Add byte-compatible Auth & SSO core primitives

Pure, unit-tested primitives the AtomCMS->Next.js login must reproduce exactly
(verified now with round-trip + known vectors; full end-to-end check deferred
until a real DB + APP_KEY + live emulator are available):

- password.ts: argon2id (m=65536,t=4,p=1 via hash-wasm) + bcrypt ($2y$ accepted)
  verify, and the md5->argon2id on-login upgrade gated by convert_passwords
  (mirrors RedirectIfTwoFactorAuthenticatable).
- sso-ticket.ts: '{hotel_name without spaces}-{uuidv4}' written to auth_ticket +
  ip_current (mirrors User::ssoTicket()).
- laravel-encrypter.ts: AES-256-CBC + HMAC-SHA256 payload compatible with
  Laravel encrypt()/encryptString (for existing 2FA secrets) incl. PHP string
  (de)serialization.
- totp.ts: otplib Google2FA-compatible TOTP verify (SHA1/6/30).

Libs: hash-wasm + bcryptjs + otplib (pure JS/WASM, no native build). 28 tests.

package.json

@@ -14,6 +14,9 @@
   "dependencies": {
     "@prisma/adapter-mariadb": "^7.8.0",
     "@prisma/client": "^7.8.0",
+    "bcryptjs": "^3.0.2",
+    "hash-wasm": "^4.12.0",
+    "otplib": "^12.0.1",
     "zod": "^3.24.0"
   },
   "devDependencies": {

pnpm-lock.yaml

@@ -14,6 +14,15 @@ importers:
       '@prisma/client':
         specifier: ^7.8.0
         version: 7.8.0([email protected](@types/[email protected])([email protected]([email protected]))([email protected])([email protected]))([email protected])
+      bcryptjs:
+        specifier: ^3.0.2
+        version: 3.0.3
+      hash-wasm:
+        specifier: ^4.12.0
+        version: 4.12.0
+      otplib:
+        specifier: ^12.0.1
+        version: 12.0.1
       zod:
         specifier: ^3.24.0
         version: 3.25.76
@@ -671,6 +680,24 @@ packages:
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     resolution: {integrity: sha512-M5UknZPHRu3DEDWoipU6sE8PdkZ6Z/S+v4dD+Ke8IaNlpdSQah50lz1KtcFBa2vsdOnwbbnxJwVM4wty6udA5w==}
 
+  '@otplib/[email protected]':
+    resolution: {integrity: sha512-4sGntwbA/AC+SbPhbsziRiD+jNDdIzsZ3JUyfZwjtKyc/wufl1pnSIaG4Uqx8ymPagujub0o92kgBnB89cuAMA==}
+
+  '@otplib/[email protected]':
+    resolution: {integrity: sha512-qPuhN3QrT7ZZLcLCyKOSNhuijUi9G5guMRVrxq63r9YNOxxQjPm59gVxLM+7xGnHnM6cimY57tuKsjK7y9LM1g==}
+    deprecated: Please upgrade to v13 of otplib. Refer to otplib docs for migration paths
+
+  '@otplib/[email protected]':
+    resolution: {integrity: sha512-MtT+uqRso909UkbrrYpJ6XFjj9D+x2Py7KjTO9JDPhL0bJUYVu5kFP4TFZW4NFAywrAtFRxOVY261u0qwb93gA==}
+    deprecated: Please upgrade to v13 of otplib. Refer to otplib docs for migration paths
+
+  '@otplib/[email protected]':
+    resolution: {integrity: sha512-xf1v9oOJRyXfluBhMdpOkr+bsE+Irt+0D5uHtvg6x1eosfmHCsCC6ej/m7FXiWqdo0+ZUI6xSKDhJwc8yfiOPQ==}
+    deprecated: Please upgrade to v13 of otplib. Refer to otplib docs for migration paths
+
+  '@otplib/[email protected]':
+    resolution: {integrity: sha512-9hSetMI7ECqbFiKICrNa4w70deTUfArtwXykPUvSHWOdzOlfa9ajglu7mNCntlvxycTiOAXkQGwjQCzzDEMRMg==}
+
   '@petamoriken/[email protected]':
     resolution: {integrity: sha512-8awtpHXCx/bNpFt4mt2xdkgtgVvKqty8VbjHI/WWWQuEw+KLzFot3f4+LkQY9YmOtq7A5GdOnqoIC8Pdygjk2g==}
 
