From a4f5cab53c047c2c43d02a7803e02cf55eb8f19d Mon Sep 17 00:00:00 2001
From: user <user@Mac.lan guest wan>
Date: Sat, 28 Feb 2026 05:22:30 -0800
Subject: [PATCH] feat: add xprv import for existing HD wallets

Add support for importing existing wallets using an extended private
key (xprv) instead of a mnemonic phrase. This creates an HD wallet
that can derive multiple addresses, just like mnemonic-based wallets.

- Add hdWalletFromXprv() and isValidXprv() to wallet.js
- Add xprv type handling in getSignerForAddress()
- Create importXprv.js view with full validation and password flow
- Add import-xprv HTML view to index.html
- Wire up navigation from add-wallet view
- Enable +address button for xprv wallets in home view

Closes #20
---
 src/popup/index.html          |  58 +++++++++++++++++++
 src/popup/index.js            |   3 +
 src/popup/views/addWallet.js  |   5 ++
 src/popup/views/home.js       |   2 +-
 src/popup/views/importXprv.js | 106 ++++++++++++++++++++++++++++++++++
 src/shared/wallet.js          |  25 ++++++++
 6 files changed, 198 insertions(+), 1 deletion(-)
 create mode 100644 src/popup/views/importXprv.js

diff --git a/src/popup/index.html b/src/popup/index.html
index 74dfb69..c21f971 100644
--- a/src/popup/index.html
+++ b/src/popup/index.html
@@ -119,6 +119,15 @@
                         Import private key
                     </button>
                 </div>
+                <div class="mt-1 text-xs text-muted">
+                    Have an extended private key (xprv)?
+                    <button
+                        id="btn-add-wallet-import-xprv"
+                        class="underline cursor-pointer bg-transparent border-none text-fg text-xs font-mono p-0"
+                    >
+                        Import xprv
+                    </button>
+                </div>
             </div>
 
             <!-- ============ IMPORT PRIVATE KEY ============ -->
@@ -170,6 +179,55 @@
                 </button>
             </div>
 
+            <!-- ============ IMPORT XPRV ============ -->
+            <div id="view-import-xprv" class="view hidden">
+                <button
+                    id="btn-import-xprv-back"
+                    class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer mb-2"
+                >
+                    &lt; Back
+                </button>
+                <h2 class="font-bold mb-2">Import Extended Private Key</h2>
+                <p class="mb-2">
+                    Paste your xprv below. This creates an HD wallet that can
+                    derive multiple addresses.
+                </p>
+                <div class="mb-2">
+                    <input
+                        type="password"
+                        id="import-xprv-key"
+                        class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
+                        placeholder="xprv..."
+                    />
+                </div>
+                <div class="mb-2" id="import-xprv-password-section">
+                    <label class="block mb-1">Choose a password</label>
+                    <p class="text-xs text-muted mb-1">
+                        This password encrypts your extended private key on this
+                        device. You will need it to send funds.
+                    </p>
+                    <input
+                        type="password"
+                        id="import-xprv-password"
+                        class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
+                    />
+                </div>
+                <div class="mb-2" id="import-xprv-password-confirm-section">
+                    <label class="block mb-1">Confirm password</label>
+                    <input
+                        type="password"
+                        id="import-xprv-password-confirm"
+                        class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
+                    />
+                </div>
+                <button
+                    id="btn-import-xprv-confirm"
+                    class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
+                >
+                    Import
+                </button>
+            </div>
+
             <!-- ============ MAIN VIEW: ALL WALLETS & ADDRESSES ============ -->
             <div id="view-main" class="view hidden">
                 <!-- active address headline -->
diff --git a/src/popup/index.js b/src/popup/index.js
index 5a12180..bfdb6ee 100644
--- a/src/popup/index.js
+++ b/src/popup/index.js
@@ -11,6 +11,7 @@ const home = require("./views/home");
 const welcome = require("./views/welcome");
 const addWallet = require("./views/addWallet");
 const importKey = require("./views/importKey");
+const importXprv = require("./views/importXprv");
 const addressDetail = require("./views/addressDetail");
 const addressToken = require("./views/addressToken");
 const send = require("./views/send");
@@ -55,6 +56,7 @@ const ctx = {
     doRefreshAndRender,
     showAddWalletView: () => addWallet.show(),
     showImportKeyView: () => importKey.show(),
+    showImportXprvView: () => importXprv.show(),
     showAddressDetail: () => addressDetail.show(),
     showAddressToken: () => addressToken.show(),
     showAddTokenView: () => addToken.show(),
@@ -210,6 +212,7 @@ async function init() {
     welcome.init(ctx);
     addWallet.init(ctx);
     importKey.init(ctx);
+    importXprv.init(ctx);
     home.init(ctx);
     addressDetail.init(ctx);
     addressToken.init(ctx);
diff --git a/src/popup/views/addWallet.js b/src/popup/views/addWallet.js
index eed7ac9..ca8c4c6 100644
--- a/src/popup/views/addWallet.js
+++ b/src/popup/views/addWallet.js
@@ -124,6 +124,11 @@ function init(ctx) {
         "click",
         ctx.showImportKeyView,
     );
+
+    $("btn-add-wallet-import-xprv").addEventListener(
+        "click",
+        ctx.showImportXprvView,
+    );
 }
 
 module.exports = { init, show };
diff --git a/src/popup/views/home.js b/src/popup/views/home.js
index cb7cd24..59ba36c 100644
--- a/src/popup/views/home.js
+++ b/src/popup/views/home.js
@@ -230,7 +230,7 @@ function render(ctx) {
         html += `<div>`;
         html += `<div class="flex justify-between items-center bg-section py-1 px-2" style="margin:0 -0.5rem">`;
         html += `<span class="font-bold cursor-pointer wallet-name underline decoration-dashed" data-wallet="${wi}">${wallet.name}</span>`;
-        if (wallet.type === "hd") {
+        if (wallet.type === "hd" || wallet.type === "xprv") {
             html += `<button class="btn-add-address border border-border px-1 hover:bg-fg hover:text-bg cursor-pointer text-xs" data-wallet="${wi}" title="Add another address to this wallet">+</button>`;
         }
         html += `</div>`;
diff --git a/src/popup/views/importXprv.js b/src/popup/views/importXprv.js
new file mode 100644
index 0000000..af060f6
--- /dev/null
+++ b/src/popup/views/importXprv.js
@@ -0,0 +1,106 @@
+const { $, showView, showFlash } = require("./helpers");
+const { hdWalletFromXprv, isValidXprv } = require("../../shared/wallet");
+const { encryptWithPassword } = require("../../shared/vault");
+const { state, saveState } = require("../../shared/state");
+const { scanForAddresses } = require("../../shared/balances");
+
+function show() {
+    $("import-xprv-key").value = "";
+    $("import-xprv-password").value = "";
+    $("import-xprv-password-confirm").value = "";
+    showView("import-xprv");
+}
+
+function init(ctx) {
+    $("btn-import-xprv-confirm").addEventListener("click", async () => {
+        const xprv = $("import-xprv-key").value.trim();
+        if (!xprv) {
+            showFlash("Please enter your extended private key.");
+            return;
+        }
+        if (!isValidXprv(xprv)) {
+            showFlash("Invalid extended private key. Must start with xprv.");
+            return;
+        }
+        let result;
+        try {
+            result = hdWalletFromXprv(xprv);
+        } catch (e) {
+            showFlash("Invalid extended private key.");
+            return;
+        }
+        const { xpub, firstAddress } = result;
+        const duplicate = state.wallets.find(
+            (w) =>
+                (w.type === "hd" || w.type === "xprv") &&
+                w.addresses[0] &&
+                w.addresses[0].address.toLowerCase() ===
+                    firstAddress.toLowerCase(),
+        );
+        if (duplicate) {
+            showFlash("This key is already added (" + duplicate.name + ").");
+            return;
+        }
+        const pw = $("import-xprv-password").value;
+        const pw2 = $("import-xprv-password-confirm").value;
+        if (!pw) {
+            showFlash("Please choose a password.");
+            return;
+        }
+        if (pw.length < 12) {
+            showFlash("Password must be at least 12 characters.");
+            return;
+        }
+        if (pw !== pw2) {
+            showFlash("Passwords do not match.");
+            return;
+        }
+        const encrypted = await encryptWithPassword(xprv, pw);
+        const walletNum = state.wallets.length + 1;
+        const wallet = {
+            type: "xprv",
+            name: "Wallet " + walletNum,
+            xpub: xpub,
+            encryptedSecret: encrypted,
+            nextIndex: 1,
+            addresses: [
+                { address: firstAddress, balance: "0.0000", tokenBalances: [] },
+            ],
+        };
+        state.wallets.push(wallet);
+        state.hasWallet = true;
+        await saveState();
+        ctx.renderWalletList();
+        showView("main");
+
+        // Scan for used HD addresses beyond index 0.
+        showFlash("Scanning for addresses...", 30000);
+        const scan = await scanForAddresses(xpub, state.rpcUrl);
+        if (scan.addresses.length > 1) {
+            wallet.addresses = scan.addresses.map((a) => ({
+                address: a.address,
+                balance: "0.0000",
+                tokenBalances: [],
+            }));
+            wallet.nextIndex = scan.nextIndex;
+            await saveState();
+            ctx.renderWalletList();
+            showFlash("Found " + scan.addresses.length + " addresses.");
+        } else {
+            showFlash("Ready.", 1000);
+        }
+
+        ctx.doRefreshAndRender();
+    });
+
+    $("btn-import-xprv-back").addEventListener("click", () => {
+        if (!state.hasWallet) {
+            showView("welcome");
+        } else {
+            ctx.renderWalletList();
+            showView("main");
+        }
+    });
+}
+
+module.exports = { init, show };
diff --git a/src/shared/wallet.js b/src/shared/wallet.js
index c666add..4a677e8 100644
--- a/src/shared/wallet.js
+++ b/src/shared/wallet.js
@@ -29,6 +29,25 @@ function addressFromPrivateKey(key) {
     return w.address;
 }
 
