commit 28467fc87102069fabb1b5b496725f9e9855256e Author: Damian Johnson atagar@torproject.org Date: Sun Jan 28 12:48:46 2018 -0800
Rename Cell.unpack to Cell.pop
Usually when we unpack cells we'll want to process everything from a response. As such having Cell.unpack provide a generator, and renaming our previous function that unpacked a single cell to Cell.pop. --- stem/client/cell.py | 30 +++++++++++++++++++++++++----- test/unit/client/cell.py | 42 +++++++++++++++++++++--------------------- 2 files changed, 46 insertions(+), 26 deletions(-)
diff --git a/stem/client/cell.py b/stem/client/cell.py index e2e589f5..59fbc14c 100644 --- a/stem/client/cell.py +++ b/stem/client/cell.py @@ -32,8 +32,9 @@ Messages communicated over a Tor relay's ORPort. |- AuthenticateCell - Client authentication. (section 4.5) |- AuthorizeCell - Client authorization. (not yet used) | - |- pack - Provides encoded bytes for this cell class. - +- unpack - Decodes bytes for this cell class. + |- pack - encodes cell into bytes + |- unpack - decodes series of cells + +- pop - decodes cell with remainder """
import datetime @@ -95,9 +96,31 @@ class Cell(object):
raise ValueError("'%s' isn't a valid cell value" % value)
+ def pack(self, link_version): + raise NotImplementedError('Unpacking not yet implemented for %s cells' % type(self).NAME) + @staticmethod def unpack(content, link_version): """ + Unpacks all cells from a response. + + :param bytes content: payload to decode + :param int link_version: link protocol version + + :returns: :class:`~stem.client.cell.Cell` generator + + :raises: + * ValueError if content is malformed + * NotImplementedError if unable to unpack any of the cell types + """ + + while content: + cell, content = Cell.pop(content, link_version) + yield cell + + @staticmethod + def pop(content, link_version): + """ Unpacks the first cell.
:param bytes content: payload to decode @@ -125,9 +148,6 @@ class Cell(object): payload, content = split(content, payload_len) return cls._unpack(payload, circ_id, link_version), content
- def pack(self, link_version): - raise NotImplementedError('Unpacking not yet implemented for %s cells' % type(self).NAME) - @classmethod def _pack(cls, link_version, payload, circ_id = 0): """ diff --git a/test/unit/client/cell.py b/test/unit/client/cell.py index ba28238e..1fde76cf 100644 --- a/test/unit/client/cell.py +++ b/test/unit/client/cell.py @@ -99,7 +99,7 @@ class TestCell(unittest.TestCase): self.assertRaises(ValueError, Cell.by_value, None)
def test_unpack_not_implemented(self): - self.assertRaisesRegexp(NotImplementedError, 'Unpacking not yet implemented for AUTHORIZE cells', Cell.unpack, '\x00\x00\x84\x00\x06\x00\x01\x00\x02\x00\x03', 2) + self.assertRaisesRegexp(NotImplementedError, 'Unpacking not yet implemented for AUTHORIZE cells', Cell.pop, '\x00\x00\x84\x00\x06\x00\x01\x00\x02\x00\x03', 2)
def test_unpack_for_new_link(self): expected_certs = ( @@ -112,10 +112,10 @@ class TestCell(unittest.TestCase):
content = test_data('new_link_cells')
- version_cell, content = Cell.unpack(content, 2) + version_cell, content = Cell.pop(content, 2) self.assertEqual(VersionsCell([3, 4, 5]), version_cell)
- certs_cell, content = Cell.unpack(content, 2) + certs_cell, content = Cell.pop(content, 2) self.assertEqual(CertsCell, type(certs_cell)) self.assertEqual(len(expected_certs), len(certs_cell.certificates))
