using System.Diagnostics; using System.Security.Cryptography; using System.Text.Json; using System.Text.RegularExpressions; using ArcaneLibs.Extensions; using LibMatrix; using LibMatrix.EventTypes.Spec; using LibMatrix.EventTypes.Spec.State.Policy; using LibMatrix.Helpers; using LibMatrix.Homeservers; using LibMatrix.RoomTypes; using LibMatrix.Services; using Microsoft.Extensions.Logging; using ModerationBot.AccountData; using ModerationBot.StateEventTypes.Policies; using ModerationBot.StateEventTypes.Policies.Implementations; namespace ModerationBot; public class PolicyEngine(AuthenticatedHomeserverGeneric hs, ILogger logger, ModerationBotConfiguration configuration, HomeserverResolverService hsResolver) { private Dictionary PolicyListAccountData { get; set; } = new(); // ReSharper disable once MemberCanBePrivate.Global public List ActivePolicyLists { get; set; } = new(); public List ActivePolicies { get; set; } = new(); public Dictionary> ActivePoliciesByType { get; set; } = new(); private GenericRoom? _logRoom; private GenericRoom? _controlRoom; public async Task ReloadActivePolicyLists() { var sw = Stopwatch.StartNew(); var botData = await hs.GetAccountDataAsync("gay.rory.moderation_bot_data"); _logRoom ??= hs.GetRoom(botData.LogRoom ?? botData.ControlRoom); _controlRoom ??= hs.GetRoom(botData.ControlRoom); await _controlRoom?.SendMessageEventAsync(MessageFormatter.FormatSuccess("Reloading policy lists!"))!; await _logRoom?.SendMessageEventAsync(MessageFormatter.FormatSuccess("Reloading policy lists!"))!; var progressMessage = await _logRoom?.SendMessageEventAsync(MessageFormatter.FormatSuccess("0/? policy lists loaded"))!; var policyLists = new List(); try { PolicyListAccountData = await hs.GetAccountDataAsync>("gay.rory.moderation_bot.policy_lists"); } catch (MatrixException e) { if (e is not { ErrorCode: "M_NOT_FOUND" }) throw; } if (!PolicyListAccountData.ContainsKey(botData.DefaultPolicyRoom!)) { PolicyListAccountData.Add(botData.DefaultPolicyRoom!, new PolicyList() { Trusted = true }); await hs.SetAccountDataAsync("gay.rory.moderation_bot.policy_lists", PolicyListAccountData); } var loadTasks = new List>(); foreach (var (roomId, policyList) in PolicyListAccountData) { var room = hs.GetRoom(roomId); loadTasks.Add(LoadPolicyListAsync(room, policyList)); } await foreach (var policyList in loadTasks.ToAsyncEnumerable()) { policyLists.Add(policyList); if (false || policyList.Policies.Count >= 256 || policyLists.Count == PolicyListAccountData.Count) { var progressMsgContent = MessageFormatter.FormatSuccess($"{policyLists.Count}/{PolicyListAccountData.Count} policy lists loaded, " + $"{policyLists.Sum(x => x.Policies.Count)} policies total, {sw.Elapsed} elapsed.") .SetReplaceRelation(progressMessage.EventId); await _logRoom?.SendMessageEventAsync(progressMsgContent); } } // Console.WriteLine($"Reloaded policy list data in {sw.Elapsed}"); // await _logRoom.SendMessageEventAsync(MessageFormatter.FormatSuccess($"Done fetching {policyLists.Count} policy lists in {sw.Elapsed}!")); ActivePolicyLists = policyLists; ActivePolicies = await GetActivePolicies(); } private async Task LoadPolicyListAsync(GenericRoom room, PolicyList policyList) { policyList.Room = room; policyList.Policies.Clear(); var stateEvents = room.GetFullStateAsync(); await foreach (var stateEvent in stateEvents) { if (stateEvent != null && ( stateEvent.MappedType.IsAssignableTo(typeof(BasePolicy)) || stateEvent.MappedType.IsAssignableTo(typeof(PolicyRuleEventContent)) )) { policyList.Policies.Add(stateEvent); } } // if (policyList.Policies.Count >= 1) // await _logRoom?.SendMessageEventAsync( // MessageFormatter.FormatSuccess($"Loaded {policyList.Policies.Count} policies for {MessageFormatter.HtmlFormatMention(room.RoomId)}!"))