feat: an "Allow weak passwords" setting lets a new wallet have a short password (closes #674)

Settings has a new "Allow weak passwords" checkbox, off in a new profile. While it is off, AddWallet refuses a password shorter than 12 characters, as before. While it is on, AddWallet accepts any password that is not empty. Key derivation is unchanged: one Argon2id derivation at libsodium's interactive setting. README's Key Decisions now states those parameters and why one light derivation is enough: the password's length is what protects the stored secret.

The screens say "password", as README's wording rules require, so the setting is "Allow weak passwords".

Model: opus-5-5

README.md

@@ -1787,18 +1787,20 @@ view would leave a wallet one click from deletion.
       without it, the lost-password route on DeleteWallet is the first they
       would hear of it. The hint line reserves its height, so switching tabs
       cannot move the password fields under the pointer.
+    - The password needs at least 12 characters. With "Allow weak passwords"
+      ticked in Settings, one character is enough.
     - "Import" button, with the error line beside it so that it adds no height
       to a screen whose button already starts near the bottom of the popup
 - **Transitions**:
-    - "Import" with a valid entry and a matching password of at least 12
-      characters → creates the wallet, clears the navigation stack, and →
-      **Home**. When no address is active yet, as on the first wallet, the new
-      wallet's first address becomes the active one. The phrase and xprv modes
-      then scan for further used addresses and report the count as a flash
-      message. When the scan finds two or more used addresses, they replace the
-      wallet's list, which then holds the first address only if it was used. If
-      the first address was active and is not in the new list, the new list's
-      first address becomes the active one and `AUTISTMASK_ACTIVE_CHANGED` is
+    - "Import" with a valid entry and a matching password that is long enough →
+      creates the wallet, clears the navigation stack, and → **Home**. When no
+      address is active yet, as on the first wallet, the new wallet's first
+      address becomes the active one. The phrase and xprv modes then scan for
+      further used addresses and report the count as a flash message. When the
+      scan finds two or more used addresses, they replace the wallet's list,
+      which then holds the first address only if it was used. If the first
+      address was active and is not in the new list, the new list's first
+      address becomes the active one and `AUTISTMASK_ACTIVE_CHANGED` is
       broadcast.
     - "Import" with a missing, short or mismatched password → full-sentence
       error on the error line, no screen change
@@ -2235,6 +2237,10 @@ view would leave a wallet one click from deletion.
     - Wallets: one row per wallet with its name (tap to rename inline), a
       `[recovery phrase]` button on HD wallets only, and an `[x]` delete button,
       plus a "+ Add wallet" button
+    - Passwords:
+        - "Allow weak passwords" checkbox, unticked until the user ticks it
+        - A sentence saying the setting lets the user choose a password shorter
+          than 12 characters on AddWallet
     - Tracked Tokens: one row per token tracked on the active network with an
       `[x]` remove button, plus a "+ Add token" button
     - Display: "Show tracked tokens with zero balance" checkbox, "UTC
@@ -3061,6 +3067,11 @@ logged.
     - The user's password is run through Argon2id (`crypto_pwhash`) to derive a
       256-bit encryption key. Argon2id is memory-hard, making GPU/ASIC brute
       force attacks expensive.
+    - Each use of the password runs one Argon2id derivation at libsodium's
+      interactive setting: `OPSLIMIT_INTERACTIVE` and `MEMLIMIT_INTERACTIVE`, 2
+      passes over 64 MiB. Every signature asks for the password, so a light
+      setting keeps signing quick. The password's length, not the derivation's
+      cost, is what protects the stored secret.
     - The derived key encrypts the secret material using XSalsa20-Poly1305
       (`crypto_secretbox`), which provides authenticated encryption (the
       ciphertext cannot be tampered with without detection).

docs/README.md

@@ -425,6 +425,8 @@ see everything unfiltered.
 Click the gear icon on the home screen to access settings:
 
 - **Wallets**: Your wallets, and "+ Add wallet".
+- **Passwords**: Tick "Allow weak passwords" to choose a password shorter than
+  12 characters when you add a wallet.
 - **Tracked Tokens**: The ERC-20 tokens tracked across all addresses, and "+ Add
   token".
 - **Display**: Toggle whether tracked tokens with zero balance are shown, switch

src/popup/index.html

@@ -980,6 +980,23 @@
                     </button>
                 </div>
 
+                <div class="bg-well p-3 mx-1 mb-3">
+                    <h3 class="font-bold mb-1">Passwords</h3>
+                    <label
+                        class="text-xs flex items-center gap-1 cursor-pointer mb-1"
+                    >
+                        <input
+                            type="checkbox"
+                            id="settings-allow-weak-passwords"
+                        />
+                        Allow weak passwords
+                    </label>
+                    <p class="text-xs text-muted">
+                        Lets you choose a password shorter than 12 characters
+                        when you add a wallet.
+                    </p>
+                </div>
+
                 <div class="bg-well p-3 mx-1 mb-3">
                     <h3 class="font-bold mb-1">Tracked Tokens</h3>
                     <p class="text-xs text-muted mb-2">

src/popup/views/addWallet.js

@@ -132,7 +132,8 @@ function validatePassword() {
         showError("add-wallet-password-error", "Please choose a password.");
         return null;
     }
-    if (pw.length < 12) {
+    // "Allow weak passwords" in Settings lifts the 12-character minimum.
+    if (!state.allowWeakPasswords && pw.length < 12) {
         showError(
             "add-wallet-password-error",
             "Password must be at least 12 characters.",

src/popup/views/settings.js

@@ -499,6 +499,12 @@ function init(_ctx) {
         await saveState();
     });
 
