Add more chat filtering.

CAPS LOCK FILTER if a line is long enough and contains mostly caps.
Shadowban filter blocks messages with configurable substrings present in them. Does not permanently shadowban the user, yet, just drops the message.
Add a test that was missed in a previous commit.

WebContent/js/cah.constants.js

@@ -136,6 +136,7 @@ cah.$.ErrorCode.TOO_MANY_GAMES = "tmg";
 cah.$.ErrorCode.INVALID_ID_CODE = "iid";
 cah.$.ErrorCode.CANNOT_JOIN_ANOTHER_GAME = "cjag";
 cah.$.ErrorCode.NO_MSG_SPECIFIED = "nms";
+cah.$.ErrorCode.CAPSLOCK = "CL";
 cah.$.ErrorCode.ALREADY_STARTED = "as";
 cah.$.ErrorCode.NOT_ADMIN = "na";
 cah.$.ErrorCode.INVALID_GAME = "ig";
@@ -199,6 +200,7 @@ cah.$.ErrorCode_msg['B&'] = "Banned.";
 cah.$.ErrorCode_msg['mtl'] = "Messages cannot be longer than 200 characters.";
 cah.$.ErrorCode_msg['in'] = "Nickname must contain only upper and lower case letters, numbers, or underscores, must be 3 to 30 characters long, and must not start with a number.";
 cah.$.ErrorCode_msg['serr'] = "An error occured on the server.";
+cah.$.ErrorCode_msg['CL'] = "Try turning caps lock off.";
 cah.$.ErrorCode_msg['dnhc'] = "You don't have that card.";
 cah.$.ErrorCode_msg['as'] = "The game has already started.";
 cah.$.ErrorCode_msg['nns'] = "No nickname specified.";

build.properties.example

@@ -11,6 +11,9 @@ pyx.id_code_salt=
 # comma-separated listed of IP addresses (v4 or v6) from which users are considered admins.
 pyx.admin_addrs=127.0.0.1,::1
 
+# comma-separated list of strings that will cause a chat message to get silently dropped without
+# notifying the user. does not currently permanently shadowban the user, but maybe it should...
+pyx.shadowban_strings=
 # Settings for global chat protection. Some of these do not apply to game chats.
 # Ratio of 'basic' characters to length of message. Basic characters are defined by
 # Character.isJavaIdentifierPart, which stipulates:
@@ -25,6 +28,9 @@ pyx.admin_addrs=127.0.0.1,::1
 pyx.global.basic_ratio=.5
 # A message must have at least this many characters for that ratio to apply.
 pyx.global.basic_min_len=10
+# Message longer than min_len characters cannot have more than ratio of CAPS CHARACTERS
+pyx.global.capslock_min_len=50
+pyx.global.capslock_ratio=.5
 # messages longer than min_len characters require at least min_count spaces between words
 pyx.global.spaces_min_len=50
 pyx.global.spaces_min_count=4

src/main/filtered-resources/WEB-INF/pyx.properties

@@ -6,12 +6,15 @@ pyx.server.broadcast_connects_and_disconnects=${pyx.broadcast_connects_and_disco
 pyx.server.global_chat_enabled=${pyx.global_chat_enabled}
 pyx.server.id_code_salt=${pyx.id_code_salt}
 pyx.server.admin_addrs=${pyx.admin_addrs}
+pyx.chat.shadowban_strings=${pyx.shadowban_strings}
 pyx.chat.global.flood_count=${pyx.global.flood_count}
 pyx.chat.global.flood_time=${pyx.global.flood_time}
 pyx.chat.global.basic_ratio=${pyx.global.basic_ratio}
 pyx.chat.global.basic_min_len=${pyx.global.basic_min_len}
 pyx.chat.global.spaces_min_len=${pyx.global.spaces_min_len}
 pyx.chat.global.spaces_min_count=${pyx.global.spaces_min_count}
+pyx.chat.global.capslock_min_len=${pyx.global.capslock_min_len}
+pyx.chat.global.capslock_ratio=${pyx.global.capslock_ratio}
 pyx.chat.game.flood_count=${pyx.game.flood_count}
 pyx.chat.game.flood_time=${pyx.game.flood_time}
 pyx.build=${buildNumber}

src/main/java/net/socialgamer/cah/Constants.java

@@ -351,6 +351,7 @@ public class Constants {
     @DuplicationAllowed
     BANNED(DisconnectReason.BANNED, "Banned."),
     CANNOT_JOIN_ANOTHER_GAME("cjag", "You cannot join another game."),
+    CAPSLOCK("CL", "Try turning caps lock off."),
     CARDCAST_CANNOT_FIND("ccf", "Cannot find Cardcast deck with given ID. If you just added this"
         + " deck to Cardcast, wait a few minutes and try again."),
     CARDCAST_INVALID_ID("cii", "Invalid Cardcast ID. Must be exactly 5 characters."),

