Add ObjCUnrecognizedSelector exception

src/chomper/core.py

@@ -19,7 +19,7 @@
 
 from . import const
 from .arch import arm_arch, arm64_arch
-from .exceptions import EmulatorCrashedException, SymbolMissingException
+from .exceptions import EmulatorCrashed, SymbolMissing
 from .file import FileManager
 from .instruction import AutomicInstruction
 from .memory import MemoryManager
@@ -244,7 +244,7 @@ def find_symbol(self, symbol_name: str) -> Symbol:
                 if symbol.name == symbol_name:
                     return symbol
 
-        raise SymbolMissingException(f"{symbol_name} not found")
+        raise SymbolMissing(f"{symbol_name} not found")
 
     def debug_symbol(self, address: int) -> str:
         """Format address to `libtest.so!0x1000` or `0x10000`."""
@@ -352,15 +352,12 @@ def crash(self, message: str, exc: Optional[Exception] = None):
             EmulatorCrashedException:
         """
         address = self.uc.reg_read(self.arch.reg_pc)
-
         self.logger.error(
             "Emulator crashed from: %s",
             " <- ".join([self.debug_symbol(t) for t in self.backtrace()]),
         )
 
-        raise EmulatorCrashedException(
-            f"{message} at {self.debug_symbol(address)}"
-        ) from exc
+        raise EmulatorCrashed(f"{message} at {self.debug_symbol(address)}") from exc
 
     def trace_symbol_call_callback(
         self, uc: Uc, address: int, size: int, user_data: dict
@@ -389,8 +386,8 @@ def missing_symbol_required_callback(*args):
         user_data = args[-1]
         symbol_name = user_data["symbol_name"]
 
-        raise EmulatorCrashedException(
-            f'Missing symbol "{symbol_name}" is required, '
+        raise EmulatorCrashed(
+            f"Missing symbol '{symbol_name}' is required, "
             f"you should load the library that contains it."
         )
 

src/chomper/exceptions.py

@@ -1,6 +1,14 @@
-class EmulatorCrashedException(Exception):
+class ChomperException(Exception):
+    """Base class for all Chomper exceptions."""
+
+
+class EmulatorCrashed(ChomperException):
     """Emulate failed when calling functions."""
 
 
-class SymbolMissingException(Exception):
+class SymbolMissing(ChomperException):
     """Symbol not found from loaded modules."""
+
+
+class ObjCUnrecognizedSelector(ChomperException):
+    """Unrecognized selector sent when calling ObjC."""

src/chomper/os/ios/fixup.py

@@ -1,6 +1,6 @@
 import lief
 
-from chomper.exceptions import SymbolMissingException
+from chomper.exceptions import SymbolMissing
 from chomper.types import Module
 
 
@@ -301,7 +301,7 @@ def fixup_dispatch_vtable(self):
                     offset = 0x30 + 0x8 * i
                     address = self.emu.read_pointer(symbol.address + offset)
                     self.add_refs_relocation(address)
-        except SymbolMissingException:
+        except SymbolMissing:
             pass
 
     def fixup_data_const_segment(self, binary: lief.MachO.Binary):

src/chomper/os/ios/hooks.py

@@ -6,7 +6,7 @@
 from functools import wraps
 from typing import Callable, Dict
 
-from chomper.exceptions import SymbolMissingException
+from chomper.exceptions import SymbolMissing, ObjCUnrecognizedSelector
 from chomper.objc import ObjC
 from chomper.utils import pyobj2cfobj
 
@@ -354,7 +354,7 @@ def hook_dlsym(uc, address, size, user_data):
     try:
         symbol = emu.find_symbol(symbol_name)
         return symbol.address
-    except SymbolMissingException:
+    except SymbolMissing:
         pass
 
     return 0
@@ -563,3 +563,13 @@ def hook_mach_vm_deallocate(uc, address, size, user_data):
     emu.memory_manager.free(mem)
 
     return 0
+
+
+@register_hook("+[NSObject(NSObject) doesNotRecognizeSelector:]")
+@register_hook("-[NSObject(NSObject) doesNotRecognizeSelector:]")
+def ns_object_does_not_recognize_selector(uc, address, size, user_data):
+    emu = user_data["emu"]
+
+    selector = emu.read_string(emu.get_arg(2))
+
+    raise ObjCUnrecognizedSelector(f"Unrecognized selector '{selector}'")

src/chomper/os/ios/os.py

@@ -3,7 +3,7 @@
 import uuid
 from typing import List
 
-from chomper.exceptions import EmulatorCrashedException
+from chomper.exceptions import EmulatorCrashed
 from chomper.loader import MachoLoader
 from chomper.os import BaseOs
 from chomper.types import Module
@@ -263,7 +263,7 @@ def init_objc(self, module: Module):
         try:
             self.emu.call_symbol("_map_images", 1, 0, mach_header_ptrs)
             self.emu.call_symbol("_load_images", 0, mach_header_ptr)
-        except EmulatorCrashedException:
+        except EmulatorCrashed:
             self.emu.logger.warning("Initialize Objective-C failed.")
         finally:
             module.binary = None

tests/conftest.py

@@ -8,8 +8,6 @@
 from chomper.const import ARCH_ARM, ARCH_ARM64, OS_IOS
 from chomper.objc import ObjC
 
