From 002c85449768054efc64ebc7bfbcd797f168d906 Mon Sep 17 00:00:00 2001
From: Davide Grilli <davide.grilli@outlook.com>
Date: Mon, 15 Jun 2026 12:03:46 +0200
Subject: [PATCH] feat(wallet): add P2PKH, P2SH-P2WPKH, and P2TR
 (Taproot/BIP86) address types
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- ScriptKind.Taproot (BIP86, purpose 86', P2WPKH → witness v1 bech32m plm1p)
  derivation wired in DerivationPaths and ChainProfiles (xprv/xpub headers,
  no SLIP-132 standard for P2TR); NBitcoin ScriptPubKeyType.TaprootBIP86
- Wizard step StepScriptType inserted between passphrase and password: 4 radio
  buttons (Legacy / Wrapped SegWit / Native SegWit★ / Taproot), localized in
  6 languages; CreateOrRestore now uses SelectedScriptKind instead of hardcoded
  NativeSegwit; back navigation updated accordingly
- BIP86 golden-vector tests (Bip86TaprootTests): output key verified against
  official Bitcoin BIP86 addresses, plm1p prefix asserted
---
 src/App/Localization/Loc.cs                   | 12 +++
 .../ViewModels/MainWindowViewModel.Wizard.cs  | 47 ++++++++--
 src/App/Views/MainView.axaml                  | 48 ++++++++++
 src/Core/Chain/ChainProfile.cs                |  3 +
 src/Core/Chain/ChainProfiles.cs               |  3 +
 src/Core/Crypto/DerivationPaths.cs            |  5 ++
 .../Crypto/Bip86TaprootTests.cs               | 89 +++++++++++++++++++
 7 files changed, 198 insertions(+), 9 deletions(-)
 create mode 100644 tests/PalladiumWallet.Tests/Crypto/Bip86TaprootTests.cs

diff --git a/src/App/Localization/Loc.cs b/src/App/Localization/Loc.cs
index 51af199..6bfa0db 100644
--- a/src/App/Localization/Loc.cs
+++ b/src/App/Localization/Loc.cs
@@ -110,6 +110,18 @@ public sealed class Loc
             "Achtung: ohne Verschlüsselung bleibt der Seed im Klartext auf der Festplatte."],
         ["wiz.back"]              = ["Indietro",                                                          "Back",                         "Atrás",                                "Retour",                                   "Voltar",                                   "Zurück"],
         ["wiz.next"]              = ["Avanti",                                                            "Next",                         "Siguiente",                            "Suivant",                                  "Próximo",                                  "Weiter"],
+        ["wiz.scripttype.title"]  = ["Tipo di script e indirizzi",                                       "Script type and addresses",    "Tipo de script y direcciones",         "Type de script et adresses",               "Tipo de script e endereços",               "Skripttyp und Adressen"],
+        ["wiz.scripttype.hint"]   = [
+            "Determina il formato degli indirizzi. Se non sai cosa scegliere, usa Native SegWit.",
+            "Determines the address format. If unsure, use Native SegWit.",
+            "Determina el formato de los direcciones. Si no sabes, usa Native SegWit.",
+            "Détermine le format des adresses. En cas de doute, utilisez Native SegWit.",
+            "Determina o formato dos endereços. Em caso de dúvida, use Native SegWit.",
+            "Bestimmt das Adressformat. Wenn Sie unsicher sind, verwenden Sie Native SegWit."],
+        ["wiz.scripttype.legacy.desc"]  = ["BIP44 · m/44'/… · indirizzi P",  "BIP44 · m/44'/… · P addresses",  "BIP44 · m/44'/… · direcciones P",  "BIP44 · m/44'/… · adresses P",  "BIP44 · m/44'/… · endereços P",  "BIP44 · m/44'/… · P-Adressen"],
+        ["wiz.scripttype.wrapped.desc"] = ["BIP49 · m/49'/… · indirizzi 3",  "BIP49 · m/49'/… · 3 addresses",  "BIP49 · m/49'/… · direcciones 3",  "BIP49 · m/49'/… · adresses 3",  "BIP49 · m/49'/… · endereços 3",  "BIP49 · m/49'/… · 3-Adressen"],
+        ["wiz.scripttype.native.desc"]  = ["BIP84 · m/84'/… · indirizzi plm1q — consigliato", "BIP84 · m/84'/… · plm1q addresses — recommended", "BIP84 · m/84'/… · direcciones plm1q — recomendado", "BIP84 · m/84'/… · adresses plm1q — recommandé", "BIP84 · m/84'/… · endereços plm1q — recomendado", "BIP84 · m/84'/… · plm1q-Adressen — empfohlen"],
+        ["wiz.scripttype.taproot.desc"] = ["BIP86 · m/86'/… · indirizzi plm1p", "BIP86 · m/86'/… · plm1p addresses", "BIP86 · m/86'/… · direcciones plm1p", "BIP86 · m/86'/… · adresses plm1p", "BIP86 · m/86'/… · endereços plm1p", "BIP86 · m/86'/… · plm1p-Adressen"],
 
