From b04325fdc0ef53253e41b834ef04e1899e918ed2 Mon Sep 17 00:00:00 2001
From: Fabrice Mouhartem <fabrice.mouhartem@xwiki.com>
Date: Fri, 12 Jun 2026 14:44:50 +0200
Subject: [PATCH] feat(recovery): add support for hashed recovery key on the
 server

+ legacy
---
 lib/challenge-commands/totp.js | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/lib/challenge-commands/totp.js b/lib/challenge-commands/totp.js
index a4ecfaa06..9292e3409 100644
--- a/lib/challenge-commands/totp.js
+++ b/lib/challenge-commands/totp.js
@@ -12,6 +12,7 @@ const Sessions = require("../storage/sessions");
 const BlockStore = require("../storage/block");
 const Block = require("../commands/block");
 const config = require("../load-config");
+const Nacl = require('tweetnacl/nacl-fast');
 
 const  Commands = module.exports;
 
@@ -37,6 +38,17 @@ var isValidRecoveryKey = otp => {
         /[A-Za-z0-9+\/]{32}/.test(otp);
 };
 
+const parseRecoveryKey = recoveryStr => {
+    let splitted = recoveryStr.split(':');
+    let type = splitted[0];
+    // Only allow authorized type. To be upgraded when supporting more recovery modes
+    if (!['secret', 'hash'].includes(type)) {
+        type = '';
+    }
+    const content = splitted.slice(1).join(':');
+    return { type, content };
+};
+
 // we'll only allow users to set up multi-factor auth
 // for keypairs they control which already have blocks
 // this check doesn't confirm that their id is valid base64
@@ -383,12 +395,24 @@ const revoke = Commands.TOTP_REVOKE = function (Env, body, cb) {
     }).nThen(function (w) {
         if (!recoveryKey) { return; }
         w.abort();
-        if (!/^secret:/.test(recoveryStored)) {
+        const recoveryParsed = parseRecoveryKey(recoveryStored);
+        if (!recoveryParsed.type) {
             return void cb("E_NO_RECOVERY_KEY");
         }
-        recoveryStored = recoveryStored.slice(7);
-        if (recoveryKey !== recoveryStored) {
-            return void cb("E_WRONG_RECOVERY_KEY");
+        switch (recoveryParsed.type) {
+            case 'secret':
+                if (recoveryKey !== recoveryParsed.content) {
+                    return void cb("E_WRONG_RECOVERY_KEY");
+                }
+                break;
+            case 'hash':
+                if (Util.encodeBase64(Nacl.hash(Util.decodeBase64(recoveryKey)))
+                    !== recoveryParsed.content) {
+                    return void cb("E_WRONG_RECOVERY_KEY");
+                }
+                break;
+            default:
+                return void cb("E_WRONG_RECOVERY_KEY");
         }
         cb();
     }).nThen(function () {