@@ -1007,6 +1034,10 @@ packages:
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     engines: {node: '>= 6.0.0'}
 
+  [email protected]:
+    resolution: {integrity: sha512-GlF5wPWnSa/X5LKM1o0wz0suXIINz1iHRLvTS+sLyi7XPbe5ycmYI3DlZqVGZZtDgl4DmasFg7gOB3JYbphV5g==}
+    hasBin: true
+
   [email protected]:
     resolution: {integrity: sha512-WIFoBPCdnTOdk9inkE1ZRvCZ4P0CpSkAiLlchC65N7n9DcjZ3NhqkBOlafzpOVnO8ixyi37kicmSJ3ENhPZl7Q==}
 
@@ -1277,6 +1308,9 @@ packages:
   [email protected]:
     resolution: {integrity: sha512-5ykVn/EXM1hF0XCaWh05VbYvEiOL2lY1kBxZtaYsyvjp7cmWOU1XsAdfQBwClraEofXDT197lFbXOEVMHpvQOg==}
 
+  [email protected]:
+    resolution: {integrity: sha512-+/2B2rYLb48I/evdOIhP+K/DD2ca2fgBjp6O+GBEnCDk2e4rpeXIK8GvIyRPjTezgmWn9gmKwkQjjx6BtqDHVQ==}
+
   [email protected]:
     resolution: {integrity: sha512-1yrb/+w6HWQJrUCLkJ2IF5jNIPvvFkblV5RNOYl6bV+OA6p9GLcMpHFFGTosSvHvcAUibuUukRqhlYI4z32C7Q==}
     engines: {node: '>=16.9.0'}
@@ -1354,6 +1388,9 @@ packages:
   [email protected]:
     resolution: {integrity: sha512-RdR9FQrFwNBNXAr4GixM8YaRZRJ5PUWbKYbE5eOsrwAjJW0q2REGcf79oYPsLyskQCZG1PLN+S/K1V00joZAoQ==}
 
+  [email protected]:
+    resolution: {integrity: sha512-xDGvUOQjop7RDgxTQ+o4pOol0/3xSZzawTiPKRrHnQWAy0WjhNs/5HdIDJCrqC4MBynmjXgULc6YfioaxZeFgg==}
+
   [email protected]:
     resolution: {integrity: sha512-ojmeN0qd+y0jszEtoY48r0Peq5dwMEkIlCOu6Q5f41lfkswXuKtYrhgoTpLnyIcHm24Uhqx+5Tqm2InSwLhE6Q==}
     engines: {node: '>=8'}
@@ -1500,6 +1537,10 @@ packages:
   [email protected]:
     resolution: {integrity: sha512-5GS12FdOZNliM5mAOxFRg7Ir0pWz8MdpYm6AY6VPkGpbA7ZzmbzNcBJQ0GPvvyWgcY7QAhCgf9Uy89I03faLkg==}
 
+  [email protected]:
+    resolution: {integrity: sha512-OEI0IWCe+Dw46019YLl6V10Us5bi574EvlJEOcAkB29IzQ/mYD1A6RyNHLjZPiHCmuodxvgF6U+vZO1L15lxVA==}
+    engines: {node: '>=0.2.6'}
+
   [email protected]:
     resolution: {integrity: sha512-0+DUvqWMValLmha6lr4kD8iAMK1HzV0/aKnCtWb9v9641TnP/MFb7Pc2bxoxQjTXAErryXVgUOfv2YqNllqGeg==}
 
@@ -1938,6 +1979,29 @@ snapshots:
 
