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1 | <?php declare(strict_types=1); |
2 | |
3 | namespace Taproot\IndieAuth; |
4 | |
5 | use BadMethodCallException; |
6 | use BarnabyWalters\Mf2 as M; |
7 | use Exception; |
8 | use GuzzleHttp\Psr7\Header as HeaderParser; |
9 | use IndieAuth\Client as IndieAuthClient; |
10 | use Mf2; |
11 | use GuzzleHttp\Psr7\Response; |
12 | use Psr\Http\Client\ClientExceptionInterface; |
13 | use Psr\Http\Client\NetworkExceptionInterface; |
14 | use Psr\Http\Client\RequestExceptionInterface; |
15 | use Psr\Http\Message\ResponseInterface; |
16 | use Psr\Http\Message\ServerRequestInterface; |
17 | use Psr\Http\Server\MiddlewareInterface; |
18 | use Psr\Log\LoggerInterface; |
19 | use Psr\Log\NullLogger; |
20 | use Taproot\IndieAuth\Callback\AuthorizationFormInterface; |
21 | use Taproot\IndieAuth\Callback\DefaultAuthorizationForm; |
22 | use Taproot\IndieAuth\Storage\TokenStorageInterface; |
23 | |
24 | /** |
25 | * IndieAuth Server |
26 | * |
27 | * A PSR-7-compatible implementation of the request-handling logic for IndieAuth authorization endpoints |
28 | * and token endpoints. |
29 | * |
30 | * Typical minimal usage looks something like this: |
31 | * |
32 | * ```php |
33 | * // Somewhere in your app set-up code: |
34 | * $server = new Taproot\IndieAuth\Server([ |
35 | * // Your server’s issuer ID URL (see __construct() docs for more details) |
36 | * 'issuer' => 'https://example.com/', |
37 | * |
38 | * // A secret key, >= 64 characters long. |
39 | * 'secret' => YOUR_APP_INDIEAUTH_SECRET, |
40 | * |
41 | * // A path to store token data, or an object implementing TokenStorageInterface. |
42 | * 'tokenStorage' => '/../data/auth_tokens/', |
43 | * |
44 | * // An authentication callback function, which either returns data about the current user, |
45 | * // or redirects to/implements an authentication flow. |
46 | * 'authenticationHandler' => function (ServerRequestInterface $request, string $authenticationRedirect, ?string $normalizedMeUrl) { |
47 | * // If the request is authenticated, return an array with a `me` key containing the |
48 | * // canonical URL of the currently logged-in user. |
49 | * if ($userUrl = getLoggedInUserUrl($request)) { |
50 | * return ['me' => $userUrl]; |
51 | * } |
52 | * |
53 | * // Otherwise, redirect the user to a login page, ensuring that they will be redirected |
54 | * // back to the IndieAuth flow with query parameters intact once logged in. |
55 | * return new Response(302, ['Location' => 'https://example.com/login?next=' . urlencode($authenticationRedirect)]); |
56 | * } |
57 | * ]); |
58 | * |
59 | * // In your authorization endpoint route: |
60 | * return $server->handleAuthorizationEndpointRequest($request); |
61 | * |
62 | * // In your token endpoint route: |
63 | * return $server->handleTokenEndpointRequest($request); |
64 | * |
65 | * // In another route (e.g. a micropub route), to authenticate the request: |
66 | * // (assuming $bearerToken is a token parsed from an “Authorization: Bearer XXXXXX” header |
67 | * // or access_token property from a request body) |
68 | * if ($accessToken = $server->getAccessToken($bearerToken)) { |
69 | * // Request is authenticated as $accessToken['me'], and is allowed to |
70 | * // act according to the scopes listed in $accessToken['scope']. |
71 | * $scopes = explode(' ', $accessToken['scope']); |
72 | * } |
73 | * ``` |
74 | * |
75 | * Refer to the {@see Server::__construct()} documentation for further configuration options, and to the |
76 | * documentation for both handling methods for further documentation about them. |
77 | * |
78 | * @link https://indieauth.spec.indieweb.org/ |
79 | * @link https://www.rfc-editor.org/rfc/rfc6749.html#section-5.2 |
80 | * @link https://github.com/indieweb/indieauth-client-php |
81 | * @link https://github.com/Zegnat/php-mindee/blob/development/index.php |
82 | */ |
83 | class Server { |
84 | const HANDLE_NON_INDIEAUTH_REQUEST = 'handleNonIndieAuthRequestCallback'; |
85 | const HANDLE_AUTHENTICATION_REQUEST = 'authenticationHandler'; |
86 | |
87 | /** |
88 | * The query string parameter key used for storing the hash used for validating authorization request parameters. |
89 | */ |
90 | const HASH_QUERY_STRING_KEY = 'taproot_indieauth_server_hash'; |
91 | |
92 | /** |
93 | * The key used to store the CSRF token everywhere it’s used: Request parameters, Request body, and Cookies. |
94 | */ |
95 | const DEFAULT_CSRF_KEY = 'taproot_indieauth_server_csrf'; |
96 | |
97 | /** |
98 | * The form data key used for identifying a request as an authorization (consent screen) form submissions. |
99 | */ |
100 | const APPROVE_ACTION_KEY = 'taproot_indieauth_action'; |
101 | |
102 | /** |
103 | * The form data value used for identifying a request as an authorization (consent screen) form submissions. |
104 | */ |
105 | const APPROVE_ACTION_VALUE = 'approve'; |
106 | |
107 | /** @var Storage\TokenStorageInterface $tokenStorage */ |
108 | protected $tokenStorage; |
109 | |
110 | /** @var AuthorizationFormInterface $authorizationForm */ |
111 | protected $authorizationForm; |
112 | |
113 | /** @var MiddlewareInterface $csrfMiddleware */ |
114 | protected $csrfMiddleware; |
115 | |
116 | /** @var LoggerInterface $logger */ |
117 | protected $logger; |
118 | |
119 | /** @var callable */ |
120 | protected $httpGetWithEffectiveUrl; |
121 | |
122 | /** @var callable */ |
123 | protected $handleAuthenticationRequestCallback; |
124 | |
125 | /** @var callable */ |
126 | protected $handleNonIndieAuthRequest; |
127 | |
128 | /** @var callable $exceptionTemplateCallback */ |
129 | protected $exceptionTemplateCallback; |
130 | |
131 | /** @var string $secret */ |
132 | protected $secret; |
133 | |
134 | /** @var bool $requirePkce */ |
135 | protected $requirePkce; |
136 | |
137 | /** @var ?string $issuer */ |
138 | protected $issuer; |
139 | |
140 | /** |
141 | * Constructor |
142 | * |
143 | * Server instances are configured by passing a config array to the constructor. |
144 | * |
145 | * The following keys are required: |
146 | * * `issuer`: the issuer identifier URL for your IndieAuth server. It must fulfil the following requirements: |
147 | * * use the `https` scheme |
148 | * * contain no query or fragment components |
149 | * * be a prefix of the your `indieauth-metadata` URL |
150 | * * exactly match the `issuer` key present in your `indieauth-metadata` endpoint |
151 | * |
152 | * See [4.1.1 IndieAuth Server Metadata](https://indieauth.spec.indieweb.org/#indieauth-server-metadata) for |
153 | * more information. As previous versions of the IndieAuth spec did not require that client redirects were |
154 | * sent with the `iss` parameter, omitting this key from the config will only result in a warning. |
155 | * * `authenticationHandler`: a callable with the signature |
