Certificate Transparency: Fetching of Signed Tree Heads (DRAFT)

components/certificate_transparency/log_proof_fetcher_unittest.cc

Index: components/certificate_transparency/log_proof_fetcher_unittest.cc
diff --git a/components/certificate_transparency/log_proof_fetcher_unittest.cc b/components/certificate_transparency/log_proof_fetcher_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..945325e533fc157ce3bbb3dd483af535da8524e7
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+++ b/components/certificate_transparency/log_proof_fetcher_unittest.cc
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+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/certificate_transparency/log_proof_fetcher.h"
+
+#include <string>
+
+#include "base/strings/stringprintf.h"
+#include "components/safe_json/testing_json_parser.h"
+#include "net/base/net_errors.h"
+#include "net/base/network_delegate.h"
+#include "net/cert/signed_tree_head.h"
+#include "net/http/http_status_code.h"
+#include "net/test/ct_test_util.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_filter.h"
+#include "net/url_request/url_request_interceptor.h"
+#include "net/url_request/url_request_job.h"
+#include "net/url_request/url_request_test_job.h"
+#include "net/url_request/url_request_test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace certificate_transparency {
+
+namespace {
+
+const char kGetSTHHeaders[] =
+    "HTTP/1.1 200 OK\0"
+    "Content-Type: application/json; charset=ISO-8859-1\0";
+
+const char kGetSTHNotFoundHeaders[] =
+    "HTTP/1.1 404 Not Found\0"
+    "Content-Type: text/html; charset=iso-8859-1\0";
+
+const char kLogSchema[] = "https";
+const char kLogHost[] = "ct.log.example.com";
+const char kLogPathPrefix[] = "somelog";
+const char kLogID[] = "some_id";
+
+class FetchSTHTestJob : public net::URLRequestTestJob {
+ public:
+  FetchSTHTestJob(const std::string& get_sth_data,
+                  const std::string& get_sth_headers,
+                  net::URLRequest* request,
+                  net::NetworkDelegate* network_delegate)
+      : URLRequestTestJob(request,
+                          network_delegate,
+                          get_sth_headers,
+                          get_sth_data,
+                          true),
+        async_io_(false) {}
+
+  void set_async_io(bool async_io) { async_io_ = async_io; }
+
+ private:
+  ~FetchSTHTestJob() override {}
+
+  bool NextReadAsync() override {
+    // Response with indication of async IO only once, otherwise the final
+    // Read would (incorrectly) be classified as async, causing the
+    // URLRequestJob to try reading another time and failing on a CHECK
+    // that the raw_read_buffer_ is not null.
+    // According to mmenke@, this is a bug in the URLRequestTestJob code.
+    // TODO(eranm): Once said bug is fixed, switch most tests to using async
+    // IO.
+    if (async_io_) {
+      async_io_ = false;
+      return true;
+    }
+    return false;
+  }
+
+  bool async_io_;
+
+  DISALLOW_COPY_AND_ASSIGN(FetchSTHTestJob);
+};
+
+class GetSTHResponseHandler : public net::URLRequestInterceptor {
+ public:
+  GetSTHResponseHandler()
+      : async_io_(false),
+        response_body_(""),
+        response_headers_(
+            std::string(kGetSTHHeaders, arraysize(kGetSTHHeaders))) {}
+  ~GetSTHResponseHandler() override {}
+
+  // URLRequestInterceptor implementation:
+  net::URLRequestJob* MaybeInterceptRequest(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate) const override {
+    std::string expected_url = base::StringPrintf(
+        "%s://%s/%s/ct/v1/get-sth", kLogSchema, kLogHost, kLogPathPrefix);
+    EXPECT_EQ(GURL(expected_url), request->url());
+    FetchSTHTestJob* job = new FetchSTHTestJob(
+        response_body_, response_headers_, request, network_delegate);
+    job->set_async_io(async_io_);
+    return job;
+  }
+
+  void set_response_body(std::string response_body) {
+    response_body_ = response_body;
+  }
+
+  void set_response_headers(std::string response_headers) {
+    response_headers_ = response_headers;
+  }
+
+  void set_async_io(bool async_io) { async_io_ = async_io; }
+
+ private:
+  bool async_io_;
+  std::string response_body_;
+  std::string response_headers_;
+
+  DISALLOW_COPY_AND_ASSIGN(GetSTHResponseHandler);
+};
+
+class RecordFetchCallbackInvocations {
+ public:
+  RecordFetchCallbackInvocations(bool expect_success)
+      : expect_success_(expect_success),
+        invoked_(false),
+        net_error_(net::OK),
+        http_response_code_(-1) {}
+
+  void STHFetched(const std::string& log_id,
+                  const net::ct::SignedTreeHead& sth) {
+    ASSERT_TRUE(expect_success_);
+    ASSERT_FALSE(invoked_);
+    invoked_ = true;
+    // If expected to succeed, expecting the known_good STH.
