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add idalib backend
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williballenthin committed Sep 20, 2024
1 parent a8e5261 commit 02b5930
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2 changes: 2 additions & 0 deletions CHANGELOG.md
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@

### New Features

- add IDA v9.0 backend via idalib #2376 @williballenthin

### Breaking Changes

### New Rules (0)
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4 changes: 3 additions & 1 deletion capa/features/extractors/ida/extractor.py
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Expand Up @@ -32,7 +32,9 @@ class IdaFeatureExtractor(StaticFeatureExtractor):
def __init__(self):
super().__init__(
hashes=SampleHashes(
md5=ida_nalt.retrieve_input_file_md5(), sha1="(unknown)", sha256=ida_nalt.retrieve_input_file_sha256()
md5=ida_nalt.retrieve_input_file_md5().hex(),
sha1="(unknown)",
sha256=ida_nalt.retrieve_input_file_sha256().hex(),
)
)
self.global_features: List[Tuple[Feature, Address]] = []
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113 changes: 113 additions & 0 deletions capa/features/extractors/ida/idalib.py
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@@ -0,0 +1,113 @@
# Copyright (C) 2024 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import os
import sys
import json
import logging
import importlib.util
from typing import Optional
from pathlib import Path

logger = logging.getLogger(__name__)


def is_idalib_installed() -> bool:
try:
return importlib.util.find_spec("ida") is not None
except ModuleNotFoundError:
return False


def get_idalib_user_config_path() -> Optional[Path]:
"""Get the path to the user's config file based on platform following IDA's user directories."""
# derived from `py-activate-idalib.py` from IDA v9.0 Beta 4

if sys.platform == "win32":
# On Windows, use the %APPDATA%\Hex-Rays\IDA Pro directory
config_dir = Path(os.getenv("APPDATA")) / "Hex-Rays" / "IDA Pro"
else:
# On macOS and Linux, use ~/.idapro
config_dir = Path.home() / ".idapro"

# Return the full path to the config file (now in JSON format)
user_config_path = config_dir / "ida-config.json"
if not user_config_path.exists():
return None
return user_config_path


def find_idalib() -> Optional[Path]:
config_path = get_idalib_user_config_path()
if not config_path:
return None

config = json.loads(config_path.read_text(encoding="utf-8"))

try:
ida_install_dir = Path(config["Paths"]["ida-install-dir"])
except KeyError:
return None

if not ida_install_dir.exists():
return None

libname = {
"win32": "idalib.dll",
"linux": "libidalib.so",
"linux2": "libidalib.so",
"darwin": "libidalib.dylib",
}[sys.platform]

if not (ida_install_dir / "ida.hlp").is_file():
return None

if not (ida_install_dir / libname).is_file():
return None

idalib_path = ida_install_dir / "idalib" / "python"
if not idalib_path.exists():
return None

if not (idalib_path / "ida" / "__init__.py").is_file():
return None

return idalib_path


def has_idalib() -> bool:
if is_idalib_installed():
logger.debug("found installed IDA idalib API")
return True

logger.debug("IDA idalib API not installed, searching...")

idalib_path = find_idalib()
if not idalib_path:
logger.debug("failed to find IDA idalib installation")

logger.debug("found IDA idalib API: %s", idalib_path)
return idalib_path is not None


def load_idalib() -> bool:
try:
import ida

return True
except ImportError:
idalib_path = find_idalib()
if not idalib_path:
return False

sys.path.append(idalib_path.absolute().as_posix())
try:
import ida # noqa: F401 unused import

return True
except ImportError:
return False
44 changes: 44 additions & 0 deletions capa/helpers.py
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Expand Up @@ -6,9 +6,12 @@
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import os
import io
import sys
import gzip
import ctypes
import inspect
import tempfile
import logging
import contextlib
import importlib.util
Expand Down Expand Up @@ -81,6 +84,47 @@ def assert_never(value) -> NoReturn:
assert False, f"Unhandled value: {value} ({type(value).__name__})" # noqa: B011


# Redirect stdout at the C runtime level,
# which lets us handle native libraries that spam stdout.
# via: https://eli.thegreenplace.net/2015/redirecting-all-kinds-of-stdout-in-python/
LIBC = ctypes.CDLL(None)
C_STDOUT = ctypes.c_void_p.in_dll(LIBC, "stdout")


@contextlib.contextmanager
def stdout_redirector(stream):
# The original fd stdout points to. Usually 1 on POSIX systems.
original_stdout_fd = sys.stdout.fileno()

def _redirect_stdout(to_fd):
"""Redirect stdout to the given file descriptor."""
# Flush the C-level buffer stdout
LIBC.fflush(C_STDOUT)
# Flush and close sys.stdout - also closes the file descriptor (fd)
sys.stdout.close()
# Make original_stdout_fd point to the same file as to_fd
os.dup2(to_fd, original_stdout_fd)
# Create a new sys.stdout that points to the redirected fd
sys.stdout = io.TextIOWrapper(os.fdopen(original_stdout_fd, 'wb'))

