From fea71a81fd7b10758c3258a629f7f8185874f1be Mon Sep 17 00:00:00 2001
From: Roeland Jago Douma <roeland@famdouma.nl>
Date: Fri, 26 Jun 2015 15:36:06 +0200
Subject: [PATCH 1/2] Cannot share the same file multiple times with remote
 user

Fix for #17183
It should not be possible to create multiple remote shares from user A
to user B of the same file/folder.
---
 lib/private/share/share.php | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/private/share/share.php b/lib/private/share/share.php
index 7fcbb695c68..a52adb8758e 100644
--- a/lib/private/share/share.php
+++ b/lib/private/share/share.php
@@ -781,6 +781,19 @@ class Share extends Constants {
 			\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName), \OCP\Util::ERROR);
 			throw new \Exception($message_t);
 		} else if ($shareType === self::SHARE_TYPE_REMOTE) {
+
+			/*
+			 * Check if file is not already shared with the remote user
+			 */
+			if ($checkExists = self::getItems($itemType, $itemSource, self::SHARE_TYPE_REMOTE,
+				$shareWith, $uidOwner, self::FORMAT_NONE, null, 1, true, true)) {
+					$message = 'Sharing %s failed, because this item is already shared with %s';
+					$message_t = $l->t('Sharing %s failed, because this item is already shared with %s', array($itemSourceName, $shareWith));
+					\OCP\Util::writeLog('OCP\Share', sprintf($message, $itemSourceName, $shareWith), \OCP\Util::ERROR);
+					throw new \Exception($message_t);
+			}
+
+
 			$token = \OC::$server->getSecureRandom()->getMediumStrengthGenerator()->generate(self::TOKEN_LENGTH, \OCP\Security\ISecureRandom::CHAR_LOWER . \OCP\Security\ISecureRandom::CHAR_UPPER .
 				\OCP\Security\ISecureRandom::CHAR_DIGITS);
 

From e35b97e4c5dd87dd03e409db0e20cd6c844d966b Mon Sep 17 00:00:00 2001
From: Roeland Jago Douma <roeland@famdouma.nl>
Date: Wed, 15 Jul 2015 12:49:26 +0200
Subject: [PATCH 2/2] Added test

---
 tests/lib/share/share.php | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/tests/lib/share/share.php b/tests/lib/share/share.php
index e225f2a4002..7cfd3e1942c 100644
--- a/tests/lib/share/share.php
+++ b/tests/lib/share/share.php
@@ -1531,6 +1531,42 @@ class Test_Share extends \Test\TestCase {
 		\OC\Share\Share::setPassword($userSession, $connection, $config, 1, 'pass');
 	}
 
+	/**
+	 * Make sure that a user cannot have multiple identical shares to remote users
+	 */
+	public function testOnlyOneRemoteShare() {
+		$oldHttpHelper = \OC::$server->query('HTTPHelper');
+		$httpHelperMock = $this->getMockBuilder('OC\HttpHelper')
+			->disableOriginalConstructor()
+			->getMock();
+		$this->setHttpHelper($httpHelperMock);
+
+		$httpHelperMock->expects($this->at(0))
+			->method('post')
+			->with($this->stringStartsWith('https://localhost/ocs/v1.php/cloud/shares'), $this->anything())
+			->willReturn(['success' => true, 'result' => json_encode(['ocs' => ['meta' => ['statuscode' => 100]]])]);
+
+		\OCP\Share::shareItem('test', 'test.txt', \OCP\Share::SHARE_TYPE_REMOTE, 'foo@localhost', \OCP\Constants::PERMISSION_READ);
+		$shares = \OCP\Share::getItemShared('test', 'test.txt');
+		$share = array_shift($shares);
+
+		//Try share again
+		try {
+			\OCP\Share::shareItem('test', 'test.txt', \OCP\Share::SHARE_TYPE_REMOTE, 'foo@localhost', \OCP\Constants::PERMISSION_READ);
+			$this->fail('Identical remote shares are not allowed');
+		} catch (\Exception $e) {
+			$this->assertEquals('Sharing test.txt failed, because this item is already shared with foo@localhost', $e->getMessage());
+		}
+
+		$httpHelperMock->expects($this->at(0))
+			->method('post')
+			->with($this->stringStartsWith('https://localhost/ocs/v1.php/cloud/shares/' . $share['id'] . '/unshare'), $this->anything())
+			->willReturn(['success' => true, 'result' => json_encode(['ocs' => ['meta' => ['statuscode' => 100]]])]);
+
+		\OCP\Share::unshare('test', 'test.txt', \OCP\Share::SHARE_TYPE_REMOTE, 'foo@localhost');
+		$this->setHttpHelper($oldHttpHelper);
+	}
+
 }
 
 class DummyShareClass extends \OC\Share\Share {