Merge commit from fork

Better repo sanitization for gitdumper

Author: TheTechromancer

bbot/core/helpers/git.py

@@ -0,0 +1,18 @@
+import regex as re
+from pathlib import Path
+
+
+def sanitize_git_repo(repo_folder: Path):
+    # sanitizing the git config is infeasible since there are too many different ways to do evil things
+    # instead, we move it out of .git and into the repo folder, so we don't miss any secrets etc. inside
+    config_file = repo_folder / ".git" / "config"
+    if config_file.exists():
+        config_file.rename(repo_folder / "git_config_original")
+    # move the index file
+    index_file = repo_folder / ".git" / "index"
+    if index_file.exists():
+        index_file.rename(repo_folder / "git_index_original")
+    # move the hooks folder
+    hooks_folder = repo_folder / ".git" / "hooks"
+    if hooks_folder.exists():
+        hooks_folder.rename(repo_folder / "git_hooks_original")

bbot/core/helpers/misc.py

@@ -17,6 +17,7 @@
 from asyncio import create_task, gather, sleep, wait_for  # noqa
 from urllib.parse import urlparse, quote, unquote, urlunparse, urljoin  # noqa F401
 
+from .git import *  # noqa F401
 from .url import *  # noqa F401
 from ... import errors
 from . import regexes as bbot_regexes

bbot/modules/git_clone.py

@@ -82,4 +82,11 @@ async def clone_git_repository(self, repository_url):
             return
 
         folder_name = output.stderr.split("Cloning into '")[1].split("'")[0]
-        return folder / folder_name
+        repo_folder = folder / folder_name
+
+        # sanitize the repo
+        # this moves the git config, index file, and hooks folder out of the .git folder to prevent nasty things
+        # Note: the index file can be regenerated by running "git checkout HEAD -- ."
+        self.helpers.sanitize_git_repo(repo_folder)
+
+        return repo_folder

bbot/modules/gitdumper.py

@@ -35,7 +35,6 @@ async def setup(self):
         else:
             self.output_dir = self.scan.temp_dir / "git_repos"
         self.helpers.mkdir(self.output_dir)
-        self.unsafe_regex = self.helpers.re.compile(r"^\s*fsmonitor|sshcommand|askpass|editor|pager", re.IGNORECASE)
         self.ref_regex = self.helpers.re.compile(r"ref: refs/heads/([a-zA-Z\d_-]+)")
         self.obj_regex = self.helpers.re.compile(r"[a-f0-9]{40}")
         self.pack_regex = self.helpers.re.compile(r"pack-([a-f0-9]{40})\.pack")
@@ -131,7 +130,6 @@ async def handle_event(self, event):
         else:
             result = await self.git_fuzz(repo_url, repo_folder)
         if result:
-            await self.sanitize_config(repo_folder)
             await self.git_checkout(repo_folder)
             codebase_event = self.make_event({"path": str(repo_folder)}, "FILESYSTEM", tags=["git"], parent=event)
             await self.emit_event(
@@ -251,15 +249,6 @@ async def download_files(self, urls, folder):
             self.debug(f"Unable to download git files to {folder}")
             return False
 
-    async def sanitize_config(self, folder):
-        config_file = folder / ".git/config"
-        if config_file.exists():
-            with config_file.open("r", encoding="utf-8", errors="ignore") as file:
-                content = file.read()
-                sanitized = await self.helpers.re.sub(self.unsafe_regex, r"# \g<0>", content)
-            with config_file.open("w", encoding="utf-8") as file:
-                file.write(sanitized)
-
     async def git_catfile(self, hash, option="-t", folder=Path()):
         command = ["git", "cat-file", option, hash]
         try:
@@ -270,8 +259,10 @@ async def git_catfile(self, hash, option="-t", folder=Path()):
         return output.stdout
 
     async def git_checkout(self, folder):
+        self.helpers.sanitize_git_repo(folder)
         self.verbose(f"Running git checkout to reconstruct the git repository at {folder}")
-        command = ["git", "checkout", "."]
+        # we do "checkout head -- ." because the sanitization deletes the index file, and it needs to be reconstructed
+        command = ["git", "checkout", "HEAD", "--", "."]
         try:
             await self.run_process(command, env={"GIT_TERMINAL_PROMPT": "0"}, cwd=folder, check=True)
         except CalledProcessError as e: