port hubzillas OpenWebAuth - remote authentification

src/Module/Owa.php

@@ -0,0 +1,94 @@
+<?php
+/**
+ * @file src/Module/Owa.php
+ */
+namespace Friendica\Module;
+
+use Friendica\BaseModule;
+use Friendica\Core\System;
+use Friendica\Database\DBM;
+use Friendica\Model\Verify;
+use Friendica\Network\Probe;
+use Friendica\Util\DateTimeFormat;
+use Friendica\Util\HTTPSig;
+
+use dba;
+
+/**
+ * @brief OpenWebAuth verifier and token generator
+ * 
+ * See https://macgirvin.com/wiki/mike/OpenWebAuth/Home
+ * 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 BaseModule
+{
+	public static function init()
+	{
+
+		$ret = [ 'success' => false ];
+
+		foreach (['REDIRECT_REMOTE_USER', 'HTTP_AUTHORIZATION'] as $head) {
+			if (array_key_exists($head, $_SERVER) && substr(trim($_SERVER[$head]), 0, 9) === 'Signature') {
+				if ($head !== 'HTTP_AUTHORIZATION') {
+					$_SERVER['HTTP_AUTHORIZATION'] = $_SERVER[$head];
+					continue;
+				}
+
+				$sigblock = HTTPSig::parseSigheader($_SERVER[$head]);
+				if ($sigblock) {
+					$keyId = $sigblock['keyId'];
+
+					if ($keyId) {
+						// Try to find the public contact entry of the handle.
+						$handle = str_replace("acct:", "", $keyId);
+						$fields = ["id", "url", "addr", "pubkey"];
+						$condition = ["addr" => $handle, "uid" => 0];
+
+						$contact = dba::selectFirst("contact", $fields, $condition);
+
+						// Not found? Try to probe with the handle.
+						if(!DBM::is_result($contact)) {
+							Probe::uri($handle, '', -1, true, true);
+							$contact = dba::selectFirst("contact", $fields, $condition);
+						}
+
+						if (DBM::is_result($contact)) {
+							// Try to verify the signed header with the public key of the contact record
+							// we have found.
+							$verified = HTTPSig::verify('', $contact['pubkey']);
+
+							if ($verified && $verified['header_signed'] && $verified['header_valid']) {
+								logger('OWA header: ' . print_r($verified, true), LOGGER_DATA);
+								logger('OWA success: ' . $contact['addr'], LOGGER_DATA);
+
+								$ret['success'] = true;
+								$token = random_string(32);
+
+								// Store the generated token in the databe.
+								Verify::create('owt', 0, $token, $contact['addr']);
+
+								$result = '';
+
+								// Encrypt the token with the public contacts publik key.
+								// Only the specific public contact will be able to encrypt it.
+								// At a later time, we will compare weather the token we're getting
+								// is really the same token we have stored in the database.
+								openssl_public_encrypt($token, $result, $contact['pubkey']);
+								$ret['encrypted_token'] = base64url_encode($result);
+							} else {
+								logger('OWA fail: ' . $contact['id'] . ' ' . $contact['addr'] . ' ' . $contact['url'], LOGGER_DEBUG);
+							}
+						} else {
+							logger('Contact not found: ' . $handle, LOGGER_DEBUG);
+						}
+					}
+				}
+			}
+		}
+		System::jsonExit($ret, 'application/x-dfrn+json');
+	}
+}