fix: Sign & Send refuses a transfer reviewed on another network (closes #524)

Settings is reachable from the confirmation screen, and Back from it only
unhides the screen as it was drawn. Sign & Send took the network at the
click, so a transfer reviewed on Sepolia went out on mainnet after a switch
in between. show() now records the chain id of the network it draws for.
Sign & Send refuses with a message on the screen when the active network
differs, and the send carries that chain id, so ethers will not populate it
for a provider on any other network.

Model: opus-5-5

README.md

@@ -1641,6 +1641,12 @@ view would leave a wallet one click from deletion.
       the contract's own answer is read at signing time only to be compared with
       it, and a disagreement is a refusal rather than a preference for either
       value (`src/shared/transferAmount.js`)
+    - "Sign & Send" after the active network was switched in Settings while this
+      screen was open → nothing is signed; "The active network changed after
+      this transaction was reviewed, so it was not sent. Please go back and
+      review it again." in the errors box, no screen change. The transaction
+      carries the chain id of the network the screen was shown for, so it cannot
+      be signed for another
     - "Sign & Send" (wrong password) → "Wrong password." on the password error
       line, no screen change
     - "Back" → **Send**

src/popup/views/confirmTx.js

@@ -101,6 +101,10 @@ function show(txInfo) {
     feeStatus = FEE_PENDING;
     feeWei = null;
     maxSendFees = null;
+    // The network this screen is drawn for, and the only one it sends on:
+    // Settings can switch the active network while the screen is open. The
+    // wait, success and error screens label the amount by it too.
+    txInfo.chainId = currentNetwork().chainId;
 
     const isErc20 = txInfo.token !== "ETH";
     // The raw symbol is the price-table key; the capped one is what the
@@ -490,7 +494,12 @@ async function populateVerifyAndSend(connectedSigner, tx, fees = null) {
         );
         request = await contract.transfer.populateTransaction(tx.to, amount);
     }
-    const populated = await connectedSigner.populateTransaction(request);
+    // The chain id of the network the screen was drawn for: ethers refuses to
+    // populate it for a provider on any other network.
+    const populated = await connectedSigner.populateTransaction({
+        ...request,
+        chainId: tx.chainId,
+    });
     assertWithinCeilings(populated);
     return connectedSigner.sendTransaction(populated);
 }
@@ -547,6 +556,17 @@ function init(_ctx) {
             return;
         }
 
+        // Back from Settings only unhides this screen, still drawn for the
+        // network that was active when it was shown.
+        if (currentNetwork().chainId !== pendingTx.chainId) {
+            showSendError(
+                "The active network changed after this transaction was" +
+                    " reviewed, so it was not sent. Please go back and review" +
+                    " it again.",
+            );
+            return;
+        }
+
         const password = $("confirm-tx-password").value;
         if (!password) {
             showError(
@@ -575,10 +595,6 @@ function init(_ctx) {
         $("btn-confirm-send").disabled = true;
         $("btn-confirm-send").classList.add("text-muted");
 
-        // The network it is sent on. The wait, success and error screens
-        // label its amount by this, not by the network active when they draw.
-        pendingTx.chainId = currentNetwork().chainId;
-
         let tx;
         try {
             const signer = getSignerForAddress(

