Files
OpenFUT/scripts/openfut-utas-observe.py
T
funman300 04c5043aba utas: My Squad filter corpus — every filter identified, root cause measured
Controlled retail capture, one criterion at a time, cleared between each.
47 transactions. Every filter the My Squad picker sends is now known from
the wire rather than guessed.

Route: GET /ut/game/fifa17/club -- the picker hits UTAS and reuses the
general club-inventory route.

  level=any|gold        quality      lowercase, ALWAYS present
  rare=SP               "Special"    uppercase, OMITTED when off
  position=ST           position     uppercase, omitted when off
  nation=52             entity id    numeric
  league=13             entity id    numeric
  team=5                entity id    numeric, NESTED under league
  sort=desc                          client constant; the UI has no sort control
  start=/count=11       pagination

Two encoding families: short string enums, and numeric FIFA ids. The ids
must never reach Core. Filters compose as plain ANDs in one query --
string and id filters alike -- so each maps independently.

THE ROOT CAUSE IS SELF-AMPLIFYING.

club_route honours type, team and league; it never reads start, count,
level, sort or year. Because start is ignored, every page returns the
same full set, so the client concludes the page was full and asks for the
next one. One scroll produced 22 requests and 6.2 MB, stopping at
start=200 only because the client gave up -- against a filtered set of 32
items that should have been three pages.

That also explains why the bug reads as erratic rather than broken:
league=13&position=ST returns every Premier League player instead of
Premier League strikers. Plausible, wrongly sized, hard to notice.

Measured filtered sets, from the real cluttered club -- these are the
acceptance test for the fix:

  unfiltered            1962
  league=13              350
  league=13&team=5        32

Two client behaviours worth carrying forward: the picker fires a query
per highlighted entry, not per selection (two requests for one club
pick), and parameter ORDER is not stable, so parsing must be key-value.

FIXTURE SIZE: bodies over 4 KB are truncated in the committed fixture,
with body_full_len and body_full_sha256 retained, because the same 1.1 MB
club response repeats ~25 times and its hash already proves identity.
13.3 MB -> 247 KB. The raw .ofcap keeps every byte, privately and
gitignored. Truncation is recorded per transaction so a trimmed fixture
is never mistaken for a whole response.

Audited across all three identifier surfaces -- headers, JSON bodies,
query strings -- before and after the size change: no leaks. 6/6
sanitiser mutations still killed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-11 19:32:57 +00:00

