harden: lost-password confirmation refuses empty input and ignores invisible characters (closes #336)

A wallet named only with spaces compared equal to an empty field, so
typing nothing would have deleted it, and a zero-width space in a name
made the name impossible to type back.

An empty typed confirmation is now refused whatever the name is. The
characters src/shared/symbolSpoof.js already defines as painting nothing
are removed from both sides before comparing. A name that shows nothing
at all is shown on the delete screens as "Wallet N", so it can still be
typed back.

Model: opus-5-5

README.md

@@ -1788,7 +1788,10 @@ view would leave a wallet one click from deletion.
       new password — and, in bold, that without that phrase written down the
       deletion loses everything the wallet holds, forever
     - That the other wallets are not touched
-    - The wallet's name, and a text input asking for it to be typed back
+    - The wallet's name, and a text input asking for it to be typed back. A name
+      that shows nothing at all (only spaces, or only characters that paint
+      nothing) is shown as "Wallet N", its position in the list, and that is
+      what is typed back.
     - Error line
     - "Delete This Wallet Forever" button
 - **Transitions**:
@@ -1796,9 +1799,9 @@ view would leave a wallet one click from deletion.
       outcomes as "Confirm Delete" above, through the same `finishDelete()`, so
       the selection repair, permission cleanup and `AUTISTMASK_ACTIVE_CHANGED`
       broadcast are identical on both routes
-    - "Delete This Wallet Forever" (name does not match) → "That is not the name
+    - "Delete This Wallet Forever" (name does not match, or the field is empty)
-      of this wallet. Type <name> to confirm." on the error line, nothing
+      → "That is not the name of this wallet. Type <name> to confirm." on
-      deleted
+      the error line, nothing deleted
     - "Back" → **DeleteWallet**, re-entered through its `show()` so the wallet
       selection comes back with it. The two delete screens are siblings rather
       than parent and child: nothing is pushed on the way here, so both have
@@ -1807,8 +1810,13 @@ view would leave a wallet one click from deletion.
   secret protects nobody: an attacker at the popup who wants the wallet gone can
   uninstall the extension, so the only person such a gate stops is the owner who
   forgot it. The typed name is a check that the user knows which wallet they are
-  on, not a secret, so it is matched with surrounding spaces and letter case
+  on, not a secret, so it is matched as the user can see it: letter case,
-  ignored.
+  surrounding spaces and repeated inner spaces are ignored, and characters that
+  paint nothing (format characters such as the zero-width space,
+  default-ignorable characters, and DELETE — the same set
+  `src/shared/symbolSpoof.js` strips) are removed from both sides before
+  comparing. An empty field, or one holding only spaces or such characters, is
+  refused whatever the wallet is called.
 - Not in `RESTORABLE_VIEWS`, alongside `delete-wallet-confirm`: a popup reopened
   by accident must not land on a screen whose button erases key material.
 

TODO.md

@@ -45,6 +45,15 @@ but the review is broader than any of them.
 
 # Completed Steps
 
+- 2026-10-05: The lost-password delete confirmation refuses an empty field and
+  ignores characters that paint nothing
+  ([#336](https://git.eeqj.de/sneak/AutistMask/issues/336)). A wallet named only
+  with spaces compared equal to an empty field, so typing nothing would have
+  deleted it, and a zero-width space in a name made the name impossible to type
+  back. An empty field is now refused whatever the name is, the same invisible
+  characters `src/shared/symbolSpoof.js` strips are removed from both sides, and
+  a name that shows nothing is shown and typed back as "Wallet N".
+
 - 2026-10-05: A `holders_count` that is not a whole number in plain digits is
   unknown, not read in part
   ([#251](https://git.eeqj.de/sneak/AutistMask/issues/251)). `parseInt` read

src/popup/views/deleteWallet.js

@@ -12,6 +12,7 @@ const {
     removeWalletFromState,
     broadcastActiveChanged,
 } = require("../../shared/walletDelete");
+const { INVISIBLE_CHARACTERS } = require("../../shared/symbolSpoof");
 
 let deleteWalletIndex = null;
 let lostPasswordIndex = null;
@@ -20,21 +21,31 @@ let ctx = null;
 // The name shown for a wallet, and on the lost-password screen the string
 // the user has to type back. One function so the two cannot disagree: a
 // confirmation that asks for a name other than the one on screen is
-// unusable.
+// unusable. A name that shows nothing at all (only spaces, or only
+// zero-width characters) is replaced by "Wallet N" for the same reason:
+// there would be nothing on screen to type back.
 function displayName(walletIdx) {
     const wallet = state.wallets[walletIdx];
-    return (wallet && wallet.name) || "Wallet " + (walletIdx + 1);
+    const name = wallet && wallet.name;
+    if (name && confirmKey(name)) return name;
+    return "Wallet " + (walletIdx + 1);
 }
 