-BINARY_URL = "https://sourceforge.net/projects/chomper-emu/files/%s/download"
-
 base_path = os.path.abspath(os.path.dirname(__file__))
 
 android_lib_path = os.path.join(base_path, "../examples/rootfs/android/system/lib")
@@ -21,24 +19,22 @@
 ios_binaries_path = os.path.join(base_path, "../examples/binaries/ios")
 
 
-def download_file(url: str, filepath: str):
+def download_binary_file(binary_path: str) -> str:
+    filepath = os.path.join(base_path, "..", binary_path)
+
     path = Path(filepath).resolve()
     if path.exists():
-        return
+        return filepath
+
     if not path.parent.exists():
         path.parent.mkdir(parents=True)
-    print(f"Downloading file: {url}")
-    urllib.request.urlretrieve(url, path)
 
+    url = "https://sourceforge.net/projects/chomper-emu/files/%s/download" % binary_path
 
-@pytest.fixture(scope="module")
-def input_str():
-    yield "chomper"
-
+    print(f"Downloading file: {url}")
+    urllib.request.urlretrieve(url, path)
 
-@pytest.fixture(scope="module")
-def input_bytes(input_str):
-    yield input_str.encode("utf-8")
+    return filepath
 
 
 @pytest.fixture(scope="module")
@@ -59,11 +55,8 @@ def libz_arm(emu_arm):
 @pytest.fixture(scope="module")
 def libdusanwa_v4856_arm(emu_arm):
     """From com.shizhuang.duapp v4.85.6"""
-    binary_path = "examples/binaries/android/com.shizhuang.duapp/libdusanwa.so"
-    module_path = os.path.join(base_path, "..", binary_path)
-    download_file(
-        url=BINARY_URL % binary_path,
-        filepath=module_path,
+    module_path = download_binary_file(
+        binary_path="examples/binaries/android/com.shizhuang.duapp/libdusanwa.so"
     )
 
     yield emu_arm.load_module(
@@ -90,11 +83,8 @@ def libz_arm64(emu_arm64):
 @pytest.fixture(scope="module")
 def libszstone_v4945_arm64(emu_arm64):
     """From com.shizhuang.duapp v4.94.5"""
-    binary_path = "examples/binaries/android/com.shizhuang.duapp/libszstone.so"
-    module_path = os.path.join(base_path, "..", binary_path)
-    download_file(
-        url=BINARY_URL % binary_path,
-        filepath=module_path,
+    module_path = download_binary_file(
+        binary_path="examples/binaries/android/com.shizhuang.duapp/libszstone.so"
     )
 
     yield emu_arm64.load_module(
@@ -106,11 +96,8 @@ def libszstone_v4945_arm64(emu_arm64):
 @pytest.fixture(scope="module")
 def libtiny_v73021_arm64(emu_arm64):
     """From com.xingin.xhs v7.30.2.1"""
-    binary_path = "examples/binaries/android/com.xingin.xhs/libtiny.so"
-    module_path = os.path.join(base_path, "..", binary_path)
-    download_file(
-        url=BINARY_URL % binary_path,
-        filepath=module_path,
+    module_path = download_binary_file(
+        binary_path="examples/binaries/android/com.xingin.xhs/libtiny.so"
     )
 
     yield emu_arm64.load_module(module_path)

tests/test_emulator.py

@@ -50,8 +50,8 @@ def test_create_buffer(emu_arm64):
     assert result is not None
 
 
-def test_create_string(emu_arm64, input_str):
-    result = emu_arm64.create_string(input_str)
+def test_create_string(emu_arm64):
+    result = emu_arm64.create_string("chomper")
 
     assert result is not None
 
@@ -71,22 +71,26 @@ def test_read_and_write_int(emu_arm64):
     assert result == value
 
 
-def test_read_and_write_bytes(emu_arm64, input_bytes):
+def test_read_and_write_bytes(emu_arm64):
+    sample_bytes = b"chomper"
+
     addr = emu_arm64.create_buffer(1024)
 
-    emu_arm64.write_bytes(addr, input_bytes)
-    result = emu_arm64.read_bytes(addr, len(input_bytes))
+    emu_arm64.write_bytes(addr, sample_bytes)
+    result = emu_arm64.read_bytes(addr, len(sample_bytes))
+
+    assert result == sample_bytes
 
-    assert result == input_bytes
 
+def test_read_and_write_string(emu_arm64):
+    sample_str = "chomper"
 
-def test_read_and_write_string(emu_arm64, input_str):
     addr = emu_arm64.create_buffer(1024)
 
-    emu_arm64.write_string(addr, input_str)
+    emu_arm64.write_string(addr, sample_str)
     result = emu_arm64.read_string(addr)
 