# Save a copy of the original stdout fd in saved_stdout_fd
saved_stdout_fd = os.dup(original_stdout_fd)
try:
# Create a temporary file and redirect stdout to it
tfile = tempfile.TemporaryFile(mode='w+b')
_redirect_stdout(tfile.fileno())
# Yield to caller, then redirect stdout back to the saved fd
yield
_redirect_stdout(saved_stdout_fd)
# Copy contents of temporary file to the given stream
tfile.flush()
tfile.seek(0, io.SEEK_SET)
stream.write(tfile.read())
finally:
tfile.close()
os.close(saved_stdout_fd)


def load_json_from_path(json_path: Path):
with gzip.open(json_path, "r") as compressed_report:
try:
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32 changes: 32 additions & 0 deletions capa/loader.py
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.
import io
import os
import sys
import logging
Expand Down Expand Up @@ -69,6 +70,7 @@
BACKEND_VMRAY = "vmray"
BACKEND_FREEZE = "freeze"
BACKEND_BINEXPORT2 = "binexport2"
BACKEND_IDA = "ida"


class CorruptFile(ValueError):
Expand Down Expand Up @@ -321,6 +323,36 @@ def get_extractor(

return capa.features.extractors.binexport2.extractor.BinExport2FeatureExtractor(be2, buf)

elif backend == BACKEND_IDA:
import capa.features.extractors.ida.idalib as idalib

if not idalib.has_idalib():
raise RuntimeError(
# TODO(williballenthin): add more details here
"cannot find IDA idalib module."
)

if not idalib.load_idalib():
raise RuntimeError("failed to load IDA idalib module.")

import ida
import ida_auto

import capa.features.extractors.ida.extractor

logger.debug("idalib: opening database...")
# idalib writes to stdout (ugh), so we have to capture that
# so as not to screw up structured output.
with capa.helpers.stdout_redirector(io.BytesIO()):
if ida.open_database(str(input_path), run_auto_analysis=True):
raise RuntimeError("failed to analyze input file")

logger.debug("idalib: waiting for analysis...")
ida_auto.auto_wait()
logger.debug("idalib: opened database.")

return capa.features.extractors.ida.extractor.IdaFeatureExtractor()

else:
raise ValueError("unexpected backend: " + backend)

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2 changes: 2 additions & 0 deletions capa/main.py
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,7 @@
from capa.rules import RuleSet
from capa.engine import MatchResults
from capa.loader import (
BACKEND_IDA,
BACKEND_VIV,
BACKEND_CAPE,
BACKEND_BINJA,
Expand Down Expand Up @@ -283,6 +284,7 @@ def install_common_args(parser, wanted=None):
backends = [
(BACKEND_AUTO, "(default) detect appropriate backend automatically"),
(BACKEND_VIV, "vivisect"),
(BACKEND_IDA, "IDA via idalib"),
(BACKEND_PEFILE, "pefile (file features only)"),
(BACKEND_BINJA, "Binary Ninja"),
(BACKEND_DOTNET, ".NET"),
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1 change: 1 addition & 0 deletions pyproject.toml
Original file line number Diff line number Diff line change
Expand Up @@ -185,6 +185,7 @@ known_first_party = [
"ghidra",
"ida",
"ida_ida",
"ida_auto",
"ida_bytes",
"ida_entry",
"ida_funcs",
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108 changes: 10 additions & 98 deletions scripts/detect-backends.py
Original file line number Diff line number Diff line change
@@ -1,6 +1,13 @@
# Copyright (C) 2024 Mandiant, Inc. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at: [package root]/LICENSE.txt
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.

import os
import sys
import json
import logging
import importlib.util
from typing import Optional
Expand All @@ -9,6 +16,8 @@
import rich
import rich.table

from capa.features.extractors.ida.idalib import find_idalib, load_idalib, is_idalib_installed

logger = logging.getLogger(__name__)


Expand Down Expand Up @@ -143,103 +152,6 @@ def load_vivisect() -> bool:
return False


def is_idalib_installed() -> bool:
try:
return importlib.util.find_spec("ida") is not None
except ModuleNotFoundError:
return False


def get_idalib_user_config_path() -> Optional[Path]:
"""Get the path to the user's config file based on platform following IDA's user directories."""
# derived from `py-activate-idalib.py` from IDA v9.0 Beta 4

if sys.platform == "win32":
# On Windows, use the %APPDATA%\Hex-Rays\IDA Pro directory
config_dir = Path(os.getenv("APPDATA")) / "Hex-Rays" / "IDA Pro"
else:
# On macOS and Linux, use ~/.idapro
config_dir = Path.home() / ".idapro"

# Return the full path to the config file (now in JSON format)
user_config_path = config_dir / "ida-config.json"
if not user_config_path.exists():
return None
return user_config_path


def find_idalib() -> Optional[Path]:
config_path = get_idalib_user_config_path()
if not config_path:
return None

config = json.loads(config_path.read_text(encoding="utf-8"))

try:
ida_install_dir = Path(config["Paths"]["ida-install-dir"])
except KeyError:
return None

if not ida_install_dir.exists():
return None

libname = {
"win32": "idalib.dll",
"linux": "libidalib.so",
"linux2": "libidalib.so",
"darwin": "libidalib.dylib",
}[sys.platform]

if not (ida_install_dir / "ida.hlp").is_file():
return None

if not (ida_install_dir / libname).is_file():
return None

idalib_path = ida_install_dir / "idalib" / "python"
if not idalib_path.exists():
return None

if not (idalib_path / "ida" / "__init__.py").is_file():
return None

return idalib_path


def has_idalib() -> bool:
if is_idalib_installed():
logger.debug("found installed IDA idalib API")
return True

logger.debug("IDA idalib API not installed, searching...")

idalib_path = find_idalib()
if not idalib_path:
logger.debug("failed to find IDA idalib installation")

logger.debug("found IDA idalib API: %s", idalib_path)
return idalib_path is not None


def load_idalib() -> bool:
try:
import ida

return True
except ImportError:
idalib_path = find_idalib()
if not idalib_path:
return False

sys.path.append(idalib_path.absolute().as_posix())
try:
import ida # noqa: F401 unused import

return True
except ImportError:
return False


def main():
logging.basicConfig(level=logging.INFO)

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