156 | * |
157 | * ```php |
158 | * function (ServerRequestInterface $request, string $authenticationRedirect, ?string $normalizedMeUrl): array|ResponseInterface |
159 | * ``` |
160 | * |
161 | * This function is called on IndieAuth authorization requests, after validating the query parameters. |
162 | * |
163 | * It should check to see if $request is authenticated, then: |
164 | * * If it is authenticated, return an array which MUST have a `me` key, mapping to the |
165 | * canonical URL of the currently logged-in user. It may additionally have a `profile` key. These |
166 | * keys will be stored in the authorization code and sent to the client, if successful. |
167 | * * If it is not authenticated, either present or redirect to an authentication flow. This flow MUST |
168 | * redirect the logged-in user back to `$authenticationRedirect`. |
169 | * |
170 | * If the request has a valid `me` parameter, the canonicalized version of it is passed as |
171 | * `$normalizedMeUrl`. Otherwise, this parameter is null. This parameter can optionally be used |
172 | * as a suggestion for which user to log in as in a multi-user authentication flow, but should NOT |
173 | * be considered valid data. |
174 | * |
175 | * If redirecting to an existing authentication flow, this callable can usually be implemented as a |
176 | * closure. The callable may also implement its own authentication logic. For an example, see |
177 | * {@see Callback\SingleUserPasswordAuthenticationCallback}. |
178 | * * `secret`: A cryptographically random string with a minimum length of 64 characters. Used |
179 | * to hash and subsequently verify request query parameters which get passed around. |
180 | * * `tokenStorage`: Either an object implementing {@see Storage\TokenStorageInterface}, or a string path to a |
181 | * folder, which will be passed to {@see Storage\FilesystemJsonStorage}. This object handles persisting authorization |
182 | * codes and access tokens, as well as implementation-specific parts of the exchange process which are |
183 | * out of the scope of the Server class (e.g. lifetimes and expiry). Refer to the {@see Storage\TokenStorageInterface} |
184 | * documentation for more details. |
185 | * |
186 | * The following keys may be required depending on which packages you have installed: |
187 | * |
188 | * * `httpGetWithEffectiveUrl`: must be a callable with the following signature: |
189 | * |
190 | * ```php |
191 | * function (string $url): array [ResponseInterface $response, string $effectiveUrl] |
192 | * ``` |
193 | * |
194 | * where `$effectiveUrl` is the final URL after following any redirects (unfortunately, neither the PSR-7 |
195 | * Response nor the PSR-18 Client interfaces offer a standard way of getting this very important |
196 | * data, hence the unusual return signature). If `guzzlehttp/guzzle` is installed, this parameter |
197 | * will be created automatically. Otherwise, the user must provide their own callable. In the event of |
198 | * an error, the callable must throw an exception implementing [one of the PSR-18 client exception |
199 | * interfaces](https://www.php-fig.org/psr/psr-18/#error-handling) |
200 | * |
201 | * The following keys are optional: |
202 | * |
203 | * * `authorizationForm`: an instance of {@see AuthorizationFormInterface}. Defaults to {@see DefaultAuthorizationForm}. |
204 | * Refer to that implementation if you wish to replace the consent screen/scope choosing/authorization form. |
205 | * * `csrfMiddleware`: an instance of `MiddlewareInterface`, which will be used to CSRF-protect the |
206 | * user-facing authorization flow. By default an instance of {@see Callback\DoubleSubmitCookieCsrfMiddleware}. |
207 | * Refer to that implementation if you want to replace it with your own middleware — you will |
208 | * likely have to either make sure your middleware sets the same request attribute, or alter your |
209 | * templates accordingly. |
210 | * * `exceptionTemplate`: string or callable. Either the path to a template which will be used for displaying user-facing |
211 | * errors (defaults to `../templates/default_exception_response.html.php`, refer to that if you wish |
212 | * to write your own template) or a user-provided function to render your chosen, with this signature: |
213 | * |
214 | * ```php |
215 | * function (array $context): string |
216 | * ``` |
217 | * |
218 | * (again, see the default template to see what context variables are available) |
219 | * * `handleNonIndieAuthRequestCallback`: A callback with the following signature: |
220 | * |
221 | * ```php |
222 | * function (ServerRequestInterface $request): ?ResponseInterface |
223 | * ``` |
224 | * |
225 | * which will be called if the authorization endpoint gets a request which is not identified as an IndieAuth |
226 | * request or authorization form submission request. You could use this to handle various requests e.g. client-side requests |
227 | * made by your authentication or authorization pages, if it’s not convenient to put them elsewhere. |
228 | * Returning `null` will result in a standard `invalid_request` error being returned. |
229 | * * `logger`: An instance of `LoggerInterface`. Will be used for internal logging, and will also be set |
230 | * as the logger for any objects passed in config which implement `LoggerAwareInterface`. |
231 | * * `requirePKCE`: bool, default true. Setting this to `false` allows requests which don’t provide PKCE |
232 | * parameters (code_challenge, code_challenge_method, code_verifier), under the following conditions: |
233 | * * If any of the PKCE parameters are present in an authorization code request, all must be present |
234 | * and valid. |
235 | * * If an authorization code request lacks PKCE parameters, the created auth code can only be exchanged |
236 | * by an exchange request without parameters. |
237 | * * If authorization codes are stored without PKCE parameters, and then `requirePKCE` is set to `true`, |
238 | * these old authorization codes will no longer be redeemable. |
239 | * |
240 | * The following keys are deprecated and should no longer be used, but are still supported for now: |
241 | * * `exceptionTemplatePath`: replaced with `exceptionTemplate`, can now either be a path or a callable. |
242 | * @param array $config An array of configuration variables |
243 | * @return self |
244 | */ |
245 | public function __construct(array $config) { |
246 | $config = array_merge([ |
247 | 'csrfMiddleware' => new Middleware\DoubleSubmitCookieCsrfMiddleware(self::DEFAULT_CSRF_KEY), |
248 | 'logger' => null, |
249 | self::HANDLE_NON_INDIEAUTH_REQUEST => function (ServerRequestInterface $request) { return null; }, // Default to no-op. |
250 | 'tokenStorage' => null, |
251 | 'httpGetWithEffectiveUrl' => null, |