603 lines
23 KiB
Python
Executable File

#!/usr/bin/env python3
"""Record real UTAS traffic between FIFA 17 and the Python oracle.
openfut-utas-observe.py record --listen 0.0.0.0:8199 --upstream 127.0.0.1:8099 \
--session captures/utas/session-001
openfut-utas-observe.py parse --session captures/utas/session-001
openfut-utas-observe.py snapshot --upstream 127.0.0.1:8099 --out before/state-manifest.json
WHY THIS EXISTS
---------------
Porting UTAS needs the exact bytes of real requests AND real responses. The
oracle's own log truncates bodies at ~200 chars, and raising that cap would mean
editing the behavioural specification to make it easier to copy -- which is
exactly backwards. A proxy gets the same evidence and leaves the oracle alone.
Standalone on purpose: NOT built into the Python container. The same tool can
later sit in front of a Rust UTAS host, so the identical captured request can be
replayed against both and diffed.
THE DESIGN RULE: TEE, DO NOT REBUILD
------------------------------------
UTAS is plaintext HTTP/1.1 served by `ThreadingHTTPServer`, so keep-alive,
pipelining and chunked transfer are all possible. A proxy that parses a request
and re-emits it can corrupt the traffic it exists to observe -- and a subtle
corruption here would look like a UTAS bug, sending the investigation in exactly
the wrong direction.
So this copies bytes VERBATIM in both directions and writes a second copy to
disk. Transactions are reconstructed later, offline, from that copy. A bug in
the parser therefore spoils the record and never the session. This is the same
reasoning that keeps the oracle unmodified: do not let the measuring apparatus
change what is being measured.
TWO LAYERS, LIKE THE BLAZE CAPTURES
-----------------------------------
raw/utas.ofcap exact bytes, mode 0600, gitignored
|
sanitizer
|
sanitized/transactions.jsonl repository-safe fixtures
Raw captures are never normalised. Normalisation happens only when producing the
committed fixture, and preserves exact bodies first, sanitises second.
"""
import argparse
import base64
import hashlib
import json
import os
import re
import socket
import sys
import threading
import time
MAGIC = "OFCAP1"
C2S = "c2s"
S2C = "s2c"
# ─────────────────────────────────────────────────────────── capture file ────
class Capture:
"""Append-only JSONL of raw byte chunks. One line per read().
JSONL with base64 rather than a packed binary format: this is a research
artefact that people will grep and eyeball, and the size cost is irrelevant
next to being able to inspect it without a decoder. Base64 is an encoding,
not a normalisation -- the bytes round-trip exactly.
"""
def __init__(self, path):
self.path = path
os.makedirs(os.path.dirname(path), exist_ok=True)
# 0600 before anything is written: captures carry session tokens.
fd = os.open(path, os.O_CREAT | os.O_WRONLY | os.O_APPEND, 0o600)
self.f = os.fdopen(fd, "w")
self.lock = threading.Lock()
self._write({"magic": MAGIC, "started_unix": time.time()})
def _write(self, obj):
with self.lock:
self.f.write(json.dumps(obj, sort_keys=True) + "\n")
self.f.flush()
def chunk(self, conn_id, direction, data, t0):
self._write({
"conn": conn_id,
"dir": direction,
"t": round(time.monotonic() - t0, 6),
"unix": time.time(),
"len": len(data),
"b64": base64.b64encode(data).decode(),
})
def event(self, conn_id, kind, detail, t0):
self._write({
"conn": conn_id,
"event": kind,
"detail": detail,
"t": round(time.monotonic() - t0, 6),
"unix": time.time(),
})
def close(self):
with self.lock:
self.f.close()
# ──────────────────────────────────────────────────────────────── record ────
def pump(src, dst, cap, conn_id, direction, t0, done):
"""Copy src->dst verbatim, teeing every chunk into the capture.
Forward FIRST, record second: the client must never wait on our disk.
"""
try:
while True:
data = src.recv(65536)
if not data:
break
try:
dst.sendall(data)
except OSError as e:
cap.event(conn_id, "forward_failed", "%s %s" % (direction, e), t0)
break
cap.chunk(conn_id, direction, data, t0)
except OSError as e:
cap.event(conn_id, "read_failed", "%s %s" % (direction, e), t0)
finally:
# Half-close so the peer sees EOF in the same direction the original
# did. Connection semantics are part of what is being captured.
try:
dst.shutdown(socket.SHUT_WR)
except OSError:
pass
cap.event(conn_id, "eof", direction, t0)
done.set()
def handle(client, addr, upstream_addr, cap, conn_id, t0):
cap.event(conn_id, "open", "%s:%d" % addr, t0)
try:
up = socket.create_connection(upstream_addr, timeout=30)
except OSError as e:
cap.event(conn_id, "upstream_failed", str(e), t0)