         // Pannello wallet
         ["wallet.close"]          = ["Chiudi wallet",                                                     "Close wallet",                 "Cerrar wallet",                        "Fermer le wallet",                         "Fechar carteira",                          "Wallet schließen"],
diff --git a/src/App/ViewModels/MainWindowViewModel.Wizard.cs b/src/App/ViewModels/MainWindowViewModel.Wizard.cs
index 1af35ff..6af00bf 100644
--- a/src/App/ViewModels/MainWindowViewModel.Wizard.cs
+++ b/src/App/ViewModels/MainWindowViewModel.Wizard.cs
@@ -23,6 +23,7 @@ public partial class MainWindowViewModel
     public const string StepConfirmSeed = "confirm-seed";
     public const string StepWords = "words";
     public const string StepPassphrase = "passphrase";
+    public const string StepScriptType = "script-type";
     public const string StepPassword = "password";
 
     [ObservableProperty]
@@ -34,18 +35,37 @@ public partial class MainWindowViewModel
     [NotifyPropertyChangedFor(nameof(IsStepConfirmSeed))]
     [NotifyPropertyChangedFor(nameof(IsStepWords))]
     [NotifyPropertyChangedFor(nameof(IsStepPassphrase))]
+    [NotifyPropertyChangedFor(nameof(IsStepScriptType))]
     [NotifyPropertyChangedFor(nameof(IsStepPassword))]
     private string setupStep = StepStart;
 
     public bool IsStepDataLocation => SetupStep == StepDataLocation;
-    public bool IsStepStart       => SetupStep == StepStart;
+    public bool IsStepStart        => SetupStep == StepStart;
     public bool IsStepChooseWallet => SetupStep == StepChooseWallet;
-    public bool IsStepOpen        => SetupStep == StepOpen;
-    public bool IsStepShowSeed    => SetupStep == StepShowSeed;
-    public bool IsStepConfirmSeed => SetupStep == StepConfirmSeed;
-    public bool IsStepWords       => SetupStep == StepWords;
-    public bool IsStepPassphrase  => SetupStep == StepPassphrase;
-    public bool IsStepPassword    => SetupStep == StepPassword;
+    public bool IsStepOpen         => SetupStep == StepOpen;
+    public bool IsStepShowSeed     => SetupStep == StepShowSeed;
+    public bool IsStepConfirmSeed  => SetupStep == StepConfirmSeed;
+    public bool IsStepWords        => SetupStep == StepWords;
+    public bool IsStepPassphrase   => SetupStep == StepPassphrase;
+    public bool IsStepScriptType   => SetupStep == StepScriptType;
+    public bool IsStepPassword     => SetupStep == StepPassword;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(IsLegacySelected))]
+    [NotifyPropertyChangedFor(nameof(IsWrappedSegwitSelected))]
+    [NotifyPropertyChangedFor(nameof(IsNativeSegwitSelected))]
+    [NotifyPropertyChangedFor(nameof(IsTaprootSelected))]
+    private ScriptKind selectedScriptKind = ScriptKind.NativeSegwit;
+
+    public bool IsLegacySelected        => SelectedScriptKind == ScriptKind.Legacy;
+    public bool IsWrappedSegwitSelected => SelectedScriptKind == ScriptKind.WrappedSegwit;
+    public bool IsNativeSegwitSelected  => SelectedScriptKind == ScriptKind.NativeSegwit;
+    public bool IsTaprootSelected       => SelectedScriptKind == ScriptKind.Taproot;
+
+    [RelayCommand] private void SelectLegacy()        => SelectedScriptKind = ScriptKind.Legacy;
+    [RelayCommand] private void SelectWrappedSegwit() => SelectedScriptKind = ScriptKind.WrappedSegwit;
+    [RelayCommand] private void SelectNativeSegwit()  => SelectedScriptKind = ScriptKind.NativeSegwit;
+    [RelayCommand] private void SelectTaproot()       => SelectedScriptKind = ScriptKind.Taproot;
 