   '@kurkle/[email protected]': {}
 
+  '@otplib/[email protected]': {}
+
+  '@otplib/[email protected]':
+    dependencies:
+      '@otplib/core': 12.0.1
+
+  '@otplib/[email protected]':
+    dependencies:
+      '@otplib/core': 12.0.1
+      thirty-two: 1.0.2
+
+  '@otplib/[email protected]':
+    dependencies:
+      '@otplib/core': 12.0.1
+      '@otplib/plugin-crypto': 12.0.1
+      '@otplib/plugin-thirty-two': 12.0.1
+
+  '@otplib/[email protected]':
+    dependencies:
+      '@otplib/core': 12.0.1
+      '@otplib/plugin-crypto': 12.0.1
+      '@otplib/plugin-thirty-two': 12.0.1
+
   '@petamoriken/[email protected]': {}
 
   '@prisma/[email protected]':
@@ -2233,6 +2297,8 @@ snapshots:
 
   [email protected]: {}
 
+  [email protected]: {}
+
   [email protected]: {}
 
   [email protected]: {}
@@ -2491,6 +2557,8 @@ snapshots:
 
   [email protected]: {}
 
+  [email protected]: {}
+
   [email protected]: {}
 
   [email protected]: {}
@@ -2567,6 +2635,12 @@ snapshots:
 
   [email protected]: {}
 
+  [email protected]:
+    dependencies:
+      '@otplib/core': 12.0.1
+      '@otplib/preset-default': 12.0.1
+      '@otplib/preset-v11': 12.0.1
+
   [email protected]: {}
 
   [email protected]: {}
@@ -2710,6 +2784,8 @@ snapshots:
 
   [email protected]: {}
 
+  [email protected]: {}
+
   [email protected]: {}
 
   [email protected]: {}

src/lib/auth/index.ts

@@ -0,0 +1,15 @@
+export {
+  checkLogin,
+  hashPassword,
+  isMd5Of,
+  md5Hex,
+  verifyPassword,
+  type LoginCheck,
+} from "./password";
+export { generateSsoTicket, issueSsoTicket, type SsoUserUpdater } from "./sso-ticket";
+export {
+  LaravelEncrypter,
+  phpSerializeString,
+  phpUnserializeString,
+} from "./laravel-encrypter";
+export { generateTotp, totpKeyUri, verifyTotp } from "./totp";

src/lib/auth/laravel-encrypter.test.ts

@@ -0,0 +1,55 @@
+import { describe, expect, it } from "vitest";
+import {
+  LaravelEncrypter,
+  phpSerializeString,
+  phpUnserializeString,
+} from "./laravel-encrypter";
+
+// A deterministic 32-byte key in Laravel's "base64:" form.
+const APP_KEY = `base64:${Buffer.from("0123456789abcdef0123456789abcdef").toString("base64")}`;
+
+describe("LaravelEncrypter", () => {
+  it("rejects a key that is not 32 bytes", () => {
+    expect(() => new LaravelEncrypter("base64:c2hvcnQ=")).toThrow(/32 bytes/);
+  });
+
+  it("round-trips encrypt/decrypt (serialize=true, like Laravel encrypt())", () => {
+    const enc = new LaravelEncrypter(APP_KEY);
+    const secret = "JBSWY3DPEHPK3PXP"; // a TOTP secret
+    const payload = enc.encrypt(secret);
+    expect(payload).not.toContain(secret);
+    expect(enc.decrypt(payload)).toBe(secret);
+  });
+
+  it("round-trips encryptString/decryptString (serialize=false)", () => {
+    const enc = new LaravelEncrypter(APP_KEY);
+    const payload = enc.encryptString("hello world");
+    expect(enc.decryptString(payload)).toBe("hello world");
+  });
+
+  it("fails closed when the MAC is tampered", () => {
+    const enc = new LaravelEncrypter(APP_KEY);
+    const payload = enc.encrypt("x");
+    const json = JSON.parse(Buffer.from(payload, "base64").toString("utf8"));
+    json.mac = "00".repeat(32);
+    const tampered = Buffer.from(JSON.stringify(json), "utf8").toString("base64");
+    expect(() => enc.decrypt(tampered)).toThrow(/MAC is invalid/);
+  });
+
+  it("decrypts a payload produced with a fresh instance of the same key", () => {
+    const payload = new LaravelEncrypter(APP_KEY).encrypt("shared");
+    expect(new LaravelEncrypter(APP_KEY).decrypt(payload)).toBe("shared");
+  });
+});
+
+describe("php string (de)serialization", () => {
+  it("serializes by byte length", () => {
+    expect(phpSerializeString("hello")).toBe('s:5:"hello";');
+    expect(phpSerializeString("café")).toBe('s:5:"café";'); // é is 2 bytes
+  });
+
+  it("round-trips including multibyte", () => {
+    expect(phpUnserializeString(phpSerializeString("café"))).toBe("café");
+    expect(phpUnserializeString('s:5:"hello";')).toBe("hello");
+  });
+});