252 | 'authorizationForm' => new DefaultAuthorizationForm(), |
253 | 'exceptionTemplate' => null, |
254 | 'exceptionTemplatePath' => null, |
255 | 'requirePKCE' => true, |
256 | 'issuer' => null |
257 | ], $config); |
258 | |
259 | // Upgrade deprecated config parameter. |
260 | if ($config['exceptionTemplate'] and !empty($config['exceptionTemplatePath'])) { |
261 | $config['exceptionTemplate'] = $config['exceptionTemplatePath']; |
262 | unset($config['exceptionTemplatePath']); |
263 | } |
264 | |
265 | if (empty($config['exceptionTemplate'])) { |
266 | $config['exceptionTemplate'] = __DIR__ . '/../templates/default_exception_response.html.php'; |
267 | } |
268 | |
269 | if (is_string($config['exceptionTemplate'])) { |
270 | $config['exceptionTemplate'] = function (array $context) use ($config): string { |
271 | return renderTemplate($config['exceptionTemplate'], $context); |
272 | }; |
273 | } |
274 | |
275 | if (!is_callable($config['exceptionTemplate'])) { |
276 | throw new BadMethodCallException("\$config['exceptionTemplatePath'] must be a string (path) or callable."); |
277 | } |
278 | |
279 | if (is_null($config['issuer'])) { |
280 | trigger_error("Taproot\IndieAuth\Server::__construct(): \$config was missing 'issuer' key, which is required for a spec-compliant IndieAuth implementation.", E_USER_WARNING); |
281 | } elseif (!is_string($config['issuer'])) { |
282 | throw new BadMethodCallException("\$config['issuer'] must be a string or null."); |
283 | } |
284 | $this->issuer = $config['issuer']; |
285 | |
286 | $this->requirePkce = $config['requirePKCE']; |
287 | |
288 | $this->exceptionTemplateCallback = $config['exceptionTemplate']; |
289 | |
290 | $secret = $config['secret'] ?? ''; |
291 | if (!is_string($secret) || strlen($secret) < 64) { |
292 | throw new BadMethodCallException("\$config['secret'] must be a string with a minimum length of 64 characters."); |
293 | } |
294 | $this->secret = $secret; |
295 | |
296 | if (!is_null($config['logger']) && !$config['logger'] instanceof LoggerInterface) { |
297 | throw new BadMethodCallException("\$config['logger'] must be an instance of \\Psr\\Log\\LoggerInterface or null."); |
298 | } |
299 | $this->logger = $config['logger'] ?? new NullLogger(); |
300 | |
301 | if (!(array_key_exists(self::HANDLE_AUTHENTICATION_REQUEST, $config) and is_callable($config[self::HANDLE_AUTHENTICATION_REQUEST]))) { |
302 | throw new BadMethodCallException('$callbacks[\'' . self::HANDLE_AUTHENTICATION_REQUEST .'\'] must be present and callable.'); |
303 | } |
304 | $this->handleAuthenticationRequestCallback = $config[self::HANDLE_AUTHENTICATION_REQUEST]; |
305 | |
306 | if (!is_callable($config[self::HANDLE_NON_INDIEAUTH_REQUEST])) { |
307 | throw new BadMethodCallException("\$config['" . self::HANDLE_NON_INDIEAUTH_REQUEST . "'] must be callable"); |
308 | } |
309 | $this->handleNonIndieAuthRequest = $config[self::HANDLE_NON_INDIEAUTH_REQUEST]; |
310 | |
311 | $tokenStorage = $config['tokenStorage']; |
312 | if (!$tokenStorage instanceof Storage\TokenStorageInterface) { |
313 | if (is_string($tokenStorage)) { |
314 | // Create a default access token storage with a TTL of 7 days. |
315 | $tokenStorage = new Storage\FilesystemJsonStorage($tokenStorage, $this->secret); |
316 | } else { |
317 | throw new BadMethodCallException("\$config['tokenStorage'] parameter must be either a string (path) or an instance of Taproot\IndieAuth\TokenStorageInterface."); |
318 | } |
319 | } |
320 | trySetLogger($tokenStorage, $this->logger); |
321 | $this->tokenStorage = $tokenStorage; |
322 | |
323 | $csrfMiddleware = $config['csrfMiddleware']; |
324 | if (!$csrfMiddleware instanceof MiddlewareInterface) { |
325 | throw new BadMethodCallException("\$config['csrfMiddleware'] must be null or implement MiddlewareInterface."); |
326 | } |
327 | trySetLogger($csrfMiddleware, $this->logger); |
328 | $this->csrfMiddleware = $csrfMiddleware; |
329 | |
330 | $httpGetWithEffectiveUrl = $config['httpGetWithEffectiveUrl']; |
331 | if (is_null($httpGetWithEffectiveUrl)) { |
332 | if (class_exists('\GuzzleHttp\Client')) { |
333 | $httpGetWithEffectiveUrl = function (string $uri): array { |
334 | // This code can’t be tested, ignore it for coverage purposes. |
335 | // @codeCoverageIgnoreStart |
336 | $resp = (new \GuzzleHttp\Client([ |
337 | \GuzzleHttp\RequestOptions::ALLOW_REDIRECTS => [ |
338 | 'max' => 10, |
339 | 'strict' => true, |
340 | 'referer' => true, |
341 | 'track_redirects' => true |
342 | ] |
343 | ]))->get($uri); |
344 | |
345 | $rdh = $resp->getHeader('X-Guzzle-Redirect-History'); |
346 | $effectiveUrl = empty($rdh) ? $uri : array_values($rdh)[count($rdh) - 1]; |
347 | |
348 | return [$resp, $effectiveUrl]; |
349 | }; |
350 | } else { |
351 | throw new BadMethodCallException("\$config['httpGetWithEffectiveUrl'] was not provided, and guzzlehttp/guzzle was not installed. Either require guzzlehttp/guzzle, or provide a valid callable."); |
352 | // @codeCoverageIgnoreEnd |
353 | } |
354 | } else { |
355 | if (!is_callable($httpGetWithEffectiveUrl)) { |
356 | throw new BadMethodCallException("\$config['httpGetWithEffectiveUrl'] must be callable."); |
357 | } |
358 | } |
359 | trySetLogger($httpGetWithEffectiveUrl, $this->logger); |
360 | $this->httpGetWithEffectiveUrl = $httpGetWithEffectiveUrl; |
361 | |
362 | if (!$config['authorizationForm'] instanceof AuthorizationFormInterface) { |
363 | throw new BadMethodCallException("When provided, \$config['authorizationForm'] must implement Taproot\IndieAuth\Callback\AuthorizationForm."); |
364 | } |
365 | $this->authorizationForm = $config['authorizationForm']; |
366 | trySetLogger($this->authorizationForm, $this->logger); |
367 | } |
368 | |
369 | public function getTokenStorage(): TokenStorageInterface { |
370 | return $this->tokenStorage; |
371 | } |
372 | |
373 | /** |
374 | * Handle Authorization Endpoint Request |
375 | * |
376 | * This method handles all requests to your authorization endpoint, passing execution off to |
377 | * other callbacks when necessary. The logical flow can be summarised as follows: |
378 | * |
379 | * * If this request an **auth code exchange for profile information**, validate the request |
380 | * and return a response or error response. |
381 | * * Otherwise, proceed, wrapping all execution in CSRF-protection middleware. |
382 | * * Validate the request’s indieauth authorization code request parameters, returning an |
383 | * error response if any are missing or invalid. |
384 | * * Call the authentication callback |
385 | * * If the callback returned an instance of ResponseInterface, the user is not currently |
386 | * logged in. Return the Response, which will presumably start an authentication flow. |
387 | * * Otherwise, the callback returned information about the currently logged-in user. Continue. |
