mirror of
https://code.mensbeam.com/MensBeam/Arsse.git
synced 2024-12-23 17:12:41 +00:00
365 lines
16 KiB
PHP
365 lines
16 KiB
PHP
<?php
|
|
/** @license MIT
|
|
* Copyright 2017 J. King, Dustin Wilson et al.
|
|
* See LICENSE and AUTHORS files for details */
|
|
|
|
declare(strict_types=1);
|
|
namespace JKingWeb\Arsse\REST\Microsub;
|
|
|
|
use JKingWeb\Arsse\Arsse;
|
|
use JKingWeb\Arsse\Misc\URL;
|
|
use JKingWeb\Arsse\Misc\Date;
|
|
use Psr\Http\Message\ServerRequestInterface;
|
|
use Psr\Http\Message\ResponseInterface;
|
|
use Zend\Diactoros\Response\HtmlResponse;
|
|
use Zend\Diactoros\Response\JsonResponse;
|
|
use Zend\Diactoros\Response\EmptyResponse;
|
|
|
|
class Auth extends \JKingWeb\Arsse\REST\AbstractHandler {
|
|
/** The scopes which we grant to Microsub clients. Mute and block are not included because they have no meaning in an RSS/Atom context; this may signal to clients to suppress muting and blocking in their UI */
|
|
const SCOPES = ["read", "follow", "channels"];
|
|
/** The list of the logical functions of this API, with their implementations */
|
|
const FUNCTIONS = [
|
|
'discovery' => ['GET' => "opDiscovery"],
|
|
'auth' => ['GET' => "opLogin", 'POST' => "opCodeVerification"],
|
|
'token' => ['GET' => "opTokenVerification", 'POST' => "opIssueAccessToken"],
|
|
];
|
|
/** The minimal set of reserved URL characters which must be escaped when comparing user ID URLs */
|
|
const USERNAME_ESCAPES = [
|
|
'#' => "%23",
|
|
'%' => "%25",
|
|
'/' => "%2F",
|
|
'?' => "%3F",
|
|
];
|
|
|
|
public function __construct() {
|
|
}
|
|
|
|
public function dispatch(ServerRequestInterface $req): ResponseInterface {
|
|
// if the path contains a slash, this is not a URL we handle
|
|
$path = parse_url($req->getRequestTarget())['path'] ?? "";
|
|
if (strpos($path, "/") !== false) {
|
|
return new EmptyResponse(404);
|
|
}
|
|
// gather the query parameters and act on the "f" (function) parameter
|
|
$process = $req->getQueryParams()['f'] ?? "";
|
|
$process = strlen($process) ? $process : "discovery";
|
|
$method = $req->getMethod();
|
|
if (isset(self::FUNCTIONS[$process]) || ($process === "discovery" && !strlen($path)) || ($process !== "discovery" && strlen($path))) {
|
|
// the function requested needs to exist
|
|
// the path should also be empty unless we're doing discovery
|
|
return new EmptyResponse(404);
|
|
} elseif ($method === "OPTIONS") {
|
|
$fields = ['Allow' => implode(",", array_keys(self::FUNCTIONS[$process]))];
|
|
if (isset(self::FUNCTIONS[$process]['POST'])) {
|
|
$fields['Accept'] = "application/x-www-form-urlencoded";
|
|
}
|
|
return new EmptyResponse(204, $fields);
|
|
} elseif (isset(self::FUNCTIONS[$process][$method])) {
|
|
return new EmptyResponse(405, ['Allow' => implode(",", array_keys(self::FUNCTIONS[$process]))]);
|
|
} else {
|
|
try {
|
|
$func = self::FUNCTIONS[$process][$method];
|
|
return $this->$func($req);
|
|
} catch (ExceptionAuth $e) {
|
|
// human-readable error messages could be added, but these must be ASCII per OAuth, so there's probably not much point
|
|
// see https://tools.ietf.org/html/rfc6749#section-5.2
|
|
return new JsonResponse(['error' => $e->getMessage()], 400);
|
|
}
|
|
}
|
|
}
|
|
|
|
/** Produces the base URL of a server request
|
|
*
|
|
* This involves reconstructing the scheme and authority based on $_SERVER
|
|
* variables; it may fail depending on server configuration
|
|
*/
|
|
protected function buildBaseURL(ServerRequestInterface $req): string {
|
|
// construct the base user identifier URL; the user is never checked against the database
|
|
$s = $req->getServerParams();
|
|
$path = $req->getRequestTarget()['path'];
|
|
$https = (strlen($s['HTTPS'] ?? "") && $s['HTTPS'] !== "off");