src/main/java/net/socialgamer/cah/handlers/ChatHandler.java

@@ -93,13 +93,18 @@ public class ChatHandler extends Handler {
 
       final ChatFilter.Result filterResult = chatFilter.filterGlobal(user, message);
       switch (filterResult) {
-        case OK:
+        case CAPSLOCK:
-          // nothing to do
+          return error(ErrorCode.CAPSLOCK);
-          break;
+        case DROP_MESSAGE:
+          // Don't tell the user we dropped it, and don't send it to everyone else...
+          return data;
         case NO_MESSAGE:
           return error(ErrorCode.NO_MSG_SPECIFIED);
         case NOT_ENOUGH_SPACES:
           return error(ErrorCode.NOT_ENOUGH_SPACES);
+        case OK:
+          // nothing to do
+          break;
         case REPEAT:
           return error(ErrorCode.REPEAT_MESSAGE);
         case TOO_FAST:

src/main/java/net/socialgamer/cah/handlers/GameChatHandler.java

@@ -78,13 +78,18 @@ public class GameChatHandler extends GameWithPlayerHandler {
 
       final ChatFilter.Result filterResult = chatFilter.filterGame(user, message);
       switch (filterResult) {
-        case OK:
+        case CAPSLOCK:
-          // nothing to do
+          return error(ErrorCode.CAPSLOCK);
-          break;
+        case DROP_MESSAGE:
+          // Don't tell the user we dropped it, and don't send it to everyone else...
+          return data;
         case NO_MESSAGE:
           return error(ErrorCode.NO_MSG_SPECIFIED);
         case NOT_ENOUGH_SPACES:
           return error(ErrorCode.NOT_ENOUGH_SPACES);
+        case OK:
+          // nothing to do
+          break;
         case REPEAT:
           return error(ErrorCode.REPEAT_MESSAGE);
         case TOO_FAST:

src/main/java/net/socialgamer/cah/util/ChatFilter.java

@@ -28,6 +28,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
+import java.util.Set;
 import java.util.TreeMap;
 import java.util.WeakHashMap;
 import java.util.concurrent.TimeUnit;
@@ -35,6 +36,7 @@ import java.util.regex.Pattern;
 
 import org.apache.log4j.Logger;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
@@ -56,6 +58,9 @@ public class ChatFilter {
   private static final double DEFAULT_BASIC_CHARACTER_RATIO = .5;
   private static final int DEFAULT_SPACES_MIN_MSG_LENGTH = 75;
   private static final int DEFAULT_SPACES_REQUIRED = 3;
+  private static final int DEFAULT_CAPSLOCK_MIN_MSG_LENGTH = 50;
+  private static final double DEFAULT_CAPSLOCK_RATIO = .5;
+  private static final String DEFAULT_SHADOWBAN_CHARACTERS = "";
 
   public static final Pattern SIMPLE_MESSAGE_PATTERN = Pattern
       .compile("^[a-zA-Z0-9 _\\-=+*()\\[\\]\\\\/|,.!:'\"`~#]+$");
@@ -64,7 +69,7 @@ public class ChatFilter {
   private final Map<User, FilterData> filterData = Collections.synchronizedMap(new WeakHashMap<>());
 
   public enum Result {
-    OK, NO_MESSAGE, NOT_ENOUGH_SPACES, REPEAT, TOO_FAST, TOO_LONG, TOO_MANY_SPECIALS
+    CAPSLOCK, DROP_MESSAGE, NO_MESSAGE, NOT_ENOUGH_SPACES, OK, REPEAT, TOO_FAST, TOO_LONG, TOO_MANY_SPECIALS
   }
 
   private enum Scope {
@@ -89,7 +94,8 @@ public class ChatFilter {
       // do some more in-depth analysis. we don't want too many emoji or non-latin characters
       final long basic = message.codePoints().filter(c -> Character.isJavaIdentifierPart(c))
           .count();
-      if (((double) basic) / total < getBasicCharacterRatio(Scope.global)) {
+      if (((double) basic) / total < getDoubleParameter(Scope.global, "basic_ratio",
+          DEFAULT_BASIC_CHARACTER_RATIO)) {
         return Result.TOO_MANY_SPECIALS;
       }
     }
@@ -100,6 +106,13 @@ public class ChatFilter {
       return Result.NOT_ENOUGH_SPACES;
     }
 
