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

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 }],