commit 9040cf46b24946d9cc3a96ab25e5a0af506cdad6 Author: Damian Johnson atagar@torproject.org Date: Sat Jun 16 11:03:08 2018 -0700

Explicitly test negative VPADDING sizes

Nitpickiest of nitpicks...

* Explicitly checking for negative VPADDING sizes so we can an error message that includes the argument.

* Testing for negative sizes in our unit tests.

* Flatten our validation checks a bit. --- stem/client/cell.py | 13 ++++++------- test/unit/client/cell.py | 2 +- 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/stem/client/cell.py b/stem/client/cell.py index d5e71e8a..61503c40 100644 --- a/stem/client/cell.py +++ b/stem/client/cell.py @@ -586,15 +586,14 @@ class VPaddingCell(Cell): IS_FIXED_SIZE = False

def __init__(self, size = None, payload = None): - if payload is None: - if size is not None: - payload = os.urandom(size) # enforces size >= 0 - else: - raise ValueError('VPaddingCell constructor must specify payload or size') - elif size is not None and size != len(payload): + if size is None and payload is None: + raise ValueError('VPaddingCell constructor must specify payload or size') + elif size is not None and size < 0: + raise ValueError('VPaddingCell size (%s) cannot be negative' % size) + elif size is not None and payload is not None and size != len(payload): raise ValueError('VPaddingCell constructor specified both a size of %i bytes and payload of %i bytes' % (size, len(payload)))

- self.payload = payload + self.payload = payload if payload is not None else os.urandom(size)

def pack(self, link_protocol): return VPaddingCell._pack(link_protocol, self.payload) diff --git a/test/unit/client/cell.py b/test/unit/client/cell.py index 785d48d2..2123cd6f 100644 --- a/test/unit/client/cell.py +++ b/test/unit/client/cell.py @@ -221,7 +221,7 @@ class TestCell(unittest.TestCase): self.assertEqual(b'', empty_constructed_cell.payload)

self.assertRaisesRegexp(ValueError, 'VPaddingCell constructor specified both a size of 5 bytes and payload of 1 bytes', VPaddingCell, 5, '\x02') - + self.assertRaisesRegexp(ValueError, re.escape('VPaddingCell size (-15) cannot be negative'), VPaddingCell, -15) self.assertRaisesRegexp(ValueError, '^%s$' % re.escape('VPaddingCell constructor must specify payload or size'), VPaddingCell)

def test_certs_cell(self):