client.close()
return
client.settimeout(None)
up.settimeout(None)
a, b = threading.Event(), threading.Event()
t1 = threading.Thread(target=pump, args=(client, up, cap, conn_id, C2S, t0, a), daemon=True)
t2 = threading.Thread(target=pump, args=(up, client, cap, conn_id, S2C, t0, b), daemon=True)
t1.start(); t2.start()
t1.join(); t2.join()
for s in (client, up):
try:
s.close()
except OSError:
pass
cap.event(conn_id, "close", "", t0)
def cmd_record(args):
lh, lp = args.listen.rsplit(":", 1)
uh, up = args.upstream.rsplit(":", 1)
session = os.path.abspath(args.session)
cap = Capture(os.path.join(session, "raw", "utas.ofcap"))
srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
srv.bind((lh, int(lp)))
srv.listen(64)
t0 = time.monotonic()
print("recording %s -> %s:%s into %s" % (args.listen, uh, up, cap.path), flush=True)
print(" raw capture is mode 0600 and must stay out of git", flush=True)
n = 0
try:
while True:
client, addr = srv.accept()
n += 1
threading.Thread(
target=handle,
args=(client, addr, (uh, int(up)), cap, n, t0),
daemon=True,
).start()
except KeyboardInterrupt:
print("\nstopped after %d connection(s)" % n, flush=True)
finally:
cap.close()
# ─────────────────────────────────────────────────────────────── parsing ────
def read_capture(path):
conns = {}
with open(path) as f:
for line in f:
r = json.loads(line)
if "magic" in r:
continue
c = conns.setdefault(r["conn"], {"c2s": bytearray(), "s2c": bytearray(),
"events": [], "marks": {"c2s": [], "s2c": []}})
if "b64" in r:
data = base64.b64decode(r["b64"])
c["marks"][r["dir"]].append((len(c[r["dir"]]), r["t"], r["unix"]))
c[r["dir"]].extend(data)
else:
c["events"].append(r)
return conns
def split_messages(buf, is_response):
"""Split an HTTP/1.1 byte stream into messages. Returns list of (head, body, end).
Framing follows RFC 7230: Transfer-Encoding: chunked wins over
Content-Length. A stream that cannot be framed stops the walk rather than
guessing -- a wrong split would silently mis-attribute bodies.
"""
out, i = [], 0
while True:
sep = buf.find(b"\r\n\r\n", i)
if sep < 0:
break
head = bytes(buf[i:sep])
hs = head.decode("latin1")
start = sep + 4
te = re.search(r"(?im)^transfer-encoding:\s*(.+)$", hs)
cl = re.search(r"(?im)^content-length:\s*(\d+)\s*$", hs)
if te and "chunked" in te.group(1).lower():
j, body = start, bytearray()
while True:
nl = buf.find(b"\r\n", j)
if nl < 0:
return out
try:
size = int(bytes(buf[j:nl]).split(b";")[0], 16)
except ValueError:
return out
j = nl + 2
if size == 0:
j = buf.find(b"\r\n", j)
j = (j + 2) if j >= 0 else len(buf)
break
body.extend(buf[j:j + size])
j += size + 2
out.append((head, bytes(body), j)); i = j
elif cl:
n = int(cl.group(1))
end = start + n
if end > len(buf):
break
out.append((head, bytes(buf[start:end]), end)); i = end
else:
status_no_body = is_response and re.match(r"HTTP/\d\.\d (1\d\d|204|304)", hs)
if is_response and not status_no_body:
# No framing header: the body runs to end-of-stream.
out.append((head, bytes(buf[start:]), len(buf))); i = len(buf)
break
out.append((head, b"", start)); i = start
return out
def time_at(marks, offset):
"""Wall/relative time of the chunk containing byte `offset`."""
last = (0.0, 0.0)
for pos, t, unix in marks:
if pos > offset:
break
last = (t, unix)
return last
def cmd_parse(args):
session = os.path.abspath(args.session)
raw = os.path.join(session, "raw", "utas.ofcap")
conns = read_capture(raw)
out_dir = os.path.join(session, "sanitized")
os.makedirs(out_dir, exist_ok=True)
out_path = os.path.join(out_dir, "transactions.jsonl")
total, skipped = 0, 0
with open(out_path, "w") as out:
for conn_id in sorted(conns):
c = conns[conn_id]
reqs = split_messages(c["c2s"], is_response=False)
resps = split_messages(c["s2c"], is_response=True)
if len(reqs) != len(resps):
# Reported, never silently trimmed: an unmatched count means the
# framing is not understood, and a quiet truncation would look
# like the client simply asked for less.
print(" conn %d: %d requests but %d responses -- pairing the common prefix"
% (conn_id, len(reqs), len(resps)), file=sys.stderr)
skipped += abs(len(reqs) - len(resps))
keepalive = None
for seq, ((rh, rb, rend), (sh, sb, send)) in enumerate(zip(reqs, resps), 1):
rl = rh.split(b"\r\n")[0].decode("latin1")
sl = sh.split(b"\r\n")[0].decode("latin1")
m = re.match(r"(\S+)\s+(\S+)\s+(HTTP/\d\.\d)", rl)
method, target, ver = (m.group(1), m.group(2), m.group(3)) if m else ("?", rl, "?")
path, _, query = target.partition("?")
st = re.match(r"HTTP/\d\.\d\s+(\d+)", sl)
req_t, req_unix = time_at(c["marks"]["c2s"], rend - 1)
res_t, res_unix = time_at(c["marks"]["s2c"], max(send - 1, 0))
