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gecko-dev/toolkit/components/downloads/ApplicationReputation.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// See
// https://wiki.mozilla.org/Security/Features/Application_Reputation_Design_Doc
// for a description of Chrome's implementation of this feature.
#include "ApplicationReputation.h"
#include "csd.pb.h"
#include "nsIArray.h"
#include "nsIApplicationReputation.h"
#include "nsIChannel.h"
#include "nsIHttpChannel.h"
#include "nsIIOService.h"
#include "nsIPrefService.h"
#include "nsISimpleEnumerator.h"
#include "nsIStreamListener.h"
#include "nsIStringStream.h"
#include "nsITimer.h"
#include "nsIUploadChannel2.h"
#include "nsIURI.h"
#include "nsIURL.h"
#include "nsIUrlClassifierDBService.h"
#include "nsIX509Cert.h"
#include "nsIX509CertDB.h"
#include "nsIX509CertList.h"
#include "mozilla/BasePrincipal.h"
#include "mozilla/Preferences.h"
#include "mozilla/Services.h"
#include "mozilla/Telemetry.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/LoadContext.h"
#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "nsDebug.h"
#include "nsError.h"
#include "nsNetCID.h"
#include "nsReadableUtils.h"
#include "nsServiceManagerUtils.h"
#include "nsString.h"
#include "nsTArray.h"
#include "nsThreadUtils.h"
#include "nsXPCOMStrings.h"
#include "nsIContentPolicy.h"
#include "nsILoadInfo.h"
#include "nsContentUtils.h"
using mozilla::BasePrincipal;
using mozilla::OriginAttributes;
using mozilla::Preferences;
using mozilla::TimeStamp;
using mozilla::Telemetry::Accumulate;
using safe_browsing::ClientDownloadRequest;
using safe_browsing::ClientDownloadRequest_CertificateChain;
using safe_browsing::ClientDownloadRequest_Resource;
using safe_browsing::ClientDownloadRequest_SignatureInfo;
// Preferences that we need to initialize the query.
#define PREF_SB_APP_REP_URL "browser.safebrowsing.appRepURL"
#define PREF_SB_MALWARE_ENABLED "browser.safebrowsing.malware.enabled"
#define PREF_SB_DOWNLOADS_ENABLED "browser.safebrowsing.downloads.enabled"
#define PREF_SB_DOWNLOADS_REMOTE_ENABLED "browser.safebrowsing.downloads.remote.enabled"
#define PREF_SB_DOWNLOADS_REMOTE_TIMEOUT "browser.safebrowsing.downloads.remote.timeout_ms"
#define PREF_GENERAL_LOCALE "general.useragent.locale"
#define PREF_DOWNLOAD_BLOCK_TABLE "urlclassifier.downloadBlockTable"
#define PREF_DOWNLOAD_ALLOW_TABLE "urlclassifier.downloadAllowTable"
// NSPR_LOG_MODULES=ApplicationReputation:5
PRLogModuleInfo *ApplicationReputationService::prlog = nullptr;
#define LOG(args) MOZ_LOG(ApplicationReputationService::prlog, mozilla::LogLevel::Debug, args)
#define LOG_ENABLED() MOZ_LOG_TEST(ApplicationReputationService::prlog, mozilla::LogLevel::Debug)
class PendingDBLookup;
// A single use class private to ApplicationReputationService encapsulating an
// nsIApplicationReputationQuery and an nsIApplicationReputationCallback. Once
// created by ApplicationReputationService, it is guaranteed to call mCallback.
// This class is private to ApplicationReputationService.
class PendingLookup final : public nsIStreamListener,
public nsITimerCallback
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIREQUESTOBSERVER
NS_DECL_NSISTREAMLISTENER
NS_DECL_NSITIMERCALLBACK
// Constructor and destructor.
PendingLookup(nsIApplicationReputationQuery* aQuery,
nsIApplicationReputationCallback* aCallback);
// Start the lookup. The lookup may have 2 parts: local and remote. In the
// local lookup, PendingDBLookups are created to query the local allow and
// blocklists for various URIs associated with this downloaded file. In the
// event that no results are found, a remote lookup is sent to the Application
// Reputation server.
nsresult StartLookup();
private:
~PendingLookup();
friend class PendingDBLookup;
// Telemetry states.