     public string DefaultDataPath => AppPaths.DefaultDataRoot();
 
@@ -96,6 +116,7 @@ public partial class MainWindowViewModel
     private void RefreshSetupState()
     {
         SetupStep = StepStart;
+        SelectedScriptKind = ScriptKind.NativeSegwit;
         MnemonicInput = ConfirmMnemonicInput = PassphraseInput = PasswordInput = ConfirmPasswordInput = "";
         WalletFileExists = AppPaths.WalletFiles(Net).Count > 0;
         StatusMessage = "";
@@ -192,6 +213,13 @@ public partial class MainWindowViewModel
 
     [RelayCommand]
     private void WizardNextFromPassphrase()
+    {
+        SetupStep = StepScriptType;
+        StatusMessage = "";
+    }
+
+    [RelayCommand]
+    private void WizardNextFromScriptType()
     {
         PasswordInput = ConfirmPasswordInput = "";
         EncryptWallet = true;
@@ -208,7 +236,8 @@ public partial class MainWindowViewModel
             StepChooseWallet or StepShowSeed or StepWords => StepStart,
             StepConfirmSeed => StepShowSeed,
             StepPassphrase => _isRestoreFlow ? StepWords : StepConfirmSeed,
-            StepPassword => StepPassphrase,
+            StepScriptType => StepPassphrase,
+            StepPassword => StepScriptType,
             _ => StepStart,
         };
         if (SetupStep == StepStart)
@@ -243,7 +272,7 @@ public partial class MainWindowViewModel
             var (doc, account) = WalletLoader.NewFromMnemonic(
                 MnemonicInput,
                 string.IsNullOrEmpty(PassphraseInput) ? null : PassphraseInput,
-                ScriptKind.NativeSegwit,
+                SelectedScriptKind,
                 Profile);
             var path = AppPaths.DefaultWalletPath(Net);
             for (var n = 2; WalletStore.Exists(path); n++)
diff --git a/src/App/Views/MainView.axaml b/src/App/Views/MainView.axaml
index bf8334f..ad40194 100644
--- a/src/App/Views/MainView.axaml
+++ b/src/App/Views/MainView.axaml
@@ -171,6 +171,54 @@
                     </StackPanel>
                 </StackPanel>
 
