Extract signed exchange contents from CBOR

This patch teaches SignedExchangeHandler to decode signed exchange
body encoded with the application/http-exchange+cbor format [1].

The test file origin-signed-response-iframe.htxg was created using
gen-signedexchange of [2] with the following command:

gen-signedexchange -uri https://example.com/test.html \
    -content test.html -o origin-signed-response-iframe.htxg \
    -miRecordSize=100

where test.html is the html part of origin-signed-response-iframe.php
before this patch.

[1] https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html#rfc.section.5
[2] https://github.com/WICG/webpackage/pull/119

Bug: 803774
Change-Id: I4d7bf5215e825cfa084c431db6d2cc87219d0a34
Reviewed-on: https://chromium-review.googlesource.com/897172
Commit-Queue: Kunihiko Sakamoto <ksakamoto@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534643}

content/browser/loader/signed_exchange_handler.h

@@ -11,51 +11,42 @@
 #include "base/optional.h"
 #include "mojo/public/cpp/system/data_pipe.h"
 #include "net/base/completion_callback.h"
-#include "net/filter/filter_source_stream.h"
 #include "net/ssl/ssl_info.h"
 #include "services/network/public/cpp/resource_response.h"
 #include "url/gurl.h"
 
+namespace net {
+class SourceStream;
+}
+
 namespace content {
 
-// IMPORTANT: Currenly SignedExchangeHandler doesn't implement any CBOR parsing
-// logic nor verifying logic. It just behaves as if the passed body is a signed
-// HTTP exchange which contains a request to "https://example.com/test.html" and
-// a response with a payload which is equal to the original body.
-// TODO(https://crbug.com/803774): Implement CBOR parsing logic and verifying
+// IMPORTANT: Currenly SignedExchangeHandler doesn't implement any verifying
 // logic.
-class SignedExchangeHandler final : public net::FilterSourceStream {
+// TODO(https://crbug.com/803774): Implement verifying logic.
+class SignedExchangeHandler final {
  public:
   // TODO(https://crbug.com/803774): Add verification status here.
   using ExchangeHeadersCallback =
-      base::OnceCallback<void(const GURL& request_url,
+      base::OnceCallback<void(net::Error error,
+                              const GURL& request_url,
                               const std::string& request_method,
                               const network::ResourceResponseHead&,
+                              std::unique_ptr<net::SourceStream> payload_stream,
                               base::Optional<net::SSLInfo>)>;
 
   // Once constructed |this| starts reading the |body| and parses the response
   // as a signed HTTP exchange. The response body of the exchange can be read
-  // from |this| as a net::SourceStream after |headers_callback| is called.
+  // from |payload_stream| passed to |headers_callback|.
   SignedExchangeHandler(std::unique_ptr<net::SourceStream> body,
                         ExchangeHeadersCallback headers_callback);
-  ~SignedExchangeHandler() override;
-
-  // net::FilterSourceStream:
-  int FilterData(net::IOBuffer* output_buffer,
-                 int output_buffer_size,
-                 net::IOBuffer* input_buffer,
-                 int input_buffer_size,
-                 int* consumed_bytes,
-                 bool upstream_eof_reached) override;
-  std::string GetTypeAsString() const override;
+  ~SignedExchangeHandler();
 
  private:
-  void DoHeaderLoop();
-  void DidReadForHeaders(bool completed_syncly, int result);
-  bool MaybeRunHeadersCallback();
-
-  // TODO(https://crbug.com/803774): Remove this.
-  void FillMockExchangeHeaders();
+  void ReadLoop();
+  void DidRead(bool completed_syncly, int result);
+  bool RunHeadersCallback();
+  void RunErrorCallback(net::Error);
 
   // Signed exchange contents.
   GURL request_url_;
@@ -64,16 +55,12 @@ class SignedExchangeHandler final : public net::FilterSourceStream {
   base::Optional<net::SSLInfo> ssl_info_;
 
   ExchangeHeadersCallback headers_callback_;
-
-  // Internal IOBuffer used during reading the header. Note that during parsing
-  // the header we don't really need the output buffer, but we still need to
-  // give some > 0 buffer.
-  scoped_refptr<net::IOBufferWithSize> header_out_buf_;
+  std::unique_ptr<net::SourceStream> source_;
 