// Status of the remote response (valid or not).
enum SERVER_RESPONSE_TYPES {
SERVER_RESPONSE_VALID = 0,
SERVER_RESPONSE_FAILED = 1,
SERVER_RESPONSE_INVALID = 2,
};
// Number of blocklist and allowlist hits we have seen.
uint32_t mBlocklistCount;
uint32_t mAllowlistCount;
// The query containing metadata about the downloaded file.
nsCOMPtr<nsIApplicationReputationQuery> mQuery;
// The callback with which to report the verdict.
nsCOMPtr<nsIApplicationReputationCallback> mCallback;
// An array of strings created from certificate information used to whitelist
// the downloaded file.
nsTArray<nsCString> mAllowlistSpecs;
// The source URI of the download, the referrer and possibly any redirects.
nsTArray<nsCString> mAnylistSpecs;
// When we started this query
TimeStamp mStartTime;
// The channel used to talk to the remote lookup server
nsCOMPtr<nsIChannel> mChannel;
// Timer to abort this lookup if it takes too long
nsCOMPtr<nsITimer> mTimeoutTimer;
// A protocol buffer for storing things we need in the remote request. We
// store the resource chain (redirect information) as well as signature
// information extracted using the Windows Authenticode API, if the binary is
// signed.
ClientDownloadRequest mRequest;
// The response from the application reputation query. This is read in chunks
// as part of our nsIStreamListener implementation and may contain embedded
// NULLs.
nsCString mResponse;
// Returns true if the file is likely to be binary.
bool IsBinaryFile();
// Returns the type of download binary for the file.
ClientDownloadRequest::DownloadType GetDownloadType(const nsAString& aFilename);
// Clean up and call the callback. PendingLookup must not be used after this
// function is called.
nsresult OnComplete(bool shouldBlock, nsresult rv);
// Wrapper function for nsIStreamListener.onStopRequest to make it easy to
// guarantee calling the callback
nsresult OnStopRequestInternal(nsIRequest *aRequest,
nsISupports *aContext,
nsresult aResult,
bool* aShouldBlock);
// Strip url parameters, fragments, and user@pass fields from the URI spec
// using nsIURL. If aURI is not an nsIURL, returns the original nsIURI.spec.
nsresult GetStrippedSpec(nsIURI* aUri, nsACString& spec);
// Escape '/' and '%' in certificate attribute values.
nsCString EscapeCertificateAttribute(const nsACString& aAttribute);
// Escape ':' in fingerprint values.
nsCString EscapeFingerprint(const nsACString& aAttribute);
// Generate whitelist strings for the given certificate pair from the same
// certificate chain.
nsresult GenerateWhitelistStringsForPair(
nsIX509Cert* certificate, nsIX509Cert* issuer);
// Generate whitelist strings for the given certificate chain, which starts
// with the signer and may go all the way to the root cert.
nsresult GenerateWhitelistStringsForChain(
const ClientDownloadRequest_CertificateChain& aChain);
// For signed binaries, generate strings of the form:
// http://sb-ssl.google.com/safebrowsing/csd/certificate/
// <issuer_cert_sha1_fingerprint>[/CN=<cn>][/O=<org>][/OU=<unit>]
// for each (cert, issuer) pair in each chain of certificates that is
// associated with the binary.
nsresult GenerateWhitelistStrings();
// Parse the XPCOM certificate lists and stick them into the protocol buffer
// version.
nsresult ParseCertificates(nsIArray* aSigArray);
// Adds the redirects to mAnylistSpecs to be looked up.
nsresult AddRedirects(nsIArray* aRedirects);
// Helper function to ensure that we call PendingLookup::LookupNext or
// PendingLookup::OnComplete.
nsresult DoLookupInternal();
// Looks up all the URIs that may be responsible for allowlisting or
// blocklisting the downloaded file. These URIs may include whitelist strings
// generated by certificates verifying the binary as well as the target URI
// from which the file was downloaded.
nsresult LookupNext();
// Sends a query to the remote application reputation service. Returns NS_OK
// on success.
nsresult SendRemoteQuery();
// Helper function to ensure that we always call the callback.