+    final long caps = message.codePoints().filter(c -> Character.isUpperCase(c)).count();
+    if (total >= getIntParameter(Scope.global, "capslock_min_len", DEFAULT_CAPSLOCK_MIN_MSG_LENGTH)
+        && ((double) caps) / total > getDoubleParameter(Scope.global, "capslock_ratio",
+            DEFAULT_CAPSLOCK_RATIO)) {
+      return Result.CAPSLOCK;
+    }
+
     getMessageTimes(user, Scope.global).add(System.currentTimeMillis());
     return Result.OK;
   }
@@ -110,8 +123,6 @@ public class ChatFilter {
       return result;
     }
 
-    // TODO?
-
     getMessageTimes(user, Scope.game).add(System.currentTimeMillis());
     return Result.OK;
   }
@@ -141,12 +152,22 @@ public class ChatFilter {
       }
     }
 
+    // TODO keep track of how much someone does this and perma-shadowban them...
+    for (final String banned : getShadowbanCharacters()) {
+      if (message.contains(banned)) {
+        LOG.info(String.format(
+            "Dropping message '%s' from user %s (%s); contains banned string %s.", message,
+            user.getNickname(), user.getHostname(), banned));
+        return Result.DROP_MESSAGE;
+      }
+    }
+
     return Result.OK;
   }
 
   private int getIntParameter(final Scope scope, final String name, final int defaultValue) {
     try {
-      return Integer.parseInt(propsProvider.get().getProperty(
+      return Integer.parseInt(getPropValue(
           String.format("pyx.chat.%s.%s", scope, name), String.valueOf(defaultValue)));
     } catch (final NumberFormatException e) {
       LOG.warn(String.format("Unable to parse pyx.chat.%s.%s as a number,"
@@ -155,6 +176,27 @@ public class ChatFilter {
     }
   }
 
+  private double getDoubleParameter(final Scope scope, final String name,
+      final double defaultValue) {
+    try {
+      return Double.parseDouble(
+          getPropValue(String.format("pyx.chat.%s.%s", scope, name), String.valueOf(defaultValue)));
+    } catch (final NumberFormatException e) {
+      LOG.warn(String.format("Unable to parse pyx.chat.%s.%s as a number,"
+          + " using default of %d", scope, name, defaultValue), e);
+      return defaultValue;
+    }
+  }
+
+  private Set<String> getShadowbanCharacters() {
+    return ImmutableSet.copyOf(getPropValue("pyx.chat.shadowban_strings",
+        DEFAULT_SHADOWBAN_CHARACTERS).split(","));
+  }
+
+  private String getPropValue(final String name, final String defaultValue) {
+    return propsProvider.get().getProperty(name, defaultValue);
+  }
+
   private int getFloodCount(final Scope scope) {
     return getIntParameter(scope, "flood_count", DEFAULT_CHAT_FLOOD_MESSAGE_COUNT);
   }
@@ -164,18 +206,6 @@ public class ChatFilter {
         .toMillis(getIntParameter(scope, "flood_time", DEFAULT_CHAT_FLOOD_TIME_SECONDS));
   }
 
-  private double getBasicCharacterRatio(final Scope scope) {
-    try {
-      return Double.parseDouble(propsProvider.get().getProperty(
-          String.format("pyx.chat.%s.basic_ratio", scope),
-          String.valueOf(DEFAULT_BASIC_CHARACTER_RATIO)));
-    } catch (final NumberFormatException e) {
-      LOG.warn(String.format("Unable to parse pyx.chat.%s.basic_ratio as a number,"
-          + " using default of %d", scope, DEFAULT_BASIC_CHARACTER_RATIO), e);
-      return DEFAULT_BASIC_CHARACTER_RATIO;
-    }
-  }
-
   private FilterData getFilterData(final User user) {
     FilterData data;
     synchronized (filterData) {

src/test/java/net/socialgamer/cah/util/ChatFilterTest.java

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) 2018, Andy Janata
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are permitted
+ * provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this list of conditions
+ *   and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice, this list of
+ *   conditions and the following disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
+ * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package net.socialgamer.cah.util;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class ChatFilterTest {
+
+  @Test
+  public void testSimpleMessagePattern() {
+    assertTrue(ChatFilter.SIMPLE_MESSAGE_PATTERN.matcher("Hello world.").matches());
+    assertTrue(ChatFilter.SIMPLE_MESSAGE_PATTERN.matcher(":) :( =\\ ._.").matches());
+    assertTrue(ChatFilter.SIMPLE_MESSAGE_PATTERN.matcher("*neat* (cool) [awesome]").matches());
+    assertFalse(ChatFilter.SIMPLE_MESSAGE_PATTERN.matcher(":$").matches());
+  }
+}