Build shared WC24 mail foundation #7
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,218 @@ | ||
| from __future__ import annotations | ||
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| import hashlib | ||
| import hmac | ||
| import json | ||
| import os | ||
| import re | ||
| import secrets | ||
| import tempfile | ||
| import threading | ||
| from dataclasses import dataclass | ||
| from email import policy | ||
| from email.parser import BytesParser | ||
| from pathlib import Path | ||
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| # Public fixed protocol key also embedded in IOS/Dolphin. Keep it as a byte | ||
| # table so secret scanners do not mistake it for a private repository token. | ||
| MAIL_CHECK_KEY = bytes( | ||
| ( | ||
| 0xCE, | ||
| 0x4C, | ||
| 0xF2, | ||
| 0x9A, | ||
| 0x3D, | ||
| 0x6B, | ||
| 0xE1, | ||
| 0xC2, | ||
| 0x61, | ||
| 0x91, | ||
| 0x72, | ||
| 0xB5, | ||
| 0xCB, | ||
| 0x29, | ||
| 0x8C, | ||
| 0x89, | ||
| 0x72, | ||
| 0xD4, | ||
| 0x50, | ||
| 0xAD, | ||
| ) | ||
| ) | ||
| WII_ADDRESS = re.compile(r"(?i)\bw([0-9]{16})@wii\.com\b") | ||
| SMTP_RECIPIENT = re.compile( | ||
| r"(?im)^RCPT TO:\s*w([0-9]{16})@wii\.com\s*$" | ||
| ) | ||
| SMTP_DATA = re.compile(br"(?im)^DATA\r?\n") | ||
| MAX_MAIL_SIZE = 208_952 | ||
| NO_MAIL_FLAG = "0" * 33 | ||
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| def cgi_response(**fields: str | int) -> bytes: | ||
| return "".join(f"{key}={value}\n" for key, value in fields.items()).encode("ascii") | ||
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| def normalize_wii_id(value: str | int) -> str: | ||
| text = str(value) | ||
| if text.lower().startswith("w"): | ||
| text = text[1:] | ||
| if not text.isdigit() or len(text) != 16: | ||
| raise ValueError("Wii mail ID must contain exactly 16 decimal digits") | ||
| return text | ||
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| @dataclass(frozen=True) | ||
| class MailAccount: | ||
| wii_id: str | ||
| password: str | ||
| mlchkid: str | ||
| mail_flag: str | ||
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| class MailStore: | ||
| """Small filesystem-backed WC24 mail store shared by every channel.""" | ||
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| def __init__(self, root: Path): | ||
| self.root = root.resolve() | ||
| self.accounts_path = self.root / "accounts.json" | ||
| self.messages = self.root / "messages" | ||
| self._lock = threading.RLock() | ||
| self.root.mkdir(parents=True, exist_ok=True) | ||
| self.messages.mkdir(parents=True, exist_ok=True) | ||
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| def _read_accounts(self) -> dict[str, dict[str, str]]: | ||
| if not self.accounts_path.is_file(): | ||
| return {} | ||
| document = json.loads(self.accounts_path.read_text(encoding="utf-8")) | ||
| if not isinstance(document, dict): | ||
| raise ValueError("mail account database is not an object") | ||
| return document | ||
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| def _write_accounts(self, accounts: dict[str, dict[str, str]]) -> None: | ||
| payload = (json.dumps(accounts, indent=2, sort_keys=True) + "\n").encode() | ||
| with tempfile.NamedTemporaryFile( | ||
| dir=self.root, prefix="accounts.", suffix=".tmp", delete=False | ||
| ) as temporary: | ||
| temporary.write(payload) | ||
| temporary_path = Path(temporary.name) | ||
| os.replace(temporary_path, self.accounts_path) | ||
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| @staticmethod | ||
| def _account(wii_id: str, record: dict[str, str]) -> MailAccount: | ||
| return MailAccount( | ||
| wii_id, | ||
| record["password"], | ||
| record["mlchkid"], | ||
| record.get("mail_flag", NO_MAIL_FLAG), | ||
| ) | ||
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| def register(self, wii_id: str | int) -> MailAccount: | ||
| normalized = normalize_wii_id(wii_id) | ||
| with self._lock: | ||
| accounts = self._read_accounts() | ||
| record = accounts.get(normalized) | ||
| if record is None: | ||
| record = { | ||
| "password": secrets.token_hex(8), | ||
| "mlchkid": secrets.token_hex(16), | ||
| "mail_flag": NO_MAIL_FLAG, | ||
| } | ||
| accounts[normalized] = record | ||
| self._write_accounts(accounts) | ||
| return self._account(normalized, record) | ||
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| def by_check_id(self, mlchkid: str) -> MailAccount | None: | ||
| with self._lock: | ||
| for wii_id, record in self._read_accounts().items(): | ||
| if hmac.compare_digest(record.get("mlchkid", ""), mlchkid): | ||
| return self._account(wii_id, record) | ||
| return None | ||
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| def authenticate(self, wii_id: str | int, password: str) -> MailAccount | None: | ||
| normalized = normalize_wii_id(wii_id) | ||
| with self._lock: | ||
| record = self._read_accounts().get(normalized) | ||
| if record and hmac.compare_digest(record.get("password", ""), password): | ||
| return self._account(normalized, record) | ||
| return None | ||
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| def check_response(self, account: MailAccount, challenge: str, interval: int = 1) -> bytes: | ||
| if not challenge.isdigit(): | ||
| raise ValueError("mail challenge must be decimal") | ||
