From 7bc69c7ea5ca73883ed1b8869929789bf7e85cd7 Mon Sep 17 00:00:00 2001
From: Lukas Reschke <lukas@statuscode.ch>
Date: Sat, 22 Feb 2014 08:07:57 +0100
Subject: [PATCH] Backport #7259 to stable5

---
 config/config.sample.php |  3 +++
 lib/request.php          | 46 +++++++++++++++++++++++++++-------------
 lib/setup.php            |  1 +
 lib/updater.php          | 15 ++++++++++++-
 4 files changed, 49 insertions(+), 16 deletions(-)

diff --git a/config/config.sample.php b/config/config.sample.php
index 092480d4f5d..77987a574e3 100755
--- a/config/config.sample.php
+++ b/config/config.sample.php
@@ -53,6 +53,9 @@ $CONFIG = array(
 /* The optional authentication for the proxy to use to connect to the internet. The format is: [username]:[password] */
 "proxyuserpwd" => "",
 
+/* List of trusted domains, to prevent host header poisoning ownCloud is only using these Host headers */
+'trusted_domains' => array('demo.owncloud.org'),
+
 /* Theme to use for ownCloud */
 "theme" => "",
 
diff --git a/lib/request.php b/lib/request.php
index d0b2feab311..2a7101efbe1 100755
--- a/lib/request.php
+++ b/lib/request.php
@@ -17,6 +17,16 @@ class OC_Request {
 			or ($type !== 'protocol' and OC_Config::getValue('forcessl', false));
 	}
 
+	/**
+	* @brief Checks whether a domain is considered as trusted. This is used to prevent Host Header Poisoning.
+	* @param string $host
+	* @return bool
+	 */
+	public static function isTrustedDomain($domain) {
+		$trustedList = \OC_Config::getValue('trusted_domains', array(''));
+ 		return in_array($domain, $trustedList);
+	}
+
 	/**
 	 * @brief Returns the server host
 	 * @returns string the server host
@@ -36,21 +46,27 @@ class OC_Request {
 				$host = trim(array_pop(explode(",", $_SERVER['HTTP_X_FORWARDED_HOST'])));
 			}
 			else{
-				$host=$_SERVER['HTTP_X_FORWARDED_HOST'];
+				$host = $_SERVER['HTTP_X_FORWARDED_HOST'];
 			}
-		}
-		else{
+		} else {
 			if (isset($_SERVER['HTTP_HOST'])) {
-				return $_SERVER['HTTP_HOST'];
+				$host = $_SERVER['HTTP_HOST'];
 			}
 			if (isset($_SERVER['SERVER_NAME'])) {
-				return $_SERVER['SERVER_NAME'];
+				$host = $_SERVER['SERVER_NAME'];
 			}
-			return 'localhost';
 		}
-		return $host;
-	}
 
+		// Verify that the host is a trusted domain if the trusted domains
+		// are defined
+		// If no trusted domain is provided the first trusted domain is returned
+		if(self::isTrustedDomain($host) || \OC_Config::getValue('trusted_domains', "") === "") {
+			return $host;
+		} else {
+			$trustedList = \OC_Config::getValue('trusted_domains', array(''));
+			return $trustedList[0];
+		}
+	}
 
 	/**
 	* @brief Returns the server protocol
@@ -64,14 +80,14 @@ class OC_Request {
 		}
 		if (isset($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
 			$proto = strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']);
-		}else{
-			if(isset($_SERVER['HTTPS']) and !empty($_SERVER['HTTPS']) and ($_SERVER['HTTPS']!='off')) {
-				$proto = 'https';
-			}else{
-				$proto = 'http';
-			}
+			// Verify that the protocol is always HTTP or HTTPS
+			// default to http if an invalid value is provided
+			return $proto === 'https' ? 'https' : 'http';
+		}
+		if (isset($_SERVER['HTTPS']) && !empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') {
+			return 'https';
 		}
-		return $proto;
+		return 'http';
 	}
 
 	/**
diff --git a/lib/setup.php b/lib/setup.php
index 2a43f7b4475..d00e860434d 100644
--- a/lib/setup.php
+++ b/lib/setup.php
@@ -84,6 +84,7 @@ class OC_Setup {
 			OC_Config::setValue('passwordsalt', $salt);
 
 			//write the config file
+			OC_Config::setValue('trusted_domains', array(OC_Request::serverHost())); 
 			OC_Config::setValue('datadirectory', $datadir);
 			OC_Config::setValue('dbtype', $dbtype);
 			OC_Config::setValue('version', implode('.', OC_Util::getVersion()));
diff --git a/lib/updater.php b/lib/updater.php
index d0ae1fb4715..ec10377a4b9 100644
--- a/lib/updater.php
+++ b/lib/updater.php
@@ -97,6 +97,19 @@ class OC_Updater extends BasicEmitter {
 		$currentVersion = implode('.', \OC_Util::getVersion());
 		\OC_Log::write('core', 'starting upgrade from ' . $installedVersion . ' to ' . $currentVersion, \OC_Log::WARN);
 		$this->emit('\OC_Updater', 'maintenanceStart');
+
+		/*
+		 * START CONFIG CHANGES FOR OLDER VERSIONS
+		 */
+		if (version_compare($currentVersion, '5.00.29', '<')) {
+			// Add the overwriteHost config if it is not existant
+			// This is added to prevent host header poisoning
+			\OC_Config::setValue('trusted_domains', \OC_Config::getValue('trusted_domains', array(\OC_Request::serverHost()))); 
+		}
+		/*
+		 * STOP CONFIG CHANGES FOR OLDER VERSIONS
+		 */
+
 		try {
 			\OC_DB::updateDbFromStructure(\OC::$SERVERROOT . '/db_structure.xml');
 			$this->emit('\OC_Updater', 'dbUpgrade');
@@ -157,4 +170,4 @@ class OC_Updater extends BasicEmitter {
 		}
 		$this->emit('\OC_Updater', 'filecacheDone');
 	}
-}
\ No newline at end of file
+}
-- 
2.39.5