@@ -124,10 +124,10 @@ class TestCell(unittest.TestCase): self.assertEqual(cert_type_int, certs_cell.certificates[i].type_int) self.assertTrue(certs_cell.certificates[i].value.startswith(cert_prefix))
- auth_challenge_cell, content = Cell.unpack(content, 2) + auth_challenge_cell, content = Cell.pop(content, 2) self.assertEqual(AuthChallengeCell([1, 3], '\x89Y\t\x99\xb2\x1e\xd9*V\xb6\x1bn\n\x05\xd8/\xe3QH\x85\x13Z\x17\xfc\x1c\x00{\xa9\xae\x83^K'), auth_challenge_cell)
- netinfo_cell, content = Cell.unpack(content, 2) + netinfo_cell, content = Cell.pop(content, 2) self.assertEqual(NetinfoCell, type(netinfo_cell)) self.assertEqual(datetime.datetime(2018, 1, 14, 1, 46, 56), netinfo_cell.timestamp) self.assertEqual(Address('127.0.0.1'), netinfo_cell.receiver_address) @@ -138,14 +138,14 @@ class TestCell(unittest.TestCase): def test_padding_cell(self): for cell_bytes, payload in PADDING_CELLS.items(): self.assertEqual(cell_bytes, PaddingCell(payload).pack(2)) - self.assertEqual(payload, Cell.unpack(cell_bytes, 2)[0].payload) + self.assertEqual(payload, Cell.pop(cell_bytes, 2)[0].payload)
def test_relay_cell(self): for cell_bytes, (command, command_int, circ_id, stream_id, data, digest) in RELAY_CELLS.items(): self.assertEqual(cell_bytes, RelayCell(circ_id, command, data, digest, stream_id).pack(2)) self.assertEqual(cell_bytes, RelayCell(circ_id, command_int, data, digest, stream_id).pack(2))
- cell = Cell.unpack(cell_bytes, 2)[0] + cell = Cell.pop(cell_bytes, 2)[0] self.assertEqual(circ_id, cell.circ_id) self.assertEqual(command, cell.command) self.assertEqual(command_int, cell.command_int) @@ -158,18 +158,18 @@ class TestCell(unittest.TestCase): self.assertEqual(cell_bytes, DestroyCell(circ_id, reason).pack(5)) self.assertEqual(cell_bytes, DestroyCell(circ_id, reason_int).pack(5))
- cell = Cell.unpack(cell_bytes, 5)[0] + cell = Cell.pop(cell_bytes, 5)[0] self.assertEqual(circ_id, cell.circ_id) self.assertEqual(reason, cell.reason) self.assertEqual(reason_int, cell.reason_int)
- self.assertRaisesRegexp(ValueError, 'Circuit closure reason should be a single byte, but was 2', Cell.unpack, '\x80\x00\x00\x00\x04\x01\x01' + ZERO * 507, 5) + self.assertRaisesRegexp(ValueError, 'Circuit closure reason should be a single byte, but was 2', Cell.pop, '\x80\x00\x00\x00\x04\x01\x01' + ZERO * 507, 5)
def test_create_fast_cell(self): for cell_bytes, (circ_id, key_material) in CREATE_FAST_CELLS.items(): self.assertEqual(cell_bytes, CreateFastCell(circ_id, key_material).pack(5))
- cell = Cell.unpack(cell_bytes, 5)[0] + cell = Cell.pop(cell_bytes, 5)[0] self.assertEqual(circ_id, cell.circ_id) self.assertEqual(key_material, cell.key_material)
@@ -179,7 +179,7 @@ class TestCell(unittest.TestCase): for cell_bytes, (circ_id, key_material, derivative_key) in CREATED_FAST_CELLS.items(): self.assertEqual(cell_bytes, CreatedFastCell(circ_id, derivative_key, key_material).pack(5))
- cell = Cell.unpack(cell_bytes, 5)[0] + cell = Cell.pop(cell_bytes, 5)[0] self.assertEqual(circ_id, cell.circ_id) self.assertEqual(key_material, cell.key_material) self.assertEqual(derivative_key, cell.derivative_key) @@ -189,13 +189,13 @@ class TestCell(unittest.TestCase): def test_versions_cell(self): for cell_bytes, versions in VERSIONS_CELLS.items(): self.assertEqual(cell_bytes, VersionsCell(versions).pack()) - self.assertEqual(versions, Cell.unpack(cell_bytes, 2)[0].versions) + self.assertEqual(versions, Cell.pop(cell_bytes, 2)[0].versions)
