commit 6a4f46614043e8423c8a45a203acf6ffcf736952 Author: Damian Johnson atagar@torproject.org Date: Fri Jan 26 12:23:19 2018 -0800

Use minimum valid circuit id by default for CREATE_FAST

To work a CREATE_FAST cell must specify a circuit id. Endosome picks one based on the link version with a similar comment to the one we're including here. Endosome also has an 'is_initiator' flag which I'm omitting right now since I suspect that's only relevant if we attempt to implement *being* a relay which isn't in the cards right now. --- stem/client/cell.py | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/stem/client/cell.py b/stem/client/cell.py index a0737765..4062edcf 100644 --- a/stem/client/cell.py +++ b/stem/client/cell.py @@ -394,7 +394,7 @@ class CreateFastCell(CircuitCell): self.key_material = key_material

@classmethod - def pack(cls, link_version, circ_id, key_material = None): + def pack(cls, link_version, circ_id = None, key_material = None): """ Provides a randomized circuit construction payload.

@@ -405,6 +405,12 @@ class CreateFastCell(CircuitCell): :returns: **bytes** with our randomized key material """

+ if circ_id is None: + # When initiating a circuit the v4 link protocol requires us to set the + # most significant bit. Otherwise any id will do. + + circ_id = 0x80000000 if link_version >= 4 else 0x01 + if key_material and len(key_material) != HASH_LEN: raise ValueError('Key material should be %i bytes, but was %i' % (HASH_LEN, len(key_material)))