{"abstract":"Multipart boundary parameter parsing: all control bytes are excluded from the delimiter.","category":"HTTP ranges","checks":18,"contract":"Parse a bounded Content-Type string with semicolon-separated parameters, quoted strings and backslash escapes inside quotes. Require multipart/byteranges (case-insensitive) and exactly one boundary parameter, with 1..12 ASCII printable characters excluding CR/LF. Other parameters ignored. Unbalanced quotes or dangling quoted escapes reject. Input x is the field string.","contract_signature":"x","evaluation_group":"s3-http_ranges-multipart-boundary-parameter","failed_approach":"The partial repair uses parts=[]\ncurrent=''\nquoted=False\nescaped=False\nfor c in x:\n    if escaped:\n        current+=c\n        escaped=False\n    elif quoted and c=='\\\\':\n        escaped=True\n    elif c=='\"':\n        quoted=not quoted\n    elif c==';' and not quoted:\n        parts.append(current)\n        current=''\n    else:\n        current+=c\nif quoted or escaped: return None\nparts.append(current)\nif parts[0].strip().lower()!='multipart/byteranges': return None\nboundaries=[]\nfor part in parts[1:]:\n    if '=' not in part: continue\n    key,value=part.split('=',1)\n    if key.strip().lower()=='boundary': boundaries.append(value.strip())\nif len(boundaries)!=1: return None\nvalue=boundaries[0]\nif not 1<=len(value)<=12: return None\nif '\\r' in value or '\\n' in value: return None\nreturn value, which still violates the stated contract.","family":"s3-http_ranges-multipart-boundary-parameter-boundary-control","id":"FA-26886","implementations":{"attempt":{"sha256":"2e546a3d730edf6ed88bd897dab2e02bd754bb5d315b1e84f4851cc163ad1e3b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    parts=[]\n    current=''\n    quoted=False\n    escaped=False\n    for c in x:\n        if escaped:\n            current+=c\n            escaped=False\n        elif quoted and c=='\\\\':\n            escaped=True\n        elif c=='\"':\n            quoted=not quoted\n        elif c==';' and not quoted:\n            parts.append(current)\n            current=''\n        else:\n            current+=c\n    if quoted or escaped: return None\n    parts.append(current)\n    if parts[0].strip().lower()!='multipart/byteranges': return None\n    boundaries=[]\n    for part in parts[1:]:\n        if '=' not in part: continue\n        key,value=part.split('=',1)\n        if key.strip().lower()=='boundary': boundaries.append(value.strip())\n    if len(boundaries)!=1: return None\n    value=boundaries[0]\n    if not 1<=len(value)<=12: return None\n    if '\\r' in value or '\\n' in value: return None\n    return value\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary-control fixture 0', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"a;b\"'))), json.loads(json.dumps('a;b')))\ncheck('boundary-control fixture 1', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"a\\\\\"b\"'))), json.loads(json.dumps('a\"b')))\ncheck('boundary-control fixture 2', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"a\\\\\\\\b\"'))), json.loads(json.dumps('a\\\\b')))\ncheck('boundary-control fixture 3', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"abc'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 4', json.loads(json.dumps(solve(' Multipart/ByteRanges ; BOUNDARY = abc '))), json.loads(json.dumps('abc')))\ncheck('boundary-control fixture 5', json.loads(json.dumps(solve('multipart/byteranges; boundary=a; boundary=a'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 6', json.loads(json.dumps(solve('multipart/byteranges; boundary=a; boundary=b'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 7', json.loads(json.dumps(solve('multipart/mixed; boundary=a'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 8', json.loads(json.dumps(solve('multipart/byteranges; boundary='))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 9', json.loads(json.dumps(solve('multipart/byteranges; boundary=abcdefghijkl'))), json.loads(json.dumps('abcdefghijkl')))\ncheck('boundary-control fixture 10', json.loads(json.dumps(solve('multipart/byteranges; boundary=abcdefghijklm'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 11', json.loads(json.dumps(solve('multipart/byteranges; boundary=a\\nb'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 12', json.loads(json.dumps(solve('multipart/byteranges; boundary=a\\x7fb'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 13', json.loads(json.dumps(solve('multipart/byteranges; x=y'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 14', json.loads(json.dumps(solve(\"p\"*N))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 15', json.loads(json.dumps(solve(\"multipart/byteranges; boundary=b\"+str(N)))), json.loads(json.dumps(\"b\"+str(N))))\ncheck('boundary-control fixture 16', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"abc\"'))), json.loads(json.dumps('abc')))\ncheck('boundary-control fixture 17', json.loads(json.dumps(solve('multipart/byteranges; x=a=b; boundary=ab'))), json.loads(json.dumps('ab')))\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"82ad04d4aa3832f0fa47acb65199031a7e94d32a9fa085688b450ae04a796a9b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    parts=[]\n    current=''\n    quoted=False\n    escaped=False\n    for c in x:\n        if escaped:\n            current+=c\n            escaped=False\n        elif quoted and c=='\\\\':\n            escaped=True\n        elif c=='\"':\n            quoted=not quoted\n        elif c==';' and not quoted:\n            parts.append(current)\n            current=''\n        else:\n            current+=c\n    if quoted or escaped: return None\n    parts.append(current)\n    if parts[0].strip().lower()!