handle utf8 decode errors

src/main/java/com/github/nkzawa/engineio/parser/Parser.java

@@ -2,6 +2,7 @@ package com.github.nkzawa.engineio.parser;
 
 
 import com.github.nkzawa.utf8.UTF8;
+import com.github.nkzawa.utf8.UTF8Exception;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -73,7 +74,11 @@ public class Parser {
         } catch (IndexOutOfBoundsException e) {
             type = -1;
         }
-        data = UTF8.decode(data);
+        try {
+            data = UTF8.decode(data);
+        } catch (UTF8Exception e) {
+            return err;
+        }
 
         if (type < 0 || type >= packetslist.size()) {
             return err;
@@ -164,7 +169,6 @@ public class Parser {
 
                 if (msg.length() != 0) {
                     Packet<String> packet = decodePacket(msg);
-
                     if (err.type.equals(packet.type) && err.data.equals(packet.data)) {
                         callback.call(err, 0, 1);
                         return;

src/main/java/com/github/nkzawa/utf8/UTF8.java

@@ -27,7 +27,7 @@ public class UTF8 {
         return byteString.toString();
     }
 
-    public static String decode(String byteString) {
+    public static String decode(String byteString) throws UTF8Exception {
         byteArray = uc2decode(byteString);
         byteCount = byteArray.length;
         byteIndex = 0;
@@ -74,7 +74,7 @@ public class UTF8 {
         return Character.toChars(((codePoint >> shift) & 0x3F) | 0x80);
     }
 
-    private static int decodeSymbol() {
+    private static int decodeSymbol() throws UTF8Exception {
         int byte1;
         int byte2;
         int byte3;
@@ -82,7 +82,7 @@ public class UTF8 {
         int codePoint;
 
         if (byteIndex > byteCount) {
-            throw new RuntimeException("Invalid byte index");
+            throw new UTF8Exception("Invalid byte index");
         }
 
         if (byteIndex == byteCount) {
@@ -102,7 +102,7 @@ public class UTF8 {
             if (codePoint >= 0x80) {
                 return codePoint;
             } else {
-                throw new RuntimeException("Invalid continuation byte");
+                throw new UTF8Exception("Invalid continuation byte");
             }
         }
 
@@ -113,7 +113,7 @@ public class UTF8 {
             if (codePoint >= 0x0800) {
                 return codePoint;
             } else {
-                throw new RuntimeException("Invalid continuation byte");
+                throw new UTF8Exception("Invalid continuation byte");
             }
         }
 
@@ -127,12 +127,12 @@ public class UTF8 {
             }
         }
 
-        throw new RuntimeException("Invalid continuation byte");
+        throw new UTF8Exception("Invalid continuation byte");
     }
 
-    private static int readContinuationByte() {
+    private static int readContinuationByte() throws UTF8Exception {
         if (byteIndex >= byteCount) {
-            throw new RuntimeException("Invalid byte index");
+            throw new UTF8Exception("Invalid byte index");
         }
 
         int continuationByte = byteArray[byteIndex] & 0xFF;
@@ -142,7 +142,7 @@ public class UTF8 {
             return continuationByte & 0x3F;
         }
 
-        throw new RuntimeException("Invalid continuation byte");
+        throw new UTF8Exception("Invalid continuation byte");
     }
 
     private static String ucs2encode(int[] array) {

src/main/java/com/github/nkzawa/utf8/UTF8Exception.java

@@ -0,0 +1,24 @@
+package com.github.nkzawa.utf8;
+
+import java.io.IOException;
+
+public class UTF8Exception extends IOException {
+
+    public String data;
+
+    public UTF8Exception() {
+        super();
+    }
+
+    public UTF8Exception(String message) {
+        super(message);
+    }
+
+    public UTF8Exception(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public UTF8Exception(Throwable cause) {
+        super(cause);
+    }
+}

src/test/java/com/github/nkzawa/engineio/parser/ParserTest.java

@@ -169,6 +169,13 @@ public class ParserTest {
         assertThat(p.data, is(ERROR_DATA));
     }
 
+    @Test
+    public void decodeInvalidUTF8() {
+        Packet<String> p = decodePacket("4\uffff");
+        assertThat(p.type, is(Packet.ERROR));
+        assertThat(p.data, is(ERROR_DATA));
+    }
+
     @Test
     public void encodePayloads() {
         encodePayload(new Packet[]{new Packet(Packet.PING), new Packet(Packet.PONG)}, new EncodeCallback<byte[]>() {
@@ -313,6 +320,20 @@ public class ParserTest {
         });
     }
 
+    @Test
+    public void decodePayloadInvalidUTF8() {
+        decodePayload("2:4\uffff", new DecodePayloadCallback<String>() {
+            @Override
+            public boolean call(Packet<String> packet, int index, int total) {
+                boolean isLast = index + 1 == total;
+                assertThat(packet.type, is(Packet.ERROR));
+                assertThat(packet.data, is(ERROR_DATA));
+                assertThat(isLast, is(true));
+                return true;
+            }
+        });
+    }
+
     @Test
     public void encodeBinaryMessage() {
         final byte[] data = new byte[5];

src/test/java/com/github/nkzawa/utf8/UTF8Test.java

@@ -55,23 +55,23 @@ public class UTF8Test {
     public ExpectedException exception = ExpectedException.none();
 
     @Test
-    public void encodeAndDecode() {
+    public void encodeAndDecode() throws UTF8Exception {
         for (Data data : DATA) {
             String reason = data.description != null? data.description : "U+" + Integer.toHexString(data.codePoint).toUpperCase();
             assertThat("Encoding: " + reason, data.encoded, is(UTF8.encode(data.decoded)));
             assertThat("Decoding: " + reason, data.decoded, is(UTF8.decode(data.encoded)));
         }
 
-        exception.expect(RuntimeException.class);
+        exception.expect(UTF8Exception.class);
         UTF8.decode("\uFFFF");
 
-        exception.expect(RuntimeException.class);
+        exception.expect(UTF8Exception.class);
         UTF8.decode("\u00E9\u0000\u0000");
 
-        exception.expect(RuntimeException.class);
+        exception.expect(UTF8Exception.class);
         UTF8.decode("\u00C2\uFFFF");
 
-        exception.expect(RuntimeException.class);
+        exception.expect(UTF8Exception.class);
         UTF8.decode("\u00F0\u009D");
     }