Skip to content

fix(appsec): use length-aware libddwaf bindings to prevent NUL byte truncation #18128

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

Closed
KowalskiThomas wants to merge 1 commit into from
Closed

fix(appsec): use length-aware libddwaf bindings to prevent NUL byte truncation #18128

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
29 changes: 25 additions & 4 deletions ddtrace/appsec/_ddwaf/ddwaf_types.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -137,7 +137,7 @@ def _build_mapping(
res_key = res_key[:max_string_length]
obj = ddwaf_object.__new__(ddwaf_object)
_build_ddwaf_object(obj, val, observator, max_objects, max_depth - 1, max_string_length)
ddwaf_object_map_add(map_o, res_key, obj)
ddwaf_object_map_addl(map_o, res_key, len(res_key), obj)
counter_object += 1


Expand All @@ -164,7 +164,7 @@ def _build_ddwaf_object(
if len(encoded) > max_string_length:
observator.set_string_length(len(encoded))
encoded = encoded[:max_string_length]
ddwaf_object_string(self, encoded)
ddwaf_object_stringl(self, encoded, len(encoded))
elif t is list:
_build_sequence(self, struct, observator, max_objects, max_depth, max_string_length)
elif t is int:
Expand All @@ -177,7 +177,7 @@ def _build_ddwaf_object(
if len(struct) > max_string_length:
observator.set_string_length(len(struct))
struct = struct[:max_string_length]
ddwaf_object_string(self, struct)
ddwaf_object_stringl(self, struct, len(struct))
elif struct is None:
ddwaf_object_null(self)
elif isinstance(struct, Sequence):
Expand All @@ -189,7 +189,7 @@ def _build_ddwaf_object(
if len(encoded) > max_string_length:
observator.set_string_length(len(encoded))
encoded = encoded[:max_string_length]
ddwaf_object_string(self, encoded)
ddwaf_object_stringl(self, encoded, len(encoded))


# to allow cyclic references, ddwaf_object fields are defined later
Expand Down Expand Up @@ -500,6 +500,15 @@ def py_ddwaf_builder_get_config_paths(builder: ddwaf_builder_capsule, filter_str
),
)

ddwaf_object_stringl = ctypes.CFUNCTYPE(ddwaf_object_p, ddwaf_object_p, ctypes.c_char_p, ctypes.c_uint64)(
("ddwaf_object_stringl", ddwaf),
(
(3, "object"),
(1, "string"),
(1, "length"),
),
)

# Not used in Python code but kept for completeness with the libddwaf API
ddwaf_object_string_from_unsigned = ctypes.CFUNCTYPE(ddwaf_object_p, ddwaf_object_p, ctypes.c_uint64)(
("ddwaf_object_string_from_unsigned", ddwaf),
Expand Down Expand Up @@ -585,6 +594,18 @@ def py_ddwaf_builder_get_config_paths(builder: ddwaf_builder_capsule, filter_str
),
)

ddwaf_object_map_addl = ctypes.CFUNCTYPE(
ctypes.c_bool, ddwaf_object_p, ctypes.c_char_p, ctypes.c_uint64, ddwaf_object_p
)(
("ddwaf_object_map_addl", ddwaf),
(
(1, "map"),
(1, "key"),
(1, "key_length"),
(1, "object"),
),
)

# unused because accessible from python part
# ddwaf_object_type
# ddwaf_object_size
Expand Down
Loading