Add AffiliationFetcher to fetch authoritative affiliation information regarding facets.

components/password_manager/core/browser/affiliation_fetcher.cc

+// Copyright 2014 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/password_manager/core/browser/affiliation_fetcher.h"
+
+#include "components/password_manager/core/browser/affiliation_api.pb.h"
+#include "components/password_manager/core/browser/affiliation_utils.h"
+#include "google_apis/google_api_keys.h"
+#include "net/base/load_flags.h"
+#include "net/base/url_util.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "url/gurl.h"
+
+namespace password_manager {
+
+AffiliationFetcher::AffiliationFetcher(
+    net::URLRequestContextGetter* request_context_getter,
+    const std::vector<FacetURI>& facet_uris,
+    AffiliationFetcherDelegate* delegate)
+    : request_context_getter_(request_context_getter),
+      requested_facet_uris_(facet_uris),
+      delegate_(delegate) {
+  for (const FacetURI& uri : requested_facet_uris_) {
+    DCHECK(uri.is_valid());
+  }
+}
+
+AffiliationFetcher::~AffiliationFetcher() {
+}
+
+// static
+AffiliationFetcher* AffiliationFetcher::Create(
+    net::URLRequestContextGetter* context_getter,
+    const std::vector<FacetURI>& facet_uris,
+    AffiliationFetcherDelegate* delegate) {
+  return new AffiliationFetcher(context_getter, facet_uris, delegate);
+}
+
+void AffiliationFetcher::StartRequest() {
+  DCHECK(!fetcher_);
+
+  fetcher_.reset(
+      net::URLFetcher::Create(BuildQueryURL(), net::URLFetcher::POST, this));
+  fetcher_->SetRequestContext(request_context_getter_.get());
+  fetcher_->SetUploadData("application/x-protobuf", PreparePayload());
+  fetcher_->SetLoadFlags(
+      net::LOAD_DO_NOT_SAVE_COOKIES | net::LOAD_DO_NOT_SEND_COOKIES |
+      net::LOAD_DO_NOT_SEND_AUTH_DATA | net::LOAD_BYPASS_CACHE |
+      net::LOAD_DISABLE_CACHE | net::LOAD_DO_NOT_PROMPT_FOR_LOGIN);
+  fetcher_->SetAutomaticallyRetryOn5xx(false);
+  fetcher_->SetAutomaticallyRetryOnNetworkChanges(0);
+  fetcher_->Start();
+}
+
+GURL AffiliationFetcher::BuildQueryURL() const {
+  return net::AppendQueryParameter(
+      GURL("https://www.googleapis.com/affiliation/v1/affiliation:lookup"),
+      "key", google_apis::GetAPIKey());
+}
+
+std::string AffiliationFetcher::PreparePayload() const {
+  affiliation_pb::LookupAffiliationRequest lookup_request;
+  for (const FacetURI& uri : requested_facet_uris_)
+    lookup_request.add_facet(uri.canonical_spec());
+
+  std::string serialized_request;
+  bool success = lookup_request.SerializeToString(&serialized_request);
+  DCHECK(success);
+  return serialized_request;
+}
+
+bool AffiliationFetcher::ParseResponse(
+    AffiliationFetcherDelegate::Result* result) const {
+  // This function parses the response protocol buffer message for a list of
+  // equivalence classes, and stores them into |results| after performing some
+  // validation and sanitization steps to make sure that the contract of
+  // AffiliationFetcherDelegate is fulfilled. Possible discrepancies are:
+  //   * The server response will not have anything for facets that are not
+  //     affiliated with any other facet, while |result| must have them.
+  //   * The server response might contain future, unknown kinds of facet URIs,
+  //     while |result| must contain only those that are FacetURI::is_valid().
+  //   * The server response being ill-formed or self-inconsistent (in the sense
+  //     that there are overlapping equivalence classes) is indicative of server
+  //     side issues likely not remedied by re-fetching. Report failure in this
+  //     case so the caller can be notified and it can act accordingly.
+  //   * The |result| will be free of duplicate or empty equivalence classes.
+
+  std::string serialized_response;
+  if (!fetcher_->GetResponseAsString(&serialized_response)) {
+    NOTREACHED();
+  }
+
+  affiliation_pb::LookupAffiliationResponse response;
+  if (!response.ParseFromString(serialized_response))
+    return false;
+
+  result->reserve(requested_facet_uris_.size());
+
+  std::map<FacetURI, size_t> facet_uri_to_class_index;
+  for (int i = 0; i < response.affiliation_size(); ++i) {
+    const affiliation_pb::Affiliation& equivalence_class(
+        response.affiliation(i));
+
+    AffiliatedFacets affiliated_uris;
+    for (int j = 0; j < equivalence_class.facet_size(); ++j) {
+      const std::string& uri_spec(equivalence_class.facet(j));
+      FacetURI uri = FacetURI::FromPotentiallyInvalidSpec(uri_spec);
+      // Ignore potential future kinds of facet URIs (e.g. for new platforms).
+      if (!uri.is_valid())
+        continue;
+      affiliated_uris.push_back(uri);
+    }
+
+    // Be lenient and ignore empty (after filtering) equivalence classes.
+    if (affiliated_uris.empty())
+      continue;
+
+    // Ignore equivalence classes that are duplicates of earlier ones. However,
+    // fail in the case of a partial overlap, which violates the invariant that
+    // affiliations must form an equivalence relation.
+    for (const FacetURI& uri : affiliated_uris) {
+      if (!facet_uri_to_class_index.count(uri))
+        facet_uri_to_class_index[uri] = result->size();
+      if (facet_uri_to_class_index[uri] !=
+          facet_uri_to_class_index[affiliated_uris[0]]) {
+        return false;
+      }
+    }
+
+    // Filter out duplicate equivalence classes in the response.
+    if (facet_uri_to_class_index[affiliated_uris[0]] == result->size())
+      result->push_back(affiliated_uris);
+  }
+
+  // Synthesize an equivalence class (of size one) for each facet that did not
+  // appear in the server response due to not being affiliated with any others.
+  for (const FacetURI& uri : requested_facet_uris_) {
+    if (!facet_uri_to_class_index.count(uri))
+      result->push_back(AffiliatedFacets(1, uri));
+  }
+
+  return true;
+}
+
+void AffiliationFetcher::OnURLFetchComplete(const net::URLFetcher* source) {
+  DCHECK_EQ(source, fetcher_.get());
+
+  scoped_ptr<AffiliationFetcherDelegate::Result> result(
+      new AffiliationFetcherDelegate::Result);
+  if (fetcher_->GetStatus().status() == net::URLRequestStatus::SUCCESS &&
+      fetcher_->GetResponseCode() == net::HTTP_OK) {
+    if (ParseResponse(result.get()))
+      delegate_->OnFetchSucceeded(result.Pass());
+    else
+      delegate_->OnMalformedResponse();
+  } else {
+    delegate_->OnFetchFailed();
+  }
+}
+
+}  // namespace password_manager