optimize CL/TE check;

replace the heavyhanded connection:close added in b4fddbc3d
with a comparison of content-length to num bytes consumed

this approach also covers incorrectly configured servers
where the reverseproxy was not detected

also adds explicit TE/CL handling, even though most
(all?) reverseproxies already prevent such issues

also adds explicit sanchk of up2k chunk-receiver,
in case any bugs are ever added there

copyparty/httpcli.py

@@ -374,6 +374,7 @@ class HttpCli(object):
 
             return False
 
+        self.sr.nb = 0
         self.conn.hsrv.nreq += 1
 
         self.ua = self.headers.get("user-agent", "")
@@ -383,6 +384,19 @@ class HttpCli(object):
         self.keepalive = "close" not in zs and (
             self.http_ver != "HTTP/1.0" or zs == "keep-alive"
         )
+
+        if (
+            "transfer-encoding" in self.headers
+            and self.headers["transfer-encoding"].lower() != "identity"
+        ):
+            self.sr.te = 1
+            if "content-length" in self.headers:
+                # rfc9112:6.2: ignore CL if TE
+                self.keepalive = False
+                self.headers.pop("content-length")
+                t = "suspicious request (has both TE and CL); ignoring CL and disabling keepalive"
+                self.log(t, 3)
+
         self.host = self.headers.get("host") or ""
         if not self.host:
             if self.s.family == socket.AF_UNIX:
@@ -396,7 +410,6 @@ class HttpCli(object):
         if n:
             zso = self.headers.get(self.args.xff_hdr)
             if zso:
-                self.keepalive = False
                 if n > 0:
                     n -= 1
 
@@ -881,7 +894,11 @@ class HttpCli(object):
                     self.terse_reply(b"", 500)
                     return False
 
-                post = self.mode in ("POST", "PUT") or "content-length" in self.headers
+                post = (
+                    self.mode in ("POST", "PUT")
+                    or "content-length" in self.headers
+                    or self.sr.te
+                )
                 if pex.code >= (300 if post else 400):
                     self.keepalive = False
 
@@ -3200,7 +3217,7 @@ class HttpCli(object):
                         t = "your chunk got corrupted somehow (received {} bytes); expected vs received hash:\n{}\n{}"
                         raise Pebkac(400, t.format(post_sz, chash, sha_b64))
 
-                    remains -= chunksize
+                    remains -= post_sz
 
                     if len(cstart) > 1 and path != os.devnull:
                         t = " & ".join(unicode(x) for x in cstart[1:])
@@ -3278,6 +3295,12 @@ class HttpCli(object):
 
         spd = self._spd(postsize)
         self.log("%70s thank %r" % (spd, cinf))
+
+        if remains:
+            t = "incorrect content-length from client"
+            self.log("%s; header=%d, remains=%d" % (t, postsize, remains), 3)
+            raise Pebkac(400, t)
+
         self.reply(b"thank")
         return True
 

copyparty/httpconn.py

@@ -222,6 +222,21 @@ class HttpConn(object):
             if not self.cli.run():
                 return
 
+            if self.sr.te == 1:
+                self.log("closing socket (leftover TE)", "90")
+                return
+
+            if (
+                "content-length" in self.cli.headers
+                and int(self.cli.headers["content-length"]) != self.sr.nb
+            ):
+                self.log("closing socket (CL mismatch)", "90")
+                return
+
+            # note: proxies reject PUT sans Content-Length; illegal for HTTP/1.1
+
+            self.sr.nb = self.sr.te = 0
+
             if self.u2idx:
                 self.hsrv.put_u2idx(str(self.addr), self.u2idx)
                 self.u2idx = None

copyparty/util.py

@@ -971,6 +971,7 @@ class _Unrecv(object):
         self.log = log
         self.buf: bytes = b""
         self.nb = 0
+        self.te = 0
 
     def recv(self, nbytes: int, spins: int = 1) -> bytes:
         if self.buf:
@@ -3008,6 +3009,7 @@ def read_socket_chunked(
         if chunklen == 0:
             x = sr.recv_ex(2, False)
             if x == b"\r\n":
+                sr.te = 2
                 return
 
             t = "protocol error after final chunk: want b'\\r\\n', got {!r}"