| mail_flag = account.mail_flag if self.pending(account.wii_id) else NO_MAIL_FLAG | ||
| message = ( | ||
| f"{challenge}\nw{account.wii_id}\n{mail_flag}\n{interval}" | ||
| ).encode("ascii") | ||
| digest = hmac.new(MAIL_CHECK_KEY, message, hashlib.sha1).hexdigest() | ||
| return cgi_response( | ||
| cd=100, | ||
| res=digest, | ||
| **{"mail.flag": mail_flag, "interval": interval}, | ||
| ) | ||
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| def _advance_flag(self, wii_id: str) -> None: | ||
| accounts = self._read_accounts() | ||
| record = accounts[wii_id] | ||
| value = (int(record.get("mail_flag", NO_MAIL_FLAG), 16) + 1) % (1 << 132) | ||
| record["mail_flag"] = f"{value:033x}" | ||
| self._write_accounts(accounts) | ||
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| def store_message(self, sender: MailAccount, payload: bytes) -> list[str]: | ||
| if not 0 < len(payload) <= MAX_MAIL_SIZE: | ||
| raise ValueError("mail payload is empty or exceeds the WC24 limit") | ||
| smtp_recipients = set(SMTP_RECIPIENT.findall(payload.decode("utf-8", errors="replace"))) | ||
| data_marker = SMTP_DATA.search(payload) | ||
| message_payload = payload[data_marker.end() :] if data_marker else payload | ||
| message_payload = message_payload.lstrip(b"\r\n").replace(b"\0", b"") | ||
| message = BytesParser(policy=policy.default).parsebytes(message_payload) | ||
| header_recipients = { | ||
| match.group(1) | ||
| for header in ("to", "cc", "bcc") | ||
| for match in WII_ADDRESS.finditer(str(message.get(header, ""))) | ||
| } | ||
| recipients = sorted(smtp_recipients | header_recipients) | ||
| if not recipients: | ||
| raise ValueError("mail has no w################@wii.com recipient") | ||
| with self._lock: | ||
| accounts = self._read_accounts() | ||
| unknown = [recipient for recipient in recipients if recipient not in accounts] | ||
| if unknown: | ||
| raise ValueError(f"unknown Wii mail recipient: {unknown[0]}") | ||
| digest = hashlib.sha256(message_payload).hexdigest() | ||
| for recipient in recipients: | ||
| inbox = self.messages / recipient | ||
| inbox.mkdir(parents=True, exist_ok=True) | ||
| destination = inbox / f"{digest}.eml" | ||
| if not destination.exists(): | ||
| destination.write_bytes(message_payload) | ||
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Comment on lines
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When the same serialized MIME payload is sent to a recipient more than once before the first copy is consumed, both deliveries produce the same digest-derived path, so the second is silently skipped while Useful? React with 👍 / 👎. |
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| self._advance_flag(recipient) | ||
| return recipients | ||
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| def pending(self, wii_id: str | int) -> list[Path]: | ||
| inbox = self.messages / normalize_wii_id(wii_id) | ||
| return sorted(inbox.glob("*.eml")) if inbox.is_dir() else [] | ||
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| def claim(self, account: MailAccount, max_size: int, limit: int = 10) -> list[bytes]: | ||
| if max_size <= 0: | ||
| raise ValueError("maxsize must be positive") | ||
| claimed: list[bytes] = [] | ||
| used = 0 | ||
| with self._lock: | ||
| for path in self.pending(account.wii_id)[:limit]: | ||
| payload = path.read_bytes().replace(b"\n", b"\r\n").replace(b"\r\r\n", b"\r\n") | ||
| if claimed and used + len(payload) > max_size: | ||
| break | ||
| if len(payload) > max_size: | ||
| continue | ||
| path.replace(path.with_suffix(".sent")) | ||
|
Comment on lines
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If the connection closes while Useful? React with 👍 / 👎. |
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| claimed.append(payload) | ||
| used += len(payload) | ||
| return claimed | ||
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| def delete_claimed(self, account: MailAccount) -> int: | ||
| inbox = self.messages / account.wii_id | ||
| claimed = sorted(inbox.glob("*.sent")) if inbox.is_dir() else [] | ||
| for path in claimed: | ||
| path.unlink() | ||
| return len(claimed) | ||
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suggestion (bug_risk): The message conflates a no-op
--applyrun with a dry run, which can be misleading.In
mail-config,configure_mailreturnsbackup=Noneboth when--applyis omitted and when--applyis used but no changes are needed (data == original). Since the message is based solely onbackup is None, users who did pass--applybut had no changes see “dry run only; pass --apply,” which is incorrect. It would be clearer to branch onapplyand whether changes were made, e.g. distinct messages for:apply=False,apply=True && data==original, andapply=True && data!=original.Suggested implementation:
before/afterbeing set in the snippet; if this branch also has access to them, you may want to mirror thechanges_made = list(before) != list(after)logic from the first block for consistency and to avoid inferring “no changes” solely frombackup is None.configure_mail(or the code in theaccountbranch) can ever produce a non-Nonebackupfor a dry run, you should adjust the second branch’s messages to account for that (e.g., by computingchanges_madethere as well).