388 | * * If this request is an authorization form submission, validate the data, store and authorization |
389 | * code and return a redirect response to the client redirect_uri with code data. On an error, return |
390 | * an appropriate error response. |
391 | * * Otherwise, fetch the client_id, parse app data if present, validate the `redirect_uri` and present |
392 | * the authorization form/consent screen to the user. |
393 | * * If none of the above apply, try calling the non-indieauth request handler. If it returns a Response, |
394 | * return that, otherwise return an error response. |
395 | * |
396 | * This route should NOT be wrapped in additional CSRF-protection, due to the need to handle API |
397 | * POST requests from the client. Make sure you call it from a route which is excluded from any |
398 | * CSRF-protection you might be using. To customise the CSRF protection used internally, refer to the |
399 | * {@see Server::__construct()} config array documentation for the `csrfMiddleware` key. |
400 | * |
401 | * Most user-facing errors are thrown as instances of {@see IndieAuthException}, which are passed off to |
402 | * `handleException` to be turned into an instance of `ResponseInterface`. If you want to customise |
403 | * error handling, one way to do so is to subclass `Server` and override that method. |
404 | * |
405 | * @param ServerRequestInterface $request |
406 | * @return ResponseInterface |
407 | */ |
408 | public function handleAuthorizationEndpointRequest(ServerRequestInterface $request): ResponseInterface { |
409 | $this->logger->info('Handling an IndieAuth Authorization Endpoint request.'); |
410 | |
411 | // If it’s a profile information request: |
412 | if (isIndieAuthAuthorizationCodeRedeemingRequest($request)) { |
413 | $this->logger->info('Handling a request to redeem an authorization code for profile information.'); |
414 | |
415 | $bodyParams = $request->getParsedBody(); |
416 | |
417 | if (!isset($bodyParams['code'])) { |
418 | $this->logger->warning('The exchange request was missing the code parameter. Returning an error response.'); |
419 | return new Response(400, [ |
420 | 'Content-Type' => 'application/json', |
421 | 'Cache-control' => 'no-store', |
422 | 'Pragma' => 'no-cache' |
423 | ], json_encode([ |
424 | 'error' => 'invalid_request', |
425 | 'error_description' => 'The code parameter was missing.' |
426 | ])); |
427 | } |
428 | |
429 | // Attempt to internally exchange the provided auth code for an access token. |
430 | // We do this before anything else so that the auth code is invalidated as soon as the request starts, |
431 | // and the resulting access token is revoked if we encounter an error. This ends up providing a simpler |
432 | // and more flexible interface for TokenStorage implementors. |
433 | try { |
434 | // Call the token exchange method, passing in a callback which performs additional validation |
435 | // on the auth code before it gets exchanged. |
436 | $tokenData = $this->tokenStorage->exchangeAuthCodeForAccessToken($bodyParams['code'], function (array $authCode) use ($request, $bodyParams) { |
437 | // Verify that all required parameters are included. |
438 | $requiredParameters = ($this->requirePkce or !empty($authCode['code_challenge'])) ? ['client_id', 'redirect_uri', 'code_verifier'] : ['client_id', 'redirect_uri']; |
439 | $missingRequiredParameters = array_filter($requiredParameters, function ($p) use ($bodyParams) { |
440 | return !array_key_exists($p, $bodyParams) || empty($bodyParams[$p]); |
441 | }); |
442 | if (!empty($missingRequiredParameters)) { |
443 | $this->logger->warning('The exchange request was missing required parameters. Returning an error response.', ['missing' => $missingRequiredParameters]); |
444 | throw IndieAuthException::create(IndieAuthException::INVALID_REQUEST, $request); |
445 | } |
446 | |
447 | // Verify that it was issued for the same client_id and redirect_uri |
448 | if ($authCode['client_id'] !== $bodyParams['client_id'] |
449 | || $authCode['redirect_uri'] !== $bodyParams['redirect_uri']) { |
450 | $this->logger->error("The provided client_id and/or redirect_uri did not match those stored in the token."); |
451 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
452 | } |
453 | |
454 | // If the auth code was requested with no code_challenge, but the exchange request provides a |
455 | // code_verifier, return an error. |
456 | if (!empty($bodyParams['code_verifier']) && empty($authCode['code_challenge'])) { |
457 | $this->logger->error("A code_verifier was provided when trying to exchange an auth code requested without a code_challenge."); |
458 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
459 | } |
460 | |
461 | if ($this->requirePkce or !empty($authCode['code_challenge'])) { |
462 | // Check that the supplied code_verifier hashes to the stored code_challenge |
463 | // TODO: support method = plain as well as S256. |
464 | if (!hash_equals($authCode['code_challenge'], generatePKCECodeChallenge($bodyParams['code_verifier']))) { |
465 | $this->logger->error("The provided code_verifier did not hash to the stored code_challenge"); |
466 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
467 | } |
468 | } |
469 | |
470 | // Check that this token either grants at most the profile scope. |
471 | $requestedScopes = array_filter(explode(' ', $authCode['scope'] ?? '')); |
472 | if (!empty($requestedScopes) && $requestedScopes != ['profile']) { |
473 | $this->logger->error("An exchange request for a token granting scopes other than “profile” was sent to the authorization endpoint."); |
474 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
475 | } |
476 | }); |
477 | } catch (IndieAuthException $e) { |
478 | // If an exception was thrown, return a corresponding error response. |
479 | return new Response(400, [ |
480 | 'Content-Type' => 'application/json', |
481 | 'Cache-control' => 'no-store', |
482 | 'Pragma' => 'no-cache' |
483 | ], json_encode([ |
484 | 'error' => $e->getInfo()['error'], |
485 | 'error_description' => $e->getMessage() |
486 | ])); |
487 | } |
488 | |
489 | if (is_null($tokenData)) { |
490 | $this->logger->error('Attempting to exchange an auth code for a token resulted in null.', $bodyParams); |
491 | return new Response(400, [ |
492 | 'Content-Type' => 'application/json', |
493 | 'Cache-control' => 'no-store', |
494 | 'Pragma' => 'no-cache' |
495 | ], json_encode([ |
496 | 'error' => 'invalid_grant', |
497 | 'error_description' => 'The provided credentials were not valid.' |
498 | ])); |
499 | } |
500 | |
501 | // TODO: return an error if the token doesn’t contain a me key. |
502 | |
503 | // If everything checked out, return {"me": "https://example.com"} response |
504 | return new Response(200, [ |
505 | 'Content-Type' => 'application/json', |