+    net::ct::SignedTreeHead expected_sth;
+    net::ct::GetSampleSignedTreeHead(&expected_sth);
+
+    EXPECT_EQ(kLogID, log_id);
+    EXPECT_EQ(expected_sth.version, sth.version);
+    EXPECT_EQ(expected_sth.timestamp, sth.timestamp);
+    EXPECT_EQ(expected_sth.tree_size, sth.tree_size);
+    EXPECT_STREQ(expected_sth.sha256_root_hash, sth.sha256_root_hash);
+    EXPECT_EQ(expected_sth.signature.hash_algorithm,
+              sth.signature.hash_algorithm);
+    EXPECT_EQ(expected_sth.signature.signature_algorithm,
+              sth.signature.signature_algorithm);
+    EXPECT_EQ(expected_sth.signature.signature_data,
+              sth.signature.signature_data);
+  }
+
+  void FetchingFailed(const std::string& log_id,
+                      int net_error,
+                      int http_response_code) {
+    ASSERT_FALSE(expect_success_);
+    ASSERT_FALSE(invoked_);
+    invoked_ = true;
+    net_error_ = net_error;
+    http_response_code_ = http_response_code;
+    if (net_error_ == net::OK) {
+      EXPECT_NE(net::HTTP_OK, http_response_code_);
+    }
+  }
+
+  bool invoked() const { return invoked_; }
+
+  int net_error() const { return net_error_; }
+
+  int http_response_code() const { return http_response_code_; }
+
+ private:
+  const bool expect_success_;
+  bool invoked_;
+  int net_error_;
+  int http_response_code_;
+};
+
+class LogProofFetcherTest : public ::testing::Test {
+ public:
+  LogProofFetcherTest()
+      : log_url_(base::StringPrintf("%s://%s/%s/",
+                                    kLogSchema,
+                                    kLogHost,
+                                    kLogPathPrefix)) {
+    scoped_ptr<GetSTHResponseHandler> handler(new GetSTHResponseHandler());
+    handler_ = handler.get();
+
+    net::URLRequestFilter::GetInstance()->AddHostnameInterceptor(
+        kLogSchema, kLogHost, handler.Pass());
+
+    fetcher_.reset(new LogProofFetcher(&context_));
+  }
+
+  ~LogProofFetcherTest() override {
+    net::URLRequestFilter::GetInstance()->RemoveHostnameHandler(kLogSchema,
+                                                                kLogHost);
+  }
+
+ protected:
+  void SetValidSTHJSONResponse() {
+    std::string sth_json_reply_data = net::ct::GetSampleSTHAsJson();
+    handler_->set_response_body(sth_json_reply_data);
+  }
+
+  void RunFetcherWithCallback(RecordFetchCallbackInvocations* callback) {
+    fetcher_->FetchSignedTreeHead(
+        log_url_, kLogID,
+        base::Bind(&RecordFetchCallbackInvocations::STHFetched,
+                   base::Unretained(callback)),
+        base::Bind(&RecordFetchCallbackInvocations::FetchingFailed,
+                   base::Unretained(callback)));
+    message_loop_.RunUntilIdle();
+  }
+
+  base::MessageLoopForIO message_loop_;
+  net::TestURLRequestContext context_;
+  safe_json::TestingJsonParser::ScopedFactoryOverride factory_override_;
+  scoped_ptr<LogProofFetcher> fetcher_;
+  const GURL log_url_;
+  GetSTHResponseHandler* handler_;
