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// Copyright (c) 2011 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 "chrome/browser/safe_browsing/download_protection_service.h"
#include "base/bind.h"
#include "base/memory/scoped_ptr.h"
#include "base/metrics/histogram.h"
#include "base/stl_util.h"
#include "chrome/browser/safe_browsing/safe_browsing_service.h"
#include "chrome/common/net/http_return.h"
#include "chrome/common/safe_browsing/csd.pb.h"
#include "content/browser/browser_thread.h"
#include "content/public/common/url_fetcher.h"
#include "net/base/load_flags.h"
#include "net/url_request/url_request_context_getter.h"
#include "net/url_request/url_request_status.h"
namespace safe_browsing {
const char DownloadProtectionService::kDownloadRequestUrl[] =
"https://sb-ssl.google.com/safebrowsing/clientreport/download";
DownloadProtectionService::DownloadInfo::DownloadInfo()
: total_bytes(0), user_initiated(false) {}
DownloadProtectionService::DownloadInfo::~DownloadInfo() {}
DownloadProtectionService::DownloadProtectionService(
SafeBrowsingService* sb_service,
net::URLRequestContextGetter* request_context_getter)
: sb_service_(sb_service),
request_context_getter_(request_context_getter),
enabled_(false) {}
DownloadProtectionService::~DownloadProtectionService() {
STLDeleteContainerPairFirstPointers(download_requests_.begin(),
download_requests_.end());
download_requests_.clear();
}
void DownloadProtectionService::SetEnabled(bool enabled) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
BrowserThread::PostTask(
BrowserThread::IO,
FROM_HERE,
base::Bind(&DownloadProtectionService::SetEnabledOnIOThread,
this, enabled));
}
void DownloadProtectionService::SetEnabledOnIOThread(bool enabled) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
if (enabled == enabled_) {
return;
}
enabled_ = enabled;
if (!enabled_) {
for (DownloadRequests::iterator it = download_requests_.begin();
it != download_requests_.end(); ++it) {
it->second.Run(SAFE);
}
STLDeleteContainerPairFirstPointers(download_requests_.begin(),
download_requests_.end());
download_requests_.clear();
}
}
void DownloadProtectionService::OnURLFetchComplete(
const content::URLFetcher* source) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
scoped_ptr<const content::URLFetcher> s(source);
if (download_requests_.find(source) != download_requests_.end()) {
CheckDownloadCallback callback = download_requests_[source];
download_requests_.erase(source);
if (!enabled_) {
// SafeBrowsing got disabled. We can't do anything. Note: the request
// object will be deleted.
RecordStats(REASON_SB_DISABLED);
return;
}
DownloadCheckResultReason reason = REASON_MAX;
reason = REASON_SERVER_PING_FAILED;
if (source->GetStatus().is_success() &&
RC_REQUEST_OK == source->GetResponseCode()) {
std::string data;
source->GetResponseAsString(&data);
if (data.size() > 0) {
// For now no matter what we'll always say the download is safe.
// TODO(noelutz): Parse the response body to see exactly what's going
// on.
reason = REASON_INVALID_RESPONSE_PROTO;
}
}
BrowserThread::PostTask(
BrowserThread::UI,
FROM_HERE,
base::Bind(&DownloadProtectionService::EndCheckClientDownload,
this, SAFE, reason, callback));
} else {
NOTREACHED();
}
}
bool DownloadProtectionService::CheckClientDownload(
const DownloadInfo& info,
const CheckDownloadCallback& callback) {
// TODO(noelutz): implement some cache to make sure we don't issue the same
// request over and over again if a user downloads the same binary multiple
// times.
if (info.download_url_chain.empty()) {
RecordStats(REASON_INVALID_URL);
return true;
}
const GURL& final_url = info.download_url_chain.back();
if (!final_url.is_valid() || final_url.is_empty() ||
!final_url.SchemeIs("http")) {
RecordStats(REASON_INVALID_URL);
return true; // For now we only support HTTP download URLs.
}
// TODO(noelutz): DownloadInfo should also contain the IP address of every
// URL in the redirect chain. We also should check whether the download URL
// is hosted on the internal network.
BrowserThread::PostTask(
BrowserThread::IO,
FROM_HERE,
base::Bind(&DownloadProtectionService::StartCheckClientDownload,
this, info, callback));
return false;
}
void DownloadProtectionService::StartCheckClientDownload(
const DownloadInfo& info,
const CheckDownloadCallback& callback) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
if (!enabled_ || !sb_service_.get()) {
// This is a hard fail. We won't even call the callback in this case.
RecordStats(REASON_SB_DISABLED);
return;
}
DownloadCheckResultReason reason = REASON_MAX;
for (size_t i = 0; i < info.download_url_chain.size(); ++i) {
if (sb_service_->MatchDownloadWhitelistUrl(info.download_url_chain[i])) {
reason = REASON_WHITELISTED_URL;
break;
}
}
if (sb_service_->MatchDownloadWhitelistUrl(info.referrer_url)) {
reason = REASON_WHITELISTED_REFERRER;
}
// TODO(noelutz): check signature and CA against whitelist.
ClientDownloadRequest request;
request.set_url(info.download_url_chain.back().spec());
request.mutable_digests()->set_sha256(info.sha256_hash);
request.set_length(info.total_bytes);
for (size_t i = 0; i < info.download_url_chain.size(); ++i) {
ClientDownloadRequest::Resource* resource = request.add_resources();
resource->set_url(info.download_url_chain[i].spec());
if (i == info.download_url_chain.size() - 1) {
// The last URL in the chain is the download URL.
resource->set_type(ClientDownloadRequest::DOWNLOAD_URL);
resource->set_referrer(info.referrer_url.spec());
} else {
resource->set_type(ClientDownloadRequest::DOWNLOAD_REDIRECT);
}
// TODO(noelutz): fill out the remote IP addresses.
}
request.set_user_initiated(info.user_initiated);
std::string request_data;
if (!request.SerializeToString(&request_data)) {
reason = REASON_INVALID_REQUEST_PROTO;
}
if (reason != REASON_MAX) {
// We stop here because the download is considered safe.
BrowserThread::PostTask(
BrowserThread::UI,
FROM_HERE,
base::Bind(&DownloadProtectionService::EndCheckClientDownload,
this, SAFE, reason, callback));
return;
}
content::URLFetcher* fetcher = content::URLFetcher::Create(
0 /* ID used for testing */, GURL(kDownloadRequestUrl),
content::URLFetcher::POST, this);
download_requests_[fetcher] = callback;
fetcher->SetLoadFlags(net::LOAD_DISABLE_CACHE);
fetcher->SetRequestContext(request_context_getter_.get());
fetcher->SetUploadData("application/octet-stream", request_data);
fetcher->Start();
}
void DownloadProtectionService::EndCheckClientDownload(
DownloadCheckResult result,
DownloadCheckResultReason reason,
const CheckDownloadCallback& callback) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
RecordStats(reason);
callback.Run(result);
}
void DownloadProtectionService::RecordStats(DownloadCheckResultReason reason) {
UMA_HISTOGRAM_ENUMERATION("SBClientDownload.CheckDownloadStats",
reason,
REASON_MAX);
}
} // namespace safe_browsing
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