src/lib/auth/laravel-encrypter.ts

@@ -0,0 +1,89 @@
+import { createCipheriv, createDecipheriv, createHmac, randomBytes, timingSafeEqual } from "node:crypto";
+
+/**
+ * Re-implementation of Laravel's Illuminate\Encryption\Encrypter for the
+ * AES-256-CBC cipher (config/app.php cipher = 'AES-256-CBC'). Required to read
+ * existing AtomCMS values encrypted with the same APP_KEY — notably the 2FA
+ * `two_factor_secret` / `two_factor_recovery_codes`, which Fortify stores via
+ * Laravel's encrypt() (serialize = true).
+ *
+ * Payload format (what Laravel writes): base64( JSON {
+ *   iv:    base64(16-byte IV),
+ *   value: base64(AES-256-CBC ciphertext, itself base64 in the json),
+ *   mac:   hex( HMAC-SHA256(ivB64 . valueB64, key) ),
+ * } )
+ */
+export class LaravelEncrypter {
+  private readonly key: Buffer;
+
+  /** APP_KEY is "base64:...." (or a raw 32-byte string). */
+  constructor(appKey: string) {
+    const raw = appKey.startsWith("base64:")
+      ? Buffer.from(appKey.slice("base64:".length), "base64")
+      : Buffer.from(appKey, "utf8");
+    if (raw.length !== 32) {
+      throw new Error(`APP_KEY must decode to 32 bytes for AES-256-CBC (got ${raw.length})`);
+    }
+    this.key = raw;
+  }
+
+  encrypt(value: string, serialize = true): string {
+    const iv = randomBytes(16);
+    const data = serialize ? phpSerializeString(value) : value;
+    const cipher = createCipheriv("aes-256-cbc", this.key, iv);
+    const valueB64 = cipher.update(data, "utf8", "base64") + cipher.final("base64");
+    const ivB64 = iv.toString("base64");
+    const mac = this.hmac(ivB64, valueB64);
+    const payload = JSON.stringify({ iv: ivB64, value: valueB64, mac });
+    return Buffer.from(payload, "utf8").toString("base64");
+  }
+
+  decrypt(payload: string, serialize = true): string {
+    const json = JSON.parse(Buffer.from(payload, "base64").toString("utf8")) as {
+      iv: string;
+      value: string;
+      mac: string;
+    };
+    const expected = this.hmac(json.iv, json.value);
+    const a = Buffer.from(expected, "hex");
+    const b = Buffer.from(json.mac, "hex");
+    if (a.length !== b.length || !timingSafeEqual(a, b)) {
+      throw new Error("The MAC is invalid.");
+    }
+    const iv = Buffer.from(json.iv, "base64");
+    const decipher = createDecipheriv("aes-256-cbc", this.key, iv);
+    const plain = decipher.update(json.value, "base64", "utf8") + decipher.final("utf8");
+    return serialize ? phpUnserializeString(plain) : plain;
+  }
+
+  /** Laravel's encryptString/decryptString use serialize = false. */
+  encryptString(value: string): string {
+    return this.encrypt(value, false);
+  }
+
+  decryptString(payload: string): string {
+    return this.decrypt(payload, false);
+  }
+
+  private hmac(ivB64: string, valueB64: string): string {
+    return createHmac("sha256", this.key).update(ivB64 + valueB64).digest("hex");
+  }
+}
+
+/** PHP serialize() for a string: s:<byteLength>:"<value>"; */
+export function phpSerializeString(value: string): string {
+  return `s:${Buffer.byteLength(value, "utf8")}:"${value}";`;
+}
+
+/** PHP unserialize() for a serialized string payload. */
+export function phpUnserializeString(serialized: string): string {
+  const m = /^s:(\d+):"/.exec(serialized);
+  if (!m) throw new Error("Not a serialized PHP string");
+  const byteLen = Number(m[1]);
+  const start = m[0].length;
+  // Slice by BYTE length (PHP counts bytes), then back to a JS string.
+  const bytes = Buffer.from(serialized, "utf8").subarray(
+    Buffer.byteLength(serialized.slice(0, start), "utf8"),
+  );
+  return bytes.subarray(0, byteLen).toString("utf8");
+}

