From b7454f9cda53faa6d901b33d8c235d2a31a35b13 Mon Sep 17 00:00:00 2001
From: Flavia Rainone <frainone@redhat.com>
Date: Thu, 22 Jun 2023 15:12:38 -0300
Subject: [PATCH] [UNDERTOW-2281] At Http2FrameHeaderParser, throw a protocol
 error when END_STREAM is absent only when:request does not contain
 Expect:100-continue header; or response contains a positive content-length
 indicating the presence of a content.

Signed-off-by: Flavia Rainone <frainone@redhat.com>
---
 .../protocols/http2/Http2FrameHeaderParser.java     |  6 ++++++
 .../protocols/http2/Http2HeaderBlockParser.java     | 13 +++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/core/src/main/java/io/undertow/protocols/http2/Http2FrameHeaderParser.java b/core/src/main/java/io/undertow/protocols/http2/Http2FrameHeaderParser.java
index 75a34ed977..cd63540920 100644
--- a/core/src/main/java/io/undertow/protocols/http2/Http2FrameHeaderParser.java
+++ b/core/src/main/java/io/undertow/protocols/http2/Http2FrameHeaderParser.java
@@ -38,6 +38,7 @@
 import static io.undertow.protocols.http2.Http2Channel.HEADERS_FLAG_END_HEADERS;
 import static org.xnio.Bits.allAreClear;
 import static org.xnio.Bits.allAreSet;
+import static org.xnio.Bits.anyAreClear;
 import static org.xnio.Bits.anyAreSet;
 
 /**
@@ -233,6 +234,11 @@ int getActualLength() {
         } else if(type == FRAME_TYPE_HEADERS) {
             final Http2StreamSourceChannel channel = http2Channel.getIncomingStream(streamId);
             if(channel != null) {
+                if(anyAreClear(flags, Http2Channel.HEADERS_FLAG_END_STREAM) && !((Http2HeadersParser) parser).isContentExpected()) {
+                    //this is a protocol error
+                    io.undertow.UndertowLogger.REQUEST_IO_LOGGER.debug("Received HTTP/2 trailers header without end stream set");
+                    http2Channel.sendGoAway(Http2Channel.ERROR_PROTOCOL_ERROR);
+                }
                 if (!channel.isHeadersEndStream() && allAreSet(flags, Http2Channel.HEADERS_FLAG_END_HEADERS | Http2Channel.HEADERS_FLAG_END_STREAM)) {
                     http2Channel.removeStreamSource(streamId);
                 }
diff --git a/core/src/main/java/io/undertow/protocols/http2/Http2HeaderBlockParser.java b/core/src/main/java/io/undertow/protocols/http2/Http2HeaderBlockParser.java
index 0c1b42613e..a812b942e9 100644
--- a/core/src/main/java/io/undertow/protocols/http2/Http2HeaderBlockParser.java
+++ b/core/src/main/java/io/undertow/protocols/http2/Http2HeaderBlockParser.java
@@ -24,6 +24,7 @@
 import java.util.HashSet;
 import java.util.Set;
 
+import io.undertow.server.protocol.http.HttpContinue;
 import org.xnio.Bits;
 import io.undertow.UndertowLogger;
 
@@ -138,6 +139,18 @@ HeaderMap getHeaderMap() {
         return headerMap;
     }
 
+    boolean isContentExpected() {
+        if (HttpContinue.requiresContinueResponse(headerMap)) {
+            return true;
+        }
+        String contentLengthString = headerMap.getFirst(Headers.CONTENT_LENGTH);
+        try {
+            return contentLengthString != null ? Long.parseLong(contentLengthString) > 0 : false;
+        } catch (NumberFormatException e) {
+            return false;
+        }
+    }
+
     @Override
     public void emitHeader(HttpString name, String value, boolean neverIndex) throws HpackException {
         if(maxHeaderListSize > 0) {