add an account limit

2026-09-09 07:01:27 -07:00 · 2026-07-14 11:49:47 -04:00
parent deffa1bfc5
commit 9d0d00992f
4 changed files with 216 additions and 28 deletions
@@ -2,14 +2,16 @@ import { Hono } from 'hono'
 import { useWorkersLogger } from 'workers-tagged-logger'

 import {
+	countAccountsByPlatformId,
+	countAccountsBySignupIp,
 	createAccount,
 	getAccount,
 	getAccountByUsername,
 	getAccountsByPlatformId,
 	getPasswordHash,
 	RoomInstanceType,
-	setDeviceInfo,
 	setLastLoginTime,
+	setLoginContext,
 	setPasswordHash,
 	setPresence,
 } from '@repo/domain'
@@ -42,6 +44,23 @@ const PLATFORM_TYPES: Record<number, string> = {
 	8: 'Pico',
 }

+/**
+ * Signup caps, enforced on create_account only (never on login — an existing account
+ * always stays reachable, however many accounts its owner has since accumulated).
+ *
+ * Two independent arms, because they fail in opposite ways:
+ *  - Per verified platform id (a Steam-proven SteamID64). The sharp one: it can't be
+ *    spoofed and can't be reset by changing networks. Only binds on a platform
+ *    create_account — the password/anonymous path has no platform identity to count,
+ *    so the IP arm is the only thing standing between it and bulk signup.
+ *  - Per signup IP. Coarse: households, NAT and shared campus/mobile networks put many
+ *    legitimate players behind one address, so this WILL be the arm that produces false
+ *    positives. It counts `signupIp` (immutable), so an abuser can't reset their own
+ *    count by hopping networks.
+ */
+const MAX_ACCOUNTS_PER_PLATFORM_ID = 3
+const MAX_ACCOUNTS_PER_IP = 3
+
 /** New players start in the Orientation room (RoomId 13) — the new-user flow. */
 const ORIENTATION_ROOM_ID = 13
 /**
@@ -227,6 +246,12 @@ const app = new Hono<App>()
 			typeof body.device_class === 'string' ? Number.parseInt(body.device_class, 10) : NaN
 		const deviceClass = Number.isNaN(deviceClassInt) ? 0 : deviceClassInt

+		// The client's real IP, per Cloudflare (the client can't spoof CF-Connecting-IP —
+		// the edge sets it — unlike X-Forwarded-For, which is why we don't read that).
+		// Recorded as the immutable `signupIp` at creation and as `lastLoginIp` on every
+		// login; both feed the per-IP signup cap. Absent (empty) outside the CF edge.
+		const clientIp = c.req.header('cf-connecting-ip') ?? ''
+
 		// A platform-authenticated login proves who you are with the platform itself,
 		// and we can ONLY verify Steam (platform 0) — via its Steam-signed platform_auth
 		// ticket. So those logins must be Steam:
@@ -275,6 +300,37 @@ const app = new Hono<App>()
 		//    via create_account or /account/me/changepassword.
 		let accountId: string
 		if (grantType === 'create_account') {
+			// Signup caps. Checked before minting anything, so a rejected signup leaves no
+			// account behind. Each arm is skipped when its identity is unknown (no verified
+			// platform id / no client IP) — an unattributable signup can't be counted against
+			// anyone, and lumping them together would lock out real players.
+			if (
+				verifiedSteamId !== null &&
+				(await countAccountsByPlatformId(c.env.DB, verifiedSteamId)) >= MAX_ACCOUNTS_PER_PLATFORM_ID
+			) {
+				logger.info('signup rejected: platform account limit', { platformId: verifiedSteamId })
+				return c.json(
+					{
+						error: 'invalid_grant',
+						error_description: 'account limit reached for this platform account',
+					},
+					400
+				)
+			}
+			if (
+				clientIp !== '' &&
+				(await countAccountsBySignupIp(c.env.DB, clientIp)) >= MAX_ACCOUNTS_PER_IP
+			) {
+				logger.info('signup rejected: per-IP account limit', { ip: clientIp })
+				return c.json(
+					{
+						error: 'invalid_grant',
+						error_description: 'too many accounts created from this network',
+					},
+					400
+				)
+			}
+
 			// Bind the platform identity ONLY when a Steam ticket proved it. That bound
 			// `platformId` (the SteamID64) is what a later cached login is checked against,
 			// so only this Steam user can log back into the account. A password/anonymous
@@ -286,6 +342,8 @@ const app = new Hono<App>()
 				lastLoginTime: new Date().toISOString(),
 				deviceId: deviceId || undefined,
 				deviceClass: deviceId ? deviceClass : undefined,
+				signupIp: clientIp || undefined,
+				lastLoginIp: clientIp || undefined,
 			})
 			accountId = String(account.accountId)
 			// Establish the login password when one is posted (raw password never stored).
@@ -332,7 +390,7 @@ const app = new Hono<App>()
 			}
 			accountId = String(account.accountId)
 			await setLastLoginTime(c.env.DB, account.accountId, new Date().toISOString())
-			await setDeviceInfo(c.env.DB, account.accountId, deviceId, deviceClass)
+			await setLoginContext(c.env.DB, account.accountId, { deviceId, deviceClass, ip: clientIp })
 		} else {
 			// Resolve the account from a posted numeric `account_id` or, as RecRoom's
 			// password grant sends, a `username` (case-insensitive; trailing whitespace
@@ -364,7 +422,7 @@ const app = new Hono<App>()
 			}
 			accountId = String(resolvedId)
 			await setLastLoginTime(c.env.DB, resolvedId, new Date().toISOString())
-			await setDeviceInfo(c.env.DB, resolvedId, deviceId, deviceClass)
+			await setLoginContext(c.env.DB, resolvedId, { deviceId, deviceClass, ip: clientIp })
 		}

