feat: Message Rate Limiters, Violation Logging, & Ban System 🔨 (#903)

* refactor: require Auth middleware in route index files

* feat: concurrent message limiter

* feat: complete concurrent message limiter with caching

* refactor: SSE response methods separated from handleText

* fix(abortMiddleware): fix req and res order to standard, use endpointOption in req.body

* chore: minor name changes

* refactor: add isUUID condition to saveMessage

* fix(concurrentLimiter): logic correctly handles the max number of concurrent messages and res closing/finalization

* chore: bump keyv and remove console.log from Message

* fix(concurrentLimiter): ensure messages are only saved in later message children

* refactor(concurrentLimiter): use KeyvFile instead, could make other stores configurable in the future

* feat: add denyRequest function for error responses

* feat(utils): add isStringTruthy function

Introduce the isStringTruthy function to the utilities module to check if a string value is a case-insensitive match for 'true'

* feat: add optional message rate limiters by IP and userId

* feat: add optional message rate limiters by IP and userId to edit route

* refactor: rename isStringTruthy to isTrue for brevity

* refactor(getError): use map to make code cleaner

* refactor: use memory for concurrent rate limiter to prevent clearing on startup/exit, add multiple log files, fix error message for concurrent violation

* feat: check if errorMessage is object, stringify if so

* chore: send object to denyRequest which will stringify it

* feat: log excessive requests

* fix(getError): correctly pluralize messages

* refactor(limiters): make type consistent between logs and errorMessage

* refactor(cache): move files out of lib/db into separate cache dir
>> feat: add getLogStores function so Keyv instance is not redundantly created on every violation
feat: separate violation logging to own function with logViolation

* fix: cache/index.js export, properly record userViolations

* refactor(messageLimiters): use new logging method, add logging to registrations

* refactor(logViolation): make userLogs an array of logs per user

* feat: add logging to login limiter

* refactor: pass req as first param to logViolation and record offending IP

* refactor: rename isTrue helper fn to isEnabled

* feat: add simple non_browser check and log violation

* fix: open handles in unit tests, remove KeyvMongo as not used and properly mock global fetch

* chore: adjust nodemon ignore paths to properly ignore logs

* feat: add math helper function for safe use of eval

* refactor(api/convos): use middleware at top of file to avoid redundancy

* feat: add delete all static method for Sessions

* fix: redirect to login on refresh if user is not found, or the session is not found but hasn't expired (ban case)

* refactor(getLogStores): adjust return type

* feat: add ban violation and check ban logic
refactor(logViolation): pass both req and res objects

* feat: add removePorts helper function

* refactor: rename getError to getMessageError and add getLoginError for displaying different login errors

* fix(AuthContext): fix type issue and remove unused code

* refactor(bans): ban by ip and user id, send response based on origin

* chore: add frontend ban messages

* refactor(routes/oauth): add ban check to handler, also consolidate logic to avoid redundancy

* feat: add ban check to AI messaging routes

* feat: add ban check to login/registration

* fix(ci/api): mock KeyvMongo to avoid tests hanging

* docs: update .env.example
> refactor(banViolation): calculate interval rate crossover, early return if duration is invalid
ci(banViolation): add tests to ensure users are only banned when expected

* docs: improve wording for mod system

* feat: add configurable env variables for violation scores

* chore: add jsdoc for uaParser.js

* chore: improve ban text log

* chore: update bun test scripts

* refactor(math.js): add fallback values

* fix(KeyvMongo/banLogs): refactor keyv instances to top of files to avoid memory leaks, refactor ban logic to use getLogStores instead
refactor(getLogStores): get a single log store by type

* fix(ci): refactor tests due to banLogs changes, also make sure to clear and revoke sessions even if ban duration is 0

* fix(banViolation.js): getLogStores import

* feat: handle 500 code error at login

* fix(middleware): handle case where user.id is _id and not just id

* ci: add ban secrets for backend unit tests

* refactor: logout user upon ban

* chore: log session delete message only if deletedCount > 0

* refactor: change default ban duration (2h) and make logic more clear in JSDOC

* fix: login and registration limiters will now return rate limiting error

* fix: userId not parsable as non ObjectId string

* feat: add useTimeout hook to properly clear timeouts when invoking functions within them
refactor(AuthContext): cleanup code by using new hook and defining types in ~/common

* fix: login error message for rate limits

* docs: add info for automated mod system and rate limiters, update other docs accordingly

* chore: bump data-provider version

api/cache/banViolation.js

@@ -0,0 +1,68 @@
+const Session = require('../models/Session');
+const getLogStores = require('./getLogStores');
+const { isEnabled, math, removePorts } = require('../server/utils');
+const { BAN_VIOLATIONS, BAN_INTERVAL } = process.env ?? {};
+const interval = math(BAN_INTERVAL, 20);
+
+/**
+ * Bans a user based on violation criteria.
+ *
+ * If the user's violation count is a multiple of the BAN_INTERVAL, the user will be banned.
+ * The duration of the ban is determined by the BAN_DURATION environment variable.
+ * If BAN_DURATION is not set or invalid, the user will not be banned.
+ * Sessions will be deleted and the refreshToken cookie will be cleared even with
+ * an invalid or nill duration, which is a "soft" ban; the user can remain active until
+ * access token expiry.
+ *
+ * @async
+ * @param {Object} req - Express request object containing user information.
+ * @param {Object} res - Express response object.
+ * @param {Object} errorMessage - Object containing user violation details.
+ * @param {string} errorMessage.type - Type of the violation.
+ * @param {string} errorMessage.user_id - ID of the user who committed the violation.
+ * @param {number} errorMessage.violation_count - Number of violations committed by the user.
+ *
+ * @returns {Promise<void>}
+ *
+ */
+const banViolation = async (req, res, errorMessage) => {
+  if (!isEnabled(BAN_VIOLATIONS)) {
+    return;
+  }
+
+  if (!errorMessage) {
+    return;
+  }
+
+  const { type, user_id, prev_count, violation_count } = errorMessage;
+
+  const prevThreshold = Math.floor(prev_count / interval);
+  const currentThreshold = Math.floor(violation_count / interval);
+
+  if (prevThreshold >= currentThreshold) {
+    return;
+  }
+
+  await Session.deleteAllUserSessions(user_id);
+  res.clearCookie('refreshToken');
+
+  const banLogs = getLogStores('ban');
+  const duration = banLogs.opts.ttl;
+
+  if (duration <= 0) {
+    return;
+  }
+
+  req.ip = removePorts(req);
+  console.log(`[BAN] Banning user ${user_id} @ ${req.ip} for ${duration / 1000 / 60} minutes`);
+  const expiresAt = Date.now() + duration;
+  await banLogs.set(user_id, { type, violation_count, duration, expiresAt });
+  await banLogs.set(req.ip, { type, user_id, violation_count, duration, expiresAt });
+
+  errorMessage.ban = true;
+  errorMessage.ban_duration = duration;
+
+  return;
+};
+
+module.exports = banViolation;