|
|
$port = (int) ($s['SERVER_PORT'] ?? 0);
|
|
$port = (!$port || ($https && $port == 443) || (!$https && $port == 80)) ? "" : ":$port";
|
|
return URL::normalize(($https ? "https" : "http")."://".$s['HTTP_HOST'].$port."/");
|
|
}
|
|
|
|
/** Produces a canoncial identity URL based on a server request and a user name
|
|
*
|
|
* This involves reconstructing the scheme and authority based on $_SERVER
|
|
* variables; it may fail depending on server configuration
|
|
*/
|
|
protected function buildIdentifier(ServerRequestInterface $req, string $user): string {
|
|
return $this->buildBaseURL($req)."u/".str_replace(array_keys(self::USERNAME_ESCAPES), array_values(self::USERNAME_ESCAPES), $user);
|
|
}
|
|
|
|
/** Matches an identity URL against its canoncial form
|
|
*
|
|
* The identifier matches if all of the following are true:
|
|
*
|
|
* 1. The scheme is http or https
|
|
* 2. The normalized hostname matches
|
|
* 3. The port matches after dropping default port numbers
|
|
* 4. No credentials are included in the authority
|
|
* 5. The path is `/u/<username>`
|
|
* 6. There is no query content
|
|
* 7. The username, when URL-decoded, matches
|
|
*
|
|
* Though IndieAuth forbids port numbers and fragments in identifiers, we do not enforce this
|
|
*/
|
|
protected function matchIdentifier(string $canonical, string $me): bool {
|
|
$me = parse_url(URL::normalize($me));
|
|
$me['scheme'] = $me['scheme'] ?? "";
|
|
$me['path'] = explode("/", $me['path'] ?? "");
|
|
$me['id'] = rawurldecode(array_pop($me['path']) ?? "");
|
|
$me['port'] == (($me['scheme'] === "http" && $me['port'] == 80) || ($me['scheme'] === "https" && $me['port'] == 443)) ? 0 : $me['port'];
|
|
$c = parse_url($canonical);
|
|
$c['path'] = explode("/", $c['path']);
|
|
$c['id'] = rawurldecode(array_pop($c['path']));
|
|
if (
|
|
!in_array($me['scheme'] ?? "", ["http", "https"]) ||
|
|
($me['host'] ?? "") !== $c['host'] ||
|
|
$me['path'] != $c['path'] ||
|
|
$me['id'] !== $c['id'] ||
|
|
strlen($me['user'] ?? "") ||
|
|
strlen($me['pass'] ?? "") ||
|
|
strlen($me['query'] ?? "") ||
|
|
($me['port'] ?? 0) != ($c['port'] ?? 0)
|
|
) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/** Presents a very basic user profile for discovery purposes
|
|
*
|
|
* The HTML document itself consists only of link elements and an
|
|
* encoding declaration; Link header-fields are also included for
|
|
* HEAD requests
|
|
*
|
|
* Since discovery is publicly accessible, we produce a discovery
|
|
* page for all potential user names so as not to facilitate user
|
|
* enumeration
|
|
*
|
|
* @see https://indieweb.org/Microsub-spec#Discovery
|
|
*/
|
|
protected function opDiscovery(ServerRequestInterface $req): ResponseInterface {
|
|
$base = $this->buildBaseURL($req);
|
|
$urlAuth = $base."u/?f=auth";
|
|
$urlToken = $base."u/?f=token";
|
|
$urlService = $base."microsub";
|
|
// output an extremely basic identity resource
|
|
$html = '<meta charset="UTF-8"><link rel="authorization_endpoint" href="'.htmlspecialchars($urlAuth).'"><link rel="token_endpoint" href="'.htmlspecialchars($urlToken).'"><link rel="microsub" href="'.htmlspecialchars($urlService).'">';
|
|
return new HtmlResponse($html, 200, [
|
|
"Link: <$urlAuth>; rel=\"authorization_endpoint\"",
|
|
"Link: <$urlToken>; rel=\"token_endpoint\"",
|
|
"Link: <$urlService>; rel=\"microsub\"",
|
|
]);
|
|
}
|
|
|
|
/** Handles the authentication process
|
|
*
|
|
* Authentication is achieved via an HTTP Basic authentiation
|
|
* challenge; once the user successfully logs in a code is issued
|
|
* and redirection occurs. Scopes are for all intents and purposes
|
|
* ignored and client information is not presented.
