGrant($refreshTokenRepositoryMock);
+        $grant->setClientRepository($clientRepositoryMock);
+        $grant->setScopeRepository($scopeRepositoryMock);
+        $grant->setAccessTokenRepository($accessTokenRepositoryMock);
+        $grant->setEncryptionKey($this->cryptStub->getKey());
+        $grant->setPrivateKey(new CryptKey('file://' . __DIR__ . '/../Stubs/private.key'));
+
+        $oldRefreshToken = $this->cryptStub->doEncrypt(
+            json_encode(
+                [
+                    'client_id'        => 'foo',
+                    'refresh_token_id' => 'zyxwvu',
+                    'access_token_id'  => 'abcdef',
+                    'scopes'           => ['foo'],
+                    'user_id'          => 123,
+                    'expire_time'      => time() + 3600,
+                ]
+            )
+        );
+
+        $serverRequest = new ServerRequest();
+        $serverRequest = $serverRequest->withParsedBody([
+            'client_id'     => 'foo',
+            'client_secret' => 'bar',
+            'refresh_token' => $oldRefreshToken,
+            'scopes'        => ['foo'],
+        ]);
+
+        $responseType = new StubResponseType();
+        $grant->respondToAccessTokenRequest($serverRequest, $responseType, new \DateInterval('PT5M'));
+
+        $this->assertInstanceOf(AccessTokenEntityInterface::class, $responseType->getAccessToken());
+        $this->assertNull($responseType->getRefreshToken());
+    }
+
    public function testRespondToReducedScopes()
    {
        $client = new ClientEntity();
--- a/tests/Middleware/AuthorizationServerMiddlewareTest.php
+++ b/tests/Middleware/AuthorizationServerMiddlewareTest.php
@@ -104,7 +104,7 @@ class AuthorizationServerMiddlewareTest extends TestCase
        $response = $exception->generateHttpResponse(new Response());

        $this->assertEquals(302, $response->getStatusCode());
-        $this->assertEquals('http://foo/bar?error=invalid_scope&message=The+requested+scope+is+invalid%2C+unknown%2C+or+malformed&hint=Check+the+%60test%60+scope',
+        $this->assertEquals('http://foo/bar?error=invalid_scope&error_description=The+requested+scope+is+invalid%2C+unknown%2C+or+malformed&hint=Check+the+%60test%60+scope&message=The+requested+scope+is+invalid%2C+unknown%2C+or+malformed',
            $response->getHeader('location')[0]);
    }

@@ -114,7 +114,7 @@ class AuthorizationServerMiddlewareTest extends TestCase
        $response = $exception->generateHttpResponse(new Response(), true);

        $this->assertEquals(302, $response->getStatusCode());
-        $this->assertEquals('http://foo/bar#error=invalid_scope&message=The+requested+scope+is+invalid%2C+unknown%2C+or+malformed&hint=Check+the+%60test%60+scope',
+        $this->assertEquals('http://foo/bar#error=invalid_scope&error_description=The+requested+scope+is+invalid%2C+unknown%2C+or+malformed&hint=Check+the+%60test%60+scope&message=The+requested+scope+is+invalid%2C+unknown%2C+or+malformed',
            $response->getHeader('location')[0]);
    }
 }
Author	SHA1	Message	Date
Andrew Millington	2eb1cf79e5	Update changelog for version 7.4.0	2019-05-05 10:22:01 +01:00
Andrew Millington	382b6f5fbf	Merge pull request #1000 from filecage/master Optional Refresh Tokens	2019-05-05 09:48:53 +01:00
sephster	86869eafbb	Add whitespace around control blocks	2019-05-05 09:03:13 +01:00
sephster	9236e842d9	Clarify changelog message	2019-05-05 08:58:34 +01:00
filecage	9bc7f6c8c5	removing simplified_null_return	2019-04-29 19:13:26 +02:00
David	1e9a468e66	Merge branch 'master' into master	2019-04-12 11:17:37 +02:00