def test_netinfo_cell(self): for cell_bytes, (timestamp, receiver_address, sender_addresses) in NETINFO_CELLS.items(): self.assertEqual(cell_bytes, NetinfoCell(receiver_address, sender_addresses, timestamp).pack(2))
- cell = Cell.unpack(cell_bytes, 2)[0] + cell = Cell.pop(cell_bytes, 2)[0] self.assertEqual(timestamp, cell.timestamp) self.assertEqual(receiver_address, cell.receiver_address) self.assertEqual(sender_addresses, cell.sender_addresses) @@ -203,31 +203,31 @@ class TestCell(unittest.TestCase): def test_vpadding_cell(self): for cell_bytes, payload in VPADDING_CELLS.items(): self.assertEqual(cell_bytes, VPaddingCell(payload = payload).pack(2)) - self.assertEqual(payload, Cell.unpack(cell_bytes, 2)[0].payload) + self.assertEqual(payload, Cell.pop(cell_bytes, 2)[0].payload)
self.assertRaisesRegexp(ValueError, 'VPaddingCell constructor specified both a size of 5 bytes and payload of 1 bytes', VPaddingCell, 5, '\x02')
def test_certs_cell(self): for cell_bytes, certs in CERTS_CELLS.items(): self.assertEqual(cell_bytes, CertsCell(certs).pack(2)) - self.assertEqual(certs, Cell.unpack(cell_bytes, 2)[0].certificates) + self.assertEqual(certs, Cell.pop(cell_bytes, 2)[0].certificates)
# extra bytes after the last certificate should be ignored
- self.assertEqual([Certificate(1, '\x08')], Cell.unpack('\x00\x00\x81\x00\x07\x01\x01\x00\x01\x08\x06\x04', 2)[0].certificates) + self.assertEqual([Certificate(1, '\x08')], Cell.pop('\x00\x00\x81\x00\x07\x01\x01\x00\x01\x08\x06\x04', 2)[0].certificates)
# ... but truncated or missing certificates should error
- self.assertRaisesRegexp(ValueError, 'CERTS cell should have a certificate with 3 bytes, but only had 1 remaining', Cell.unpack, '\x00\x00\x81\x00\x05\x01\x01\x00\x03\x08', 2) - self.assertRaisesRegexp(ValueError, 'CERTS cell indicates it should have 2 certificates, but only contained 1', Cell.unpack, '\x00\x00\x81\x00\x05\x02\x01\x00\x01\x08', 2) + self.assertRaisesRegexp(ValueError, 'CERTS cell should have a certificate with 3 bytes, but only had 1 remaining', Cell.pop, '\x00\x00\x81\x00\x05\x01\x01\x00\x03\x08', 2) + self.assertRaisesRegexp(ValueError, 'CERTS cell indicates it should have 2 certificates, but only contained 1', Cell.pop, '\x00\x00\x81\x00\x05\x02\x01\x00\x01\x08', 2)
def test_auth_challenge_cell(self): for cell_bytes, (challenge, methods) in AUTH_CHALLENGE_CELLS.items(): self.assertEqual(cell_bytes, AuthChallengeCell(methods, challenge).pack(2))
- cell = Cell.unpack(cell_bytes, 2)[0] + cell = Cell.pop(cell_bytes, 2)[0] self.assertEqual(challenge, cell.challenge) self.assertEqual(methods, cell.methods)
- self.assertRaisesRegexp(ValueError, 'AUTH_CHALLENGE cell should have a payload of 38 bytes, but only had 16', Cell.unpack, '\x00\x00\x82\x00&%s\x00\x02\x00\x01\x00\x03' % CHALLENGE[:10], 2) - self.assertRaisesRegexp(ValueError, 'AUTH_CHALLENGE should have 3 methods, but only had 4 bytes for it', Cell.unpack, '\x00\x00\x82\x00&%s\x00\x03\x00\x01\x00\x03' % CHALLENGE, 2) + self.assertRaisesRegexp(ValueError, 'AUTH_CHALLENGE cell should have a payload of 38 bytes, but only had 16', Cell.pop, '\x00\x00\x82\x00&%s\x00\x02\x00\x01\x00\x03' % CHALLENGE[:10], 2) + self.assertRaisesRegexp(ValueError, 'AUTH_CHALLENGE should have 3 methods, but only had 4 bytes for it', Cell.pop, '\x00\x00\x82\x00&%s\x00\x03\x00\x01\x00\x03' % CHALLENGE, 2)