keepalive = len(reqs) > 1
rec = {
"conn": conn_id,
"seq": seq,
"t_request": req_t,
"t_response": res_t,
"elapsed_ms": round((res_t - req_t) * 1000, 3),
"unix_request": req_unix,
"request": {
"method": method, "path": path, "query": query, "version": ver,
"headers": header_list(rh),
"body_b64": base64.b64encode(rb).decode(),
"body_len": len(rb),
},
"response": {
"status": int(st.group(1)) if st else None,
"status_line": sl,
"headers": header_list(sh),
"body_b64": base64.b64encode(sb).decode(),
"body_len": len(sb),
},
"connection": {
"requests_on_this_connection": len(reqs),
"keepalive_observed": keepalive,
},
}
rec = sanitize(rec)
if getattr(args, "max_body", 0):
for side in ("request", "response"):
raw = base64.b64decode(rec[side]["body_b64"])
if len(raw) > args.max_body:
rec[side]["body_b64"] = base64.b64encode(
raw[: args.max_body]
).decode()
rec[side]["body_truncated"] = True
rec[side]["body_full_len"] = len(raw)
rec[side]["body_full_sha256"] = hashlib.sha256(raw).hexdigest()
out.write(json.dumps(rec, sort_keys=True) + "\n")
total += 1
os.chmod(out_path, 0o644)
print("wrote %s (%d transactions across %d connections%s)"
% (out_path, total, len(conns),
"; %d unpaired messages reported above" % skipped if skipped else ""))
return 0
def header_list(head):
"""Headers in RECEIVED ORDER, as a list of pairs. Order can be protocol-
relevant and a dict would silently discard duplicates."""
lines = head.decode("latin1").split("\r\n")[1:]
out = []
for l in lines:
if not l:
continue
k, _, v = l.partition(":")
out.append([k, v.strip()])
return out
SECRET_HEADERS = {"authorization", "cookie", "set-cookie", "x-ut-sid", "easw-session-data-nucleus-id"}
# Substring-matched against lowercased JSON keys. Extended after auditing the
# first real corpus: session tokens were being redacted correctly, but the
# client also sends hardware and device identifiers in `POST /ut/auth`, and a
# committed fixture is a published fixture. Audit the output before publishing,
# every time -- "the sanitiser handles it" is a belief until it is checked.
SECRET_BODY_KEYS = (
"sid", "token", "password", "answer", "secret",
"macaddress", "deviceid", "authcode",
)
def sanitize(rec):
"""Repository-safe form. Bodies are preserved EXACTLY; only credentials go.
THREE input surfaces carry identifiers, not two. The first version handled
headers and JSON bodies and was still about to publish a device id, because
`GET /ut/game/fifa17/phishing/trusteddevice?deviceId=...` puts it in the
QUERY STRING. Caught by auditing the output rather than by trusting the
sanitiser -- which is the only reason it is a comment and not a leak.
Exact bodies first, sanitise second: the corpus is worthless if response
payloads are reshaped, so nothing here touches structure -- it replaces
known-secret header values and known-secret JSON keys, and records that it
did so.
"""
redacted = []
# Query string: same key rules as bodies.
q = rec["request"].get("query") or ""
if q:
parts, hit = [], False
for kv in q.split("&"):
k, eq, v = kv.partition("=")
if eq and any(x in k.lower() for x in SECRET_BODY_KEYS):
parts.append(k + "=<REDACTED>")
redacted.append("request.query." + k)
hit = True
else:
parts.append(kv)
if hit:
rec["request"]["query"] = "&".join(parts)
for side in ("request", "response"):
hs = rec[side]["headers"]
for pair in hs:
if pair[0].lower() in SECRET_HEADERS:
redacted.append("%s.%s" % (side, pair[0]))
pair[1] = "<REDACTED>"
body = base64.b64decode(rec[side]["body_b64"])
new, hit = redact_json(body)
if hit:
redacted.extend("%s.body.%s" % (side, h) for h in hit)
rec[side]["body_b64"] = base64.b64encode(new).decode()
rec[side]["body_len_original"] = len(body)
if redacted:
rec["redacted"] = sorted(set(redacted))
return rec
def redact_json(body):
if not body[:1] in (b"{", b"["):
return body, []
try:
doc = json.loads(body)
except Exception:
return body, []
hits = []
def walk(o):
if isinstance(o, dict):
for k in list(o):
if any(s in k.lower() for s in SECRET_BODY_KEYS) and isinstance(o[k], str):
o[k] = "<REDACTED>"
hits.append(k)
else:
walk(o[k])
elif isinstance(o, list):
for v in o:
walk(v)
walk(doc)
if not hits:
return body, []
return json.dumps(doc, sort_keys=True).encode(), hits
# ────────────────────────────────────────────────────────────── snapshot ────
# Read-only GETs only. `/openfut/account/sync` is deliberately NOT here: it is a
# POST that selects and writes an account, so using it as a snapshot would
# mutate the state the snapshot exists to observe.
#
# All six were confirmed to answer 200 without a session token.
SNAPSHOT_ROUTES = [