+                <!-- Passo: scelta del tipo di script/indirizzi -->
+                <StackPanel IsVisible="{Binding IsStepScriptType}" Spacing="12">
+                    <TextBlock Text="{Binding Loc[wiz.scripttype.title]}" FontSize="18" FontWeight="Bold"/>
+                    <TextBlock Text="{Binding Loc[wiz.scripttype.hint]}" TextWrapping="Wrap" Foreground="Gray"/>
+
+                    <RadioButton GroupName="ScriptType"
+                                 IsChecked="{Binding IsLegacySelected, Mode=OneWay}"
+                                 Command="{Binding SelectLegacyCommand}">
+                        <StackPanel Spacing="2">
+                            <TextBlock Text="Legacy (P2PKH)" FontWeight="SemiBold"/>
+                            <TextBlock Text="{Binding Loc[wiz.scripttype.legacy.desc]}" Foreground="Gray" FontSize="12"/>
+                        </StackPanel>
+                    </RadioButton>
+
+                    <RadioButton GroupName="ScriptType"
+                                 IsChecked="{Binding IsWrappedSegwitSelected, Mode=OneWay}"
+                                 Command="{Binding SelectWrappedSegwitCommand}">
+                        <StackPanel Spacing="2">
+                            <TextBlock Text="Wrapped SegWit (P2SH-P2WPKH)" FontWeight="SemiBold"/>
+                            <TextBlock Text="{Binding Loc[wiz.scripttype.wrapped.desc]}" Foreground="Gray" FontSize="12"/>
+                        </StackPanel>
+                    </RadioButton>
+
+                    <RadioButton GroupName="ScriptType"
+                                 IsChecked="{Binding IsNativeSegwitSelected, Mode=OneWay}"
+                                 Command="{Binding SelectNativeSegwitCommand}">
+                        <StackPanel Spacing="2">
+                            <TextBlock Text="Native SegWit (P2WPKH)" FontWeight="SemiBold"/>
+                            <TextBlock Text="{Binding Loc[wiz.scripttype.native.desc]}" Foreground="Gray" FontSize="12"/>
+                        </StackPanel>
+                    </RadioButton>
+
+                    <RadioButton GroupName="ScriptType"
+                                 IsChecked="{Binding IsTaprootSelected, Mode=OneWay}"
+                                 Command="{Binding SelectTaprootCommand}">
+                        <StackPanel Spacing="2">
+                            <TextBlock Text="Taproot (P2TR)" FontWeight="SemiBold"/>
+                            <TextBlock Text="{Binding Loc[wiz.scripttype.taproot.desc]}" Foreground="Gray" FontSize="12"/>
+                        </StackPanel>
+                    </RadioButton>
+
+                    <StackPanel Orientation="Horizontal" Spacing="10">
+                        <Button Content="{Binding Loc[wiz.back]}" Command="{Binding WizardBackCommand}"/>
+                        <Button Content="{Binding Loc[wiz.next]}" Classes="accent"
+                                Command="{Binding WizardNextFromScriptTypeCommand}"/>
+                    </StackPanel>
+                </StackPanel>
+
                 <!-- Passo finale: password del file (cifratura, stile Electrum) -->
                 <StackPanel IsVisible="{Binding IsStepPassword}" Spacing="12">
                     <TextBlock Text="{Binding Loc[wiz.password.title]}" FontSize="18" FontWeight="Bold"/>
diff --git a/src/Core/Chain/ChainProfile.cs b/src/Core/Chain/ChainProfile.cs
index ae4f908..70824a5 100644
--- a/src/Core/Chain/ChainProfile.cs
+++ b/src/Core/Chain/ChainProfile.cs
@@ -29,6 +29,9 @@ public enum ScriptKind
 
     /// <summary>P2WSH (multisig native).</summary>
     NativeSegwitMultisig,
+
+    /// <summary>P2TR key-path only (Taproot, BIP86) — witness v1, bech32m.</summary>
+    Taproot,
 }
 
