Skip to content

Fix Socket Mode builtin WebSocket masked payload unmasking (RFC 6455) #1858

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
beejak wants to merge 1 commit into
base: main
Choose a base branch
from
+6 −3
Open

Fix Socket Mode builtin WebSocket masked payload unmasking (RFC 6455) #1858

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 6 additions & 3 deletions slack_sdk/socket_mode/builtin/internals.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,7 @@ def _generate_sec_websocket_key() -> str:

def _validate_sec_websocket_accept(sec_websocket_key: str, headers: dict) -> bool:
v = (sec_websocket_key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11").encode("utf-8")
# RFC 6455 section 1.3: Sec-WebSocket-Accept must use SHA-1 over the challenge key.
expected = encodebytes(hashlib.sha1(v).digest()).decode("utf-8").strip()
actual = headers.get("sec-websocket-accept", "").strip()
return compare_digest(expected, actual)
Expand Down Expand Up @@ -306,10 +307,12 @@ def _fetch_messages(

current_data = bytes()
if current_header.masked > 0:
for i in range(data_to_append): # type: ignore[call-overload]
# bytes is immutable; RFC 6455 masking XORs octets (use bytearray).
mutable_payload = bytearray(data_to_append)
for i in range(len(mutable_payload)):
mask = current_mask_key[i % 4] # type: ignore[index]
data_to_append[i] ^= mask # type: ignore[index]
current_data += data_to_append
mutable_payload[i] ^= mask
current_data += bytes(mutable_payload)
else:
current_data += data_to_append
if len(current_data) == current_data_length:
Expand Down