='multipart/byteranges': return None\n    boundaries=[]\n    for part in parts[1:]:\n        if '=' not in part: continue\n        key,value=part.split('=',1)\n        if key.strip().lower()=='boundary': boundaries.append(value.strip())\n    if len(boundaries)!=1: return None\n    value=boundaries[0]\n    if not 1<=len(value)<=12: return None\n    if '\\r' in value: return None\n    return value\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary-control fixture 0', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"a;b\"'))), json.loads(json.dumps('a;b')))\ncheck('boundary-control fixture 1', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"a\\\\\"b\"'))), json.loads(json.dumps('a\"b')))\ncheck('boundary-control fixture 2', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"a\\\\\\\\b\"'))), json.loads(json.dumps('a\\\\b')))\ncheck('boundary-control fixture 3', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"abc'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 4', json.loads(json.dumps(solve(' Multipart/ByteRanges ; BOUNDARY = abc '))), json.loads(json.dumps('abc')))\ncheck('boundary-control fixture 5', json.loads(json.dumps(solve('multipart/byteranges; boundary=a; boundary=a'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 6', json.loads(json.dumps(solve('multipart/byteranges; boundary=a; boundary=b'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 7', json.loads(json.dumps(solve('multipart/mixed; boundary=a'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 8', json.loads(json.dumps(solve('multipart/byteranges; boundary='))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 9', json.loads(json.dumps(solve('multipart/byteranges; boundary=abcdefghijkl'))), json.loads(json.dumps('abcdefghijkl')))\ncheck('boundary-control fixture 10', json.loads(json.dumps(solve('multipart/byteranges; boundary=abcdefghijklm'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 11', json.loads(json.dumps(solve('multipart/byteranges; boundary=a\\nb'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 12', json.loads(json.dumps(solve('multipart/byteranges; boundary=a\\x7fb'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 13', json.loads(json.dumps(solve('multipart/byteranges; x=y'))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 14', json.loads(json.dumps(solve(\"p\"*N))), json.loads(json.dumps(None)))\ncheck('boundary-control fixture 15', json.loads(json.dumps(solve(\"multipart/byteranges; boundary=b\"+str(N)))), json.loads(json.dumps(\"b\"+str(N))))\ncheck('boundary-control fixture 16', json.loads(json.dumps(solve('multipart/byteranges; boundary=\"abc\"'))), json.loads(json.dumps('abc')))\ncheck('boundary-control fixture 17', json.loads(json.dumps(solve('multipart/byteranges; x=a=b; boundary=ab'))), json.loads(json.dumps('ab')))\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Deterministic simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. 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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"s3-http_ranges-multipart-boundary-parameter-boundary-control","generated_at":"2026-09-29T14:41:20.007976+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Range responses combine representation identity, conditional requests, framing, and partial-object state.","root_cause":"The multipart-boundary-parameter-boundary-control decision uses parts=[]\ncurrent=''\nquoted=False\nescaped=False\nfor c in x:\n    if escaped:\n        current+=c\n        escaped=False\n    elif quoted and c=='\\\\':\n        escaped=True\n    elif c=='\"':\n        quoted=not quoted\n    elif c==';' and not quoted:\n        parts.append(current)\n        current=''\n    else:\n        current+=c\nif quoted or escaped: return None\nparts.append(current)\nif parts[0].strip().lower()!='multipart/byteranges': return None\nboundaries=[]\nfor part in parts[1:]:\n    if '=' not in part: continue\n    key,value=part.split('=',1)\n    if key.strip().lower()=='boundary': boundaries.append(value.strip())\nif len(boundaries)!=1: return None\nvalue=boundaries[0]\nif not 1<=len(value)<=12: return None\nif '\\r' in value: return None\nreturn value.","sha256":"efe3414e26e61ea1a5ae312d69445b51235b949ec0d9e429561d0fd36f247850","title":"Multipart boundary parameter parsing: all control bytes are excluded from the delimiter · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":39.998,"exit_code":1,"observations":[{"actual":"a;b","check":"boundary-control fixture 0","expected":"a;b","passed":true},{"actual":"a\"b","check":"boundary-control fixture 1","expected":"a\"b","passed":true},{"actual":"a\\b","check":"boundary-control fixture 2","expected":"a\\b","passed":true},{"actual":null,"check":"boundary-control fixture 3","expected":null,"passed":true},{"actual":"abc","check":"boundary-control fixture 4","expected":"abc","passed":true},{"actual":null,"check":"boundary-control fixture 5","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 6","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 7","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 