Files
eberkheev a0c996b19d refactor(server): extract helpers and simplify auth dispatch
- Move `sha256_hex` and cookie constants to module level; drop `token_is_hash` param in favour of regex auto-detection
- Make `_respond()` accept `status`/`headers`; add `_redirect()` helper to eliminate boilerplate in auth routes
- Simplify `_dispatch()` with a `PUBLIC_ROUTES` set and positive-logic early-return
- Restrict CORS header to file API; auth responses no longer send `Access-Control-Allow-Origin: *`
- Extract `clearPager()` in frontend and deduplicate `copyText` fallback path
2026-07-29 18:08:36 +04:00

324 lines
12 KiB
Python

"""HTTP server and request handler."""
import email.parser
import email.policy
import hashlib
import hmac
import http.server
import json
import mimetypes
import re
import ssl
import stat
import urllib.parse
from datetime import datetime
from pathlib import Path
from config import CHUNK_SIZE, SNIFF_SIZE, SSL_HANDSHAKE_TIMEOUT
# Keeps `?token=...` out of the log / journald.
_TOKEN_RE = re.compile(r"([?&]token=)[^&\s\"]*")
_SHA256_RE = re.compile(r"[0-9a-f]{64}")
COOKIE_NAME = "share_token"
_COOKIE_ATTRS = "Path=/; HttpOnly; Secure; SameSite=Strict"
_COOKIE_MAX_AGE = 31536000
def sha256_hex(value: str) -> str:
return hashlib.sha256(value.encode()).hexdigest()
def file_type(path: Path) -> str:
ct = mimetypes.guess_type(path.name)[0] or ''
if ct.startswith('image/'):
return 'image'
if ct.startswith('text/'):
return 'text'
try:
with path.open('rb') as f:
return 'text' if b'\x00' not in f.read(SNIFF_SIZE) else 'other'
except OSError:
return 'other'
def _disposition_filename(name: str) -> str:
"""Content-Disposition filename params: ASCII fallback + RFC 5987 UTF-8 form.
HTTP headers are latin-1 only, so a non-ASCII name must be percent-encoded.
"""
ascii_name = name.encode("ascii", "replace").decode("ascii")
ascii_name = ascii_name.replace("\\", "_").replace('"', "_").replace("?", "_")
return f'filename="{ascii_name}"; filename*=UTF-8\'\'{urllib.parse.quote(name, safe="")}'
class ShareServer(http.server.ThreadingHTTPServer):
def __init__(self, addr, handler, *, upload_dir: Path, html: bytes, ssl_ctx: ssl.SSLContext | None = None, token: str = ""):
super().__init__(addr, handler)
self.upload_dir = upload_dir
self.html = html
self.ssl_ctx = ssl_ctx
# `share.py hash` emits a digest, so a 64-char hex token is already hashed.
if not token:
self.token_hash = ""
elif _SHA256_RE.fullmatch(token):
self.token_hash = token
else:
self.token_hash = sha256_hex(token)
def get_request(self):
client, addr = self.socket.accept()
if self.ssl_ctx:
client.settimeout(SSL_HANDSHAKE_TIMEOUT)
try:
client = self.ssl_ctx.wrap_socket(client, server_side=True)
except (ssl.SSLError, OSError):
client.close()
raise
client.settimeout(None)
return client, addr
class Handler(http.server.BaseHTTPRequestHandler):
server: ShareServer
def finish(self):
try:
super().finish()
except (ssl.SSLError, BrokenPipeError, ConnectionResetError, OSError):
pass
def end_headers(self):
# Stops a `?token=` link from leaking the token via Referer on outbound clicks.
self.send_header("Referrer-Policy", "no-referrer")
super().end_headers()
def log_message(self, fmt, *args):
msg = str(args[0]) if args else fmt
print(f" [{datetime.now():%H:%M:%S}] {_TOKEN_RE.sub(r'\1<redacted>', msg)}")
