reinvent fail2ban

README.md

@@ -1108,6 +1108,8 @@ some notes on hardening
   * `--hardlink` creates hardlinks instead of symlinks when deduplicating uploads, which is less maintenance
     * however note if you edit one file it will also affect the other copies
   * `--vague-403` returns a "404 not found" instead of "403 forbidden" which is a common enterprise meme
+  * `--ban-404=50,60,1440` ban client for 1440min (24h) if they hit 50 404's in 60min
+    * **NB:** will ban anyone who enables up2k turbo
   * `--nih` removes the server hostname from directory listings
 
 * option `-sss` is a shortcut for the above plus:

copyparty/__main__.py

@@ -628,7 +628,7 @@ def run_argparse(argv: list[str], formatter: Any, retry: bool) -> argparse.Names
 
     ap2 = ap.add_argument_group('safety options')
     ap2.add_argument("-s", action="count", default=0, help="increase safety: Disable thumbnails / potentially dangerous software (ffmpeg/pillow/vips), hide partial uploads, avoid crawlers.\n └─Alias of\033[32m --dotpart --no-thumb --no-mtag-ff --no-robots --force-js")
-    ap2.add_argument("-ss", action="store_true", help="further increase safety: Prevent js-injection, accidental move/delete, broken symlinks, 404 on 403.\n └─Alias of\033[32m -s --no-dot-mv --no-dot-ren --unpost=0 --no-del --no-mv --hardlink --vague-403 -nih")
+    ap2.add_argument("-ss", action="store_true", help="further increase safety: Prevent js-injection, accidental move/delete, broken symlinks, 404 on 403, ban on excessive 404s.\n └─Alias of\033[32m -s --no-dot-mv --no-dot-ren --unpost=0 --no-del --no-mv --hardlink --vague-403 --ban-404=50,60,1440 -nih")
     ap2.add_argument("-sss", action="store_true", help="further increase safety: Enable logging to disk, scan for dangerous symlinks.\n └─Alias of\033[32m -ss -lo=cpp-%%Y-%%m%%d-%%H%%M%%S.txt.xz --ls=**,*,ln,p,r")
     ap2.add_argument("--ls", metavar="U[,V[,F]]", type=u, help="do a sanity/safety check of all volumes on startup; arguments USER,VOL,FLAGS; example [**,*,ln,p,r]")
     ap2.add_argument("--salt", type=u, default="hunter2", help="up2k file-hash salt; used to generate unpredictable internal identifiers for uploads -- doesn't really matter")
@@ -641,6 +641,8 @@ def run_argparse(argv: list[str], formatter: Any, retry: bool) -> argparse.Names
     ap2.add_argument("--force-js", action="store_true", help="don't send folder listings as HTML, force clients to use the embedded json instead -- slight protection against misbehaving search engines which ignore --no-robots")
     ap2.add_argument("--no-robots", action="store_true", help="adds http and html headers asking search engines to not index anything")
     ap2.add_argument("--logout", metavar="H", type=float, default="8086", help="logout clients after H hours of inactivity (0.0028=10sec, 0.1=6min, 24=day, 168=week, 720=month, 8760=year)")
+    ap2.add_argument("--ban-pw", metavar="N,W,B", type=u, default="9,60,1440", help="more than N wrong passwords in W minutes = ban for B minutes (disable with \"no\")")
+    ap2.add_argument("--ban-404", metavar="N,W,B", type=u, default="no", help="hitting more than N 404's in W minutes = ban for B minutes (disabled by default since turbo-up2k counts as 404s)")
 
     ap2 = ap.add_argument_group('shutdown options')
     ap2.add_argument("--ign-ebind", action="store_true", help="continue running even if it's impossible to listen on some of the requested endpoints")

copyparty/httpcli.py

@@ -24,6 +24,11 @@ try:
 except:
     pass
 
+try:
+    from ipaddress import IPv6Address
+except:
+    pass
+
 from .__init__ import ANYWIN, PY2, TYPE_CHECKING, EnvParams, unicode
 from .authsrv import VFS  # typechk
 from .bos import bos
@@ -111,6 +116,7 @@ class HttpCli(object):
         self.u2fh = conn.u2fh  # mypy404
         self.log_func = conn.log_func  # mypy404
         self.log_src = conn.log_src  # mypy404
+        self.bans = conn.hsrv.bans
         self.gen_fk = self._gen_fk if self.args.log_fk else gen_filekey
         self.tls: bool = hasattr(self.s, "cipher")
 
@@ -264,6 +270,21 @@ class HttpCli(object):
 
                 self.log_src = self.conn.set_rproxy(self.ip)
 