+};
+
+TEST_F(LogProofFetcherTest, TestValidGetReply) {
+  SetValidSTHJSONResponse();
+
+  RecordFetchCallbackInvocations callback(true);
+
+  RunFetcherWithCallback(&callback);
+
+  ASSERT_TRUE(callback.invoked());
+}
+
+TEST_F(LogProofFetcherTest, TestValidGetReplyAsyncIO) {
+  SetValidSTHJSONResponse();
+  handler_->set_async_io(true);
+
+  RecordFetchCallbackInvocations callback(true);
+  RunFetcherWithCallback(&callback);
+
+  ASSERT_TRUE(callback.invoked());
+}
+
+TEST_F(LogProofFetcherTest, TestInvalidGetReplyIncompleteJSON) {
+  std::string sth_json_reply_data = net::ct::CreateSignedTreeHeadJsonString(
+      21 /* tree_size */, 123456u /* timestamp */, std::string(),
+      std::string());
+  handler_->set_response_body(sth_json_reply_data);
+
+  RecordFetchCallbackInvocations callback(false);
+  RunFetcherWithCallback(&callback);
+
+  ASSERT_TRUE(callback.invoked());
+  EXPECT_EQ(net::ERR_CT_STH_INCOMPLETE, callback.net_error());
+}
+
+TEST_F(LogProofFetcherTest, TestInvalidGetReplyInvalidJSON) {
+  std::string sth_json_reply_data = "{\"tree_size\":21,\"timestamp\":}";
+  handler_->set_response_body(sth_json_reply_data);
+
+  RecordFetchCallbackInvocations callback(false);
+  RunFetcherWithCallback(&callback);
+
+  ASSERT_TRUE(callback.invoked());
+  EXPECT_EQ(net::ERR_CT_STH_PARSING_FAILED, callback.net_error());
+}
+
+TEST_F(LogProofFetcherTest, TestLogReplyIsTooLong) {
+  std::string sth_json_reply_data = net::ct::GetSampleSTHAsJson();
+  // Add kMaxLogResponseSizeInBytes to make sure the response is too big.
+  sth_json_reply_data.append(
+      std::string(LogProofFetcher::kMaxLogResponseSizeInBytes, ' '));
+  handler_->set_response_body(sth_json_reply_data);
+
+  RecordFetchCallbackInvocations callback(false);
+  RunFetcherWithCallback(&callback);
+
+  ASSERT_TRUE(callback.invoked());
+  EXPECT_EQ(net::ERR_FILE_TOO_BIG, callback.net_error());
+  EXPECT_EQ(net::HTTP_OK, callback.http_response_code());
+}
+
+TEST_F(LogProofFetcherTest, TestLogReplyIsExactlyMaxSize) {
+  std::string sth_json_reply_data = net::ct::GetSampleSTHAsJson();
+  // Extend the reply to be exactly kMaxLogResponseSizeInBytes.
+  sth_json_reply_data.append(std::string(
+      LogProofFetcher::kMaxLogResponseSizeInBytes - sth_json_reply_data.size(),
+      ' '));
+  handler_->set_response_body(sth_json_reply_data);
+
+  RecordFetchCallbackInvocations callback(true);
+  RunFetcherWithCallback(&callback);
+
+  ASSERT_TRUE(callback.invoked());
+}
+
+TEST_F(LogProofFetcherTest, TestLogRepliesWithHttpError) {
+  handler_->set_response_headers(
+      std::string(kGetSTHNotFoundHeaders, arraysize(kGetSTHNotFoundHeaders)));
+
+  RecordFetchCallbackInvocations callback(false);
+  RunFetcherWithCallback(&callback);
+
+  ASSERT_TRUE(callback.invoked());
+  EXPECT_EQ(net::OK, callback.net_error());
+  EXPECT_EQ(net::HTTP_NOT_FOUND, callback.http_response_code());
+}
+
+}  // namespace
+
+}  // namespace certificate_transparency