RequestWhiteList.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using Waher.Content.Html;
using Waher.Content.Markdown;
using Waher.Events;
using Waher.Networking.HTTP;
using Waher.Runtime.Inventory;
using Waher.Runtime.Settings;
using Waher.Security;
 
namespace Waher.Networking.XMPP.Server.Mail
{
    public class RequestWhiteList : HttpSynchronousResource, IHttpGetMethod
    {
        internal static string whiteListKey = null;
        private readonly XmppServer xmppServer;
 
        public RequestWhiteList(XmppServer XmppServer)
            : base("/RequestWhiteList")
        {
            this.xmppServer = XmppServer;
        }
 
        public bool AllowsGET => true;
 
        public override bool HandlesSubPaths => false;
 
        public override bool UserSessions => false;
 
        public async Task GET(HttpRequest Request, HttpResponse Response)
        {
            if (!Request.Header.TryGetQueryParameter("Sender", out string Sender) ||
                !Request.Header.TryGetQueryParameter("Receiver", out string Receiver) ||
                !Request.Header.TryGetQueryParameter("Expires", out string Expires) ||
                !Request.Header.TryGetQueryParameter("MAC", out string MAC) ||
                !Expires.StartsWith("P") ||
                !long.TryParse(Expires.Substring(1), out long Ticks))
            {
                Log.Warning("White-list request link not valid.", this.ResourceName, Request.RemoteEndPoint,
                    new KeyValuePair<string, object>("URL", Request.Header.GetURL(true)));
 
                throw new BadRequestException("Invalid request.");
            }
 
            StringBuilder sb = new StringBuilder();
            sb.Append(Sender);
            sb.Append(" | ");
            sb.Append(Receiver);
            sb.Append(" | ");
            sb.Append(Ticks);
 
            if (whiteListKey is null)
            {
                string Key = await RuntimeSettings.GetAsync("WhiteList.Key", string.Empty);
                if (string.IsNullOrEmpty(Key))
                {
                    Key = Convert.ToBase64String(XmppServer.GetRandomNumbers(32));
                    RuntimeSettings.Set("WhiteList.Key", Key);
                }
 
                whiteListKey = Key;
            }
 
            if (string.Compare(MAC, Hashes.ComputeHMACSHA256HashString(System.Convert.FromBase64String(RequestWhiteList.whiteListKey),
                Encoding.UTF8.GetBytes(sb.ToString())), true) != 0)
            {
                Log.Warning("White-list request link MAC not valid.", Receiver, Sender,
                    new KeyValuePair<string, object>("Sender", Sender),
                    new KeyValuePair<string, object>("Receiver", Receiver),
                    new KeyValuePair<string, object>("Expires", Ticks),
                    new KeyValuePair<string, object>("MAC", MAC));
 
                throw new BadRequestException("Invalid MAC in request.");
            }
 
            StringBuilder Markdown = new StringBuilder();
 
            Markdown.AppendLine("Title: Requesting White-Listing");
            Markdown.AppendLine("Description: Page allows mail-users to request white-listing.");
            Markdown.AppendLine("Author: Peter Waher");
            Markdown.AppendLine("Copyright: Copyright.md");
            Markdown.AppendLine("Master: Master.md");
            Markdown.AppendLine();
            Markdown.AppendLine("=========");
            Markdown.AppendLine();
            Markdown.AppendLine("Approval request");
            Markdown.AppendLine("=========================");
            Markdown.AppendLine();
 
            if (Ticks < DateTime.Now.Ticks)
            {
                Log.Notice("White-list request link old.", Receiver, Sender,
                    new KeyValuePair<string, object>("Sender", Sender),
                    new KeyValuePair<string, object>("Receiver", Receiver),
                    new KeyValuePair<string, object>("Expires", Expires),
                    new KeyValuePair<string, object>("MAC", MAC));
 
                Markdown.AppendLine("The request link is no longer valid.");
            }
            else
            {
                await this.xmppServer.Presence("subscribe", string.Empty, new XmppAddress(Receiver), new XmppAddress(Sender), string.Empty, string.Empty, this.xmppServer);
 
                StringBuilder Markdown2 = new StringBuilder();
 
                Markdown2.AppendLine("Request sent");
                Markdown2.AppendLine("==============");
                Markdown2.AppendLine();
 
                Markdown2.Append("A request has been sent to **");
                Markdown2.Append(MarkdownDocument.Encode(Receiver));
                Markdown2.Append("** to approve messages from **");
                Markdown2.Append(MarkdownDocument.Encode(Sender));
                Markdown2.AppendLine("**. You will be notified when an response to the request is provided.");
 
                await this.xmppServer.SendMailMessage(Receiver, Sender, "White-listing request sent", Markdown2.ToString());
 
                Log.Notice("White-listing request mail sent.", Sender, Receiver);
 
                Markdown.Append("A request has been sent to `");
                Markdown.Append(Receiver);
                Markdown.Append("` to approve that e - mail messages from `");
                Markdown.Append(Sender);
                Markdown.AppendLine("` be forwarded. You will be notified by e-mail when a response is available.");
            }
 
            MarkdownSettings Settings = new MarkdownSettings();
            if (Types.TryGetModuleParameter("Root", out object Obj) && Obj is string Root)
                Settings.RootFolder = Root;
 
            MarkdownDocument Doc = await MarkdownDocument.CreateAsync(Markdown.ToString(), Settings,
                Path.Combine(Settings.RootFolder, "RequestWhiteList.md"), string.Empty,
                Request.Header.GetURL(false, false));
            string Html = await Doc.GenerateHTML();
 
            Response.ContentType = HtmlCodec.DefaultContentType;
            await Response.Write(Html);
        }
    }
}