feat: add two factor auth (#643)

Add two factor authentication for users who wish to enhance the security of their accounts.

packages/lib/server-only/2fa/verify-2fa-token.ts

@@ -0,0 +1,33 @@
+import { base32 } from '@scure/base';
+import { TOTPController } from 'oslo/otp';
+
+import { User } from '@documenso/prisma/client';
+
+import { DOCUMENSO_ENCRYPTION_KEY } from '../../constants/crypto';
+import { symmetricDecrypt } from '../../universal/crypto';
+
+const totp = new TOTPController();
+
+type VerifyTwoFactorAuthenticationTokenOptions = {
+  user: User;
+  totpCode: string;
+};
+
+export const verifyTwoFactorAuthenticationToken = async ({
+  user,
+  totpCode,
+}: VerifyTwoFactorAuthenticationTokenOptions) => {
+  const key = DOCUMENSO_ENCRYPTION_KEY;
+
+  if (!user.twoFactorSecret) {
+    throw new Error('user missing 2fa secret');
+  }
+
+  const secret = Buffer.from(symmetricDecrypt({ key, data: user.twoFactorSecret })).toString(
+    'utf-8',
+  );
+
+  const isValidToken = await totp.verify(totpCode, base32.decode(secret));
+
+  return isValidToken;
+};