506 | 'Cache-control' => 'no-store', |
507 | 'Pragma' => 'no-cache' |
508 | ], json_encode(array_filter($tokenData, function (string $k) { |
509 | // Prevent codes exchanged at the authorization endpoint from returning any information other than |
510 | // me and profile. |
511 | return in_array($k, ['me', 'profile']); |
512 | }, ARRAY_FILTER_USE_KEY))); |
513 | } |
514 | |
515 | // Because the special case above isn’t allowed to be CSRF-protected, we have to do some rather silly |
516 | // closure gymnastics here to selectively-CSRF-protect requests which do need it. |
517 | return $this->csrfMiddleware->process($request, new Middleware\ClosureRequestHandler(function (ServerRequestInterface $request) { |
518 | // Wrap the entire user-facing handler in a try/catch block which catches any exception, converts it |
519 | // to IndieAuthException if necessary, then passes it to $this->handleException() to be turned into a |
520 | // response. |
521 | try { |
522 | $queryParams = $request->getQueryParams(); |
523 | |
524 | /** @var ResponseInterface|null $clientIdResponse */ |
525 | /** @var string|null $clientIdEffectiveUrl */ |
526 | /** @var array|null $clientIdMf2 */ |
527 | list($clientIdResponse, $clientIdEffectiveUrl, $clientIdMf2) = [null, null, null]; |
528 | |
529 | // If this is an authorization or approval request (allowing POST requests as well to accommodate |
530 | // approval requests and custom auth form submission. |
531 | if (isIndieAuthAuthorizationRequest($request, ['get', 'post'])) { |
532 | $this->logger->info('Handling an authorization request', ['method' => $request->getMethod()]); |
533 | |
534 | // Validate the Client ID. |
535 | // isClientIdentifier is strict about client IDs containing path segments. For the moment we want to |
536 | // be a little more lenient about that, so we normalize it to include a path segment before checking. |
537 | if (!isset($queryParams['client_id']) || false === filter_var($queryParams['client_id'], FILTER_VALIDATE_URL) || !isClientIdentifier(IndieAuthClient::normalizeMeURL($queryParams['client_id']))) { |
538 | $this->logger->warning("The client_id provided in an authorization request was not valid.", $queryParams); |
539 | throw IndieAuthException::create(IndieAuthException::INVALID_CLIENT_ID, $request); |
540 | } |
541 | |
542 | // Validate the redirect URI. |
543 | if (!isset($queryParams['redirect_uri']) || false === filter_var($queryParams['redirect_uri'], FILTER_VALIDATE_URL)) { |
544 | $this->logger->warning("The redirect_uri provided in an authorization request was not valid.", $queryParams); |
545 | throw IndieAuthException::create(IndieAuthException::INVALID_REDIRECT_URI, $request); |
546 | } |
547 | |
548 | // How most errors are handled depends on whether or not the request has a valid redirect_uri. In |
549 | // order to know that, we need to also validate, fetch and parse the client_id. |
550 | // If the request lacks a hash, or if the provided hash was invalid, perform the validation. |
551 | $currentRequestHash = hashAuthorizationRequestParameters($request, $this->secret, null, null, $this->requirePkce); |
552 | if (!isset($queryParams[self::HASH_QUERY_STRING_KEY]) or is_null($currentRequestHash) or !hash_equals($currentRequestHash, $queryParams[self::HASH_QUERY_STRING_KEY])) { |
553 | |
554 | // All we need to know at this stage is whether the redirect_uri is valid. If it |
555 | // sufficiently matches the client_id, we don’t (yet) need to fetch the client_id. |
556 | if (!urlComponentsMatch($queryParams['client_id'], $queryParams['redirect_uri'], [PHP_URL_SCHEME, PHP_URL_HOST, PHP_URL_PORT])) { |
557 | // If we do need to fetch the client_id, store the response and effective URL in variables |
558 | // we defined earlier, so they’re available to the approval request code path, which additionally |
559 | // needs to parse client_id for h-app markup. |
560 | try { |
561 | list($clientIdResponse, $clientIdEffectiveUrl) = call_user_func($this->httpGetWithEffectiveUrl, IndieAuthClient::normalizeMeURL($queryParams['client_id'])); |
562 | $clientIdMf2 = Mf2\parse((string) $clientIdResponse->getBody(), $clientIdEffectiveUrl); |
563 | } catch (ClientExceptionInterface | RequestExceptionInterface | NetworkExceptionInterface $e) { |
564 | $this->logger->error("Caught an HTTP exception while trying to fetch the client_id. Returning an error response.", [ |
565 | 'client_id' => $queryParams['client_id'], |
566 | 'exception' => $e->__toString() |
567 | ]); |
568 | |
569 | throw IndieAuthException::create(IndieAuthException::HTTP_EXCEPTION_FETCHING_CLIENT_ID, $request, $e); |
570 | } catch (Exception $e) { |
571 | $this->logger->error("Caught an unknown exception while trying to fetch the client_id. Returning an error response.", [ |
572 | 'exception' => $e->__toString() |
573 | ]); |
574 | |
575 | throw IndieAuthException::create(IndieAuthException::INTERNAL_EXCEPTION_FETCHING_CLIENT_ID, $request, $e); |
576 | } |
577 | |
578 | // Search for all link@rel=redirect_uri at the client_id. |
579 | $clientIdRedirectUris = []; |
580 | if (array_key_exists('redirect_uri', $clientIdMf2['rels'])) { |
581 | $clientIdRedirectUris = array_merge($clientIdRedirectUris, $clientIdMf2['rels']['redirect_uri']); |
582 | } |
583 | |
584 | foreach (HeaderParser::parse($clientIdResponse->getHeader('Link')) as $link) { |
585 | if (array_key_exists('rel', $link) && mb_strpos(" {$link['rel']} ", " redirect_uri ") !== false) { |
586 | // Strip off the < > which surround the link URL for some reason. |
587 | $clientIdRedirectUris[] = substr($link[0], 1, strlen($link[0]) - 2); |
588 | } |
589 | } |
590 | |
591 | // If the authority of the redirect_uri does not match the client_id, or exactly match one of their redirect URLs, return an error. |
592 | if (!in_array($queryParams['redirect_uri'], $clientIdRedirectUris)) { |
593 | $this->logger->warning("The provided redirect_uri did not match either the client_id, nor the discovered redirect URIs.", [ |
594 | 'provided_redirect_uri' => $queryParams['redirect_uri'], |
595 | 'provided_client_id' => $queryParams['client_id'], |
596 | 'discovered_redirect_uris' => $clientIdRedirectUris |
597 | ]); |
598 | |
599 | throw IndieAuthException::create(IndieAuthException::INVALID_REDIRECT_URI, $request); |
600 | } |
601 | } |
602 | } |
603 | |
604 | // From now on, we can assume that redirect_uri is valid. Any IndieAuth-related errors should be |
605 | // reported by redirecting to redirect_uri with error parameters. |
606 | |
607 | // Validate the state parameter. |
608 | if (!isset($queryParams['state']) or !isValidState($queryParams['state'])) { |
609 | $this->logger->warning("The state provided in an authorization request was not valid.", $queryParams); |
610 | throw IndieAuthException::create(IndieAuthException::INVALID_STATE, $request); |