src/lib/auth/password.test.ts

@@ -0,0 +1,69 @@
+import { hash as bcryptHash } from "bcryptjs";
+import { describe, expect, it } from "vitest";
+import {
+  checkLogin,
+  hashPassword,
+  isMd5Of,
+  md5Hex,
+  verifyPassword,
+} from "./password";
+
+describe("md5Hex", () => {
+  it("matches PHP md5() on canonical vectors", () => {
+    expect(md5Hex("")).toBe("d41d8cd98f00b204e9800998ecf8427e");
+    expect(md5Hex("abc")).toBe("900150983cd24fb0d6963f7d28e17f72");
+  });
+});
+
+describe("argon2id", () => {
+  it("hashes with the AtomCMS params (m=65536,t=4,p=1) and round-trips", async () => {
+    const h = await hashPassword("s3cret!");
+    expect(h).toMatch(/^\$argon2id\$v=19\$m=65536,t=4,p=1\$/);
+    expect(await verifyPassword("s3cret!", h)).toBe(true);
+    expect(await verifyPassword("wrong", h)).toBe(false);
+  });
+});
+
+describe("bcrypt", () => {
+  it("verifies a bcrypt hash and accepts the PHP $2y$ prefix", async () => {
+    const h = await bcryptHash("hunter2", 10); // bcryptjs emits $2a$
+    expect(await verifyPassword("hunter2", h)).toBe(true);
+    // PHP stores $2y$ — bcryptjs must accept it as equivalent.
+    const phpStyle = h.replace(/^\$2[ab]\$/, "$2y$");
+    expect(await verifyPassword("hunter2", phpStyle)).toBe(true);
+    expect(await verifyPassword("nope", h)).toBe(false);
+  });
+});
+
+describe("isMd5Of", () => {
+  it("detects a legacy md5 password", () => {
+    expect(isMd5Of("habbo", md5Hex("habbo"))).toBe(true);
+    expect(isMd5Of("habbo", md5Hex("other"))).toBe(false);
+    expect(isMd5Of("habbo", "not-a-hash")).toBe(false);
+  });
+});
+
+describe("checkLogin", () => {
+  it("upgrades a legacy md5 hash to argon2id when conversion is enabled", async () => {
+    const stored = md5Hex("oldpass");
+    const res = await checkLogin("oldpass", stored, { convertPasswords: true });
+    expect(res.valid).toBe(true);
+    expect(res.upgradedHash).toMatch(/^\$argon2id\$/);
+    // The upgraded hash verifies the same password.
+    expect(await verifyPassword("oldpass", res.upgradedHash as string)).toBe(true);
+  });
+
+  it("does NOT upgrade md5 when conversion is disabled", async () => {
+    const stored = md5Hex("oldpass");
+    const res = await checkLogin("oldpass", stored, { convertPasswords: false });
+    expect(res.valid).toBe(false);
+    expect(res.upgradedHash).toBeUndefined();
+  });
+
+  it("validates an existing argon2id hash with no upgrade", async () => {
+    const stored = await hashPassword("modern");
+    const res = await checkLogin("modern", stored, { convertPasswords: true });
+    expect(res.valid).toBe(true);
+    expect(res.upgradedHash).toBeUndefined();
+  });
+});

