core/Zotlabs/Module/Owa.php

<?php

namespace Zotlabs\Module;

use Zotlabs\Web\HTTPSig;
use Zotlabs\Lib\Verify;
use Zotlabs\Web\Controller;

/**
 * OpenWebAuth verifier and token generator
 * See spec/OpenWebAuth/Home.md
 * Requests to this endpoint should be signed using HTTP Signatures
 * using the 'Authorization: Signature' authentication method
 * If the signature verifies a token is returned.
 *
 * This token may be exchanged for an authenticated cookie.
 */

class Owa extends Controller {

	public function init(): void
	{

		$ret = [ 'success' => false ];

		// try OpenWebAuth over RFC9421

		$sigdata = HTTPSig::verify(EMPTY_STR);

		if ($sigdata && $sigdata['portable_id'] && $sigdata['header_valid']) {
			$portable_id = $sigdata['portable_id'];

			if (!check_channelallowed($portable_id)) {
				json_return_and_die($ret, 'application/x-zot+json');
			}

			if (!check_siteallowed($sigdata['signer'])) {
				json_return_and_die($ret, 'application/x-zot+json');
			}

			$hubs = q("SELECT * FROM hubloc LEFT JOIN xchan ON hubloc_hash = xchan_hash
				WHERE hubloc_hash = '%s' ORDER BY hubloc_id DESC",
				dbesc($portable_id)
			);

			if ($hubs) {
				logger('OWA RFC9421 success: ' . $hubs[0]['hubloc_id_url'], LOGGER_DATA);
				$ret['success'] = true;
				$token = random_string(32);
				Verify::create('owt', 0, $token, $hubs[0]['hubloc_id_url']);
				$result = '';
				openssl_public_encrypt($token, $result, $hubs[0]['xchan_pubkey']);
				$ret['encrypted_token'] = base64url_encode($result);
			}
		}
		else {
			if (!$this->validateAuthorizationHeader()) {
				$this->error('Missing or invalid authorization header.');
			}

			$_SERVER['HTTP_AUTHORIZATION'] = $_SERVER['HTTP_AUTHORIZATION'] ?? $_SERVER['REDIRECT_REMOTE_USER'];

			$sigblock = HTTPSig::parse_sigheader($_SERVER['HTTP_AUTHORIZATION']);
			if ($sigblock) {
				$keyId = $sigblock['keyId'];
				$parsed = parse_url($keyId);
				if (str_starts_with($parsed['scheme'],'http')) {
					unset($parsed['fragment']);
					unset($parsed['query']);
					$keyId = unparse_url($parsed);
				}
				else {
					$keyId = str_replace('acct:', '', $keyId);
				}
				if ($keyId) {
					$r = q("SELECT * FROM hubloc LEFT JOIN xchan ON hubloc_hash = xchan_hash
						WHERE (hubloc_addr = '%s' OR hubloc_id_url = '%s' OR xchan_hash = '%s')
						AND hubloc_deleted = 0 AND xchan_pubkey != ''
						ORDER BY hubloc_id DESC",
						dbesc($keyId),
						dbesc($keyId),
						dbesc($keyId)
					);
					if (! $r) {
						$found = discover_by_webbie($keyId);
						logger('found = ' . print_r($found, true));
						if ($found) {
							$r = q("SELECT * FROM hubloc LEFT JOIN xchan ON hubloc_hash = xchan_hash
								WHERE (hubloc_addr = '%s' OR hubloc_id_url = '%s' OR xchan_hash = '%s') AND hubloc_deleted = 0 AND xchan_pubkey != '' ORDER BY hubloc_id DESC ",
								dbesc($keyId),
								dbesc($keyId),
								dbesc($keyId)
							);
						}
					}

					if ($r) {
						foreach ($r as $hubloc) {
							$verified = HTTPSig::verify(file_get_contents('php://input'), $hubloc['xchan_pubkey']);
							if ($verified && $verified['header_signed'] && $verified['header_valid'] && ($verified['content_valid'] || (! $verified['content_signed']))) {
								logger('OWA header: ' . print_r($verified,true),LOGGER_DATA);
								logger('OWA success: ' . $hubloc['hubloc_id_url'],LOGGER_DATA);
								$ret['success'] = true;
								$token = random_string(32);
								Verify::create('owt',0,$token,$hubloc['hubloc_id_url']);
								$result = '';
								openssl_public_encrypt($token,$result,$hubloc['xchan_pubkey']);
								$ret['encrypted_token'] = base64url_encode($result);
								break;
							} else {
								logger('OWA fail: ' . $hubloc['hubloc_id'] . ' ' . $hubloc['hubloc_id_url']);
							}
						}

						if (!$ret['success']) {

							// Possible a reinstall?
							// In this case we probably already have an old hubloc
							// but not the new one yet.

							$found = discover_by_webbie($keyId);

							if ($found) {
								$r = q("SELECT * FROM hubloc LEFT JOIN xchan ON hubloc_hash = xchan_hash
									WHERE (hubloc_addr = '%s' OR hubloc_id_url = '%s') AND hubloc_deleted = 0 ORDER BY hubloc_id DESC LIMIT 1",
									dbesc(str_replace('acct:', '', $keyId)),
									dbesc($keyId)
								);

								if ($r) {
									$verified = HTTPSig::verify(file_get_contents('php://input'), $r[0]['xchan_pubkey']);
									if ($verified && $verified['header_signed'] && $verified['header_valid'] && ($verified['content_valid'] || (! $verified['content_signed']))) {
										logger('OWA header: ' . print_r($verified,true), LOGGER_DATA);
										logger('OWA success: ' . $r[0]['hubloc_id_url'], LOGGER_DATA);
										$ret['success'] = true;
										$token = random_string(32);
										Verify::create('owt', 0, $token, $r[0]['hubloc_id_url']);
										$result = '';
										openssl_public_encrypt($token, $result, $r[0]['xchan_pubkey']);
										$ret['encrypted_token'] = base64url_encode($result);
									} else {
										logger('OWA fail: ' . $hubloc['hubloc_id'] . ' ' . $hubloc['hubloc_id_url']);
									}
								}
							}
						}
					}
				}
			}
		}

		json_return_and_die($ret,'application/x-zot+json');
	}

	private function validateAuthorizationHeader(): bool
	{
		if (!empty($_SERVER['HTTP_AUTHORIZATION'])) {
			$auth = trim($_SERVER['HTTP_AUTHORIZATION']);
		} else if (!empty($_SERVER['REDIRECT_REMOTE_USER'])) {
			$auth = trim($_SERVER['REDIRECT_REMOTE_USER']);
		} else {
			return false;
		}

		return strncmp($auth, 'Signature', 9) === 0;
	}

	/**
	 * Terminates the request, and return a json error response.
	 *
	 * @Note This function does not return!
	 *
	 * @param string $msg	The error message for the response.
	 */
	private function error(string $msg): void {
		$ret = [
			'success' => false,
			'message' => $msg
		];

		json_return_and_die($ret,'application/x-zot+json');
	}
}