|
|
*
|
|
* @see https://indieauth.spec.indieweb.org/#authentication-request
|
|
* @see https://indieauth.spec.indieweb.org/#authorization-endpoint-0
|
|
*/
|
|
protected function opLogin(ServerRequestInterface $req): ResponseInterface {
|
|
if (!$req->getAttribute("authenticated", false)) {
|
|
// user has not yet logged in, or has failed to log in
|
|
return new EmptyResponse(401);
|
|
} else {
|
|
// user has logged in
|
|
$query = $req->getQueryParams();
|
|
$redir = URL::normalize(rawurldecode($query['redirect_uri']));
|
|
// check that the redirect URL is an absolute one
|
|
if (!URL::absolute($redir)) {
|
|
return new EmptyResponse(400);
|
|
}
|
|
try {
|
|
// ensure the logged-in user matches the IndieAuth identifier URL
|
|
$user = $req->getAttribute("authenticatedUser");
|
|
if (!$this->matchIdentifier($this->buildIdentifier($req, $user), $query['me'])) {
|
|
throw new ExceptionAuth("access_denied");
|
|
}
|
|
$type = !strlen($query['response_type'] ?? "") ? "id" : $query['response_type'];
|
|
if (!in_array($type, ["code", "id"])) {
|
|
throw new ExceptionAuth("unsupported_response_type");
|
|
}
|
|
$state = $query['state'] ?? "";
|
|
// store the identity URL, client ID, redirect URL, and response type
|
|
$data = json_encode([
|
|
'me' => $query['me'],
|
|
'client' => $query['client_id'],
|
|
'redir' => $query['redirect_uri'],
|
|
'type' => $type,
|
|
], \JSON_UNESCAPED_SLASHES | \JSON_UNESCAPED_UNICODE);
|
|
// issue an authorization code and build the redirect URL
|
|
$code = Arsse::$db->tokenCreate($user, "microsub.auth", null, Date::add("PT2M"), $data);
|
|
$next = URL::queryAppend($redir, "code=$code&state=$state");
|
|
return new EmptyResponse(302, ["Location: $next"]);
|
|
} catch (ExceptionAuth $e) {
|
|
$next = URL::queryAppend($redir, "state=$state&error=".$e->getMessage());
|
|
return new EmptyResponse(302, ["Location: $next"]);
|
|
}
|
|
}
|
|
}
|
|
|
|
/** Handles the auth code verification of the basic "Authentication" flow of IndieAuth
|
|
*
|
|
* This is not used by Microsub, but is part of the IndieAuth specification
|
|
*
|
|
* @see https://indieauth.spec.indieweb.org/#authorization-code-verification
|
|
*/
|
|
protected function opCodeVerification(ServerRequestInterface $req): ResponseInterface {
|
|
$post = $req->getParsedBody();
|
|
$tr = Arsse::$db->begin();
|
|
// validate the request parameters; an exception will be thrown if not
|
|
list($user, $type) = $this->validateAuthCode($post['code'] ?? "", $post['client_id'] ?? "", $post['redirect_uri'] ?? "");
|
|
if ($type !== "id") {
|
|
throw new ExceptionAuth("invalid_grant");
|
|
}
|
|
// delete the auth code since it is valid and may only be used once
|
|
Arsse::$db->tokenRevoke($user, "microsub.auth", $post['code']);
|
|
$tr->commit();
|
|
// return the canonical identity URL
|
|
return new JsonResponse(['me' => $this->buildIdentifier($req, $user)]);
|
|
}
|
|
|
|
/** Handles the auth code verification and token issuance of the "Authorization" flow of IndieAuth
|
|
*
|
|
* @see https://indieauth.spec.indieweb.org/#token-endpoint-0
|
|
*/
|
|
protected function opIssueAccessToken(ServerRequestInterface $req): ResponseInterface {
|
|
$post = $req->getParsedBody();
|
|
// revocation is a special case of POSTing to the token URL
|
|
if ($post['action'] ?? "" === "revoke") {
|
|
return $this->opRevokeToken($req);
|
|
}
|
|
if (($post['grant_type'] ?? "") !== "authorization_code") {
|
|
throw new ExceptionAuth("unsupported_grant_type");
|
|
}
|
|
$tr = Arsse::$db->begin();
|
|
list($user, $type) = $this->validateAuthCode($post['code'] ?? "", $post['client_id'] ?? "", $post['redirect_url'] ?? "", $post['me'] ?? "");
|
|
if ($type !== "code") {
|
|
throw new ExceptionAuth("invalid_grant");
|
|
}
|
|
// issue an access token
|
|
$data = json_encode([
|
|
'me' => $post['me'],
|
|
'client_id' => $post['client_id'],
|
|
], \JSON_UNESCAPED_SLASHES | \JSON_UNESCAPED_UNICODE);
|
|
$token = Arsse::$db->tokenCreate($user, "microsub.access", null, null, $data);
|
|
Arsse::$db->tokenRevoke($user, "microsub.auth", $post['code']);
|
|