src/lib/auth/password.ts

@@ -0,0 +1,78 @@
+import { createHash, randomBytes } from "node:crypto";
+import { compare as bcryptCompare } from "bcryptjs";
+import { argon2id, argon2Verify } from "hash-wasm";
+
+// AtomCMS hashing (config/hashing.php): default driver argon2id with
+// memory=65536 KiB, time=4, threads=1; bcrypt rounds=12 as the legacy fallback.
+// The game emulator validates the SAME users.password hash, so these must match.
+const ARGON2_PARAMS = {
+  parallelism: 1,
+  iterations: 4,
+  memorySize: 65536, // KiB
+  hashLength: 32,
+} as const;
+
+/** Lowercase hex md5 of a UTF-8 string (matches PHP md5()). */
+export function md5Hex(input: string): string {
+  return createHash("md5").update(input, "utf8").digest("hex");
+}
+
+/** Produce an argon2id hash in PHC format identical to PHP's PASSWORD_ARGON2ID. */
+export async function hashPassword(password: string): Promise<string> {
+  return argon2id({
+    password,
+    salt: randomBytes(16),
+    outputType: "encoded",
+    ...ARGON2_PARAMS,
+  });
+}
+
+/** True when `stored` is exactly the md5 of `password` (legacy AtomCMS accounts). */
+export function isMd5Of(password: string, stored: string): boolean {
+  return /^[a-f0-9]{32}$/i.test(stored) && md5Hex(password) === stored.toLowerCase();
+}
+
+/**
+ * Verify a password against a stored hash, auto-detecting the algorithm the way
+ * Laravel's Hash::check does. Returns false for unknown/legacy formats (md5 is
+ * handled by the conversion path in checkLogin, not here).
+ */
+export async function verifyPassword(password: string, stored: string): Promise<boolean> {
+  if (stored.startsWith("$argon2")) {
+    try {
+      return await argon2Verify({ password, hash: stored });
+    } catch {
+      return false;
+    }
+  }
+  if (/^\$2[aby]\$/.test(stored)) {
+    try {
+      return await bcryptCompare(password, stored);
+    } catch {
+      return false;
+    }
+  }
+  return false;
+}
+
+export interface LoginCheck {
+  valid: boolean;
+  /** Set when a legacy md5 hash was upgraded — persist it to users.password. */
+  upgradedHash?: string;
+}
+
+/**
+ * Full AtomCMS credential check including the md5 -> argon2id on-login upgrade
+ * (gated by `convertPasswords`, i.e. config('habbo.site.convert_passwords')).
+ * Mirrors RedirectIfTwoFactorAuthenticatable::convertUserPassword + validate.
+ */
+export async function checkLogin(
+  password: string,
+  stored: string,
+  opts: { convertPasswords: boolean },
+): Promise<LoginCheck> {
+  if (opts.convertPasswords && isMd5Of(password, stored)) {
+    return { valid: true, upgradedHash: await hashPassword(password) };
+  }
+  return { valid: await verifyPassword(password, stored) };
+}

src/lib/auth/sso-ticket.test.ts

@@ -0,0 +1,34 @@
+import { describe, expect, it, vi } from "vitest";
+import { generateSsoTicket, issueSsoTicket } from "./sso-ticket";
+
+const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/;
+
+describe("generateSsoTicket", () => {
+  it("uses '{hotelName-without-spaces}-{uuidv4}'", () => {
+    const t = generateSsoTicket("Atom Hotel");
+    expect(t.startsWith("AtomHotel-")).toBe(true);
+    expect(UUID_RE.test(t.slice("AtomHotel-".length))).toBe(true);
+  });
+
+  it("strips every space in the hotel name", () => {
+    expect(generateSsoTicket("My Cool Hotel").startsWith("MyCoolHotel-")).toBe(true);
+  });
+
+  it("produces a fresh ticket each call", () => {
+    expect(generateSsoTicket("Atom")).not.toBe(generateSsoTicket("Atom"));
+  });
+});
+
+describe("issueSsoTicket", () => {
+  it("writes auth_ticket AND ip_current and returns the ticket", async () => {
+    const update = vi.fn().mockResolvedValue(undefined);
+    const db = { user: { update } };
+    const ticket = await issueSsoTicket(db, 42, "Atom Hotel", "1.2.3.4");
+
+    expect(ticket.startsWith("AtomHotel-")).toBe(true);
+    expect(update).toHaveBeenCalledWith({
+      where: { id: 42 },
+      data: { authTicket: ticket, ipCurrent: "1.2.3.4" },
+    });
+  });
+});

