Adds the ability to skip Cookie crumbling in HpackEncoder.

This is preparation for fixing the issue described in envoyproxy/envoy#32611.

Protected by new code path, not yet enabled in the GFE binary.

PiperOrigin-RevId: 613330788

quiche/spdy/core/hpack/hpack_encoder.cc

@@ -86,7 +86,8 @@ HpackEncoder::HpackEncoder()
       listener_(NoOpListener),
       should_index_(DefaultPolicy),
       enable_compression_(true),
-      should_emit_table_size_(false) {}
+      should_emit_table_size_(false),
+      crumble_cookies_(true) {}
 
 HpackEncoder::~HpackEncoder() = default;
 
@@ -101,7 +102,11 @@ std::string HpackEncoder::EncodeHeaderBlock(
       // Note that there can only be one "cookie" header, because header_set is
       // a map.
       found_cookie = true;
-      CookieToCrumbs(header, &regular_headers);
+      if (crumble_cookies_) {
+        CookieToCrumbs(header, &regular_headers);
+      } else {
+        DecomposeRepresentation(header, &regular_headers);
+      }
     } else if (!header.first.empty() &&
                header.first[0] == kPseudoHeaderPrefix) {
       DecomposeRepresentation(header, &pseudo_headers);
@@ -302,7 +307,11 @@ HpackEncoder::Encoderator::Encoderator(const Http2HeaderBlock& header_set,
       // Note that there can only be one "cookie" header, because header_set
       // is a map.
       found_cookie = true;
-      CookieToCrumbs(header, &regular_headers_);
+      if (encoder_->crumble_cookies_) {
+        CookieToCrumbs(header, &regular_headers_);
+      } else {
+        DecomposeRepresentation(header, &regular_headers_);
+      }
     } else if (!header.first.empty() &&
                header.first[0] == kPseudoHeaderPrefix) {
       DecomposeRepresentation(header, &pseudo_headers_);
@@ -321,7 +330,11 @@ HpackEncoder::Encoderator::Encoderator(const Representations& representations,
     : encoder_(encoder), has_next_(true) {
   for (const auto& header : representations) {
     if (header.first == "cookie") {
-      CookieToCrumbs(header, &regular_headers_);
+      if (encoder_->crumble_cookies_) {
+        CookieToCrumbs(header, &regular_headers_);
+      } else {
+        DecomposeRepresentation(header, &regular_headers_);
+      }
     } else if (!header.first.empty() &&
                header.first[0] == kPseudoHeaderPrefix) {
       pseudo_headers_.push_back(header);

quiche/spdy/core/hpack/hpack_encoder.h

@@ -97,6 +97,12 @@ class QUICHE_EXPORT HpackEncoder {
 
   void DisableCompression() { enable_compression_ = false; }
 
+  // Disables the deconstruction of Cookie header values into individual
+  // components, as described in
+  // https://httpwg.org/specs/rfc9113.html#CompressCookie. The deconstructed
+  // representation can cause problems for some HTTP/2 endpoints.
+  void DisableCookieCrumbling() { crumble_cookies_ = false; }
+
   // Returns the current dynamic table size, including the 32 bytes per entry
   // overhead mentioned in RFC 7541 section 4.1.
   size_t GetDynamicTableSize() const { return header_table_.size(); }
@@ -142,6 +148,7 @@ class QUICHE_EXPORT HpackEncoder {
   IndexingPolicy should_index_;
   bool enable_compression_;
   bool should_emit_table_size_;
+  bool crumble_cookies_;
 };
 
 }  // namespace spdy

quiche/spdy/core/hpack/hpack_encoder_test.cc

@@ -325,6 +325,39 @@ TEST_P(HpackEncoderTestWithDefaultStrategy, EncodeRepresentations) {
   EXPECT_GE(kInitialDynamicTableSize, encoder_.GetDynamicTableSize());
 }
 
+TEST_P(HpackEncoderTestWithDefaultStrategy, WithoutCookieCrumbling) {
+  EXPECT_EQ(kInitialDynamicTableSize, encoder_.GetDynamicTableSize());
+  encoder_.SetHeaderListener(
+      [this](absl::string_view name, absl::string_view value) {
+        this->SaveHeaders(name, value);
+      });
+  encoder_.DisableCookieCrumbling();
+
+  const std::vector<std::pair<absl::string_view, absl::string_view>>
+      header_list = {{"cookie", "val1; val2;val3"},
+                     {":path", "/home"},
+                     {"accept", "text/html, text/plain,application/xml"},
+                     {"cookie", "val4"},
+                     {"withnul", absl::string_view("one\0two", 7)}};
+  ExpectNonIndexedLiteralWithNameIndex(peer_.table()->GetByName(":path"),
+                                       "/home");
+  ExpectIndexedLiteral(peer_.table()->GetByName("cookie"), "val1; val2;val3");
+  ExpectIndexedLiteral(peer_.table()->GetByName("accept"),
+                       "text/html, text/plain,application/xml");
+  ExpectIndexedLiteral(peer_.table()->GetByName("cookie"), "val4");
+  ExpectIndexedLiteral("withnul", absl::string_view("one\0two", 7));
+
+  CompareWithExpectedEncoding(header_list);
+  EXPECT_THAT(
+      headers_observed_,
+      ElementsAre(Pair(":path", "/home"), Pair("cookie", "val1; val2;val3"),
+                  Pair("accept", "text/html, text/plain,application/xml"),
+                  Pair("cookie", "val4"),
+                  Pair("withnul", absl::string_view("one\0two", 7))));
+  // Insertions and evictions have happened over the course of the test.
+  EXPECT_GE(kInitialDynamicTableSize, encoder_.GetDynamicTableSize());
+}
+
 TEST_P(HpackEncoderTestWithDefaultStrategy, DynamicTableGrows) {
   EXPECT_EQ(kInitialDynamicTableSize, encoder_.GetDynamicTableSize());
   peer_.table()->SetMaxSize(4096);
@@ -446,6 +479,15 @@ TEST_P(HpackEncoderTest, CookieHeaderIsCrumbled) {
   CompareWithExpectedEncoding(headers);
 }
 
+TEST_P(HpackEncoderTest, CookieHeaderIsNotCrumbled) {
+  encoder_.DisableCookieCrumbling();
+  ExpectIndexedLiteral(peer_.table()->GetByName("cookie"), "a=bb; c=dd; e=ff");
+
+  Http2HeaderBlock headers;
+  headers["cookie"] = "a=bb; c=dd; e=ff";
+  CompareWithExpectedEncoding(headers);
+}
+
 TEST_P(HpackEncoderTest, MultiValuedHeadersNotCrumbled) {
   ExpectIndexedLiteral("foo", "bar, baz");
   Http2HeaderBlock headers;