Add some HPackDecoderTests for empty header names and values (#57032)

Sanity checking for https://www.cve.org/CVERecord?id=CVE-2019-9516

Author: amcasey

src/Shared/test/Shared.Tests/runtime/Http2/HPackDecoderTest.cs

@@ -87,6 +87,10 @@ public class HPackDecoderTests
             .Concat(_headerValueHuffmanBytes)
             .ToArray();
 
+        private static readonly byte[] _literalEmptyString = new byte[] { 0x00 };
+
+        private static readonly byte[] _literalEmptyStringHuffman = new byte[] { 0x80 };
+
         // &        *
         // 11111000 11111111
         private static readonly byte[] _huffmanLongPadding = new byte[] { 0x82, 0xf8, 0xff };
@@ -243,6 +247,43 @@ public void DecodesLiteralHeaderFieldWithoutIndexing_NewName()
             TestDecodeWithoutIndexing(encoded, _headerNameString, _headerValueString);
         }
 
+        [Fact]
+        public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_EmptyName()
+        {
+            byte[] encoded = _literalHeaderFieldWithoutIndexingNewName
+                .Concat(_literalEmptyString)
+                .Concat(_headerValue)
+                .ToArray();
+
+            HPackDecodingException exception = Assert.Throws<HPackDecodingException>(() => _decoder.Decode(encoded, endHeaders: true, handler: _handler));
+            Assert.Equal(SR.Format(SR.net_http_invalid_header_name, string.Empty), exception.Message);
+            Assert.Empty(_handler.DecodedHeaders);
+        }
+
+        [Fact]
+        public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_EmptyValue()
+        {
+            byte[] encoded = _literalHeaderFieldWithoutIndexingNewName
+                .Concat(_headerName)
+                .Concat(_literalEmptyString)
+                .ToArray();
+
+            TestDecodeWithoutIndexing(encoded, _headerNameString, string.Empty);
+        }
+
+        [Fact]
+        public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_EmptyNameAndValue()
+        {
+            byte[] encoded = _literalHeaderFieldWithoutIndexingNewName
+                .Concat(_literalEmptyString)
+                .Concat(_literalEmptyString)
+                .ToArray();
+
+            HPackDecodingException exception = Assert.Throws<HPackDecodingException>(() => _decoder.Decode(encoded, endHeaders: true, handler: _handler));
+            Assert.Equal(SR.Format(SR.net_http_invalid_header_name, string.Empty), exception.Message);
+            Assert.Empty(_handler.DecodedHeaders);
+        }
+
         [Fact]
         public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedName()
         {
@@ -254,6 +295,19 @@ public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedName(
             TestDecodeWithoutIndexing(encoded, _headerNameString, _headerValueString);
         }
 
+        [Fact]
+        public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedName_Empty()
+        {
+            byte[] encoded = _literalHeaderFieldWithoutIndexingNewName
+                .Concat(_literalEmptyStringHuffman)
+                .Concat(_headerValue)
+                .ToArray();
+
+            HPackDecodingException exception = Assert.Throws<HPackDecodingException>(() => _decoder.Decode(encoded, endHeaders: true, handler: _handler));
+            Assert.Equal(SR.Format(SR.net_http_invalid_header_name, string.Empty), exception.Message);
+            Assert.Empty(_handler.DecodedHeaders);
+        }
+
         [Fact]
         public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedValue()
         {
@@ -265,6 +319,17 @@ public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedValue
             TestDecodeWithoutIndexing(encoded, _headerNameString, _headerValueString);
         }
 
+        [Fact]
+        public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedValue_Empty()
+        {
+            byte[] encoded = _literalHeaderFieldWithoutIndexingNewName
+                .Concat(_headerName)
+                .Concat(_literalEmptyStringHuffman)
+                .ToArray();
+
+            TestDecodeWithoutIndexing(encoded, _headerNameString, string.Empty);
+        }
+
         [Fact]
         public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedNameAndValue()
         {
@@ -276,6 +341,19 @@ public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedNameA
             TestDecodeWithoutIndexing(encoded, _headerNameString, _headerValueString);
         }
 
+        [Fact]
+        public void DecodesLiteralHeaderFieldWithoutIndexing_NewName_HuffmanEncodedNameAndValue_Empty()
+        {
+            byte[] encoded = _literalHeaderFieldWithoutIndexingNewName
+                .Concat(_literalEmptyStringHuffman)
+                .Concat(_literalEmptyStringHuffman)
+                .ToArray();
+
+            HPackDecodingException exception = Assert.Throws<HPackDecodingException>(() => _decoder.Decode(encoded, endHeaders: true, handler: _handler));
+            Assert.Equal(SR.Format(SR.net_http_invalid_header_name, string.Empty), exception.Message);
+            Assert.Empty(_handler.DecodedHeaders);
+        }
+
         [Fact]
         public void DecodesLiteralHeaderFieldWithoutIndexing_IndexedName()
         {