FA-7666 / WebSocket and browser transport policies / Open access

Cors origin wildcard is incompatible with credentialed response · case 01

Cors origin wildcard is incompatible with credentialed response.

Verified by executionVariant 1 · 4 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The faulty implementation uses `True` for the cors-origin-wildcard-is-incompatible-with-credentialed-response decision.

VERIFIED REPAIR

Apply the explicit cors-origin-wildcard-is-incompatible-with-credentialed-response contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `origin != "*"` and still violates a separate fixture.

Case contract

Bounded offline decision model: cors origin wildcard is incompatible with credentialed response. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.

Why this case matters

This deterministic websocket and browser transport policies model isolates the cors-origin-wildcard-is-incompatible-with-credentialed-response policy at a network component boundary.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(origin, credentials):
    return True
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('*', True), False)", "check('fixture 2', solve('*', False), True)", "check('fixture 3', solve('https://a', True), True)", "check('fixture 4', solve('https://a', False), True)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 2	`True`	`True`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`True`	`False`	Failed

SHA-256 / fa1e9269eb21da2e64fcba74622a3d5dd5db636221bb5f0e87b0bb519a53f670

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(origin, credentials):
    return origin != "*"
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('*', True), False)", "check('fixture 2', solve('*', False), True)", "check('fixture 3', solve('https://a', True), True)", "check('fixture 4', solve('https://a', False), True)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 2	`False`	`True`	Failed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`False`	`False`	Passed

SHA-256 / ef9d7b8e47f12829e94506805c77e2690437b6174e296611c551afd6a2dde7b5

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(origin, credentials):
    return origin != "*" or not credentials
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('*', True), False)", "check('fixture 2', solve('*', False), True)", "check('fixture 3', solve('https://a', True), True)", "check('fixture 4', solve('https://a', False), True)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 2	`True`	`True`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`False`	`False`	Passed

SHA-256 / 7f14eed7490e6b4a3a81a5f977155e9376ccbea8e61eb740df7fc2e6b82f516e

Verification & scope

Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:38:14.160801+00:00.

Case digest / 72ed6199b2d3dbdbdfe139e065ab07b1affab9430ae6eafe8aa8685563864560