 /// <summary>
diff --git a/src/Core/Chain/ChainProfiles.cs b/src/Core/Chain/ChainProfiles.cs
index cda8b99..ce7490f 100644
--- a/src/Core/Chain/ChainProfiles.cs
+++ b/src/Core/Chain/ChainProfiles.cs
@@ -33,6 +33,8 @@ public static class ChainProfiles
             [ScriptKind.WrappedSegwitMultisig] = new(0x0295b005, 0x0295b43f), // Yprv / Ypub
             [ScriptKind.NativeSegwit] = new(0x04b2430c, 0x04b24746),          // zprv / zpub
             [ScriptKind.NativeSegwitMultisig] = new(0x02aa7a99, 0x02aa7ed3),  // Zprv / Zpub
+            // Nessun SLIP-132 per P2TR: il contesto è dato dal path m/86'/…
+            [ScriptKind.Taproot] = new(0x0488ade4, 0x0488b21e),               // xprv / xpub (BIP32 standard)
         },
         // Server di indicizzazione noti per il primo contatto (§3/§9); altri
         // peer vengono scoperti via server.peers.subscribe.
@@ -70,6 +72,7 @@ public static class ChainProfiles
             [ScriptKind.WrappedSegwitMultisig] = new(0x024285b5, 0x024289ef), // Uprv / Upub
             [ScriptKind.NativeSegwit] = new(0x045f18bc, 0x045f1cf6),          // vprv / vpub
             [ScriptKind.NativeSegwitMultisig] = new(0x02575048, 0x02575483),  // Vprv / Vpub
+            [ScriptKind.Taproot] = new(0x04358394, 0x043587cf),               // tprv / tpub (BIP32 standard)
         },
         BootstrapServers = [],
         Checkpoints = [],
diff --git a/src/Core/Crypto/DerivationPaths.cs b/src/Core/Crypto/DerivationPaths.cs
index 40731bb..b8215b9 100644
--- a/src/Core/Crypto/DerivationPaths.cs
+++ b/src/Core/Crypto/DerivationPaths.cs
@@ -22,12 +22,16 @@ public static class DerivationPaths
     /// <summary>Purpose BIP48 (multisig — fase successiva, §16 passo 8).</summary>
     public const int PurposeMultisig = 48;
 
+    /// <summary>Purpose BIP86 (P2TR key-path, Taproot).</summary>
+    public const int PurposeTaproot = 86;
+
     public static int PurposeFor(ScriptKind kind) => kind switch
     {
         ScriptKind.Legacy => PurposeLegacy,
         ScriptKind.WrappedSegwit => PurposeWrappedSegwit,
         ScriptKind.NativeSegwit => PurposeNativeSegwit,
         ScriptKind.WrappedSegwitMultisig or ScriptKind.NativeSegwitMultisig => PurposeMultisig,
+        ScriptKind.Taproot => PurposeTaproot,
         _ => throw new ArgumentOutOfRangeException(nameof(kind)),
     };
 
