Remove argon2id, use bcrypt-only password hashing

src/lib/auth/password.ts

@@ -1,7 +1,5 @@
 import { randomBytes } from "node:crypto";
 import {
-	argon2id,
-	argon2Verify,
 	bcrypt,
 	bcryptVerify,
 	md5,
@@ -9,55 +7,7 @@ import {
 
 import { env } from "@/env";
 
-// AtomCMS hashing (config/hashing.php): 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.
-function argon2Params() {
-	return {
-		parallelism: env.ARGON2_PARALLELISM,
-		iterations: env.ARGON2_ITERATIONS,
-		memorySize: env.ARGON2_MEMORY_SIZE,
-		hashLength: 32,
-	} as const;
-}
-
-
-// Which algorithm hashPassword() emits for NEW/upgraded passwords.
-//   - "bcrypt"  (DEFAULT): 60-char $2y$ hash. Fits varchar(255) users.password.
-//   - "argon2id": ~97-char PHC hash. Opt in with PASSWORD_HASH=argon2id.
-// verifyPassword() always accepts BOTH, so logins keep working either way.
-function hashDriver(): "bcrypt" | "argon2id" {
-	return env.PASSWORD_HASH === "argon2id" ? "argon2id" : "bcrypt";
-}
-
-/**
- * Lowercase hex md5 of a UTF-8 string (matches PHP md5()).
- *
- * This uses hash-wasm's MD5 (not node:crypto) to match PHP's md5() output,
- * enabling verification of legacy AtomCMS password hashes during the on-login
- * upgrade path (isMd5Of → checkLogin). It is NOT used to hash new passwords
- * and does NOT affect credential security.
- */
-export async function md5Hex(input: string): Promise<string> {
-	return await md5(input);
-}
-
-/**
- * Hash a new password with the configured driver. Defaults to bcrypt ($2y$,
- * rounds=12) so the result fits a varchar(64) column; set PASSWORD_HASH=argon2id
- * for argon2id (requires a wider column). Both are verifiable by verifyPassword.
- */
 export async function hashPassword(password: string): Promise<string> {
-	if (hashDriver() === "argon2id") {
-		return argon2id({
-			password,
-			salt: randomBytes(16),
-			outputType: "encoded",
-			...argon2Params(),
-		});
-	}
-	// hash-wasm bcrypt emits $2a$; normalise to the PHP-canonical $2y$ the
-	// emulator and existing AtomCMS rows use.
 	const h = await bcrypt({
 		password,
 		salt: randomBytes(16),
@@ -67,7 +17,10 @@ export async function hashPassword(password: string): Promise<string> {
 	return h.replace(/^\$2[ab]\$/, "$2y$");
 }
 
-/** True when `stored` is exactly the md5 of `password` (legacy AtomCMS accounts). */
+export async function md5Hex(input: string): Promise<string> {
+	return await md5(input);
+}
+
 export async function isMd5Of(
 	password: string,
 	stored: string,
@@ -78,22 +31,10 @@ export async function isMd5Of(
 	);
 }
 
-/**
- * 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 bcryptVerify({ password, hash: stored });
@@ -106,15 +47,9 @@ export async function verifyPassword(
 
 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,
@@ -124,4 +59,4 @@ export async function checkLogin(
 		return { valid: true, upgradedHash: await hashPassword(password) };
 	}
 	return { valid: await verifyPassword(password, stored) };
-}
+}