Add key mismatch error handling

webroot/blah/en-cat.json

@@ -125,6 +125,8 @@
   "desc.no.dms": "no direct meowchats :c",
   "action.dm.opening": "opening meowchat...",
   "dm.open.failed": "failed to open meowchat :c",
+  "keys.local.server.mismatch": "this device has different nametags than server :c use the device u first logged in on",
+  "keys.server.decrypt.failed": "wrong password for ur secret nametag bundle :c",
   "dm.messages.fetch.failed": "failed to fetch meows :c",
   "messages.decrypt.failed": "failed to decrypt meow :c"
 }

webroot/blah/en-us.json

@@ -124,6 +124,8 @@
   "desc.no.dms": "No direct messages",
   "action.dm.opening": "Opening DM...",
   "dm.open.failed": "Failed to open DM",
+  "keys.local.server.mismatch": "This device has different encryption keys than the server. Use the device where you first logged in, or restore server keys from backup.",
+  "keys.server.decrypt.failed": "Could not decrypt your account keys with this password.",
   "dm.messages.fetch.failed": "Failed to fetch messages",
   "messages.decrypt.failed": "Failed to decrypt message"
 }

webroot/main.js

@@ -297,6 +297,11 @@ async function deriveHybridKeyFromSetup(otherPublicKeysObj, ciphertextMlKemBase6
     return aesKeyBytes;
 }
 
+function userPublicKeysFingerprint(pub) {
+    if (!pub) return "";
+    return `${pub.pubX25519 || ""}|${pub.pubMlKem || ""}`;
+}
+
 async function fetchDmKey(dmId) {
     return await fetchEncrypted("dm/key/get", dmId);
 }
@@ -331,6 +336,7 @@ async function ensureDmRoomKey(dmId) {
         const roomKey = await decryptAesGcmFromBase64(setupPayload.enc, aesKeyBytes);
 
         const selfWrapped = await wrapRoomKeyForSelf(roomKey);
+        await unwrapRoomKeyForSelf(selfWrapped);
         await updateDmKey(dmId, selfWrapped);
         return roomKey;
     }
@@ -918,10 +924,12 @@ async function ensureUserKeys() {
     const lsEncKey = `userKeys.enc.v1:${id}`;
     const lsPubKey = `userKeys.pub.v1:${id}`;
 
+    let serverKeys = null;
+    let serverKeysRaw = "";
     try { //1. check server
-        const serverKeysRaw = await fetchEncrypted("user/key/get");
+        serverKeysRaw = await fetchEncrypted("user/key/get");
         if (serverKeysRaw && serverKeysRaw.trim() !== "" && serverKeysRaw.trim().startsWith("{")) {
-            const serverKeys = JSON.parse(serverKeysRaw);
+            serverKeys = JSON.parse(serverKeysRaw);
             const serverEncPriv = serverKeys.string1;
             const serverPub = serverKeys.string2;
             if (serverEncPriv && serverPub) {
@@ -935,7 +943,9 @@ async function ensureUserKeys() {
             }
         }
     } catch (e) {
-        //ignore, fallback to local
+        if (serverKeys?.string1) {
+            throw new Error("error:keys.server.decrypt.failed");
+        }
     }
 
     //fallback to local
@@ -943,30 +953,45 @@ async function ensureUserKeys() {
     const localPub = localStorage.getItem(lsPubKey);
     if (localEnc && localPub) {
         try {
+            const localPubObj = JSON.parse(localPub);
+            if (serverKeys?.string2) {
+                const serverPubObj = JSON.parse(serverKeys.string2);
+                if (userPublicKeysFingerprint(localPubObj) !== userPublicKeysFingerprint(serverPubObj)) {
+                    throw new Error("error:keys.local.server.mismatch");
+                }
+            }
+
             userKeysEncrypted = localEnc;
-            userKeysPublic = JSON.parse(localPub);
+            userKeysPublic = localPubObj;
             userKeysPrivate = await decryptJsonWithPassword(userKeysEncrypted, password);
 
-            //push keys to server
-            try {
-                await fetchEncrypted(
+            //push keys to server only when server has none yet
+            if (!serverKeys?.string1) {
+                const updateRes = await fetchEncrypted(
                     "user/key/update",
                     JSON.stringify({
                         string1: userKeysEncrypted,
                         string2: JSON.stringify(userKeysPublic)
                     })
                 );
-            } catch (e) {
-
+                if (updateRes === "error:keys.public.mismatch") {
+                    throw new Error("error:keys.local.server.mismatch");
+                }
             }
 
             publishUserKeysGlobals();
             return "success:keys.local";
         } catch (e) {
-            
+            if (e.message && e.message.startsWith("error:keys.")) {
+                throw e;
+            }
         }
     }
 
+    if (serverKeys?.string1) {
+        throw new Error("error:keys.server.decrypt.failed");
+    }
+
     //new keys, encrypt private with user's password
     const bundle = await generateUserKeysBundle();
     userKeysPublic = bundle.pub;
@@ -1796,7 +1821,11 @@ async function openDm(dmId, username, targetId) {
     } catch (e) {
         clearAction("dmopen");
         console.error(e);
-        showBlahNotification("error:dm.open.failed");
+        if (e.message === "error:keys.local.server.mismatch" || e.message === "error:keys.server.decrypt.failed") {
+            showBlahNotification(e.message);
+        } else {
+            showBlahNotification("error:dm.open.failed");
+        }
     }
 }