 		const accessToken = await generateToken(
@@ -69,24 +69,29 @@ function decodePayload(token: string): Record<string, unknown> {
 	) as Record<string, unknown>
 }

-async function accessTokenFor(body: string): Promise<string> {
-	const res = await exports.default.fetch(`${ORIGIN}/connect/token`, {
-		method: 'POST',
-		headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
-		body,
-	})
-	return ((await res.json()) as { access_token: string }).access_token
+async function accessTokenFor(body: string, ip?: string): Promise<string> {
+	return (await postToken(body, ip)).json.access_token as string
 }

-async function tokenFor(body: string): Promise<Record<string, unknown>> {
-	return decodePayload(await accessTokenFor(body))
+async function tokenFor(body: string, ip?: string): Promise<Record<string, unknown>> {
+	return decodePayload(await accessTokenFor(body, ip))
 }

-/** POST a form-urlencoded body to /connect/token, returning status + parsed JSON. */
-async function postToken(body: string): Promise<{ status: number; json: Record<string, unknown> }> {
+/**
+ * POST a form-urlencoded body to /connect/token, returning status + parsed JSON.
+ * `ip` sets CF-Connecting-IP (what Cloudflare's edge sets in production); omit it and
+ * the request looks IP-less, which is how the other tests dodge the per-IP signup cap.
+ */
+async function postToken(
+	body: string,
+	ip?: string
+): Promise<{ status: number; json: Record<string, unknown> }> {
 	const res = await exports.default.fetch(`${ORIGIN}/connect/token`, {
 		method: 'POST',
-		headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+		headers: {
+			'Content-Type': 'application/x-www-form-urlencoded',
+			...(ip ? { 'CF-Connecting-IP': ip } : {}),
+		},
 		body,
 	})
 	return { status: res.status, json: (await res.json()) as Record<string, unknown> }
@@ -362,6 +367,20 @@ describe('auth worker routes', () => {
 		expect(shared.map((a) => a.accountId)).toContain(sub)
 	})