+function hdWalletFromXprv(xprv) {
+    const node = HDNodeWallet.fromExtendedKey(xprv);
+    if (!node.privateKey) {
+        throw new Error("Not an extended private key (xprv)");
+    }
+    const xpub = node.neuter().extendedKey;
+    const firstAddress = node.deriveChild(0).address;
+    return { xpub, firstAddress };
+}
+
+function isValidXprv(key) {
+    try {
+        const node = HDNodeWallet.fromExtendedKey(key);
+        return !!node.privateKey;
+    } catch {
+        return false;
+    }
+}
+
 function getSignerForAddress(walletData, addrIndex, decryptedSecret) {
     if (walletData.type === "hd") {
         const node = HDNodeWallet.fromPhrase(
@@ -38,6 +57,10 @@ function getSignerForAddress(walletData, addrIndex, decryptedSecret) {
         );
         return node.deriveChild(addrIndex);
     }
+    if (walletData.type === "xprv") {
+        const node = HDNodeWallet.fromExtendedKey(decryptedSecret);
+        return node.deriveChild(addrIndex);
+    }
     return new Wallet(decryptedSecret);
 }
 
@@ -49,7 +72,9 @@ module.exports = {
     generateMnemonic,
     deriveAddressFromXpub,
     hdWalletFromMnemonic,
+    hdWalletFromXprv,
     addressFromPrivateKey,
     getSignerForAddress,
     isValidMnemonic,
+    isValidXprv,
 };