Issue #4890 Large HTTP2 Fields encoded

Only index 0 content-length Signed-off-by: Greg Wilkins <gregw@webtide.com>
jetty · Jun 1, 2020 · 916817c · 916817c
1 parent 2667974
commit 916817c
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Showing 2 changed files with 25 additions and 2 deletions.
diff --git a/jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java b/jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java
@@ -395,9 +395,9 @@ else if (DO_NOT_INDEX.contains(header))
                             (huffman ? "HuffV" : "LitV") +
                             (neverIndex ? "!!Idx" : "!Idx");
                 }
-                else if (fieldSize >= _context.getMaxDynamicTableSize() || header == HttpHeader.CONTENT_LENGTH && field.getValue().length() > 2)
+                else if (fieldSize >= _context.getMaxDynamicTableSize() || header == HttpHeader.CONTENT_LENGTH && field.getIntValue() != 0)
                 {
-                    // Non indexed if field too large or a content length for 3 digits or more
+                    // The field is too large or a non zero content length, so do not index.
                     indexed = false;
                     encodeName(buffer, (byte)0x00, 4, header.asString(), name);
                     encodeValue(buffer, true, field.getValue());

diff --git a/jetty-http2/http2-hpack/src/test/java/org/eclipse/jetty/http2/hpack/HpackEncoderTest.java b/jetty-http2/http2-hpack/src/test/java/org/eclipse/jetty/http2/hpack/HpackEncoderTest.java
@@ -22,6 +22,7 @@
 
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFields;
+import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.MetaData;
 import org.eclipse.jetty.util.BufferUtil;
@@ -171,6 +172,28 @@ public void testLargeFieldsNotIndexed()
         assertThat(ctx.getDynamicTableSize(), Matchers.is(dynamicTableSize));
     }
 
+    @Test
+    public void testIndexContentLength()
+    {
+        HpackEncoder encoder = new HpackEncoder(38 * 5);
+        HpackContext ctx = encoder.getHpackContext();
+
+        ByteBuffer buffer = BufferUtil.allocate(4096);
+
+        // Index zero content length
+        int pos = BufferUtil.flipToFill(buffer);
+        encoder.encode(buffer, new HttpField(HttpHeader.CONTENT_LENGTH, "0"));
+        BufferUtil.flipToFlush(buffer, pos);
+        int dynamicTableSize = ctx.getDynamicTableSize();
+        assertThat(dynamicTableSize, Matchers.greaterThan(0));
+
+        // Do not index non zero content length
+        pos = BufferUtil.flipToFill(buffer);
+        encoder.encode(buffer, new HttpField(HttpHeader.CONTENT_LENGTH, "42"));
+        BufferUtil.flipToFlush(buffer, pos);
+        assertThat(ctx.getDynamicTableSize(), Matchers.is(dynamicTableSize));
+    }
+
     @Test
     public void testNeverIndexSetCookie() throws Exception
     {