# The file API is deliberately CORS-open; auth responses are not.
_CORS = (("Access-Control-Allow-Origin", "*"),)
def _respond(self, data: bytes, ct: str, *, status: int = 200, headers: tuple = ()):
self.send_response(status)
self.send_header("Content-Type", ct)
self.send_header("Content-Length", str(len(data)))
self.send_header("Connection", "close")
for name, value in headers:
self.send_header(name, value)
self.end_headers()
self.wfile.write(data)
def _json(self, data, *, status: int = 200, headers: tuple = _CORS):
self._respond(json.dumps(data).encode(), "application/json", status=status, headers=headers)
def _redirect(self, location: str, cookie: str):
self.send_response(302)
self.send_header("Location", location)
self.send_header("Set-Cookie", cookie)
self.send_header("Cache-Control", "no-store")
self.send_header("Content-Length", "0")
self.send_header("Connection", "close")
self.end_headers()
# ── Auth ──
def _match(self, value: str) -> bool:
return hmac.compare_digest(sha256_hex(value), self.server.token_hash)
def _query_token(self) -> str:
qs = urllib.parse.parse_qs(urllib.parse.urlparse(self.path).query)
return qs.get("token", [""])[0]
def _cookie(self, token: str) -> str:
return f"{COOKIE_NAME}={sha256_hex(token)}; {_COOKIE_ATTRS}; Max-Age={_COOKIE_MAX_AGE}"
def _check_auth(self) -> bool:
# NB: `?token=` is deliberately not accepted here — a token in the URL
# leaks into logs, browser history and Referer. It is exchanged for a
# cookie on the index route only (see _dispatch).
if not self.server.token_hash:
return True
scheme, _, bearer = self.headers.get("Authorization", "").partition(" ")
if scheme == "Bearer" and self._match(bearer):
return True
for part in self.headers.get("Cookie", "").split(";"):
name, _, value = part.strip().partition("=")
if name == COOKIE_NAME and hmac.compare_digest(value, self.server.token_hash):
return True
return False
_AUTH_PAGE = b'''<!DOCTYPE html>
<html><head>
<meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
<title>Share</title>
<style>
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:system-ui,-apple-system,sans-serif;background:#0a0a0a;color:#e0e0e0;min-height:100vh;display:flex;align-items:center;justify-content:center}
.card{background:#141414;border-radius:12px;padding:40px 32px;width:100%;max-width:360px;text-align:center}
h1{font-size:1.3rem;color:#fff;margin-bottom:24px}
input{width:100%;padding:12px 14px;background:#1a1a1a;border:1px solid #333;border-radius:8px;color:#e0e0e0;font-size:.95rem;outline:none;margin-bottom:16px;transition:border-color .2s}
input:focus{border-color:#4fc3f7}
button{width:100%;padding:12px;background:#4fc3f7;color:#000;border:none;border-radius:8px;font-size:.95rem;font-weight:600;cursor:pointer;transition:opacity .2s}
button:hover{opacity:.85}
.err{color:#ef5350;font-size:.85rem;margin-top:12px;min-height:1.2em}
</style>
</head><body>
<div class="card">
<h1>Share</h1>
<form id="f">
<input type="password" id="tok" placeholder="Token" autofocus>
<button type="submit">Login</button>
</form>
<div class="err" id="err"></div>
</div>
<script>
const f=document.getElementById('f'),tok=document.getElementById('tok'),err=document.getElementById('err');
f.onsubmit=e=>{e.preventDefault();err.textContent='';
fetch('auth',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({token:tok.value})})
.then(r=>{if(r.ok)location.reload();else{err.textContent='Invalid token';tok.select()}})
.catch(()=>{err.textContent='Connection error'})};
</script>
</body></html>'''
def _token_to_cookie(self, token: str):
"""Swap a valid `?token=` link for a cookie, then redirect to a clean URL."""
