mirror of
https://github.com/freedomofpress/dangerzone.git
synced 2025-04-29 02:12:36 +02:00
0b45360384
In d632908a44 we improved our
`replace_control_chars()` function, by replacing every control or
invalid Unicode character with a placeholder one. This change, however,
made our debug logs harder to read, since newlines were not preserved.
There are indeed various cases in which replacing newlines is wise
(e.g., in filenames), so we should keep this behavior by default.
However, specifically for reading debug logs, we add an option to keep
newlines to improve readability, at no expense to security.
100 lines
3.4 KiB
Python
100 lines
3.4 KiB
Python
import pathlib
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import platform
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import string
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import subprocess
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import sys
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import unicodedata
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from typing import Optional
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import appdirs
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def get_config_dir() -> str:
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return appdirs.user_config_dir("dangerzone")
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def get_tmp_dir() -> Optional[str]:
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"""Get the parent dir for the Dangerzone temporary dirs.
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This function returns the parent directory where Dangerzone will store its temporary
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directories. The default behavior is to let Python choose for us (e.g., in `/tmp`
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for Linux), which is why we return None. However, we still need to define this
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function in order to be able to set this dir via mocking in our tests.
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"""
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return None
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def get_resource_path(filename: str) -> str:
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if getattr(sys, "dangerzone_dev", False):
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# Look for resources directory relative to python file
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project_root = pathlib.Path(__file__).parent.parent
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prefix = project_root.joinpath("share")
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else:
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if platform.system() == "Darwin":
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bin_path = pathlib.Path(sys.executable)
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app_path = bin_path.parent.parent
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prefix = app_path.joinpath("Resources", "share")
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elif platform.system() == "Linux":
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prefix = pathlib.Path(sys.prefix).joinpath("share", "dangerzone")
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elif platform.system() == "Windows":
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exe_path = pathlib.Path(sys.executable)
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dz_install_path = exe_path.parent
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prefix = dz_install_path.joinpath("share")
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else:
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raise NotImplementedError(f"Unsupported system {platform.system()}")
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resource_path = prefix.joinpath(filename)
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return str(resource_path)
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def get_version() -> str:
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try:
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with open(get_resource_path("version.txt")) as f:
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version = f.read().strip()
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except FileNotFoundError:
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# In dev mode, in Windows, get_resource_path doesn't work properly for the container, but luckily
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# it doesn't need to know the version
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version = "unknown"
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return version
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def get_subprocess_startupinfo(): # type: ignore [no-untyped-def]
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if platform.system() == "Windows":
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startupinfo = subprocess.STARTUPINFO()
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startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
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return startupinfo
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else:
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return None
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def replace_control_chars(untrusted_str: str, keep_newlines: bool = False) -> str:
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"""Remove control characters from string. Protects a terminal emulator
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from obscure control characters.
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Control characters are replaced by <20> U+FFFD Replacement Character.
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If a user wants to keep the newline character (e.g., because they are sanitizing a
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multi-line text), they must pass `keep_newlines=True`.
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"""
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def is_safe(chr: str) -> bool:
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"""Return whether Unicode character is safe to print in a terminal
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emulator, based on its General Category.
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The following General Category values are considered unsafe:
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* C* - all control character categories (Cc, Cf, Cs, Co, Cn)
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* Zl - U+2028 LINE SEPARATOR only
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* Zp - U+2029 PARAGRAPH SEPARATOR only
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"""
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categ = unicodedata.category(chr)
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if categ.startswith("C") or categ in ("Zl", "Zp"):
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return False
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return True
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sanitized_str = ""
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for char in untrusted_str:
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if (keep_newlines and char == "\n") or is_safe(char):
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sanitized_str += char
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else:
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sanitized_str += "<EFBFBD>"
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return sanitized_str
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