Andrew Millington	c7f4998497	Update links	2019-03-29 18:19:35 +00:00
Andrew Millington	0a78236f17	Update changelog for version 7.3.3	2019-03-29 18:18:35 +00:00
Andrew Millington	a68f8001a4	Merge pull request #1006 from marc-mabe/fix-958-error_description spec compliant 'error_description' but keep 'message' for BC	2019-03-29 16:28:33 +00:00
Marc Bennewitz	b88198a9a4	spec compliant 'error_description' but keep 'message' for BC	2019-03-29 16:00:26 +01:00
filecage	8cf39fd9cd	applies style CI diff	2019-03-16 13:15:38 +01:00
filecage	6f6820f629	removes @var hints the @var hints make PHP stan fail together with PHPUnit 6.3	2019-03-16 13:12:34 +01:00
filecage	0742d5150c	explicit is better than implicit :)	2019-03-13 10:08:57 +01:00
filecage	64f0d89fad	`getNewRefreshToken()` can also return `NULL`	2019-03-11 23:28:47 +01:00
filecage	ebf78132d7	`refreshTokenRepository` parameter can not be null, condition is obsolete	2019-03-11 23:28:20 +01:00
filecage	aa5bbe5f06	boyscout: style CI tweaks	2019-03-11 23:26:35 +01:00
filecage	66d4ce6de8	Update CHANGELOG.md	2019-03-08 18:21:55 +01:00
filecage	2ea76ca4fd	Adds handling for `null` issued refresh token to Grant implementations	2019-03-08 18:19:16 +01:00
filecage	b2840474fd	AbstractGrant no longer tries to issue a refresh token if the Repository returned `null`	2019-03-08 18:16:16 +01:00
Andrew Millington	0227f14b7b	Merge pull request #988 from lordrhodos/feature/test-cleanup Cleanup: remove unused local variable $scopeEntity from ImplicitGrantTest	2019-01-22 20:59:33 +00:00
Patrick Rodacker	fad42a88fd	removes unused local variable $scopeEntity from ImplicitGrantTest	2019-01-20 22:11:22 +01:00
Andrew Millington	2a16dbeb7f	Merge pull request #981 from Sephster/support-php-7.3 Add support for PHP 7.3	2018-12-06 23:53:55 +00:00
sephster	faa350792a	Add support for PHP 7.3	2018-12-06 23:46:28 +00:00
Andrew Millington	dc3181bbb0	Merge pull request #977 from spideyfusion/symfony-community-integration Add Symfony community integration to README.md	2018-11-28 12:47:30 +00:00
Petar Obradović	1e3a7adb19	Add Symfony community integration to README.md	2018-11-28 12:24:16 +01:00
sephster	b71f382cd7	Update changelog	2018-11-21 21:42:43 +00:00
Andrew Millington	9783388523	Merge pull request #969 from ceeram/fix-bc-break Fix bc breaking change	2018-11-21 21:38:37 +00:00
sephster	46493c461e	Update changelog for 7.3.2 release	2018-11-21 21:29:55 +00:00
sephster	8b421818f2	Add blank line to better format	2018-11-21 21:26:54 +00:00
Marc Ypes	b09154af33	Add test to prove bc break	2018-11-16 13:29:47 +01:00
Marc Ypes	f1454cde36	Fix bc breaking change	2018-11-16 12:44:41 +01:00
Andrew Millington	f2cd3646ff	Merge pull request #970 from Sephster/interface-revert Revert Interface Change	2018-11-15 22:37:18 +00:00
sephster	7839a61170	Update changelog	2018-11-15 22:33:34 +00:00
sephster	443d7c485a	Revert interface change so class can be extende	2018-11-15 22:22:08 +00:00
Andrew Millington	a61c6a318a	Update changelog for 7.3.0 release	2018-11-13 20:17:20 +00:00
sephster	94e75ba6f3	Fix bug	2018-11-13 12:56:06 +00:00
Andrew Millington	efa8ef6fce	Merge pull request #965 from ceeram/add-previous Include previous exception in catch and throw	2018-11-13 12:44:43 +00:00
sephster	7982275757	Fix docblock alignment	2018-11-13 12:34:16 +00:00
sephster	f6c1070ccc	Add use Throwable	2018-11-13 12:32:52 +00:00
sephster	d64fb3f526	Merge master into this branch	2018-11-13 12:28:39 +00:00
Andrew Millington	95a9f4649d	Merge pull request #966 from ceeram/fully_qualified_strict_types Replace fqn with unqualified name	2018-11-13 11:58:31 +00:00
