Merge pull request #17008 from owncloud/fix-17006

Improve splitting of username and remote adress when username contains an `@`

2 files changed, 69 insertions, 23 deletions

diff --git a/lib/private/share/helper.php b/lib/private/share/helper.php
index 65167dd7549..1988324a996 100644
--- a/lib/private/share/helper.php
+++ b/lib/private/share/helper.php
@@ -27,6 +27,8 @@
 
 namespace OC\Share;
 
+use OC\HintException;
+
 class Helper extends \OC\Share\Constants {
 
 	/**
@@ -216,32 +218,74 @@ class Helper extends \OC\Share\Constants {
 	}
 
 	/**
-	 * Extracts the necessary remote name from a given link
+	 * Strips away a potential file names and trailing slashes:
+	 * - http://localhost
+	 * - http://localhost/
+	 * - http://localhost/index.php
+	 * - http://localhost/index.php/s/{shareToken}
 	 *
-	 * Strips away a potential file name, to allow
-	 * - user
-	 * - user@localhost
-	 * - user@http://localhost
-	 * - user@http://localhost/
-	 * - user@http://localhost/index.php
-	 * - user@http://localhost/index.php/s/{shareToken}
+	 * all return: http://localhost
 	 *
 	 * @param string $shareWith
 	 * @return string
 	 */
-	public static function fixRemoteURLInShareWith($shareWith) {
-		if (strpos($shareWith, '@')) {
-			list($user, $remote) = explode('@', $shareWith, 2);
+	protected static function fixRemoteURL($remote) {
+		$remote = str_replace('\\', '/', $remote);
+		if ($fileNamePosition = strpos($remote, '/index.php')) {
+			$remote = substr($remote, 0, $fileNamePosition);
+		}
+		$remote = rtrim($remote, '/');
 
-			$remote = str_replace('\\', '/', $remote);
-			if ($fileNamePosition = strpos($remote, '/index.php')) {
-				$remote = substr($remote, 0, $fileNamePosition);
-			}
-			$remote = rtrim($remote, '/');
+		return $remote;
+	}
+
+	/**
+	 * split user and remote from federated cloud id
+	 *
+	 * @param string $id
+	 * @return array
+	 * @throws HintException
+	 */
+	public static function splitUserRemote($id) {
+		if (strpos($id, '@') === false) {
+			$l = \OC::$server->getL10N('core');
+			$hint = $l->t('Invalid Federated Cloud ID');
+			throw new HintException('Invalid Federated Cloud ID', $hint);
+		}
+
+		// Find the first character that is not allowed in user names
+		$id = str_replace('\\', '/', $id);
+		$posSlash = strpos($id, '/');
+		$posColon = strpos($id, ':');
+
+		if ($posSlash === false && $posColon === false) {
+			$invalidPos = strlen($id);
+		} else if ($posSlash === false) {
+			$invalidPos = $posColon;
+		} else if ($posColon === false) {
+			$invalidPos = $posSlash;
+		} else {
+			$invalidPos = min($posSlash, $posColon);
+		}
+
+		// Find the last @ before $invalidPos
+		$pos = $lastAtPos = 0;
+		while ($lastAtPos !== false && $lastAtPos <= $invalidPos) {
+			$pos = $lastAtPos;
+			$lastAtPos = strpos($id, '@', $pos + 1);
+		}
 
-			$shareWith = $user . '@' . $remote;
+		if ($pos !== false) {
+			$user = substr($id, 0, $pos);
+			$remote = substr($id, $pos + 1);
+			$remote = self::fixRemoteURL($remote);
+			if (!empty($user) && !empty($remote)) {
+				return array($user, $remote);
+			}
 		}
 
-		return rtrim($shareWith, '/');
+		$l = \OC::$server->getL10N('core');
+		$hint = $l->t('Invalid Federated Cloud ID');
+		throw new HintException('Invalid Fededrated Cloud ID', $hint);
 	}
 }
diff --git a/lib/private/share/share.php b/lib/private/share/share.php
index b2ac9ee6a42..fd24fc686b1 100644
--- a/lib/private/share/share.php
+++ b/lib/private/share/share.php
@@ -554,6 +554,7 @@ class Share extends Constants {
 	 * @param string $itemSourceName
 	 * @param \DateTime $expirationDate
 	 * @return boolean|string Returns true on success or false on failure, Returns token on success for links
+	 * @throws \OC\HintException when the share type is remote and the shareWith is invalid
 	 * @throws \Exception
 	 */
 	public static function shareItem($itemType, $itemSource, $shareType, $shareWith, $permissions, $itemSourceName = null, \DateTime $expirationDate = null) {
@@ -749,7 +750,8 @@ class Share extends Constants {
 			$token = \OC::$server->getSecureRandom()->getMediumStrengthGenerator()->generate(self::TOKEN_LENGTH, \OCP\Security\ISecureRandom::CHAR_LOWER . \OCP\Security\ISecureRandom::CHAR_UPPER .
 				\OCP\Security\ISecureRandom::CHAR_DIGITS);
 
-			$shareWith = Helper::fixRemoteURLInShareWith($shareWith);
+			list($user, $remote) = Helper::splitUserRemote($shareWith);
+			$shareWith = $user . '@' . $remote;
 			$shareId = self::put($itemType, $itemSource, $shareType, $shareWith, $uidOwner, $permissions, null, $token, $itemSourceName);
 
 			$send = false;
@@ -1300,8 +1302,8 @@ class Share extends Constants {
 		$hookParams['deletedShares'] = $deletedShares;
 		\OC_Hook::emit('OCP\Share', 'post_unshare', $hookParams);
 		if ((int)$item['share_type'] === \OCP\Share::SHARE_TYPE_REMOTE && \OC::$server->getUserSession()->getUser()) {
-			$urlParts = explode('@', $item['share_with'], 2);
-			self::sendRemoteUnshare($urlParts[1], $item['id'], $item['token']);
+			list(, $remote) = Helper::splitUserRemote($item['share_with']);
+			self::sendRemoteUnshare($remote, $item['id'], $item['token']);
 		}
 	}
 
@@ -2436,10 +2438,10 @@ class Share extends Constants {
 	 */
 	private static function sendRemoteShare($token, $shareWith, $name, $remote_id, $owner) {
 
-		list($user, $remote) = explode('@', $shareWith, 2);
+		list($user, $remote) = Helper::splitUserRemote($shareWith);
 
 		if ($user && $remote) {
-			$url = rtrim($remote, '/') . self::BASE_PATH_TO_SHARE_API . '?format=' . self::RESPONSE_FORMAT;
+			$url = $remote . self::BASE_PATH_TO_SHARE_API . '?format=' . self::RESPONSE_FORMAT;
 
 			$local = \OC::$server->getURLGenerator()->getAbsoluteURL('/');