tests/confirmTxNetworkSwitch.test.js

@@ -0,0 +1,259 @@
+// A transfer is sent only on the network its confirmation screen was drawn for
+// (https://git.eeqj.de/sneak/AutistMask/issues/524).
+//
+// Settings is reachable from the confirmation screen, and Back from it only
+// unhides the screen, still labelled for the network it was drawn for. Sign &
+// Send used to take the network at the moment of the click, so 1 SepoliaETH
+// reviewed on Sepolia went out as 1 ETH on mainnet once mainnet was chosen in
+// Settings in between.
+//
+// Driven through the real confirmation screen, signer and chain switch, with
+// only the node and the DOM stubbed. The stub node is on the network its
+// provider was built for, so a broadcast records the network it went to.
+
+"use strict";
+
+// The signed transactions the stub node was handed, with its network's chain id.
+const mockNode = { broadcast: [] };
+
+jest.mock("ethers", () => {
+    const actual = jest.requireActual("ethers");
+    class StubProvider {
+        constructor(url, network) {
+            this.network = network;
+        }
+        async getNetwork() {
+            return this.network;
+        }
+        async getFeeData() {
+            return {
+                maxFeePerGas: 20000000000n,
+                maxPriorityFeePerGas: 1000000000n,
+                gasPrice: 10000000000n,
+            };
+        }
+        async estimateGas() {
+            return 21000n;
+        }
+        async getCode() {
+            return "0x";
+        }
+        async getTransactionCount() {
+            return 1;
+        }
+        async lookupAddress() {
+            return null;
+        }
+        async broadcastTransaction(signed) {
+            mockNode.broadcast.push({ chainId: this.network.chainId, signed });
+            return { hash: "0x" + "ab".repeat(32) };
+        }
+    }
+    return { ...actual, JsonRpcProvider: StubProvider };
+});
+
+jest.mock("../src/shared/log", () => ({
+    log: {
+        debugf: () => {},
+        infof: () => {},
+        warnf: () => {},
+        errorf: () => {},
+    },
+    debugFetch: jest.fn(async () => ({
+        ok: true,
+        status: 200,
+        json: async () => ({ items: [] }),
+    })),
+    urlOrigin: () => "",
+    setRuntimeDebug: () => {},
+    isDebug: () => false,
+}));
+
+// The wait screen polls for a receipt; these tests stop at the broadcast.
+jest.mock("../src/popup/views/txStatus", () => ({
+    showWait: jest.fn(),
+    showError: jest.fn(),
+}));
+
+global.fetch = jest.fn(() => {
+    throw new Error("tests must not perform network requests");
+});
+
+const { makeStorageStub } = require("./support/storageStub");
+global.chrome = { storage: makeStorageStub(), runtime: { sendMessage() {} } };
+
+// A stub DOM: every id resolves to a recording element.
+const elements = new Map();
+
+function makeEl(id) {
+    const handlers = new Map();
+    return {
+        id,
+        textContent: "",
+        innerHTML: "",
+        value: "",
+        disabled: false,
+        style: {},
+        dataset: {},
+        classList: {
+            add() {},
+            remove() {},
+            toggle() {},
+            contains: () => false,
+        },
+        handlers,
+        addEventListener(name, fn) {
+            handlers.set(name, fn);
+        },
+        querySelectorAll: () => [],
+        querySelector: () => null,
+        remove() {},
+        focus() {},
+    };
+}
+
+global.document = {
+    getElementById(id) {
+        if (!elements.has(id)) elements.set(id, makeEl(id));
+        return elements.get(id);
+    },
+    createElement: (tag) => makeEl(tag),
+    body: { prepend() {}, appendChild() {} },
+    addEventListener() {},
+};
+global.navigator = { clipboard: { writeText() {} } };
+
+const { BaseWallet, Transaction, Wallet } = require("ethers");
+const { encryptWithPassword } = require("../src/shared/vault");
+const { state, loadState } = require("../src/shared/state");
+const { onChainSwitch } = require("../src/shared/chainSwitch");
+const { NETWORKS } = require("../src/shared/networks");
+const txStatus = require("../src/popup/views/txStatus");
+const confirmTx = require("../src/popup/views/confirmTx");
+
+const PRIVATE_KEY = "0x" + "11".repeat(32);
+const HOLDER = new Wallet(PRIVATE_KEY).address;