$tr->commit();
|
|
// return the Bearer token and associated data
|
|
return new JsonResponse([
|
|
'me' => $this->buildIdentifier($req, $user),
|
|
'token_type' => "Bearer",
|
|
'access_token' => $token,
|
|
'scope' => implode(" ", self::SCOPES),
|
|
]);
|
|
}
|
|
|
|
/** Validates an auth code and throws appropriate exceptions otherwise
|
|
*
|
|
* Returns an indexed array containing the username and the grant type (either "id" or "code")
|
|
*
|
|
* It is the responsibility of the calling function to revoke the auth code if the code is ultimately accepted
|
|
*/
|
|
protected function validateAuthCode(string $code, string $clientId, string $redirUrl, string $me = null): array {
|
|
if (!strlen($code) || !strlen($clientId) || !strlen($redirUrl)) {
|
|
throw new ExceptionAuth("invalid_request");
|
|
}
|
|
// check that the auth code exists
|
|
try {
|
|
$token = Arsse::$db->tokenLookup("microsub.auth", $code);
|
|
} catch (\JKingWeb\Arsse\Db\ExceptionInput $e) {
|
|
throw new ExceptionAuth("invalid_grant");
|
|
}
|
|
$data = @json_decode($token['data'], true);
|
|
// validate the auth code
|
|
if (!is_array($data)) {
|
|
throw new ExceptionAuth("invalid_grant");
|
|
} elseif ($data['client'] !== $clientId || $data['redir'] !== $redirUrl) {
|
|
throw new ExceptionAuth("invalid_client");
|
|
} elseif (isset($me) && $me !== $data['me']) {
|
|
throw new ExceptionAuth("invalid_grant");
|
|
}
|
|
// return the associated user name and the auth-code type
|
|
return [$token['user'], $data['type'] ?? "id"];
|
|
}
|
|
|
|
/** Handles token verification as an API call
|
|
*
|
|
* The static `validateBearer` method should be used to check the validity of a bearer token in normal use
|
|
*
|
|
* @see https://indieauth.spec.indieweb.org/#access-token-verification
|
|
*/
|
|
protected function opTokenVerification(ServerRequestInterface $req): ResponseInterface {
|
|
try {
|
|
if (!$req->hasHeader("Authorization")) {
|
|
throw new ExceptionAuth("invalid_token");
|
|
}
|
|
$authorization = $req->getHeader("Authorization")[0];
|
|
list($user, $data) = self::validateBearer($authorization);
|
|
} catch (ExceptionAuth $e) {
|
|
$errCode = $e->getMessage();
|
|
$httpCode = [
|
|
'invalid_request' => 400,
|
|
'invalid_token' => 401,
|
|
][$errCode] ?? 500;
|
|
return new EmptyResponse($httpCode, ['WWW-Authenticate' => "Bearer error=\"$erroCode\""]);
|
|
}
|
|
return new JsonResponse([
|
|
'me' => $data['me'] ?? "",
|
|
'client_id' => $data['client_id'] ?? "",
|
|
'scope' => $data['scope'] ?? self::SCOPES,
|
|
]);
|
|
}
|
|
|
|
/** Handles token revocation
|
|
*
|
|
* @see https://indieauth.spec.indieweb.org/#token-revocation
|
|
*/
|
|
protected function opRevokeToken(ServerRequestInterface $req): ResponseInterface {
|
|
$token = ($req->getParsedBody() ?? [])['token'] ?? "";
|
|
if (!strlen($token)) {
|
|
return new EmptyResponse(422);
|
|
}
|
|
try {
|
|
$info = Arsse::$db->tokenLookup("microsub.access", $token);
|
|
Arsse::$db->tokenRevoke($info['user'], "mucrosub.access", $token);
|
|
} catch (\JKingWeb\Arsse\Db\ExceptionInput $e) {
|
|
}
|
|
return new EmptyResponse(200);
|
|
}
|
|
|
|
/** Checks that the supplied bearer token is valid i.e. logs a bearer in
|
|
*
|
|
* Returns an indexed array with the user associated with the token, as well as other data
|
|
*
|
|
* @throws \JKingWeb\Arsse\REST\Microsub\ExceptionAuth
|
|
*/
|
|
public static function validateBearer(string $authorization, array $scopes = []): array {
|
|
if (!preg_match("/^Bearer (.+)/", $authorization, $match)) {
|
|
throw new ExceptionAuth("invalid_request");
|
|
}
|
|
$token = $match[1];
|
|
try {
|
|
$token = Arsse::$db->tokenLookup("microsub.access", $token);
|
|
} catch (\JKingWeb\Arsse\Db\ExceptionInput $e) {
|
|
throw new ExceptionAuth("invalid_token");
|
|
}
|
|
$data = @json_decode($token['data'], true) ?? [];
|
|
$data['scope'] = $data['scope'] ?? self::SCOPES;
|
|
// scope is hard-coded for now
|
|
if (array_diff($scopes, $data['scope'])) {
|
|
throw new ExceptionAuth("insufficient_scope");
|
|
}
|
|
return [$token['user'], $data];
|
|
}
|
|
}
|