8","expected":null,"passed":true},{"actual":"abcdefghijkl","check":"boundary-control fixture 9","expected":"abcdefghijkl","passed":true},{"actual":null,"check":"boundary-control fixture 10","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 11","expected":null,"passed":true},{"actual":"ab","check":"boundary-control fixture 12","expected":null,"passed":false},{"actual":null,"check":"boundary-control fixture 13","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 14","expected":null,"passed":true},{"actual":"b1","check":"boundary-control fixture 15","expected":"b1","passed":true},{"actual":"abc","check":"boundary-control fixture 16","expected":"abc","passed":true},{"actual":"ab","check":"boundary-control fixture 17","expected":"ab","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary-control fixture 0\", \"actual\": \"a;b\", \"expected\": \"a;b\", \"passed\": true}, {\"check\": \"boundary-control fixture 1\", \"actual\": \"a\\\"b\", \"expected\": \"a\\\"b\", \"passed\": true}, {\"check\": \"boundary-control fixture 2\", \"actual\": \"a\\\\b\", \"expected\": \"a\\\\b\", \"passed\": true}, {\"check\": \"boundary-control fixture 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 4\", \"actual\": \"abc\", \"expected\": \"abc\", \"passed\": true}, {\"check\": \"boundary-control fixture 5\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 6\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 7\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 8\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 9\", \"actual\": \"abcdefghijkl\", \"expected\": \"abcdefghijkl\", \"passed\": true}, {\"check\": \"boundary-control fixture 10\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 11\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 12\", \"actual\": \"ab\", \"expected\": null, \"passed\": false}, {\"check\": \"boundary-control fixture 13\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 14\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 15\", \"actual\": \"b1\", \"expected\": \"b1\", \"passed\": true}, {\"check\": \"boundary-control fixture 16\", \"actual\": \"abc\", \"expected\": \"abc\", \"passed\": true}, {\"check\": \"boundary-control fixture 17\", \"actual\": \"ab\", \"expected\": \"ab\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.813,"exit_code":1,"observations":[{"actual":"a;b","check":"boundary-control fixture 0","expected":"a;b","passed":true},{"actual":"a\"b","check":"boundary-control fixture 1","expected":"a\"b","passed":true},{"actual":"a\\b","check":"boundary-control fixture 2","expected":"a\\b","passed":true},{"actual":null,"check":"boundary-control fixture 3","expected":null,"passed":true},{"actual":"abc","check":"boundary-control fixture 4","expected":"abc","passed":true},{"actual":null,"check":"boundary-control fixture 5","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 6","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 7","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 8","expected":null,"passed":true},{"actual":"abcdefghijkl","check":"boundary-control fixture 9","expected":"abcdefghijkl","passed":true},{"actual":null,"check":"boundary-control fixture 10","expected":null,"passed":true},{"actual":"a\nb","check":"boundary-control fixture 11","expected":null,"passed":false},{"actual":"ab","check":"boundary-control fixture 12","expected":null,"passed":false},{"actual":null,"check":"boundary-control fixture 13","expected":null,"passed":true},{"actual":null,"check":"boundary-control fixture 14","expected":null,"passed":true},{"actual":"b1","check":"boundary-control fixture 15","expected":"b1","passed":true},{"actual":"abc","check":"boundary-control fixture 16","expected":"abc","passed":true},{"actual":"ab","check":"boundary-control fixture 17","expected":"ab","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary-control fixture 0\", \"actual\": \"a;b\", \"expected\": \"a;b\", \"passed\": true}, {\"check\": \"boundary-control fixture 1\", \"actual\": \"a\\\"b\", \"expected\": \"a\\\"b\", \"passed\": true}, {\"check\": \"boundary-control fixture 2\", \"actual\": \"a\\\\b\", \"expected\": \"a\\\\b\", \"passed\": true}, {\"check\": \"boundary-control fixture 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 4\", \"actual\": \"abc\", \"expected\": \"abc\", \"passed\": true}, {\"check\": \"boundary-control fixture 5\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 6\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 7\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 8\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 9\", \"actual\": \"abcdefghijkl\", \"expected\": \"abcdefghijkl\", \"passed\": true}, {\"check\": \"boundary-control fixture 10\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 11\", \"actual\": \"a\\nb\", \"expected\": null, \"passed\": false}, {\"check\": \"boundary-control fixture 12\", \"actual\": \"ab\", \"expected\": null, \"passed\": false}, {\"check\": \"boundary-control fixture 13\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 14\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"boundary-control fixture 15\", \"actual\": \"b1\", \"expected\": \"b1\", \"passed\": true}, {\"check\": \"boundary-control fixture 16\", \"actual\": \"abc\", \"expected\": \"abc\", \"passed\": true}, {\"check\": \"boundary-control fixture 17\", \"actual\": \"ab\", \"expected\": \"ab\", \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}