 // What the typed confirmation and the wallet name are compared as. HTML
 // collapses runs of whitespace when it renders the name, so a wallet named
 // "My  Wallet" with two spaces DISPLAYS as "My Wallet": the user cannot
 // see the second space and cannot type a string that matches the stored
-// name. Comparing collapsed on both sides is what keeps the confirmation
+// name. Characters that paint nothing, such as a zero-width space, are
-// satisfiable, on the one screen whose whole purpose is unwedging a user
+// invisible the same way and are removed first. Comparing this form on
-// who is already stuck. Case and surrounding space go the same way.
+// both sides is what keeps the confirmation satisfiable, on the one screen
+// whose whole purpose is unwedging a user who is already stuck. Case and
+// surrounding space go the same way.
 function confirmKey(name) {
-    return name.trim().replace(/\s+/g, " ").toLowerCase();
+    return name
+        .replace(INVISIBLE_CHARACTERS, "")
+        .trim()
+        .replace(/\s+/g, " ")
+        .toLowerCase();
 }
 
 // Drop the password from the DOM and the wallet selection from the
@@ -174,14 +185,16 @@ function init(_ctx) {
             return;
         }
 
-        // Case, surrounding spaces and repeated inner spaces are not part
+        // Case, surrounding spaces, repeated inner spaces and invisible
-        // of the confirmation; see confirmKey(). This asks whether the
+        // characters are not part of the confirmation; see confirmKey().
-        // user knows which wallet they are on; it is not a secret, and
+        // This asks whether the user knows which wallet they are on; it is
-        // refusing "wallet 2" for "Wallet 2" would only teach the user to
+        // not a secret, and refusing "wallet 2" for "Wallet 2" would only
-        // distrust the control.
+        // teach the user to distrust the control. An empty field is
-        const typed = $("delete-wallet-lost-name-input").value;
+        // refused whatever the wallet is called, so no stored name can
+        // ever be confirmed by typing nothing.
+        const typed = confirmKey($("delete-wallet-lost-name-input").value);
         const expected = displayName(lostPasswordIndex);
-        if (confirmKey(typed) !== confirmKey(expected)) {
+        if (typed === "" || typed !== confirmKey(expected)) {
             $("delete-wallet-lost-flash").textContent =
                 "That is not the name of this wallet. Type " +
                 expected +

tests/deleteWalletLostPassword.test.js

@@ -46,6 +46,9 @@ const A1 = "0xdAC17F958D2ee523a2206206994597C13D831ec7";
 const B0 = "0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599";
 const C0 = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
 
+// U+200B, built from its code point so that it can be seen in this file.
+const ZERO_WIDTH_SPACE = String.fromCodePoint(0x200b);
+
 // ------------------------------------------------------------ DOM stub
 
 function makeElement(id) {
@@ -342,6 +345,72 @@ describe("the typed confirmation", () => {
             "secret-three",
         ]);
     });
+
+    // A name of only spaces compares as nothing, and so does an empty
+    // field. Typing nothing must still delete nothing.
+    test.each(["", "   "])(
+        "typing %j deletes nothing when the name is only spaces",
+        async (typedValue) => {
+            const { deleteWallet, state, storage } = load();
+            state.wallets[1].name = "   ";
+            await openLostPassword(deleteWallet, 1);
+
+            node("delete-wallet-lost-name-input").value = typedValue;
+            await click("btn-delete-wallet-lost-confirm");
+
+            expect(node("delete-wallet-lost-flash").style.visibility).toBe(
+                "visible",
+            );
+            expect(state.wallets).toHaveLength(3);
+            expect(await persistedWallets(storage)).toHaveLength(3);
+        },
+    );
+
+    // A name that shows nothing would leave nothing on screen to type
+    // back, so the screen names the wallet by its position instead, and
+    // that is what the user types.
+    test.each([
+        ["spaces", "   "],
+        ["a zero-width space", ZERO_WIDTH_SPACE],
+    ])(
+        "a name of only %s is shown and typed back as Wallet 2",
+        async (_label, storedName) => {
+            const { deleteWallet, state, storage } = load();
+            state.wallets[1].name = storedName;
+            await openLostPassword(deleteWallet, 1);
+
+            expect(node("delete-wallet-lost-name").textContent).toBe(
+                "Wallet 2",
+            );
+            node("delete-wallet-lost-name-input").value = "Wallet 2";
+            await click("btn-delete-wallet-lost-confirm");
+
+            const persisted = await persistedWallets(storage);
+            expect(persisted.map((w) => w.encryptedSecret)).toEqual([
+                "secret-one",
+                "secret-three",
+            ]);
+        },
+    );
+
+    // A zero-width space paints nothing, so "My", a zero-width space and
+    // "Wallet" reads as "MyWallet", and that is all the user can type. HTML
+    // does not collapse it the way it collapses spaces, so it has to be
+    // removed explicitly.
+    test("a zero-width space inside the name is not part of it", async () => {
+        const { deleteWallet, state, storage } = load();
+        state.wallets[1].name = "My" + ZERO_WIDTH_SPACE + "Wallet";
+        await openLostPassword(deleteWallet, 1);
+
+        node("delete-wallet-lost-name-input").value = "MyWallet";
+        await click("btn-delete-wallet-lost-confirm");
+
+        const persisted = await persistedWallets(storage);
+        expect(persisted.map((w) => w.encryptedSecret)).toEqual([
+            "secret-one",
+            "secret-three",
+        ]);
+    });
 });
 
 describe("deleting without the password", () => {