Socks5Component.cs

using System;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using Waher.Content.Xml;
using Waher.Persistence;
using Waher.Security;
 
namespace Waher.Networking.XMPP.Server.SOCKS5
{
    public class Socks5Component : Component
    {
        private Socks5Server socks5Server;
        private string hostOverride = null;
        private readonly int port;
 
        public const string Socks5Namespace = "http://jabber.org/protocol/bytestreams";
 
        public Socks5Component(XmppServer Server, CaseInsensitiveString Subdomain, int Port)
            : base(Server, Subdomain, "SOCKS5 proxy")
        {
            this.port = Port;
            this.socks5Server = new Socks5Server(Port);
 
            this.RegisterIqGetHandler("query", Socks5Namespace, this.QueryGet, true);
            this.RegisterIqSetHandler("query", Socks5Namespace, this.QuerySet, false);
        }
 
        public override void Dispose()
        {
            base.Dispose();
 
            this.UnregisterIqGetHandler("query", Socks5Namespace, this.QueryGet, true);
            this.UnregisterIqSetHandler("query", Socks5Namespace, this.QuerySet, false);
 
            this.socks5Server?.Dispose();
            this.socks5Server = null;
        }
 
        public string HostOverride
        {
            get => this.hostOverride;
            set => this.hostOverride = value;
        }
 
        public override bool SupportsAccounts => false;
 
        protected override Task AppendServiceDiscoveryIdentities(StringBuilder Xml, IqEventArgs e, string Node)
        {
            Xml.Append("<identity category='proxy' type='bytestreams' name='SOCKS5 Proxy'/>");
            return Task.CompletedTask;
        }
 
        private async Task QueryGet(object Sender, IqEventArgs e)
        {
            if (!this.socks5Server.IsOpen)
                await e.IqErrorNotAllowed(e.To, "SOCKS5 server not open.", "en");
            else if (await this.Server.PersistenceLayer.IsPermitted(e.From.BareJid, "SOCKS5"))
            {
                StringBuilder Xml = new StringBuilder();
 
                Xml.Append("<query xmlns='");
                Xml.Append(Socks5Namespace);
                Xml.Append("'>");
                Xml.Append("<streamhost host='");
 
                if (!string.IsNullOrEmpty(this.hostOverride))
                    Xml.Append(XML.Encode(this.hostOverride));
                else
                    Xml.Append(XML.Encode(this.Server.Domain));
 
                Xml.Append("' jid='");
                Xml.Append(XML.Encode(e.To.Address));
                Xml.Append("' port='");
                Xml.Append(this.port.ToString());
                Xml.Append("'/></query>");
 
                await e.IqResult(Xml.ToString(), e.To);
            }
            else
                await e.IqErrorForbidden(e.To, "Account blocked from using SOCKS5.", "en");
        }
 
        private async Task QuerySet(object Sender, IqEventArgs e)
        {
            if (await this.Server.PersistenceLayer.IsPermitted(e.From.BareJid, "SOCKS5"))
            {
                string Sid = XML.Attribute(e.Query, "sid");
                CaseInsensitiveString Jid = null;
 
                foreach (XmlNode N in e.Query.ChildNodes)
                {
                    if (N.LocalName == "activate")
                    {
                        Jid = N.InnerText;
                        break;
                    }
                }
 
                if (CaseInsensitiveString.IsNullOrEmpty(Jid))
                    await e.IqErrorBadRequest(e.To, "Missing JID.", "en");
                else
                {
                    string s = Sid + e.From + Jid;
                    string StreamId = Hashes.ComputeSHA1HashString(Encoding.UTF8.GetBytes(s));
 
                    if (this.socks5Server.Activate(StreamId))
                        await e.IqResult(string.Empty, e.To);
                    else
                        await e.IqErrorNotAllowed(e.To, "Stream not active.", "en");
                }
            }
            else
                await e.IqErrorForbidden(e.To, "Account blocked from using SOCKS5.", "en");
        }
 
    }
}