Add Optional 2FA Support (#61)

* Add TOTP MFA Support

* Add Passkey MFA Support

It's not impossible I missed some minor cleanup, but most things make sense and there isn't a lot of obvious duplication anymore.

---------

Co-authored-by: Bruno Bernardino <me@brunobernardino.com>

routes/api/auth/multi-factor/totp/setup.ts

@@ -0,0 +1,66 @@
+import { Handlers } from 'fresh/server.ts';
+
+import { FreshContextState } from '/lib/types.ts';
+import { UserModel } from '/lib/models/user.ts';
+import { AppConfig } from '/lib/config.ts';
+import { MultiFactorAuthModel } from '/lib/models/multi-factor-auth.ts';
+import { TOTPModel } from '/lib/models/multi-factor-auth/totp.ts';
+
+export interface RequestBody {}
+
+export interface ResponseBody {
+  success: boolean;
+  error?: string;
+  data?: {
+    methodId: string;
+    secret?: string;
+    qrCodeUrl?: string;
+    backupCodes?: string[];
+  };
+}
+
+export const handler: Handlers<unknown, FreshContextState> = {
+  async POST(request, context) {
+    if (!context.state.user) {
+      return new Response('Unauthorized', { status: 401 });
+    }
+
+    const isMultiFactorAuthEnabled = await AppConfig.isMultiFactorAuthEnabled();
+
+    if (!isMultiFactorAuthEnabled) {
+      const responseBody: ResponseBody = {
+        success: false,
+        error: 'Multi-factor authentication is not enabled on this server',
+      };
+
+      return new Response(JSON.stringify(responseBody), { status: 403 });
+    }
+
+    const { user } = context.state;
+
+    const config = await AppConfig.getConfig();
+    const issuer = new URL(config.auth.baseUrl).hostname;
+    const methodId = MultiFactorAuthModel.generateMethodId();
+    const setup = await TOTPModel.createMethod(methodId, 'Authenticator App', issuer, user.email);
+
+    if (!user.extra.multi_factor_auth_methods) {
+      user.extra.multi_factor_auth_methods = [];
+    }
+
+    user.extra.multi_factor_auth_methods.push(setup.method);
+
+    await UserModel.update(user);
+
+    const responseData: ResponseBody = {
+      success: true,
+      data: {
+        methodId: setup.method.id,
+        secret: setup.plainTextSecret,
+        qrCodeUrl: setup.qrCodeUrl,
+        backupCodes: setup.plainTextBackupCodes,
+      },
+    };
+
+    return new Response(JSON.stringify(responseData));
+  },
+};