self._redirect("/", self._cookie(token))
def _send_auth_page(self):
self._respond(self._AUTH_PAGE, "text/html; charset=utf-8", status=401)
# ── Routes ──
ROUTES = {
"GET": [
("/", "_route_index"),
("/index.html","_route_index"),
("/files", "_route_files"),
("/dl/", "_route_download"),
("/logout", "_route_logout"),
],
"POST": [("/upload", "_route_upload"), ("/auth", "_route_auth")],
"DELETE": [("/del/", "_route_delete")],
}
# Routes reachable without a valid token.
PUBLIC_ROUTES = {"_route_auth"}
def _dispatch(self):
path_only = urllib.parse.urlparse(self.path).path
for prefix, method in self.ROUTES.get(self.command, []):
if path_only == prefix or (len(prefix) > 1 and prefix.endswith("/") and path_only.startswith(prefix)):
if method in self.PUBLIC_ROUTES or self._check_auth():
return getattr(self, method)(prefix)
if self.command == "GET" and path_only in ("/", "/index.html"):
tok = self._query_token()
if tok and self._match(tok):
return self._token_to_cookie(tok)
return self._send_auth_page()
return self._json({"error": "unauthorized"}, status=401, headers=())
self.send_error(404)
do_GET = do_POST = do_DELETE = _dispatch
def _route_index(self, _prefix):
self._respond(self.server.html, "text/html; charset=utf-8")
def _route_files(self, _prefix):
entries = [(p, p.stat()) for p in self.server.upload_dir.iterdir() if p.is_file()]
entries.sort(key=lambda e: e[1].st_mtime, reverse=True)
self._json([{"name": p.name, "size": st.st_size, "type": file_type(p)} for p, st in entries])
def _safe_path(self, prefix: str) -> Path:
parsed = urllib.parse.urlparse(self.path)
name = urllib.parse.unquote(parsed.path[len(prefix):])
return self.server.upload_dir / Path(name).name
def _route_download(self, prefix):
safe = self._safe_path(prefix)
try:
st = safe.stat()
except FileNotFoundError:
self.send_error(404)
return
if not stat.S_ISREG(st.st_mode):
self.send_error(404)
return
ct = mimetypes.guess_type(safe.name)[0] or "application/octet-stream"
self.send_response(200)
self.send_header("Content-Type", ct)
self.send_header("Content-Disposition", f"attachment; {_disposition_filename(safe.name)}")
self.send_header("Content-Length", str(st.st_size))
self.send_header("Connection", "close")
self.end_headers()
with safe.open("rb") as f:
while chunk := f.read(CHUNK_SIZE):
self.wfile.write(chunk)
def _route_upload(self, _prefix):
ct = self.headers.get("Content-Type", "")
if "multipart/form-data" not in ct:
self.send_error(400)
return
length = int(self.headers.get("Content-Length", 0))
if not length:
self.send_error(400)
return
body = self.rfile.read(length)
count = self._save_parts(ct, body)
self._json({"ok": True, "count": count})
def _route_auth(self, _prefix):
length = int(self.headers.get("Content-Length", 0))
body = self.rfile.read(length) if length else b""
try:
data = json.loads(body)
except (json.JSONDecodeError, ValueError):
data = {}
token = data.get("token")
if token and self._match(token):
self._json({"ok": True}, headers=(("Set-Cookie", self._cookie(token)),))
else:
self._json({"ok": False}, status=401, headers=())
def _route_logout(self, _prefix):
self._redirect("/", f"{COOKIE_NAME}=; {_COOKIE_ATTRS}; Max-Age=0")
def _route_delete(self, prefix):
safe = self._safe_path(prefix)
if safe.is_file():
safe.unlink()
self._json({"ok": True})
# ── Helpers ──
def _save_parts(self, content_type: str, body: bytes) -> int:
header = f"Content-Type: {content_type}\r\n\r\n".encode()
# policy=HTTP decodes headers as UTF-8; the default compat32 policy mangles
# non-ASCII filenames into replacement characters.
msg = email.parser.BytesParser(policy=email.policy.HTTP).parsebytes(header + body)
count = 0
for part in msg.walk():
fname = part.get_filename()
if not fname:
continue
fname = Path(fname).name or f"paste_{datetime.now():%H%M%S}"
data = part.get_payload(decode=True)
if not data:
continue
dest = self._unique_path(fname)
dest.write_bytes(data)
count += 1
print(f" + {dest.name} ({len(data)} bytes)")
return count
def _unique_path(self, filename: str) -> Path:
dest = self.server.upload_dir / filename
stem, suffix = dest.stem, dest.suffix
i = 1
while dest.exists():
dest = self.server.upload_dir / f"{stem}_{i}{suffix}"
i += 1
return dest