("credits", "/ut/game/fifa17/user/credits"),
("userMassInfo", "/ut/game/fifa17/userMassInfo"),
("unassigned", "/ut/game/fifa17/purchased/items"),
("activeSquad", "/ut/game/fifa17/squad/active"),
("tradePile", "/ut/game/fifa17/tradePile"),
("accountInfo", "/ut/game/fifa17/user/accountinfo"),
]
def http_get(host, port, path):
s = socket.create_connection((host, int(port)), timeout=10)
s.sendall(("GET %s HTTP/1.1\r\nHost: %s:%s\r\nConnection: close\r\n\r\n"
% (path, host, port)).encode())
buf = b""
while True:
d = s.recv(65536)
if not d:
break
buf += d
s.close()
head, _, body = buf.partition(b"\r\n\r\n")
line = head.split(b"\r\n")[0].decode("latin1")
status = int(line.split()[1]) if len(line.split()) > 1 else None
return status, body
def cmd_snapshot(args):
"""A state manifest for pairing before/after around a capture session.
A summary plus a hash, not a database dump. The named fields are what a
human reads; the sha256 of each full body is the safety net, because a
summary can only report changes in fields somebody thought to list. If the
hash moves and no field does, the summary is incomplete -- and that is
itself a finding rather than a silent miss.
Raw bodies are written alongside at mode 0600 so a real diff is possible
later without re-running the session.
"""
import hashlib
uh, up = args.upstream.rsplit(":", 1)
out_path = os.path.abspath(args.out)
raw_dir = os.path.join(os.path.dirname(out_path), "bodies")
os.makedirs(raw_dir, exist_ok=True)
man = {"unix": time.time(), "upstream": args.upstream, "routes": {}}
for name, path in SNAPSHOT_ROUTES:
try:
status, body = http_get(uh, up, path)
except Exception as e:
# Recorded as an error, never omitted: a missing section must not
# be mistakable for an empty one.
man["routes"][name] = {"error": str(e)}
continue
bp = os.path.join(raw_dir, name + ".json")
fd = os.open(bp, os.O_CREAT | os.O_WRONLY | os.O_TRUNC, 0o600)
with os.fdopen(fd, "wb") as f:
f.write(body)
man["routes"][name] = {
"status": status,
"body_len": len(body),
"sha256": hashlib.sha256(body).hexdigest(),
"fields": extract(name, body),
}
os.makedirs(os.path.dirname(out_path), exist_ok=True)
with open(out_path, "w") as f:
json.dump(man, f, indent=2, sort_keys=True)
f.write("\n")
print("wrote %s" % out_path)
for k, v in man["routes"].items():
print(" %-13s %s" % (k, v.get("fields", v)))
return 0
def extract(name, body):
"""Named fields per route. Unknown shapes report what they can rather than
raising -- the hash still covers everything."""
try:
d = json.loads(body)
except Exception:
return {"unparsed_len": len(body)}
f = {}
if name == "credits":
f["credits"] = d.get("credits")
elif name == "userMassInfo":
ui = d.get("userInfo", {})
for k in ("personaId", "clubName", "clubAbbr", "trophies"):
if k in ui:
f[k] = ui[k]
for k, v in d.items():
if isinstance(v, list):
f[k + ".count"] = len(v)
elif name == "unassigned":
f["itemData.count"] = len(d.get("itemData", []))
elif name == "activeSquad":
f["id"] = d.get("id")
f["formation"] = d.get("formation")
players = d.get("players", [])
f["players.count"] = len(players)
# Slot -> item id, so a two-player swap is visible in the diff.
f["slots"] = {
str(p.get("index", i)): (p.get("itemData") or {}).get("id")
for i, p in enumerate(players)
}
elif name == "tradePile":
f["auctionInfo.count"] = len(d.get("auctionInfo", []))
elif name == "accountInfo":
f["keys"] = sorted(d.keys()) if isinstance(d, dict) else None
return f
def main():
ap = argparse.ArgumentParser(description=__doc__,
formatter_class=argparse.RawDescriptionHelpFormatter)
sub = ap.add_subparsers(dest="cmd", required=True)
r = sub.add_parser("record")
r.add_argument("--listen", required=True)
r.add_argument("--upstream", required=True)
r.add_argument("--session", required=True)
r.set_defaults(fn=cmd_record)
p = sub.add_parser("parse")
p.add_argument("--session", required=True)
# Repository-safe size. The raw .ofcap keeps every byte privately; a
# committed fixture that repeats an identical 1.1MB response 25 times is
# 13MB of git history proving something its own sha256 already proves.
# Bodies over the limit are replaced by a bounded head sample, and the
# omission is RECORDED per transaction so nobody mistakes a truncated
# fixture for the whole response.
p.add_argument("--max-body", type=int, default=0,
help="bytes; 0 = keep every body in full")
p.set_defaults(fn=cmd_parse)
s = sub.add_parser("snapshot")
s.add_argument("--upstream", required=True)
s.add_argument("--out", required=True)
s.set_defaults(fn=cmd_snapshot)
args = ap.parse_args()
return args.fn(args) or 0
if __name__ == "__main__":
sys.exit(main())