-    assert result == input_str
+    assert result == sample_str
 
 
 @pytest.mark.usefixtures("libz_arm64")

tests/test_examples.py

@@ -4,14 +4,16 @@
 
 
 @pytest.mark.usefixtures("libc_arm", "libz_arm")
-def test_libdusanwa_v4856_arm(emu_arm, libdusanwa_v4856_arm, input_bytes):
+def test_libdusanwa_v4856_arm(emu_arm, libdusanwa_v4856_arm):
+    sample_bytes = b"chomper"
+
     a1 = emu_arm.create_buffer(32)
     a2 = 32
     a3 = emu_arm.create_buffer(32)
     a4 = emu_arm.create_buffer(32)
 
-    emu_arm.write_bytes(a1, input_bytes)
-    emu_arm.write_bytes(a4, input_bytes)
+    emu_arm.write_bytes(a1, sample_bytes)
+    emu_arm.write_bytes(a4, sample_bytes)
 
     emu_arm.call_address((libdusanwa_v4856_arm.base + 0xA588) | 1, a1, a2, a3, a4)
     result = emu_arm.read_bytes(a3, a2)
@@ -20,12 +22,14 @@ def test_libdusanwa_v4856_arm(emu_arm, libdusanwa_v4856_arm, input_bytes):
 
 
 @pytest.mark.usefixtures("libc_arm64", "libz_arm64")
-def test_libszstone_v4945_arm64(emu_arm64, libszstone_v4945_arm64, input_bytes):
-    a1 = emu_arm64.create_buffer(len(input_bytes))
-    a2 = len(input_bytes)
+def test_libszstone_v4945_arm64(emu_arm64, libszstone_v4945_arm64):
+    sample_bytes = b"chomper"
+
+    a1 = emu_arm64.create_buffer(len(sample_bytes))
+    a2 = len(sample_bytes)
     a3 = emu_arm64.create_buffer(1024)
 
-    emu_arm64.write_bytes(a1, input_bytes)
+    emu_arm64.write_bytes(a1, sample_bytes)
 
     result_size = emu_arm64.call_address(
         libszstone_v4945_arm64.base + 0x2F1C8, a1, a2, a3
@@ -36,13 +40,15 @@ def test_libszstone_v4945_arm64(emu_arm64, libszstone_v4945_arm64, input_bytes):
 
 
 @pytest.mark.usefixtures("libc_arm64", "libz_arm64")
-def test_libtiny_v73021_arm64(emu_arm64, libtiny_v73021_arm64, input_bytes):
+def test_libtiny_v73021_arm64(emu_arm64, libtiny_v73021_arm64):
+    sample_bytes = b"chomper"
+
     a1 = emu_arm64.create_buffer(32)
     a2 = emu_arm64.create_buffer(32)
     a3 = emu_arm64.create_buffer(32)
 
-    emu_arm64.write_bytes(a1, input_bytes * 4)
-    emu_arm64.write_bytes(a2, input_bytes * 4)
+    emu_arm64.write_bytes(a1, sample_bytes * 4)
+    emu_arm64.write_bytes(a2, sample_bytes * 4)
 
     emu_arm64.call_address(libtiny_v73021_arm64.base + 0x289A4, a1, a2, a3)
     result = emu_arm64.read_bytes(a3, 32)

tests/test_exceptions.py

@@ -6,11 +6,11 @@
 
 from chomper import Chomper
 from chomper.const import ARCH_ARM64
-from chomper.exceptions import EmulatorCrashedException
+from chomper.exceptions import EmulatorCrashed
 
 
 def test_unhandled_system_call_exception():
-    with pytest.raises(EmulatorCrashedException, match=r"Unhandled system call.*"):
+    with pytest.raises(EmulatorCrashed, match=r"Unhandled system call.*"):
         emu = Chomper(arch=ARCH_ARM64)
         emu.hooks.pop("malloc")
 
@@ -19,21 +19,20 @@ def test_unhandled_system_call_exception():
         emu.call_symbol("malloc")
 
 
-def test_missing_symbol_required_exception(input_bytes):
-    with pytest.raises(EmulatorCrashedException, match=r"Missing symbol.*"):
-        binary_path = "examples/binaries/android/com.shizhuang.duapp/libszstone.so"
-        module_path = os.path.join(conftest.base_path, "..", binary_path)
-        conftest.download_file(
-            url=conftest.BINARY_URL % binary_path,
-            filepath=module_path,
+def test_missing_symbol_required_exception():
+    with pytest.raises(EmulatorCrashed, match=r"Missing symbol.*"):
+        module_path = conftest.download_binary_file(
+            binary_path="examples/binaries/android/com.shizhuang.duapp/libszstone.so"
         )
 
+        sample_bytes = b"chomper"
+
         emu = Chomper(arch=ARCH_ARM64)
         libszstone = emu.load_module(module_path)
 
-        a1 = emu.create_buffer(len(input_bytes))
-        a2 = len(input_bytes)
+        a1 = emu.create_buffer(len(sample_bytes))
+        a2 = len(sample_bytes)
         a3 = emu.create_buffer(1024)
 
-        emu.write_bytes(a1, input_bytes)
+        emu.write_bytes(a1, sample_bytes)
         emu.call_address(libszstone.base + 0x289A4, a1, a2, a3)