浅念
c5f900f3bd
- 体积守门改 UTF-8 字节数（原按字符数，"汉"*1500 约 4.5KB 可绕过 4096 上限）
- 字符串长度检查并入 _walk_props 递归，嵌套字符串同样受 MAX_STR_LEN 约束
（顺序：体积先行，故同一值既超长又超体积时报 properties_too_large）
- properties 传了但非 dict（[]/""/0/None）不再被 or {} 静默放行，缺省键仍放行
Co-Authored-By: Claude Code <noreply@anthropic.com>
90 lines
3.9 KiB
Python
90 lines
3.9 KiB
Python
import json
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import re
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from datetime import datetime
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from urllib.parse import parse_qsl, urlencode, urlparse
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from django.utils import timezone
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from tracker import constants as C
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_SENSITIVE = re.compile("|".join(C.SENSITIVE_KEY_PATTERNS), re.I)
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_URL_DROP_KEY = re.compile("|".join(C.URL_PARAM_DROP_PATTERNS), re.I)
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def sanitize_url(url: str) -> str:
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"""按参数名整键删除（fullmatch 防止误伤 monkey 这类含 key 子串的参数）。"""
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p = urlparse(url)
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kept = [(k, v) for k, v in parse_qsl(p.query, keep_blank_values=True)
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if not _URL_DROP_KEY.fullmatch(k)]
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return p._replace(query=urlencode(kept)).geturl()
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def _walk_props(v, depth=0):
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"""单次递归同时做深度检查、敏感键扫描与字符串超长检查。
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dict 所有层级的键都过 _SENSITIVE，所有层级的字符串都受 MAX_STR_LEN 约束。
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返回 (depth_ok, sensitive_hit, str_too_long)。深度超限即停止下探，防恶意深嵌套递归爆栈。"""
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if depth > C.MAX_PROP_DEPTH:
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return False, False, False
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if isinstance(v, dict):
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depth_ok, sens, too_long = True, False, False
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for k, x in v.items():
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if _SENSITIVE.search(str(k)):
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sens = True
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d, s, l = _walk_props(x, depth + 1)
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depth_ok = depth_ok and d
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sens = sens or s
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too_long = too_long or l
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return depth_ok, sens, too_long
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if isinstance(v, list):
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depth_ok, sens, too_long = True, False, False
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for x in v:
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d, s, l = _walk_props(x, depth + 1)
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depth_ok = depth_ok and d
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sens = sens or s
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too_long = too_long or l
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return depth_ok, sens, too_long
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if isinstance(v, str) and len(v) > C.MAX_STR_LEN:
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return True, False, True
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return True, False, False
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def validate_event(ev) -> str | None:
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"""返回 None 表示通过；否则返回拒绝原因码。类型/白名单/体积/深度全在此守门。"""
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if not isinstance(ev, dict):
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return "event_invalid_shape"
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if ev.get("event_name") not in C.EVENT_NAMES:
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return "event_name_not_allowed"
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eid = ev.get("event_id")
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if not isinstance(eid, str) or not eid or len(eid) > 64:
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return "invalid_event_id"
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for k in ("path", "title"):
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if ev.get(k) is not None and not isinstance(ev[k], str):
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return "invalid_field_type"
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occ = ev.get("occurred_at")
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if not isinstance(occ, datetime):
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return "invalid_occurred_at"
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if timezone.is_naive(occ):
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return "invalid_occurred_at"
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skew = (timezone.now() - occ).total_seconds()
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if abs(skew) > C.CLOCK_SKEW_REJECT_SEC:
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return "occurred_at_out_of_window"
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props = ev.get("properties", {})
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if not isinstance(props, dict) or len(props) > C.MAX_PROP_KEYS:
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return "properties_invalid" # 传了但非 dict（[]/""/0/None）一律拒
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# 敏感键扫描（含嵌套层级）先于属性白名单：白名单内无任何键命中敏感模式，
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# 若放在白名单之后，sensitive_field 将不可达（见 test_sensitive_property_rejected）。
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depth_ok, sensitive_hit, str_too_long = _walk_props(props)
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if sensitive_hit:
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return "sensitive_field"
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if not set(props) <= C.EVENT_PROP_WHITELIST.get(ev["event_name"], set()):
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return "property_not_allowed"
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if not depth_ok:
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return "properties_depth"
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# 体积按 UTF-8 字节数守门（汉字多字节，按字符数会被绕过）
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if len(json.dumps(props, ensure_ascii=False, default=str).encode("utf-8")) > C.MAX_PROP_JSON_BYTES:
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return "properties_too_large"
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if str_too_long:
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return "properties_too_long"
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if len(ev.get("path") or "") > C.MAX_PATH_LEN:
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ev["path"] = ev["path"][:C.MAX_PATH_LEN]
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if len(ev.get("title") or "") > C.MAX_TITLE_LEN:
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ev["title"] = ev["title"][:C.MAX_TITLE_LEN]
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if ev.get("path"):
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ev["path"] = sanitize_url(ev["path"])
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return None
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