+const RECIPIENT = "0xC0FfEE0000000000000000000000000000c0fFEe";
+const PASSWORD = "correct horse battery staple";
+
+function el(id) {
+    return global.document.getElementById(id);
+}
+
+let encryptedSecret;
+let signTransaction;
+
+beforeAll(async () => {
+    await loadState();
+    encryptedSecret = await encryptWithPassword(PRIVATE_KEY, PASSWORD);
+});
+
+beforeEach(() => {
+    elements.clear();
+    mockNode.broadcast = [];
+    txStatus.showWait.mockClear();
+    txStatus.showError.mockClear();
+    signTransaction = jest.spyOn(BaseWallet.prototype, "signTransaction");
+});
+
+afterEach(() => {
+    signTransaction.mockRestore();
+});
+
+// Show the confirmation screen for 1 of the native token on `networkId`, as
+// Review on the Send screen does, with its fee estimate settled.
+async function review(networkId) {
+    await onChainSwitch(networkId);
+    state.wallets = [
+        {
+            type: "key",
+            name: "Wallet 1",
+            encryptedSecret,
+            addresses: [{ address: HOLDER, balance: "5.0" }],
+        },
+    ];
+    state.selectedWallet = 0;
+    state.selectedAddress = 0;
+    confirmTx.init({});
+    confirmTx.show({
+        from: HOLDER,
+        to: RECIPIENT,
+        ensName: null,
+        amount: "1",
+        token: "ETH",
+        balance: "5.0",
+        tokenSymbol: null,
+        tokenBalance: null,
+        tokenDecimals: null,
+        max: false,
+    });
+    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
+}
+
+async function signAndSend() {
+    el("confirm-tx-password").value = PASSWORD;
+    await el("btn-confirm-send").handlers.get("click")();
+}
+
+test("a transfer reviewed on Sepolia and sent goes out on Sepolia", async () => {
+    await review("sepolia");
+    expect(el("confirm-type").textContent).toBe("Native SepoliaETH transfer");
+    expect(el("btn-confirm-send").disabled).toBe(false);
+    await signAndSend();
+    expect(mockNode.broadcast).toHaveLength(1);
+    expect(mockNode.broadcast[0].chainId).toBe(11155111n);
+    expect(Transaction.from(mockNode.broadcast[0].signed).chainId).toBe(
+        11155111n,
+    );
+    expect(txStatus.showWait).toHaveBeenCalledTimes(1);
+});
+
+describe.each([
+    ["sepolia", "mainnet", "SepoliaETH"],
+    ["mainnet", "sepolia", "ETH"],
+])(
+    "a transfer reviewed on %s, with %s chosen in Settings before Sign & Send",
+    (reviewedOn, switchedTo, symbol) => {
+        test("is neither signed nor sent, and the screen says why", async () => {
+            await review(reviewedOn);
+            expect(el("confirm-type").textContent).toBe(
+                "Native " + symbol + " transfer",
+            );
+            // Settings' network select, then Back, which only unhides the
+            // screen as it was drawn.
+            await onChainSwitch(switchedTo);
+            await signAndSend();
+
+            expect(signTransaction).not.toHaveBeenCalled();
+            expect(mockNode.broadcast).toEqual([]);
+            expect(txStatus.showWait).not.toHaveBeenCalled();
+            expect(txStatus.showError).not.toHaveBeenCalled();
+            expect(el("confirm-errors").style.visibility).toBe("visible");
+            expect(el("confirm-errors").innerHTML).toContain(
+                "The active network changed after this transaction was" +
+                    " reviewed, so it was not sent. Please go back and review" +
+                    " it again.",
+            );
+        });
+    },
+);
+
+// The check in the click handler tells the user; the send itself carries the
+// chain id the screen was drawn for, so a signer on another network's node
+// cannot sign it even if the network changes after that check.
+test("the send is refused by a signer on another network's node", async () => {
+    const { getProvider } = require("../src/shared/balances");
+    const signer = new Wallet(PRIVATE_KEY).connect(
+        getProvider("https://rpc.example.invalid", "mainnet"),
+    );
+    await expect(
+        confirmTx.populateVerifyAndSend(signer, {
+            token: "ETH",
+            to: RECIPIENT,
+            amount: "1",
+            chainId: NETWORKS.sepolia.chainId,
+        }),
+    ).rejects.toThrow("transaction chainId mismatch");
+    expect(signTransaction).not.toHaveBeenCalled();
+    expect(mockNode.broadcast).toEqual([]);
+});