!; return policyList; } public async Task ReloadActivePolicyListById(string roomId) { if (!ActivePolicyLists.Any(x => x.Room.RoomId == roomId)) return; await LoadPolicyListAsync(hs.GetRoom(roomId), ActivePolicyLists.Single(x => x.Room.RoomId == roomId)); ActivePolicies = await GetActivePolicies(); } public async Task> GetActivePolicies() { var sw = Stopwatch.StartNew(); List activePolicies = new(); foreach (var activePolicyList in ActivePolicyLists) { foreach (var policyEntry in activePolicyList.Policies) { // TODO: implement rule translation var policy = policyEntry.TypedContent is BasePolicy ? policyEntry.TypedContent as BasePolicy : policyEntry.RawContent.Deserialize(); if (policy?.Entity is null) continue; policy.PolicyList = activePolicyList; policy.OriginalEvent = policyEntry; activePolicies.Add(policy); } } Console.WriteLine($"Translated policy list data in {sw.Elapsed}"); ActivePoliciesByType = activePolicies.GroupBy(x => x.GetType().Name).ToDictionary(x => x.Key, x => x.ToList()); await _logRoom.SendMessageEventAsync(MessageFormatter.FormatSuccess($"Translated policy list data in {sw.GetElapsedAndRestart()}")); // await _logRoom.SendMessageEventAsync(MessageFormatter.FormatSuccess($"Built policy type map in {sw.GetElapsedAndRestart()}")); var summary = SummariseStateTypeCounts(activePolicies.Select(x => x.OriginalEvent).ToList()); await _logRoom?.SendMessageEventAsync(new RoomMessageEventContent() { Body = summary.Raw, FormattedBody = summary.Html, Format = "org.matrix.custom.html" })!; return activePolicies; } public async Task> GetMatchingPolicies(StateEventResponse @event) { List matchingPolicies = new(); if (@event.Sender == @hs.UserId) return matchingPolicies; //ignore self at all costs if (ActivePoliciesByType.TryGetValue(nameof(ServerPolicyRuleEventContent), out var serverPolicies)) { var userServer = @event.Sender.Split(':', 2)[1]; matchingPolicies.AddRange(serverPolicies.Where(x => x.Entity == userServer)); } if (ActivePoliciesByType.TryGetValue(nameof(UserPolicyRuleEventContent), out var userPolicies)) { matchingPolicies.AddRange(userPolicies.Where(x => x.Entity == @event.Sender)); } if (@event.TypedContent is RoomMessageEventContent msgContent) { matchingPolicies.AddRange(await CheckMessageContent(@event)); // if (msgContent.MessageType == "m.text" || msgContent.MessageType == "m.notice") ; //TODO: implement word etc. filters if (msgContent.MessageType == "m.image" || msgContent.MessageType == "m.file" || msgContent.MessageType == "m.audio" || msgContent.MessageType == "m.video") matchingPolicies.AddRange(await CheckMedia(@event)); } return matchingPolicies; } #region Policy matching private async Task> CheckMessageContent(StateEventResponse @event) { var matchedRules = new List(); var msgContent = @event.TypedContent as RoomMessageEventContent; if (ActivePoliciesByType.TryGetValue(nameof(MessagePolicyContainsText), out var messageContainsPolicies)) foreach (var policy in messageContainsPolicies) { if ((@msgContent?.Body?.ToLowerInvariant().Contains(policy.Entity.ToLowerInvariant()) ?? false) || (@msgContent?.FormattedBody?.ToLowerInvariant().Contains(policy.Entity.ToLowerInvariant()) ?? false)) matchedRules.Add(policy); } return matchedRules; } private async Task> CheckMedia(StateEventResponse @event) { var matchedRules = new List(); var hashAlgo = SHA3_256.Create(); var mxcUri = @event.RawContent["url"].GetValue(); //check server policies before bothering with hashes if (ActivePoliciesByType.TryGetValue(nameof(MediaPolicyHomeserver), out var mediaHomeserverPolicies)) foreach (var policy in mediaHomeserverPolicies) { logger.LogInformation("Checking rule {rule}: {data}", policy.OriginalEvent.StateKey, policy.OriginalEvent.TypedContent.ToJson(ignoreNull: true, indent: false)); policy.Entity = policy.Entity.Replace("\\*", ".