Add automatic message scanning against phishing (#37)

Signed-off-by: Plerx <50530305+Plerx2493@users.noreply.github.com>

ModularAssistentForDiscordServer/Commands/Slash/Translation.cs

@@ -72,7 +72,7 @@ public async Task TranslateText
         [Description("The text you want to translate")]
         string text,
         [Description("The language you want to get (default: en)"), SlashAutoCompleteProvider(typeof(TargetLanguageAutoCompletion))]
-        string language = "en",
+        string? language = null,
         [Description("Weather the result should be public or not (default: false)")]
         bool publicResult = false
     )
@@ -85,6 +85,13 @@ await ctx.EditResponseAsync(new DiscordWebhookBuilder()
                 .WithContent("⚠️ Text can't be empty!"));
             return;
         }
+
+        if (language is null)
+        {
+            string? lang = await _translationUserInfo.GetPreferredLanguageAsync(ctx.User.Id);
+
+            language = lang ?? "en-US";
+        }
 
         TextResult translatedText = await _translator.TranslateTextAsync(text, null, language);
 

ModularAssistentForDiscordServer/Entities/AntiFishResponse.cs

@@ -0,0 +1,44 @@
+// Copyright 2023 Plerx2493
+// 
+// Licensed under the Apache License, Version 2.0 (the "License")
+// You may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using Newtonsoft.Json;
+
+namespace MADS.Entities;
+
+public record AntiFishResponse
+{
+    [JsonProperty("match")]
+    public bool IsMatch { get; set; }
+
+    [JsonProperty("matches")]
+    public List<PhishingMatch> Matches { get; set; }
+}
+
+public record PhishingMatch
+{
+    [JsonProperty("followed")]
+    public bool WasFollowed { get; set; }
+
+    [JsonProperty("domain")]
+    public string Domain { get; set; }
+
+    [JsonProperty("source")]
+    public string Source { get; set; }
+
+    [JsonProperty("type")]
+    public string Type { get; set; }
+
+    [JsonProperty("trust_rating")]
+    public double Trust { get; set; }
+}

ModularAssistentForDiscordServer/Entities/PhishggResponse.cs

@@ -0,0 +1,26 @@
+// Copyright 2023 Plerx2493
+// 
+// Licensed under the Apache License, Version 2.0 (the "License")
+// You may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using Newtonsoft.Json;
+
+namespace MADS.Entities;
+
+public record PhishggResponse
+{
+    [JsonProperty("match")]
+    public bool IsMatch { get; set; }
+
+    [JsonProperty("reason")]
+    public string? Reason { get; set; }
+};

ModularAssistentForDiscordServer/ModularDiscordBot.cs

@@ -113,6 +113,7 @@ await Host.CreateDefaultBuilder()
                         .AddSingleton<TranslateInformationService>()
                         .AddSingleton<LoggingService>()
                         .AddSingleton<UserManagerService>()
+                        .AddSingleton<AntiPhishingService>()
                         .AddHttpClient();
                     
                     Services = services.BuildServiceProvider();