+	test('POST /connect/token stores deviceClass as an integer, not a REAL', async () => {
+		// D1 binds a JS number as a SQLite REAL, so a naive json_set writes `"deviceClass":2.0`
+		// into the blob. JSON.parse tolerates that, but the raw JSON is what other readers
+		// (and any strict int parser) see, so assert on the stored TEXT, not the parsed value.
+		await postToken(
+			`grant_type=password&username=Player77&password=${LOGIN_PASSWORD}&device_id=dev-int&device_class=2`
+		)
+		const row = await env.DB.prepare('SELECT data FROM account WHERE account_id = ?1')
+			.bind(77)
+			.first<{ data: string }>()
+		expect(row!.data).toContain('"deviceClass":2')
+		expect(row!.data).not.toContain('2.0')
+	})
+
 	test('POST /connect/token refreshes the stored device on a credential login', async () => {
 		// Account 42 was seeded with no device; a later login records the one it came from.
 		const res = await postToken(
@@ -376,6 +395,44 @@ describe('auth worker routes', () => {
 		expect(account.deviceClass).toBe(3)
 	})

+	test('POST /connect/token create_account records the client IP', async () => {
+		const payload = await tokenFor('grant_type=create_account&platform_id=steam-ip1', '203.0.113.7')
+		const sub = Number.parseInt(payload.sub as string, 10)
+		const row = await env.DB.prepare('SELECT data FROM account WHERE account_id = ?1')
+			.bind(sub)
+			.first<{ data: string }>()
+		const account = JSON.parse(row!.data) as { signupIp: string; lastLoginIp: string }
+		expect(account.signupIp).toBe('203.0.113.7')
+		expect(account.lastLoginIp).toBe('203.0.113.7')
+	})
+
+	test('POST /connect/token caps the accounts created from one IP', async () => {
+		const ip = '198.51.100.22'
+		for (let i = 0; i < 3; i++) {
+			const ok = await postToken(`grant_type=create_account&platform_id=steam-cap${i}`, ip)
+			expect(ok.status).toBe(200)
+		}
+		// The 4th signup from that IP is refused — the cap is 3.
+		const capped = await postToken('grant_type=create_account&platform_id=steam-cap3', ip)
+		expect(capped.status).toBe(400)
+		expect(capped.json.error).toBe('invalid_grant')
+		expect(capped.json.error_description).toMatch(/network/)
+
+		// A different IP is unaffected, and the capped IP can still LOG IN to what it has.
+		const other = await postToken('grant_type=create_account&platform_id=steam-cap4', '198.51.100.23')
+		expect(other.status).toBe(200)
+	})
+
+	test('POST /connect/token does not cap logins, only signups', async () => {
+		// Account 42's owner may be over the signup cap; that must never lock them out of
+		// an account they already have.
+		const res = await postToken(
+			`grant_type=password&username=Player42&password=${LOGIN_PASSWORD}`,
+			'198.51.100.22'
+		)
+		expect(res.status).toBe(200)
+	})
+
 	test('POST /connect/token create_account seeds the new player into Orientation', async () => {
 		const payload = await tokenFor('grant_type=create_account&platform_id=steam-456')
 		const sub = payload.sub as string
@@ -169,7 +169,11 @@ async function syncMemberCount(db: D1Database, clubId: number): Promise<number>
 		.first<{ n: number }>()
 	const count = row?.n ?? 0
 	await db
-		.prepare("UPDATE club SET data = json_set(data, '$.MemberCount', ?2) WHERE club_id = ?1")
+		// CAST to INTEGER: D1 binds a JS number as a SQLite REAL, which json_set would write
+		// into the blob as `"MemberCount":3.0` — and this blob is served to the client.
+		.prepare(
+			"UPDATE club SET data = json_set(data, '$.MemberCount', CAST(?2 AS INTEGER)) WHERE club_id = ?1"
+		)
 		.bind(clubId, count)
 		.run()
 	return count
@@ -506,7 +510,11 @@ export async function setHomeClub(
 	clubId: number
 ): Promise<void> {
 	await db
-		.prepare("UPDATE account SET data = json_set(data, '$.homeClubId', ?2) WHERE account_id = ?1")
+		// CAST to INTEGER — see syncMemberCount: a bound JS number lands as a REAL, so this
+		// would otherwise store `"homeClubId":7.0`.
+		.prepare(
+			"UPDATE account SET data = json_set(data, '$.homeClubId', CAST(?2 AS INTEGER)) WHERE account_id = ?1"
+		)
 		.bind(accountId, clubId)
 		.run()
 }