+        if self.bans:
+            ip = self.ip
+            if ":" in ip and not PY2:
+                ip = IPv6Address(ip).exploded[:-20]
+
+            if ip in self.bans:
+                ban = self.bans[ip] - time.time()
+                if ban < 0:
+                    self.log("client unbanned", 3)
+                    del self.bans[ip]
+                else:
+                    self.log("banned for {:.0f} sec".format(ban), 6)
+                    self.reply(b"thank you for playing", 403)
+                    return False
+
         if self.args.ihead:
             keys = self.args.ihead
             if "*" in keys:
@@ -466,7 +487,13 @@ class HttpCli(object):
         headers: Optional[dict[str, str]] = None,
         volsan: bool = False,
     ) -> bytes:
-        # TODO something to reply with user-supplied values safely
+        if status == 404:
+            g = self.conn.hsrv.g404
+            if g.lim:
+                bonk, ip = g.bonk(self.ip, self.vpath)
+                if bonk:
+                    self.log("client banned: 404s", 1)
+                    self.conn.hsrv.bans[ip] = bonk
 
         if volsan:
             vols = list(self.asrv.vfs.all_vols.values())
@@ -1230,6 +1257,14 @@ class HttpCli(object):
             msg = "login ok"
             dur = int(60 * 60 * self.args.logout)
         else:
+            self.log("invalid password: {}".format(pwd), 3)
+            g = self.conn.hsrv.gpwd
+            if g.lim:
+                bonk, ip = g.bonk(self.ip, pwd)
+                if bonk:
+                    self.log("client banned: invalid passwords", 1)
+                    self.conn.hsrv.bans[ip] = bonk
+
             msg = "naw dude"
             pwd = "x"  # nosec
             dur = None

copyparty/httpsrv.py

@@ -33,6 +33,7 @@ from .bos import bos
 from .httpconn import HttpConn
 from .util import (
     FHC,
+    Garda,
     Magician,
     min_ex,
     shut_socket,
@@ -69,6 +70,9 @@ class HttpSrv(object):
 
         nsuf = "-n{}-i{:x}".format(nid, os.getpid()) if nid else ""
         self.magician = Magician()
+        self.bans: dict[str, int] = {}
+        self.gpwd = Garda(self.args.ban_pw)
+        self.g404 = Garda(self.args.ban_404)
 
         self.name = "hsrv" + nsuf
         self.mutex = threading.Lock()

copyparty/svchub.py

@@ -89,6 +89,7 @@ class SvcHub(object):
             args.no_mv = True
             args.hardlink = True
             args.vague_403 = True
+            args.ban_404 = "50,60,1440"
             args.nih = True
 
         if args.s:

copyparty/util.py

@@ -36,6 +36,11 @@ try:
 except:
     pass
 
+try:
+    from ipaddress import IPv6Address
+except:
+    pass
+
 try:
     HAVE_SQLITE3 = True
     import sqlite3  # pylint: disable=unused-import  # typechk
@@ -691,6 +696,78 @@ class Magician(object):
                 raise Exception()
 
 
+class Garda(object):
+    """ban clients for repeated offenses"""
+
+    def __init__(self, cfg: str) -> None:
+        try:
+            a, b, c = cfg.strip().split(",")
+            self.lim = int(a)
+            self.win = int(b) * 60
+            self.pen = int(c) * 60
+        except:
+            self.lim = self.win = self.pen = 0
+
+        self.ct: dict[str, list[int]] = {}
+        self.prev: dict[str, str] = {}
+        self.last_cln = 0
+
+    def cln(self, ip: str) -> None:
+        n = 0
+        ok = int(time.time() - self.win)
+        for v in self.ct[ip]:
+            if v < ok:
+                n += 1
+            else:
+                break
+        if n:
+            te = self.ct[ip][n:]
+            if te:
+                self.ct[ip] = te
+            else:
+                del self.ct[ip]
+                try:
+                    del self.prev[ip]
+                except:
+                    pass
+
+    def allcln(self) -> None:
+        for k in list(self.ct):
+            self.cln(k)
+
+        self.last_cln = int(time.time())
+
+    def bonk(self, ip: str, prev: str) -> tuple[int, str]:
+        if not self.lim:
+            return 0, ip
+
+        if ":" in ip and not PY2:
+            # assume /64 clients; drop 4 groups
+            ip = IPv6Address(ip).exploded[:-20]
+
+        if prev:
+            if self.prev.get(ip) == prev:
+                return 0, ip
+
+            self.prev[ip] = prev
+
+        now = int(time.time())
+        try:
+            self.ct[ip].append(now)
+        except:
+            self.ct[ip] = [now]
+
+        if now - self.last_cln > 300:
+            self.allcln()
+        else:
+            self.cln(ip)
+
+        if len(self.ct[ip]) >= self.lim:
+            return now + self.pen, ip
+        else:
+            return 0, ip
+
+
 if WINDOWS and sys.version_info < (3, 8):
     _popen = sp.Popen