zulip/zerver/lib/unminify.py

73 lines
3.2 KiB
Python

import os
import re
from typing import Dict, List, Optional
import sourcemap
from zerver.lib.pysa import mark_sanitized
class SourceMap:
"""Map (line, column) pairs from generated to source file."""
def __init__(self, sourcemap_dirs: List[str]) -> None:
self._dirs = sourcemap_dirs
self._indices: Dict[str, sourcemap.SourceMapDecoder] = {}
def _index_for(self, minified_src: str) -> Optional[sourcemap.SourceMapDecoder]:
"""Return the source map index for minified_src, loading it if not
already loaded."""
# Prevent path traversal
assert ".." not in minified_src and "/" not in minified_src
if minified_src not in self._indices:
for source_dir in self._dirs:
filename = os.path.join(source_dir, minified_src + ".map")
if os.path.isfile(filename):
# Use 'mark_sanitized' to force Pysa to ignore the fact that
# 'filename' is user controlled. While putting user
# controlled data into a filesystem operation is bad, in
# this case it's benign because 'filename' can't traverse
# directories outside of the pre-configured 'sourcemap_dirs'
# (due to the above assertions) and will always end in
# '.map'. Additionally, the result of this function is used
# for error logging and not returned to the user, so
# controlling the loaded file would not be useful to an
# attacker.
with open(mark_sanitized(filename)) as fp:
self._indices[minified_src] = sourcemap.load(fp)
break
return self._indices.get(minified_src)
def annotate_stacktrace(self, stacktrace: str) -> str:
out: str = ""
for ln in stacktrace.splitlines():
out += ln + "\n"
match = re.search(r"/static/webpack-bundles/([^:]+):(\d+):(\d+)", ln)
if match:
# Get the appropriate source map for the minified file.
minified_src = match.groups()[0]
index = self._index_for(minified_src)
if index is None:
out += " [Unable to look up in source map]\n"
continue
gen_line, gen_col = list(map(int, match.groups()[1:3]))
# The sourcemap lib is 0-based, so subtract 1 from line and col.
try:
result = index.lookup(line=gen_line - 1, column=gen_col - 1)
display_src = result.src
if display_src is not None:
webpack_prefix = "webpack:///"
if display_src.startswith(webpack_prefix):
display_src = display_src[len(webpack_prefix) :]
out += f" = {display_src} line {result.src_line+1} column {result.src_col+1}\n"
except IndexError:
out += " [Unable to look up in source map]\n"
if ln.startswith(" at"):
out += "\n"
return out