A relay client could send data with no end-of-line (an unterminated method
or header line) and dribble its payload, making WeeChat accumulate it in the
partial message buffer that grew without limit, until all memory was
exhausted. This path is reachable before authentication during websocket
initialization with the "weechat" and "irc" protocols.
The accumulated partial message is now bounded by
RELAY_HTTP_PARTIAL_MESSAGE_MAX_LENGTH: once the limit is reached, the extra
data is ignored.
A relay client could announce a huge websocket frame (or HTTP body via
"Content-Length") and dribble its payload, making WeeChat accumulate it
in a buffer that grew without limit, until all memory was exhausted. The
websocket frame path is reachable before authentication with the
"weechat" and "irc" protocols.
The announced websocket frame length and HTTP "Content-Length" are now
bounded by WEBSOCKET_FRAME_MAX_LENGTH and RELAY_HTTP_BODY_MAX_LENGTH: an
oversized websocket frame closes the connection, and an oversized body is
rejected.
The IRC relay protocol's PASS handler compared the server password with
the client-supplied value using strcmp, leaking the password byte-by-byte
via response timing. This is the same class of bug fixed for the api and
weechat protocols, on a separate code path that did not go through
relay_auth_check_password_plain.
Extract the HMAC-then-constant-time-compare logic from
relay_auth_check_password_plain into relay_auth_password_equals, then
use it in both the plain-auth wrapper and the IRC PASS handler.
The relay authentication used non-constant-time comparisons (strcasecmp,
strcmp) to verify password hashes and plaintext passwords, allowing an
attacker to derive the expected hash byte-by-byte from response timing
and then authenticate without knowing the password.
- SHA/PBKDF2 hex hash comparisons: normalize the client-supplied hash to
uppercase and compare in constant time over the fixed expected length.
- Plaintext password comparison: HMAC-SHA256 both passwords with a fresh
per-call random key and compare the fixed-size MACs in constant time,
hiding both per-byte timing and the password length.
Add string_memcmp_constant_time helper in core, exposed via the plugin
API. Bump WEECHAT_PLUGIN_API_VERSION accordingly.
An authenticated relay client using the permessage-deflate websocket
extension could send a small compressed frame that decompresses to an
unbounded amount of data, exhausting all memory and crashing WeeChat.
The output buffer in relay_websocket_inflate is now capped to
WEBSOCKET_INFLATE_MAX_SIZE: frames decompressing beyond this limit are
rejected and the connection is closed.
Move the respective include_directories() stansas to the top-level
cmakefile. While this technically adds them to targets where they are
not needed, there is no harm is having them.
This maskes the find_dependency/use_includes/use_libs more consistent
across the board and helps it stand out where it's forgotten. Fixes for
which will be coming at a later date.
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
When invalid data is received (not an HTTP request), client->http_req->method
is NULL, so we have to check it's not NULL before comparing it to the supported
methods.
This fixes a regression introduced in commit
93ec10b563.
This fixes the API probe made by schemathesis, so it detects immediately that
such NULL byte is not allowed by WeeChat, instead of timing out after 10
seconds:
✅ API capabilities:
Supports NULL byte in headers: ✘
This reverts commit e64ab3c675.
This was causing incorrect conversion of strings "0x..." to pointers on systems
like Solaris/illumos.
And as a side effect, buffers were sometimes empty in weechat relay clients
like glowing-bear.
Sébastien Helleu