611 | } |
612 | // From now on, any redirect error responses should include the state parameter. |
613 | // This is handled automatically in `handleException()` and is only noted here |
614 | // for reference. |
615 | |
616 | // If either PKCE parameter is present, validate both. |
617 | if (isset($queryParams['code_challenge']) or isset($queryParams['code_challenge_method'])) { |
618 | if (!isset($queryParams['code_challenge']) or !isValidCodeChallenge($queryParams['code_challenge'])) { |
619 | $this->logger->warning("The code_challenge provided in an authorization request was not valid.", $queryParams); |
620 | throw IndieAuthException::create(IndieAuthException::INVALID_CODE_CHALLENGE, $request); |
621 | } |
622 | |
623 | if (!isset($queryParams['code_challenge_method']) or !in_array($queryParams['code_challenge_method'], ['S256', 'plain'])) { |
624 | $this->logger->error("The code_challenge_method parameter was missing or invalid.", $queryParams); |
625 | throw IndieAuthException::create(IndieAuthException::INVALID_CODE_CHALLENGE, $request); |
626 | } |
627 | } else { |
628 | // If neither PKCE parameter is defined, and PKCE is required, throw an error. Otherwise, proceed. |
629 | if ($this->requirePkce) { |
630 | $this->logger->warning("PKCE is required, and both code_challenge and code_challenge_method were missing."); |
631 | throw IndieAuthException::create(IndieAuthException::INVALID_REQUEST_REDIRECT, $request); |
632 | } |
633 | } |
634 | |
635 | // Validate the scope parameter, if provided. |
636 | if (array_key_exists('scope', $queryParams) && !isValidScope($queryParams['scope'])) { |
637 | $this->logger->warning("The scope provided in an authorization request was not valid.", $queryParams); |
638 | throw IndieAuthException::create(IndieAuthException::INVALID_SCOPE, $request); |
639 | } |
640 | |
641 | // Normalise the me parameter, if it exists. |
642 | if (array_key_exists('me', $queryParams)) { |
643 | $queryParams['me'] = IndieAuthClient::normalizeMeURL($queryParams['me']); |
644 | // If the me parameter is not a valid profile URL, ignore it. |
645 | if (false === $queryParams['me'] || !isProfileUrl($queryParams['me'])) { |
646 | $queryParams['me'] = null; |
647 | } |
648 | } |
649 | |
650 | // Build a URL containing the indieauth authorization request parameters, hashing them |
651 | // to protect them from being changed. |
652 | // Make a hash of the protected indieauth-specific parameters. If PKCE is in use, include |
653 | // the PKCE parameters in the hash. Otherwise, leave them out. |
654 | $hash = hashAuthorizationRequestParameters($request, $this->secret, null, null, $this->requirePkce); |
655 | // Operate on a copy of $queryParams, otherwise requests will always have a valid hash! |
656 | $redirectQueryParams = $queryParams; |
657 | $redirectQueryParams[self::HASH_QUERY_STRING_KEY] = $hash; |
658 | $authenticationRedirect = $request->getUri()->withQuery(buildQueryString($redirectQueryParams))->__toString(); |
659 | |
660 | // User-facing requests always start by calling the authentication request callback. |
661 | $this->logger->info('Calling handle_authentication_request callback'); |
662 | $authenticationResult = call_user_func($this->handleAuthenticationRequestCallback, $request, $authenticationRedirect, $queryParams['me'] ?? null); |
663 | |
664 | // If the authentication handler returned a Response, return that as-is. |
665 | if ($authenticationResult instanceof ResponseInterface) { |
666 | return $authenticationResult; |
667 | } elseif (is_array($authenticationResult)) { |
668 | // Check the resulting array for errors. |
669 | if (!array_key_exists('me', $authenticationResult)) { |
670 | $this->logger->error('The handle_authentication_request callback returned an array with no me key.', ['array' => $authenticationResult]); |
671 | throw IndieAuthException::create(IndieAuthException::AUTHENTICATION_CALLBACK_MISSING_ME_PARAM, $request); |
672 | } |
673 | |
674 | // If this is a POST request sent from the authorization (i.e. scope-choosing) form: |
675 | if (isAuthorizationApprovalRequest($request)) { |
676 | // Authorization approval requests MUST include a hash protecting the sensitive IndieAuth |
677 | // authorization request parameters from being changed, e.g. by a malicious script which |
678 | // found its way onto the authorization form. |
679 | if (!array_key_exists(self::HASH_QUERY_STRING_KEY, $queryParams)) { |
680 | $this->logger->warning("An authorization approval request did not have a " . self::HASH_QUERY_STRING_KEY . " parameter."); |
681 | throw IndieAuthException::create(IndieAuthException::AUTHORIZATION_APPROVAL_REQUEST_MISSING_HASH, $request); |
682 | } |
683 | |
684 | $expectedHash = hashAuthorizationRequestParameters($request, $this->secret, null, null, $this->requirePkce); |
685 | if (!isset($queryParams[self::HASH_QUERY_STRING_KEY]) or is_null($expectedHash) or !hash_equals($expectedHash, $queryParams[self::HASH_QUERY_STRING_KEY])) { |
686 | $this->logger->warning("The hash provided in the URL was invalid!", [ |
687 | 'expected' => $expectedHash, |
688 | 'actual' => $queryParams[self::HASH_QUERY_STRING_KEY] |
689 | ]); |
690 | throw IndieAuthException::create(IndieAuthException::AUTHORIZATION_APPROVAL_REQUEST_INVALID_HASH, $request); |
691 | } |
692 | |
693 | // Assemble the data for the authorization code, store it somewhere persistent. |
694 | $code = array_merge($authenticationResult, [ |
695 | 'client_id' => $queryParams['client_id'], |
696 | 'redirect_uri' => $queryParams['redirect_uri'], |
697 | 'state' => $queryParams['state'], |
698 | 'code_challenge' => $queryParams['code_challenge'] ?? null, |
699 | 'code_challenge_method' => $queryParams['code_challenge_method'] ?? null, |
700 | 'requested_scope' => $queryParams['scope'] ?? '', |
701 | ]); |
702 | |
703 | // Pass it to the auth code customisation callback. |
704 | $code = $this->authorizationForm->transformAuthorizationCode($request, $code); |
705 | $this->logger->info("Creating an authorization code:", ['data' => $code]); |
706 | |
707 | // Store the authorization code. |
708 | $authCode = $this->tokenStorage->createAuthCode($code); |
709 | if (is_null($authCode)) { |
710 | // If saving the authorization code failed silently, there isn’t much we can do about it, |
711 | // but should at least log and return an error. |
712 | $this->logger->error("Saving the authorization code failed and returned false without raising an exception."); |
713 | throw IndieAuthException::create(IndieAuthException::INTERNAL_ERROR_REDIRECT, $request); |
714 | } |
715 | |
716 | // Return a redirect to the client app. |
717 | $clientRedirectQueryParams = [ |
718 | 'code' => $authCode, |
719 | 'state' => $code['state'] |
720 | ]; |
721 | if ($this->issuer) { |