Marc Ypes	4bb5b747c1	Replace fqn with unqualified name	2018-11-13 01:33:11 +01:00
Marc Ypes	5868996961	Add test for previous exceptions	2018-11-13 00:25:22 +01:00
sephster	9542af627e	Update changelog	2018-11-12 19:57:35 +00:00
Marc Ypes	3b983ad0b4	Include previous exception in catch and throw	2018-11-12 13:58:31 +01:00
sephster	34ec35019b	Remove additional whitespace	2018-11-08 13:10:22 +00:00
Andrew Millington	ac818bd921	Minor formatting adjustment	2018-11-06 21:42:05 +00:00
Andrew Millington	73698e28d9	Update CHANGELOG.md	2018-11-06 21:38:31 +00:00
Andrew Millington	c87be9477c	Merge pull request #960 from marc-mabe/stateless-server Make AuthorizationServer stateless	2018-11-06 21:34:26 +00:00
Marc Bennewitz	d288a2ad8a	Make AuthorizationServer stateless	2018-11-05 09:08:02 +01:00
Andrew Millington	a34f5dd7db	Merge pull request #953 from Sephster/code-tidyup Code Tidyup	2018-10-13 17:06:21 +01:00
sephster	c0efdf0dd0	Revert changes to throws and returns ordering	2018-10-13 16:54:31 +01:00
sephster	f96fca3b48	Minor code tidyup	2018-10-13 16:44:40 +01:00
sephster	20b355b025	Re-order docblock throws	2018-10-13 16:31:36 +01:00
sephster	793f65d3a3	Remove unused scope entity interface	2018-10-13 16:14:15 +01:00
sephster	322b55eddf	Remove getScopes function and use validateScopes instead	2018-10-13 16:11:44 +01:00
sephster	50ab9dd8ac	Remove unused import	2018-10-13 15:28:39 +01:00
sephster	b624124d5a	Chaneg param types to satisfy PHPStan	2018-10-13 15:25:49 +01:00
sephster	dbf2b55bc5	Fix docblock alignment	2018-10-13 15:16:50 +01:00
sephster	b11d628e8b	Change docblock type for	2018-10-13 14:49:29 +01:00
sephster	0515129c9c	Fix coding standards issues	2018-10-13 14:37:36 +01:00
sephster	50566cdc87	Reduce complexity of respondToAccessTokenRequest	2018-10-13 14:34:35 +01:00
sephster	b4d88995de	Add throws tag for DateInterval exception	2018-10-13 13:42:27 +01:00
sephster	398029be56	Add roave security advisories	2018-10-13 13:35:36 +01:00
sephster	30ed221481	Add Andy to authors list	2018-10-13 13:27:31 +01:00
sephster	939c0619d0	Shorten variable name	2018-10-13 13:22:27 +01:00
sephster	4042a31159	Update composer dependency versions	2018-10-13 13:17:45 +01:00
Andrew Millington	0bdd02cdb4	Merge pull request #952 from Sephster/add-scope-entity-trait Add Scope Entity Trait	2018-10-13 13:14:33 +01:00
sephster	7bf7700645	Update changelog	2018-10-12 23:32:44 +01:00
sephster	d76025d613	Change example to use scope trait	2018-10-12 23:23:24 +01:00
sephster	d6792c1662	Add scope entity trait	2018-10-12 23:05:07 +01:00
Andrew Millington	9882f6716c	Merge pull request #923 from christiaangoossens/fix_implicit_grant_scopes ImplicitGrant finalizes scopes without user identifier	2018-09-23 18:31:53 +01:00
sephster	71c605117a	Add missing word	2018-09-23 18:31:26 +01:00
sephster	6bc6ac09d2	Update changelog	2018-09-23 18:30:14 +01:00
Andrew Millington	b7b7dda28c	Merge pull request #945 from ezimuel/add-expressive-readme Added Expressive in the community integration of README	2018-09-19 11:28:31 +01:00
Enrico Zimuel	ef864b5cba	Added Expressive in the community integration of README	2018-09-19 12:02:06 +02:00
Andrew Millington	27b956c149	Merge pull request #932 from JasonTheAdams/patch-1 Added docbloc to UniqueTokenIdentifierConstraintViolationException	2018-08-19 11:39:03 +01:00
Jason Adams	6949a007e5	Added docbloc to UniqueTokenIdentifierConstraintViolationException	2018-08-18 16:57:31 -07:00
Christiaan Goossens	acf16e924a	Actually use finalizedScopes in access token	2018-07-13 13:11:18 +02:00
Christiaan Goossens	a479b5762e	Fix implicit grant scopes	2018-07-13 11:47:32 +02:00