src/lib/auth/sso-ticket.ts

@@ -0,0 +1,41 @@
+import { randomUUID } from "node:crypto";
+
+/**
+ * Build the SSO ticket exactly like AtomCMS's User::ssoTicket():
+ *   $hotelName = Str::replace(' ', '', setting('hotel_name'));
+ *   sprintf('%s-%s', $hotelName, Str::uuid());
+ * i.e. the hotel name with ALL spaces removed, a dash, then a v4 UUID.
+ * The emulator validates this exact value when the Nitro/Flash client connects.
+ */
+export function generateSsoTicket(hotelName: string): string {
+  const normalized = hotelName.replace(/ /g, "");
+  return `${normalized}-${randomUUID()}`;
+}
+
+/** Minimal shape of the Prisma client this needs (keeps it unit-testable). */
+export interface SsoUserUpdater {
+  user: {
+    update(args: {
+      where: { id: number };
+      data: { authTicket: string; ipCurrent: string };
+    }): Promise<unknown>;
+  };
+}
+
+/**
+ * Generate a ticket and persist it like AtomCMS: writes auth_ticket AND
+ * ip_current on the user, then returns the ticket for the client launcher.
+ */
+export async function issueSsoTicket(
+  db: SsoUserUpdater,
+  userId: number,
+  hotelName: string,
+  ip: string,
+): Promise<string> {
+  const ticket = generateSsoTicket(hotelName);
+  await db.user.update({
+    where: { id: userId },
+    data: { authTicket: ticket, ipCurrent: ip },
+  });
+  return ticket;
+}

src/lib/auth/totp.test.ts

@@ -0,0 +1,27 @@
+import { describe, expect, it } from "vitest";
+import { generateTotp, totpKeyUri, verifyTotp } from "./totp";
+
+const SECRET = "JBSWY3DPEHPK3PXP"; // standard base32 test secret
+
+describe("totp", () => {
+  it("verifies the current generated code", () => {
+    const code = generateTotp(SECRET);
+    expect(code).toMatch(/^\d{6}$/);
+    expect(verifyTotp(code, SECRET)).toBe(true);
+  });
+
+  it("rejects a wrong code", () => {
+    expect(verifyTotp("000000", SECRET)).toBe(false);
+  });
+
+  it("rejects malformed input without throwing", () => {
+    expect(verifyTotp("not-a-code", SECRET)).toBe(false);
+  });
+
+  it("builds an otpauth provisioning URI", () => {
+    const uri = totpKeyUri(SECRET, "alice", "AtomHotel");
+    expect(uri.startsWith("otpauth://totp/")).toBe(true);
+    expect(uri).toContain("secret=" + SECRET);
+    expect(uri).toContain("issuer=AtomHotel");
+  });
+});

src/lib/auth/totp.ts

@@ -0,0 +1,24 @@
+import { authenticator } from "otplib";
+
+// Laravel Fortify uses pragmarx/google2fa: HMAC-SHA1, 6 digits, 30s period.
+// otplib already defaults to SHA1/6/30; window=1 tolerates one step of skew.
+authenticator.options = { window: 1 };
+
+/** Verify a 6-digit TOTP code against a base32 secret. */
+export function verifyTotp(token: string, secret: string): boolean {
+  try {
+    return authenticator.check(token, secret);
+  } catch {
+    return false;
+  }
+}
+
+/** Current TOTP code for a secret (used in tests / tooling). */
+export function generateTotp(secret: string): string {
+  return authenticator.generate(secret);
+}
+
+/** otpauth:// URI for provisioning a QR code. */
+export function totpKeyUri(secret: string, accountName: string, issuer: string): string {
+  return authenticator.keyuri(accountName, issuer, secret);
+}