722 | $clientRedirectQueryParams['iss'] = $this->issuer; |
723 | } |
724 | return new Response(302, [ |
725 | 'Location' => appendQueryParams($queryParams['redirect_uri'], $clientRedirectQueryParams) |
726 | ]); |
727 | } |
728 | |
729 | // Otherwise, the user is authenticated and needs to authorize the client app + choose scopes. |
730 | |
731 | // Fetch the client_id URL to find information about the client to present to the user. |
732 | // TODO: in order to comply with https://datatracker.ietf.org/doc/html/rfc6749#section-4.1.2.1, |
733 | // it may be necessary to do this before returning any other kind of error response, as, per |
734 | // the spec, errors should only be shown to the user if the client_id and redirect_uri parameters |
735 | // are missing or invalid. Otherwise, they should be sent back to the client with an error |
736 | // redirect response. |
737 | // |
738 | // Per the spec, an un-fetchable client_id isn’t necessarily a hard fail. For maximum flexibility, |
739 | // pass the exception to the authorization form in place of the h-app/null we would pass if the |
740 | // request succeeded. Leave it up to the authorization form to decide what to do about it. |
741 | // https://github.com/Taproot/indieauth/issues/14 |
742 | if (is_null($clientIdResponse) || is_null($clientIdEffectiveUrl) || is_null($clientIdMf2)) { |
743 | try { |
744 | /** @var ResponseInterface $clientIdResponse */ |
745 | /** @var string $clientIdEffectiveUrl */ |
746 | list($clientIdResponse, $clientIdEffectiveUrl) = call_user_func($this->httpGetWithEffectiveUrl, $queryParams['client_id']); |
747 | $clientIdMf2 = Mf2\parse((string) $clientIdResponse->getBody(), $clientIdEffectiveUrl); |
748 | } catch (Exception $e) { |
749 | $this->logger->error("Caught non-fatal exception while trying to fetch the client_id. Passing exception to the authorization form.", [ |
750 | 'client_id' => $queryParams['client_id'], |
751 | 'exception' => $e->__toString() |
752 | ]); |
753 | |
754 | $clientHAppOrException = $e; |
755 | } |
756 | } |
757 | |
758 | if (M\isMicroformatCollection($clientIdMf2)) { |
759 | // Search for an h-app or h-x-app with u-url matching the client_id. |
760 | // TODO: if/when client_id gets normalised, we might have to do a normalised comparison rather than plain string comparison here. |
761 | $clientHApps = M\findMicroformatsByProperty(M\findMicroformatsByCallable($clientIdMf2, function ($mf) { |
762 | return count(array_intersect($mf['type'], ['h-app', 'h-x-app'])) > 0; |
763 | }), 'url', $queryParams['client_id']); |
764 | $clientHAppOrException = empty($clientHApps) ? null : $clientHApps[0]; |
765 | } |
766 | |
767 | // Present the authorization UI. |
768 | return $this->authorizationForm->showForm($request, $authenticationResult, $authenticationRedirect, $clientHAppOrException) |
769 | ->withAddedHeader('Cache-control', 'no-store') |
770 | ->withAddedHeader('Pragma', 'no-cache') |
771 | ->withAddedHeader('X-Frame-Options', 'DENY') |
772 | ->withAddedHeader('Content-Security-Policy', "frame-ancestors 'none'"); |
773 | } else { |
774 | // The authentication callback function returned something other than an array or Response! |
775 | $this->logger->error('The authenticationHandler callback function returned an invalid value (not an array or Response)', ['array' => $authenticationResult]); |
776 | throw IndieAuthException::create(IndieAuthException::AUTHENTICATION_CALLBACK_INVALID_RETURN_VALUE, $request); |
777 | } |
778 | } |
779 | |
780 | // If the request isn’t an IndieAuth Authorization or Code-redeeming request, it’s either an invalid |
781 | // request or something to do with a custom auth handler (e.g. sending a one-time code in an email.) |
782 | $nonIndieAuthRequestResult = call_user_func($this->handleNonIndieAuthRequest, $request); |
783 | if ($nonIndieAuthRequestResult instanceof ResponseInterface) { |
784 | return $nonIndieAuthRequestResult; |
785 | } else { |
786 | // In this code path we have not validated the redirect_uri, so show a regular error page |
787 | // rather than returning a redirect error. |
788 | throw IndieAuthException::create(IndieAuthException::INTERNAL_ERROR, $request); |
789 | } |
790 | } catch (IndieAuthException $e) { |
791 | // All IndieAuthExceptions will already have been logged. |
792 | return $this->handleException($e); |
793 | } catch (Exception $e) { |
794 | // Unknown exceptions will not have been logged; do so now. |
795 | $this->logger->error("Caught unknown exception: {$e}"); |
796 | return $this->handleException(IndieAuthException::create(0, $request, $e)); |
797 | } |
798 | })); |
799 | } |
800 | |
801 | /** |
802 | * Handle Token Endpoint Request |
803 | * |
804 | * Handles requests to the IndieAuth token endpoint. The logical flow can be summarised as follows: |
805 | * |
806 | * * Check that the request is a code redeeming request. Return an error if not. |
807 | * * Ensure that all required parameters are present. Return an error if not. |
808 | * * Attempt to exchange the `code` parameter for an access token. Return an error if it fails. |
809 | * * Make sure the client_id and redirect_uri request parameters match those stored in the auth code. If not, revoke the access token and return an error. |
810 | * * Make sure the provided code_verifier hashes to the code_challenge stored in the auth code. If not, revoke the access token and return an error. |
811 | * * Make sure the granted scope stored in the auth code is not empty. If it is, revoke the access token and return an error. |
812 | * * Otherwise, return a success response containing information about the issued access token. |
813 | * |
814 | * This method must NOT be CSRF-protected as it accepts external requests from client apps. |
815 | * |
816 | * @param ServerRequestInterface $request |
817 | * @return ResponseInterface |
818 | */ |
819 | public function handleTokenEndpointRequest(ServerRequestInterface $request): ResponseInterface { |
820 | if (isIndieAuthAuthorizationCodeRedeemingRequest($request)) { |
821 | $this->logger->info('Handling a request to redeem an authorization code for an access token.'); |
822 | |
823 | $bodyParams = $request->getParsedBody(); |
824 | |
825 | if (!isset($bodyParams['code'])) { |
826 | $this->logger->warning('The exchange request was missing the code parameter. Returning an error response.'); |
827 | return new Response(400, [ |
828 | 'Content-Type' => 'application/json', |
829 | 'Cache-Control' => 'no-store', |
830 | 'Pragma' => 'no-cache' |
831 | ], json_encode([ |
832 | 'error' => 'invalid_request', |
833 | 'error_description' => 'The code parameter was missing.' |
834 | ])); |
835 | } |
836 | |
837 | // Attempt to internally exchange the provided auth code for an access token. |
838 | // We do this before anything else so that the auth code is invalidated as soon as the request starts, |
