| |
| """解密并校验数美 deviceprofile 请求体（payload.json） |
| |
| 用途： |
| 1. 用 uid 派生 priId 解密 data，还原明文指纹对象（对照 capture_payload.js 的输出） |
| 2. 校验完整性字段 er/tn：按 JS 语义重算拼接串并比对 |
| 3. 校验各字段的 DES 明文（可选，需提供密钥表） |
| |
| 依赖：pip install pycryptodome |
| |
| 用法： |
| python decode_payload.py payload.json --uid 88888888-8888-4888-8888-888888888888 [--dump] |
| """ |
| import argparse |
| import base64 |
| import gzip |
| import hashlib |
| import json |
| import sys |
|
|
| try: |
| from Crypto.Cipher import DES |
| except ImportError: |
| print("需要 pycryptodome: pip install pycryptodome", file=sys.stderr) |
| sys.exit(1) |
|
|
| AES_IV = "0102030405060708" |
|
|
|
|
| def aes_cbc_decrypt_hex(pri_id: str, data_hex: str) -> bytes: |
| from Crypto.Cipher import AES |
|
|
| raw = bytes.fromhex(data_hex) |
| dec = AES.new(pri_id.encode(), AES.MODE_CBC, AES_IV.encode()).decrypt(raw) |
| return dec.rstrip(b"\x00") |
|
|
|
|
| def des_decrypt_b64(key: str, value: str) -> str: |
| raw = base64.b64decode(value) |
| out = DES.new(key.encode(), DES.MODE_ECB).decrypt(raw) |
| return out.rstrip(b"\x00").decode("utf-8", "replace") |
|
|
|
|
| def js_value_string(v) -> str: |
| """复刻 JS 中 ``'' + value`` 的字符串化行为。""" |
| if isinstance(v, bool): |
| return "true" if v else "false" |
| if isinstance(v, dict): |
| return "[object Object]" |
| if isinstance(v, list): |
| return ",".join("" if x is None else js_value_string(x) for x in v) |
| if v is None: |
| return "null" |
| return str(v) |
|
|
|
|
| def compute_tn(obj: dict) -> str: |
| """复刻 SDK 的 tn：按键排序拼接值，数字 ×10000（键名与分隔符不参与）。""" |
| parts = [] |
| for k in sorted(obj.keys()): |
| v = obj[k] |
| if isinstance(v, bool): |
| parts.append(js_value_string(v)) |
| elif isinstance(v, (int, float)): |
| parts.append(str(int(v * 0x2710))) |
| else: |
| parts.append(js_value_string(v)) |
| return hashlib.md5("".join(parts).encode("utf-8")).hexdigest() |
|
|
|
|
| def main() -> int: |
| ap = argparse.ArgumentParser() |
| ap.add_argument("payload", help="capture_payload.js 产出的 payload.json") |
| ap.add_argument("--uid", required=True, help="签发时的 uid（priId = md5(uid)[:16]）") |
| ap.add_argument("--dump", action="store_true", help="打印全部明文字段") |
| ap.add_argument("--er-key", default="2j48yowr", help="er/tn 字段的 DES 密钥（默认当前版本）") |
| ap.add_argument( |
| "--undefined-key", |
| action="append", |
| default=None, |
| help="值为 undefined、只在 tn 里以 \"undefined\" 出现的字段（默认 yu，可重复传）", |
| ) |
| args = ap.parse_args() |
|
|
| payload = json.load(open(args.payload, encoding="utf-8")) |
| pri_id = hashlib.md5(args.uid.encode()).hexdigest()[:16] |
| b64 = aes_cbc_decrypt_hex(pri_id, payload["data"]) |
| obj = json.loads(gzip.decompress(base64.b64decode(b64))) |
|
|
| print("解密成功：字段数 =", len(obj), "| protocol =", obj.get("protocol")) |
|
|
| er = obj.get("er") |
| if er: |
| got_tn = des_decrypt_b64(args.er_key, er) |
| |
| undefined_keys = args.undefined_key if args.undefined_key is not None else ["yu"] |
| tn_input = {k: v for k, v in obj.items() if k != "er"} |
| for k in undefined_keys: |
| tn_input.setdefault(k, "undefined") |
| calc_tn = compute_tn(tn_input) |
| print("er 解密 =", got_tn) |
| print("本地重算 =", calc_tn) |
| print("tn 校验:", "一致 ✅" if got_tn == calc_tn else "不一致 ❌（拼接语义或字段集合有差异）") |
| else: |
| print("payload 中没有 er 字段（旧版本协议可能是明文 tn/nb）") |
|
|
| if args.dump: |
| for k in sorted(obj.keys()): |
| print("%-16s %s" % (k, js_value_string(obj[k])[:100])) |
| return 0 |
|
|
|
|
| if __name__ == "__main__": |
| sys.exit(main()) |