   // TODO(https://crbug.cxom/803774): Just for now. Implement the streaming
   // parser.
+  scoped_refptr<net::IOBufferWithSize> read_buf_;
   std::string original_body_string_;
-  size_t body_string_offset_ = 0;
 
   base::WeakPtrFactory<SignedExchangeHandler> weak_factory_;
 

content/browser/loader/source_stream_to_data_pipe.cc

@@ -10,10 +10,10 @@
 namespace content {
 
 SourceStreamToDataPipe::SourceStreamToDataPipe(
-    net::SourceStream* source,
+    std::unique_ptr<net::SourceStream> source,
     mojo::ScopedDataPipeProducerHandle dest,
     base::OnceCallback<void(int)> completion_callback)
-    : source_(source),
+    : source_(std::move(source)),
       dest_(std::move(dest)),
       completion_callback_(std::move(completion_callback)),
       writable_handle_watcher_(FROM_HERE,

content/browser/loader/source_stream_to_data_pipe.h

@@ -22,9 +22,7 @@ namespace content {
 class SourceStreamToDataPipe {
  public:
   // Reads out the data from |source| and write into |dest|.
-  // Note that this does not take the ownership of |source|, the caller
-  // needs to take care that it is kept alive.
-  SourceStreamToDataPipe(net::SourceStream* source,
+  SourceStreamToDataPipe(std::unique_ptr<net::SourceStream> source,
                          mojo::ScopedDataPipeProducerHandle dest,
                          base::OnceCallback<void(int)> completion_callback);
   ~SourceStreamToDataPipe();
@@ -40,7 +38,7 @@ class SourceStreamToDataPipe {
   void OnDataPipeClosed(MojoResult result);
   void OnComplete(int result);
 
-  net::SourceStream* source_;  // Not owned.
+  std::unique_ptr<net::SourceStream> source_;
   mojo::ScopedDataPipeProducerHandle dest_;
   base::OnceCallback<void(int)> completion_callback_;
 

content/browser/loader/web_package_loader.cc

@@ -190,10 +190,18 @@ void WebPackageLoader::ConnectToClient(
 }
 
 void WebPackageLoader::OnHTTPExchangeFound(
+    net::Error error,
     const GURL& request_url,
     const std::string& request_method,
     const network::ResourceResponseHead& resource_response,
+    std::unique_ptr<net::SourceStream> payload_stream,
     base::Optional<net::SSLInfo> ssl_info) {
+  if (error) {
+    // This will eventually delete |this|.
+    client_->OnComplete(network::URLLoaderCompletionStatus(error));
+    return;
+  }
+
   // TODO(https://crbug.com/803774): Handle no-GET request_method as a error.
   DCHECK(original_response_timing_info_);
   forwarding_client_->OnReceiveRedirect(
@@ -213,7 +221,7 @@ void WebPackageLoader::OnHTTPExchangeFound(
   pending_body_consumer_ = std::move(data_pipe.consumer_handle);
 
   body_data_pipe_adapter_ = std::make_unique<SourceStreamToDataPipe>(
-      signed_exchange_handler_.get(), std::move(data_pipe.producer_handle),
+      std::move(payload_stream), std::move(data_pipe.producer_handle),
       base::BindOnce(&WebPackageLoader::FinishReadingBody,
                      base::Unretained(this)));
 

content/browser/loader/web_package_loader.h

@@ -13,6 +13,10 @@
 #include "services/network/public/cpp/net_adapters.h"
 #include "services/network/public/interfaces/url_loader.mojom.h"
 
+namespace net {
+class SourceStream;
+}  // namespace net
+
 namespace content {
 
 class SignedExchangeHandler;
@@ -66,9 +70,11 @@ class WebPackageLoader final : public network::mojom::URLLoaderClient,
   // Called from |signed_exchange_handler_| when it finds an origin-signed HTTP
   // exchange.
   void OnHTTPExchangeFound(
+      net::Error error,
       const GURL& request_url,
       const std::string& request_method,
       const network::ResourceResponseHead& resource_response,
+      std::unique_ptr<net::SourceStream> payload_stream,
       base::Optional<net::SSLInfo> ssl_info);
 
   void FinishReadingBody(int result);

third_party/WebKit/LayoutTests/http/tests/loading/htxg/origin-signed-response.html

@@ -26,8 +26,6 @@ promise_test(function(t) {
       return promise;
     })
     .then((event) => {
-      // TODO(https://crbug.com/80374): Currently this URL is hard coded in
-      // SignedExchangeHandler.
       assert_equals(event.data.location, 'https://example.com/test.html');
     });
 }, 'Location of origin-signed HTTP response');

third_party/WebKit/LayoutTests/http/tests/loading/htxg/resources/origin-signed-response-iframe.php

 <?php
+$fp = fopen("origin-signed-response-iframe.htxg", "rb");
 header('Content-Type: application/http-exchange+cbor');
+header("HTTP/1.0 200 OK");
+fpassthru($fp);
 ?>
-<!DOCTYPE html>
-<body>
-<script>
-window.addEventListener('message', (event) => {
-  event.data.port.postMessage({location: document.location.href});
-}, false);
-</script>
-hello<br>
-world
-</body>