+    $("settings-allow-weak-passwords").checked = state.allowWeakPasswords;
+    $("settings-allow-weak-passwords").addEventListener("change", async () => {
+        state.allowWeakPasswords = $("settings-allow-weak-passwords").checked;
+        await saveState();
+    });
+
     $("btn-main-add-wallet").addEventListener("click", ctx.showAddWalletView);
 
     $("btn-settings-add-token").addEventListener(

src/shared/persistedState.js

@@ -56,6 +56,9 @@ const DEFAULT_STATE = {
     // else.
     useBlockscout: false,
     checkRecipientsOnEtherscan: false,
+    // "Allow weak passwords" in Settings. While it is off, AddWallet refuses a
+    // password shorter than 12 characters.
+    allowWeakPasswords: false,
     fraudContracts: [],
     tokenHolderCache: {},
     theme: "system",
@@ -418,6 +421,9 @@ function normalizePersisted(saved) {
     // service.
     out.useBlockscout = saved.useBlockscout === true;
     out.checkRecipientsOnEtherscan = saved.checkRecipientsOnEtherscan === true;
+    // Anything but true is off: the setting lets AddWallet accept a short
+    // password.
+    out.allowWeakPasswords = saved.allowWeakPasswords === true;
     // A list of contract addresses, floored the same way: send.js builds its
     // fraud set as `(state.fraudContracts || []).map((a) => a.toLowerCase())`
     // and filterTransactions() maps the same list through normalizeAddress(),

tests/allowWeakPasswords.test.js

@@ -0,0 +1,87 @@
+// "Allow weak passwords" in Settings is off until the user ticks it. While it
+// is off, AddWallet refuses a password shorter than 12 characters. While it is
+// on, AddWallet accepts any password that is not empty
+// (https://git.eeqj.de/sneak/AutistMask/issues/674). These boot the real popup,
+// set the checkbox in Settings as the user does, and then add a wallet.
+
+jest.mock("../src/shared/vault", () => ({
+    decryptWithPassword: jest.fn(),
+    encryptWithPassword: jest.fn(async () => ({
+        salt: "salt",
+        nonce: "nonce",
+        ciphertext: "ciphertext",
+    })),
+}));
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+
+const CHECKBOX = "settings-allow-weak-passwords";
+const ERROR = "add-wallet-password-error";
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// Boots a popup that holds one wallet and opens Settings, where the checkbox
+// starts unticked. Ticks it when `allow` is true. Then opens AddWallet and
+// presses the die for a recovery phrase.
+async function openAddWallet(allow) {
+    const page = await bootPopup(unversionedValidProfile());
+    await page.click("btn-settings");
+    const checkbox = page.node(CHECKBOX);
+    expect(checkbox.checked).toBe(false);
+    if (allow) {
+        checkbox.checked = true;
+        for (const fn of checkbox.listeners.change) await fn();
+        expect(page.storage.read("autistmask").allowWeakPasswords).toBe(true);
+    }
+    await page.click("btn-main-add-wallet");
+    await page.click("btn-generate-phrase");
+    return page;
+}
+
+// Types `password` into both password fields and presses Import.
+async function importWith(page, password) {
+    page.node("add-wallet-password").value = password;
+    page.node("add-wallet-password-confirm").value = password;
+    await page.click("btn-add-wallet-confirm");
+}
+
+function storedWalletCount(page) {
+    return page.storage.read("autistmask").wallets.length;
+}
+
+describe("Allow weak passwords", () => {
+    test("unticked: a password shorter than 12 characters is refused", async () => {
+        const page = await openAddWallet(false);
+        await importWith(page, "short");
+        expect(page.text(ERROR)).toBe(
+            "Password must be at least 12 characters.",
+        );
+        expect(storedWalletCount(page)).toBe(1);
+        expect(page.visibleViews()).toEqual(["add-wallet"]);
+    });
+
+    test("ticked: a password shorter than 12 characters is accepted", async () => {
+        const page = await openAddWallet(true);
+        await importWith(page, "short");
+        expect(page.text(ERROR)).toBe("");
+        expect(storedWalletCount(page)).toBe(2);
+        expect(page.visibleViews()).toEqual(["main"]);
+    });
+
+    test.each([false, true])(
+        "an empty password is refused (ticked: %s)",
+        async (allow) => {
+            const page = await openAddWallet(allow);
+            await importWith(page, "");
+            expect(page.text(ERROR)).toBe("Please choose a password.");
+            expect(storedWalletCount(page)).toBe(1);
+            expect(page.visibleViews()).toEqual(["add-wallet"]);
+        },
+    );
+});

tests/persistedFieldContract.test.js

@@ -629,8 +629,15 @@ const CONTRACT = [
         // the falsy answer is also the DEFAULT_STATE default.
         falsy: [0],
     })),
-    // Each lets a request reach another service, so anything but true is off.
-    ...["useBlockscout", "checkRecipientsOnEtherscan"].map((field) => ({
+    // Anything but true is off for these three settings:
+    // - useBlockscout and checkRecipientsOnEtherscan let a request reach
+    //   another service.
+    // - allowWeakPasswords lets AddWallet accept a short password.
+    ...[
+        "useBlockscout",
+        "checkRecipientsOnEtherscan",
+        "allowWeakPasswords",
+    ].map((field) => ({
         field,
         kind: KIND.SCALAR,
         hostile: [42, "notabool", { a: 1 }],