def test_no_space_for_new_load_command(self) -> None:
# Given a binary with 0x5630 bytes of free space at the end of the Mach-O header
binary = MachoParser(self.THIN_PATH).get_arm64_slice()
assert binary
dylib_path = "@rpath/load_cmd_with_32_chrcters"
# If I have a dylib load command which will take up `0x20 + len(dylib_path) = 0x38` bytes
# Then I should be able to add this load command exactly 344 times before the binary runs out of space
for _ in range(344):
binary = binary.insert_load_dylib_cmd(dylib_path)
with pytest.raises(NoEmptySpaceForLoadCommandError):
binary.insert_load_dylib_cmd(dylib_path)
def test_add_load_command(self) -> None:
# Given a binary with some known load-commands
binary = MachoParser(self.CLASSLIST_DATA_CONST).get_arm64_slice()
assert binary
original_dylibs = [
"/System/Library/Frameworks/Foundation.framework/Foundation",
"/usr/lib/libobjc.A.dylib",
"/usr/lib/libSystem.B.dylib",
"/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation",
"/System/Library/Frameworks/Security.framework/Security",
"/System/Library/Frameworks/UIKit.framework/UIKit",
]
found_dylibs = [binary.dylib_name_for_library_ordinal(i + 1) for i in range(len(binary.load_dylib_commands))]
assert found_dylibs == original_dylibs
# If I create a new binary with an inserted load command
modified_binary = binary.insert_load_dylib_cmd("@rpath/Frameworks/Interject.framework/Interject")
modified_dylibs = [
"/System/Library/Frameworks/Foundation.framework/Foundation",
"/usr/lib/libobjc.A.dylib",
"/usr/lib/libSystem.B.dylib",
"/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation",
"/System/Library/Frameworks/Security.framework/Security",
"/System/Library/Frameworks/UIKit.framework/UIKit",
"@rpath/Frameworks/Interject.framework/Interject",
]
found_dylibs = [
modified_binary.dylib_name_for_library_ordinal(i + 1)
for i in range(len(modified_binary.load_dylib_commands))
]
assert found_dylibs == modified_dylibs
def test_write_thin_binary(self) -> None:
binary = MachoParser(self.THIN_PATH).get_arm64_slice()
assert binary
original_dylibs = [binary.dylib_name_for_library_ordinal(i + 1) for i in range(len(binary.load_dylib_commands))]
# Given I add a load command to a binary
new_dylib_name = "@rpath/Frameworks/Interject.framework/Interject"
modified_binary = binary.insert_load_dylib_cmd(new_dylib_name)
with TemporaryDirectory() as tempdir:
output_binary_path = pathlib.Path(tempdir) / "modified_binary"
# If I write the binary to disk, then parse the on-disk version
modified_binary.write_binary(output_binary_path)
on_disk_binary = MachoParser(output_binary_path).get_arm64_slice()
assert on_disk_binary
# Then the new on-disk binary contains the modification
new_dylibs = [
on_disk_binary.dylib_name_for_library_ordinal(i + 1)
for i in range(len(on_disk_binary.load_dylib_commands))
]
assert new_dylibs == original_dylibs + [new_dylib_name]