offline signer for neo-cli

[dusmart]

build this neo cli plugin and you will have the ability to sign the transaction generated by neooffline

<PackageReference Include="Neo.ConsoleService" Version="1.2.0" />

using Neo.Network.P2P.Payloads;
using Neo.Wallets;
using Neo.ConsoleService;
using Neo.IO;
namespace Neo.Plugins;
public class OfflineSigner : Plugin
{
    public override string Description => "Offline Transaction Signer";
    private IWalletProvider? walletProvider;
    private Wallets.Wallet? w;
    public NeoSystem? neoSystem;
    protected override void OnSystemLoaded(NeoSystem system)
    {
        neoSystem = system;
        neoSystem.ServiceAdded += NeoSystem_ServiceAdded!;
    }
    private void NeoSystem_ServiceAdded(object sender, object service)
    {
        if (service is IWalletProvider)
        {
            walletProvider = service as IWalletProvider;
            neoSystem!.ServiceAdded -= NeoSystem_ServiceAdded!;
            walletProvider!.WalletChanged += WalletProvider_WalletChanged!;
        }
    }
    private void WalletProvider_WalletChanged(object sender, Wallet wallet)
    {
        walletProvider!.WalletChanged -= WalletProvider_WalletChanged!;
        w = wallet;
    }

    [ConsoleCommand("offsign", Category = "Lazynode", Description = "sign the hex encoded transaction")]
    private void OnOffSign(string txhex)
    {
        if (w == null)
        {
            ConsoleHelper.Error("You have to open the wallet first.");
            return;
        }

        byte[] data = Convert.FromHexString(txhex);
        Transaction tx = new();
        MemoryReader reader = new(data);
        tx.DeserializeUnsigned(ref reader);
        tx.Witnesses = tx.Signers.Select(v => new Witness { }).ToArray();
        Console.WriteLine(tx.ToJson(neoSystem.Settings).ToString(true));

        w.GetAccounts().Where(v => tx.Signers.Any(w => w.Account == v.ScriptHash)).Select(account =>
        {
            var signature = tx.Sign(account.GetKey(), neoSystem!.Settings.Network);
            Console.WriteLine($"{account.Address}: {signature.ToHexString()}");
            return 0;
        }).ToArray().ToString();
    }
}