*").Replace("\\?", "."); var regex = new Regex($"mxc://({policy.Entity})/.*", RegexOptions.Compiled | RegexOptions.IgnoreCase); if (regex.IsMatch(@event.RawContent["url"]!.GetValue())) { logger.LogInformation("{url} matched rule {rule}", @event.RawContent["url"], policy.ToJson(ignoreNull: true)); matchedRules.Add(policy); // continue; } } var resolvedUri = await hsResolver.ResolveMediaUri(mxcUri.Split('/')[2], mxcUri); var uriHash = hashAlgo.ComputeHash(mxcUri.AsBytes().ToArray()); byte[]? fileHash = null; try { fileHash = await hashAlgo.ComputeHashAsync(await hs.ClientHttpClient.GetStreamAsync(resolvedUri)); } catch (Exception ex) { await _logRoom.SendMessageEventAsync( MessageFormatter.FormatException($"Error calculating file hash for {mxcUri} via {mxcUri.Split('/')[2]} ({resolvedUri}), retrying via {hs.BaseUrl}...", ex)); try { resolvedUri = await hsResolver.ResolveMediaUri(hs.BaseUrl, mxcUri); fileHash = await hashAlgo.ComputeHashAsync(await hs.ClientHttpClient.GetStreamAsync(resolvedUri)); } catch (Exception ex2) { await _logRoom.SendMessageEventAsync( MessageFormatter.FormatException($"Error calculating file hash via {hs.BaseUrl} ({resolvedUri})!", ex2)); } } logger.LogInformation("Checking media {url} with hash {hash}", resolvedUri, fileHash); if (ActivePoliciesByType.ContainsKey(nameof(MediaPolicyFile))) foreach (MediaPolicyFile policy in ActivePoliciesByType[nameof(MediaPolicyFile)]) { logger.LogInformation("Checking rule {rule}: {data}", policy.OriginalEvent.StateKey, policy.OriginalEvent.TypedContent.ToJson(ignoreNull: true, indent: false)); if (policy.Entity is not null && Convert.ToBase64String(uriHash).SequenceEqual(policy.Entity)) { logger.LogInformation("{url} matched rule {rule} by uri hash", @event.RawContent["url"], policy.ToJson(ignoreNull: true)); matchedRules.Add(policy); // continue; } else logger.LogInformation("uri hash {uriHash} did not match rule's {ruleUriHash}", Convert.ToHexString(uriHash), policy.Entity); if (policy.FileHash is not null && fileHash is not null && policy.FileHash == Convert.ToBase64String(fileHash)) { logger.LogInformation("{url} matched rule {rule} by file hash", @event.RawContent["url"], policy.ToJson(ignoreNull: true)); matchedRules.Add(policy); // continue; } else logger.LogInformation("file hash {fileHash} did not match rule's {ruleFileHash}", Convert.ToBase64String(fileHash), policy.FileHash); //check pixels every 10% of the way through the image using ImageSharp // var image = Image.Load(await _hs._httpClient.GetStreamAsync(resolvedUri)); } else logger.LogInformation("No active media file policies"); // logger.LogInformation("{url} did not match any rules", @event.RawContent["url"]); return matchedRules; } #endregion #region Internal code #region Summarisation private static (string Raw, string Html) SummariseStateTypeCounts(IList states) { string raw = "Count | State type | Mapped type", html = ""; var groupedStates = states.GroupBy(x => x.Type).ToDictionary(x => x.Key, x => x.ToList()).OrderByDescending(x => x.Value.Count); foreach (var (type, stateGroup) in groupedStates) { raw += $"\n{stateGroup.Count} | {type} | {stateGroup[0].MappedType.Name}"; html += $""; } html += "
CountState typeMapped type
{stateGroup.Count}{type}{stateGroup[0].MappedType.Name}
"; return (raw, html); } #endregion #endregion }