From 2eb6ad8578fa9d764c21a92acd8e054e3202ad19 Mon Sep 17 00:00:00 2001 From: Christian Heimes Date: Mon, 10 Dec 2018 11:22:37 +0100 Subject: bpo-35050: AF_ALG length check off-by-one error (GH-10058) The length check for AF_ALG salg_name and salg_type had a off-by-one error. The code assumed that both values are not necessarily NULL terminated. However the Kernel code for alg_bind() ensures that the last byte of both strings are NULL terminated. Signed-off-by: Christian Heimes --- Lib/test/test_socket.py | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'Lib/test') diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py index a2c047daa3..626a077973 100644 --- a/Lib/test/test_socket.py +++ b/Lib/test/test_socket.py @@ -5969,6 +5969,24 @@ class LinuxKernelCryptoAPI(unittest.TestCase): with self.assertRaises(TypeError): sock.sendmsg_afalg(op=socket.ALG_OP_ENCRYPT, assoclen=-1) + def test_length_restriction(self): + # bpo-35050, off-by-one error in length check + sock = socket.socket(socket.AF_ALG, socket.SOCK_SEQPACKET, 0) + self.addCleanup(sock.close) + + # salg_type[14] + with self.assertRaises(FileNotFoundError): + sock.bind(("t" * 13, "name")) + with self.assertRaisesRegex(ValueError, "type too long"): + sock.bind(("t" * 14, "name")) + + # salg_name[64] + with self.assertRaises(FileNotFoundError): + sock.bind(("type", "n" * 63)) + with self.assertRaisesRegex(ValueError, "name too long"): + sock.bind(("type", "n" * 64)) + + @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows") class TestMSWindowsTCPFlags(unittest.TestCase): knownTCPFlags = { -- cgit v1.2.1