From cba28c39ad63920c05241f59ce7e1ad6b47039df Mon Sep 17 00:00:00 2001 From: Joas Schilling Date: Fri, 27 Sep 2013 01:18:28 +0200 Subject: [PATCH 1/2] [ticket/11873] Do not hash very large passwords in order to safe resources. PHPBB3-11873 --- phpBB/includes/functions.php | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php index b2b12c1445..eef4ade4e7 100644 --- a/phpBB/includes/functions.php +++ b/phpBB/includes/functions.php @@ -502,6 +502,13 @@ function phpbb_hash($password) */ function phpbb_check_hash($password, $hash) { + if (strlen($password) > 4096) + { + // If the password is too huge, we will simply reject it + // and not let the server try to hash it. + return false; + } + $itoa64 = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'; if (strlen($hash) == 34) { From c6aefcf555b51e7bcf00332290c9d94beddec02c Mon Sep 17 00:00:00 2001 From: Joas Schilling Date: Fri, 27 Sep 2013 01:19:55 +0200 Subject: [PATCH 2/2] [ticket/11873] Add unit test for large password input. The password should be rejected quite fast. PHPBB3-11873 --- tests/security/hash_test.php | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tests/security/hash_test.php b/tests/security/hash_test.php index 0c2580c19b..e226365ef3 100644 --- a/tests/security/hash_test.php +++ b/tests/security/hash_test.php @@ -17,5 +17,13 @@ class phpbb_security_hash_test extends phpbb_test_case $this->assertTrue(phpbb_check_hash('test', '$P$9isfrtKXWqrz8PvztXlL3.daw4U0zI1')); $this->assertFalse(phpbb_check_hash('foo', '$H$9isfrtKXWqrz8PvztXlL3.daw4U0zI1')); } + + public function test_check_hash_with_large_input() + { + // 16 MB password, should be rejected quite fast + $start_time = time(); + $this->assertFalse(phpbb_check_hash(str_repeat('a', 1024 * 1024 * 16), '$H$9isfrtKXWqrz8PvztXlL3.daw4U0zI1')); + $this->assertLessThanOrEqual(5, time() - $start_time); + } }