839 | // and the resulting access token is revoked if we encounter an error. This ends up providing a simpler |
840 | // and more flexible interface for TokenStorage implementors. |
841 | try { |
842 | // Call the token exchange method, passing in a callback which performs additional validation |
843 | // on the auth code before it gets exchanged. |
844 | $tokenData = $this->tokenStorage->exchangeAuthCodeForAccessToken($bodyParams['code'], function (array $authCode) use ($request, $bodyParams) { |
845 | // Verify that all required parameters are included. |
846 | $requiredParameters = ($this->requirePkce or !empty($authCode['code_challenge'])) ? ['client_id', 'redirect_uri', 'code_verifier'] : ['client_id', 'redirect_uri']; |
847 | $missingRequiredParameters = array_filter($requiredParameters, function ($p) use ($bodyParams) { |
848 | return !array_key_exists($p, $bodyParams) || empty($bodyParams[$p]); |
849 | }); |
850 | if (!empty($missingRequiredParameters)) { |
851 | $this->logger->warning('The exchange request was missing required parameters. Returning an error response.', ['missing' => $missingRequiredParameters]); |
852 | throw IndieAuthException::create(IndieAuthException::INVALID_REQUEST, $request); |
853 | } |
854 | |
855 | // Verify that it was issued for the same client_id and redirect_uri |
856 | if ($authCode['client_id'] !== $bodyParams['client_id'] |
857 | || $authCode['redirect_uri'] !== $bodyParams['redirect_uri']) { |
858 | $this->logger->error("The provided client_id and/or redirect_uri did not match those stored in the token."); |
859 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
860 | } |
861 | |
862 | // If the auth code was requested with no code_challenge, but the exchange request provides a |
863 | // code_verifier, return an error. |
864 | if (!empty($bodyParams['code_verifier']) && empty($authCode['code_challenge'])) { |
865 | $this->logger->error("A code_verifier was provided when trying to exchange an auth code requested without a code_challenge."); |
866 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
867 | } |
868 | |
869 | if ($this->requirePkce or !empty($authCode['code_challenge'])) { |
870 | // Check that the supplied code_verifier hashes to the stored code_challenge |
871 | // TODO: support method = plain as well as S256. |
872 | if (!hash_equals($authCode['code_challenge'], generatePKCECodeChallenge($bodyParams['code_verifier']))) { |
873 | $this->logger->error("The provided code_verifier did not hash to the stored code_challenge"); |
874 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
875 | } |
876 | } |
877 | |
878 | // Check that scope is not empty. |
879 | if (empty($authCode['scope'])) { |
880 | $this->logger->error("An exchange request for a token with an empty scope was sent to the token endpoint."); |
881 | throw IndieAuthException::create(IndieAuthException::INVALID_GRANT, $request); |
882 | } |
883 | }); |
884 | } catch (IndieAuthException $e) { |
885 | // If an exception was thrown, return a corresponding error response. |
886 | return new Response(400, [ |
887 | 'Content-Type' => 'application/json', |
888 | 'Cache-Control' => 'no-store', |
889 | 'Pragma' => 'no-cache' |
890 | ], json_encode([ |
891 | 'error' => $e->getInfo()['error'], |
892 | 'error_description' => $e->getMessage() |
893 | ])); |
894 | } |
895 | |
896 | if (is_null($tokenData)) { |
897 | $this->logger->error('Attempting to exchange an auth code for a token resulted in null.', $bodyParams); |
898 | return new Response(400, [ |
899 | 'Content-Type' => 'application/json', |
900 | 'Cache-Control' => 'no-store', |
901 | 'Pragma' => 'no-cache' |
902 | ], json_encode([ |
903 | 'error' => 'invalid_grant', |
904 | 'error_description' => 'The provided credentials were not valid.' |
905 | ])); |
906 | } |
907 | |
908 | // TODO: return an error if the token doesn’t contain a me key. |
909 | |
910 | // If everything checked out, return {"me": "https://example.com"} response |
911 | return new Response(200, [ |
912 | 'Content-Type' => 'application/json', |
913 | 'Cache-Control' => 'no-store', |
914 | 'Pragma' => 'no-cache' |
915 | ], json_encode(array_merge([ |
916 | // Ensure that the token_type key is present, if tokenStorage doesn’t include it. |
917 | 'token_type' => 'Bearer' |
918 | ], array_filter($tokenData, function (string $k) { |
919 | // We should be able to trust the return data from tokenStorage, but there’s no harm in |
920 | // preventing code_challenges from leaking, per OAuth2. |
921 | return !in_array($k, ['code_challenge', 'code_challenge_method']); |
922 | }, ARRAY_FILTER_USE_KEY)))); |
923 | } |
924 | |
925 | return new Response(400, [ |
926 | 'Content-Type' => 'application/json', |
927 | 'Cache-Control' => 'no-store', |
928 | 'Pragma' => 'no-cache' |
929 | ], json_encode([ |
930 | 'error' => 'invalid_request', |
931 | 'error_description' => 'Request to token endpoint was not a valid code exchange request.' |
932 | ])); |
933 | } |
934 | |
935 | /** |
936 | * Get Access Token |
937 | * |
938 | * A convenient shortcut for `$server->getTokenStorage()->getAccessToken()` |
939 | */ |
940 | public function getAccessToken(string $token): ?array { |
941 | return $this->getTokenStorage()->getAccessToken($token); |
942 | } |
943 | |
944 | /** |
945 | * Handle Exception |
946 | * |
947 | * Turns an instance of {@see IndieAuthException} into an appropriate instance of `ResponseInterface`. |
948 | */ |
949 | protected function handleException(IndieAuthException $exception): ResponseInterface { |
950 | $exceptionData = $exception->getInfo(); |
951 | |
952 | if ($exceptionData['statusCode'] == 302) { |
953 | // This exception is handled by redirecting to the redirect_uri with error parameters. |
954 | $redirectQueryParams = [ |
955 | 'error' => $exceptionData['error'] ?? 'invalid_request', |
956 | 'error_description' => (string) $exception |
957 | ]; |
958 | |
959 | // If the state parameter was valid, include it in the error redirect. |
960 | if ($exception->getCode() !== IndieAuthException::INVALID_STATE) { |
961 | $redirectQueryParams['state'] = $exception->getRequest()->getQueryParams()['state']; |
962 | } |
963 | |
964 | return new Response($exceptionData['statusCode'], [ |
965 | 'Location' => appendQueryParams((string) $exception->getRequest()->getQueryParams()['redirect_uri'], $redirectQueryParams) |
966 | ]); |
967 | } else { |
968 | // This exception should be shown to the user. |
969 | return new Response($exception->getStatusCode(), [ |
970 | 'Content-Type' => 'text/html', |
971 | 'Cache-Control' => 'no-store', |
972 | 'Pragma' => 'no-cache' |
973 | ], call_user_func($this->exceptionTemplateCallback, [ |
974 | 'request' => $exception->getRequest(), |
975 | 'exception' => $exception |
976 | ])); |
977 | } |
978 | } |
979 | } |