@@ -41,6 +45,7 @@ public static class DerivationPaths
         ScriptKind.Legacy => ScriptPubKeyType.Legacy,
         ScriptKind.WrappedSegwit => ScriptPubKeyType.SegwitP2SH,
         ScriptKind.NativeSegwit => ScriptPubKeyType.Segwit,
+        ScriptKind.Taproot => ScriptPubKeyType.TaprootBIP86,
         ScriptKind.WrappedSegwitMultisig or ScriptKind.NativeSegwitMultisig =>
             throw new NotSupportedException(
                 "I tipi multisig derivano da redeem script: supporto previsto con i wallet M-di-N (§4.5)."),
diff --git a/tests/PalladiumWallet.Tests/Crypto/Bip86TaprootTests.cs b/tests/PalladiumWallet.Tests/Crypto/Bip86TaprootTests.cs
new file mode 100644
index 0000000..2ac4df6
--- /dev/null
+++ b/tests/PalladiumWallet.Tests/Crypto/Bip86TaprootTests.cs
@@ -0,0 +1,89 @@
+using NBitcoin;
+using PalladiumWallet.Core.Chain;
+using PalladiumWallet.Core.Crypto;
+
+namespace PalladiumWallet.Tests.Crypto;
+
+/// <summary>
+/// Vettori di test BIP86 (mnemonica abandon-about, senza passphrase).
+/// La chiave pubblica tweakizzata (output key, 32 byte x-only) è chain-independent:
+/// viene verificata contro i vettori ufficiali Bitcoin, poi si controlla che
+/// l'indirizzo PLM abbia il prefisso plm1p (witness v1, bech32m).
+/// Il path m/86'/0'/0' usa coin_type=0 (non 746) per aderire ai vettori BIP86.
+/// </summary>
+public class Bip86TaprootTests
+{
+    private static HdAccount Account()
+    {
+        Assert.True(Bip39.TryParse(
+            "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about",
+            out var mnemonic));
+        return HdAccount.FromSeed(
+            Bip39.ToSeed(mnemonic!),
+            ScriptKind.Taproot,
+            ChainProfiles.Mainnet,
+            new KeyPath("86'/0'/0'"));
+    }
+
+    [Fact]
+    public void Il_derivation_path_di_un_account_taproot_usa_purpose_86()
+    {
+        var path = DerivationPaths.AccountPath(ScriptKind.Taproot, ChainProfiles.Mainnet, 0);
+        Assert.Equal($"86'/{ChainProfiles.Mainnet.Bip44CoinType}'/0'", path.ToString());
+    }
+
+    [Fact]
+    public void Gli_indirizzi_plm_taproot_iniziano_con_plm1p()
+    {
+        var account = Account();
+        var addr0 = account.GetReceiveAddress(0).ToString();
+        var addr1 = account.GetReceiveAddress(1).ToString();
+        var change0 = account.GetChangeAddress(0).ToString();
+
+        Assert.StartsWith("plm1p", addr0);
+        Assert.StartsWith("plm1p", addr1);
+        Assert.StartsWith("plm1p", change0);
+    }
+
+    /// <summary>
+    /// L'output key (chiave tweakizzata x-only, 32 byte) è identica al vettore BIP86
+    /// indipendentemente dalla rete: la rete cambia solo HRP e checksum, non il programma.
+    /// Indirizzi Bitcoin da https://github.com/bitcoin/bips/blob/master/bip-0086.mediawiki
+    /// </summary>
+    [Theory]
+    [InlineData(false, 0, "bc1p5cyxnuxmeuwuvkwfem96lqzszd02n6xdcjrs20cac6yqjjwudpxqkedrcr")]
+    [InlineData(false, 1, "bc1p4qhjn9zdvkux4e44uhx8tc55attvtyu358kutcqkudyccelu0was9fqzwh")]
+    [InlineData(true,  0, "bc1p3qkhfews2uk44qtvauqyr2ttdsw7svhkl9nkm9s9c3x4ax5h60wqwruhk7")]
+    public void L_output_key_coincide_col_vettore_bip86(
+        bool isChange, int index, string bitcoinAddress)
+    {
+        var account = Account();
+        var plmAddr = account.GetAddress(isChange, index);
+
+        // Il witness program (output key tweakizzata) è chain-independent
+        var btcAddr = (TaprootAddress)BitcoinAddress.Create(bitcoinAddress, Network.Main);
+        var plmTaproot = (TaprootAddress)plmAddr;
+        Assert.Equal(btcAddr.PubKey, plmTaproot.PubKey);
+    }
+
+    [Fact]
+    public void Il_wallet_taproot_e_watch_only_se_creato_da_xpub()
+    {
+        var full = Account();
+        var watchOnly = HdAccount.FromAccountXpub(
+            full.AccountXpub, ScriptKind.Taproot, ChainProfiles.Mainnet);
+        Assert.True(watchOnly.IsWatchOnly);
+        Assert.Equal(
+            full.GetReceiveAddress(0).ToString(),
+            watchOnly.GetReceiveAddress(0).ToString());
+    }
+
+    [Fact]
+    public void I_tipi_multisig_lanciano_not_supported()
+    {
+        Assert.Throws<NotSupportedException>(
+            () => DerivationPaths.ScriptPubKeyTypeFor(ScriptKind.WrappedSegwitMultisig));
+        Assert.Throws<NotSupportedException>(
+            () => DerivationPaths.ScriptPubKeyTypeFor(ScriptKind.NativeSegwitMultisig));
+    }
+}