ModularAssistentForDiscordServer/Services/AntiPhishingService.cs

@@ -0,0 +1,197 @@
+// Copyright 2023 Plerx2493
+// 
+// Licensed under the Apache License, Version 2.0 (the "License")
+// You may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.Net;
+using System.Net.Http.Json;
+using System.Text.RegularExpressions;
+using DSharpPlus;
+using DSharpPlus.Entities;
+using DSharpPlus.EventArgs;
+using Humanizer;
+using MADS.Entities;
+using Microsoft.Extensions.Logging;
+
+namespace MADS.Services;
+
+public partial class AntiPhishingService
+{
+    private readonly DiscordClient _discordClient;
+    private readonly HttpClient _antiFishClient;
+    private readonly HttpClient _phishggClient;
+
+    private ILogger Logger { get; set; }
+
+    [GeneratedRegex("(?:[A-z0-9](?:[A-z0-9-]{0,61}[A-z0-9])?\\.)+[A-z0-9][A-z0-9-]{0,61}[A-z0-9]", RegexOptions.CultureInvariant | RegexOptions.IgnoreCase, 50)]
+    private partial Regex LinkRegex();
+
+    [GeneratedRegex(@"(https?:\/\/)?(.*?@)?(www\.)?(discord\.(gg)|discord(app)?\.com\/invite)\/(?<code>[\w-]+)", RegexOptions.CultureInvariant | RegexOptions.IgnoreCase, 50)]
+    private partial Regex InviteRegex();
+
+    public AntiPhishingService(DiscordClient discordClient, ILogger<AntiPhishingService> logger)
+    {
+        Logger = logger;
+        _discordClient = discordClient;
+
+        HttpClientHandler httpHandler = new()
+        {
+            UseCookies = false,
+            AutomaticDecompression = DecompressionMethods.All
+        };
+
+        _antiFishClient = new HttpClient(httpHandler)
+        {
+            BaseAddress = new Uri("https://anti-fish.bitflow.dev/check")
+        };
+
+        _antiFishClient.DefaultRequestHeaders.TryAddWithoutValidation("User-Agent",
+            "MadsDiscordBot (https://github.com/Plerx2493/Mads, v1)");
+
+
+        _phishggClient = new HttpClient(httpHandler)
+        {
+            BaseAddress = new Uri("https://api.phish.gg/")
+        };
+
+        _phishggClient.DefaultRequestHeaders.TryAddWithoutValidation("User-Agent",
+            "MadsDiscordBot (https://github.com/Plerx2493/Mads, v1)");
+
+
+        discordClient.MessageCreated += HandleMessage;
+        discordClient.MessageUpdated += HandleMessageUpdate;
+    }
+
+    private Task HandleMessageUpdate(DiscordClient sender, MessageUpdatedEventArgs args)
+    {
+        return CheckLinksAsync(args.Message);
+    }
+
+    private async Task HandleMessage(DiscordClient sender, MessageCreatedEventArgs args)
+    {
+        AntiFishResponse? links = await CheckLinksAsync(args.Message);
+        IEnumerable<PhishggResponse>? invites = await CheckServerAsync(args.Message);
+
+        if (invites is not null)
+        {
+            foreach (PhishggResponse invite in invites)
+            {
+                if (invite.IsMatch)
+                {
+                    await args.Message.RespondAsync($"This message contains at least one link to a suspicious server ({invite.Reason})");
+                    break;
+                }
+            }
+        }
+
+        if (links is not null && links.IsMatch)
+        {
+            await args.Message.RespondAsync("This message contains at least one link to a suspicious website");
+        }
+    }
+
+    private async Task<AntiFishResponse?> CheckLinksAsync(DiscordMessage message)
+    {
+        if (string.IsNullOrWhiteSpace(message.Content))
+        {
+            return null;
+        }
+
+        MatchCollection matches = LinkRegex().Matches(message.Content);
+
+        if (matches.Count == 0)
+        {
+            return null;
+        }
+
+        Logger.LogDebug("Links will be checked");
+
+        var payload = new
+        {
+            message
+        };
+
+        HttpResponseMessage res = await _antiFishClient.PostAsJsonAsync("", payload);
+
+        if (res.StatusCode == HttpStatusCode.NotFound)
+        {
+            return null;
+        }
+
+        if (res.StatusCode != HttpStatusCode.OK)
+        {
+            Logger.LogError("AntiPhishing failed: {StatusCOde} {Reason}", res.StatusCode.Humanize(), res.ReasonPhrase);
+            return null;
+        }
+
+        return await res.Content.ReadFromJsonAsync<AntiFishResponse>();
+    }
+
+    private async Task<PhishggResponse?> CheckUsernameAsync(string username)
+    {
+        var payload = new
+        {
+            username
+        };
+
+        HttpResponseMessage res = await _antiFishClient.PostAsJsonAsync("username", payload);
+
+        if (res.StatusCode != HttpStatusCode.OK)
+        {
+            Logger.LogError("AntiPhishing failed: {StatusCOde} {Reason}", res.StatusCode.Humanize(), res.ReasonPhrase);
+            return null;
+        }
+
+        return await res.Content.ReadFromJsonAsync<PhishggResponse>();
+    }
+
+    private async Task<IEnumerable<PhishggResponse>?> CheckServerAsync(DiscordMessage message)
+    {
+        if (string.IsNullOrWhiteSpace(message.Content))
+        {
+            return null;
+        }
+
+        MatchCollection matches = InviteRegex().Matches(message.Content);
+
+        if (matches.Count == 0)
+        {
+            return null;
+        }
+
+        List<PhishggResponse> responses = [];
+
+        foreach (Match match in matches)
+        {
+            DiscordInvite invite = await _discordClient.GetInviteByCodeAsync(match.Groups["code"].Value);
+
+            HttpResponseMessage res = await _phishggClient.GetAsync($"server?id={invite.Guild.Id}");
+
+            if (res.StatusCode != HttpStatusCode.OK)
+            {
+                Logger.LogError("PhishGG failed: {StatusCOde} {Reason}", res.StatusCode.Humanize(), res.ReasonPhrase);
+                continue;
+            }
+            Console.WriteLine(await  res.Content.ReadAsStringAsync());
+            PhishggResponse? phishggResponse = await res.Content.ReadFromJsonAsync<PhishggResponse>();
+
+            if (phishggResponse is null)
+            {
+                continue;
+            }
+
+            responses.Add(phishggResponse);
+        }
+
+        return responses;
+    }
+}