nsresult SendRemoteQueryInternal();
};
// A single-use class for looking up a single URI in the safebrowsing DB. This
// class is private to PendingLookup.
class PendingDBLookup final : public nsIUrlClassifierCallback
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIURLCLASSIFIERCALLBACK
// Constructor and destructor
explicit PendingDBLookup(PendingLookup* aPendingLookup);
// Look up the given URI in the safebrowsing DBs, optionally on both the allow
// list and the blocklist. If there is a match, call
// PendingLookup::OnComplete. Otherwise, call PendingLookup::LookupNext.
nsresult LookupSpec(const nsACString& aSpec, bool aAllowlistOnly);
private:
~PendingDBLookup();
// The download appeared on the allowlist, blocklist, or no list (and thus
// could trigger a remote query.
enum LIST_TYPES {
ALLOW_LIST = 0,
BLOCK_LIST = 1,
NO_LIST = 2,
};
nsCString mSpec;
bool mAllowlistOnly;
nsRefPtr<PendingLookup> mPendingLookup;
nsresult LookupSpecInternal(const nsACString& aSpec);
};
NS_IMPL_ISUPPORTS(PendingDBLookup,
nsIUrlClassifierCallback)
PendingDBLookup::PendingDBLookup(PendingLookup* aPendingLookup) :
mAllowlistOnly(false),
mPendingLookup(aPendingLookup)
{
LOG(("Created pending DB lookup [this = %p]", this));
}
PendingDBLookup::~PendingDBLookup()
{
LOG(("Destroying pending DB lookup [this = %p]", this));
mPendingLookup = nullptr;
}
nsresult
PendingDBLookup::LookupSpec(const nsACString& aSpec,
bool aAllowlistOnly)
{
LOG(("Checking principal %s [this=%p]", aSpec.Data(), this));
mSpec = aSpec;
mAllowlistOnly = aAllowlistOnly;
nsresult rv = LookupSpecInternal(aSpec);
if (NS_FAILED(rv)) {
LOG(("Error in LookupSpecInternal"));
return mPendingLookup->OnComplete(false, NS_OK);
}
// LookupSpecInternal has called nsIUrlClassifierCallback.lookup, which is
// guaranteed to call HandleEvent.
return rv;
}
nsresult
PendingDBLookup::LookupSpecInternal(const nsACString& aSpec)
{
nsresult rv;
nsCOMPtr<nsIURI> uri;
nsCOMPtr<nsIIOService> ios = do_GetService(NS_IOSERVICE_CONTRACTID, &rv);
rv = ios->NewURI(aSpec, nullptr, nullptr, getter_AddRefs(uri));
NS_ENSURE_SUCCESS(rv, rv);
OriginAttributes attrs;
nsCOMPtr<nsIPrincipal> principal =
BasePrincipal::CreateCodebasePrincipal(uri, attrs);
if (!principal) {
return NS_ERROR_FAILURE;
}
// Check local lists to see if the URI has already been whitelisted or
// blacklisted.
LOG(("Checking DB service for principal %s [this = %p]", mSpec.get(), this));
nsCOMPtr<nsIUrlClassifierDBService> dbService =
do_GetService(NS_URLCLASSIFIERDBSERVICE_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
nsAutoCString tables;
nsAutoCString allowlist;
Preferences::GetCString(PREF_DOWNLOAD_ALLOW_TABLE, &allowlist);
if (!allowlist.IsEmpty()) {
tables.Append(allowlist);
}
nsAutoCString blocklist;
Preferences::GetCString(PREF_DOWNLOAD_BLOCK_TABLE, &blocklist);
if (!mAllowlistOnly && !blocklist.IsEmpty()) {
tables.Append(',');
tables.Append(blocklist);
}
return dbService->Lookup(principal, tables, this);
}
NS_IMETHODIMP
PendingDBLookup::HandleEvent(const nsACString& tables)
{
// HandleEvent is guaranteed to call either:
// 1) PendingLookup::OnComplete if the URL matches the blocklist, or
// 2) PendingLookup::LookupNext if the URL does not match the blocklist.
// Blocklisting trumps allowlisting.
nsAutoCString blockList;
Preferences::GetCString(PREF_DOWNLOAD_BLOCK_TABLE, &blockList);
if (!mAllowlistOnly && FindInReadable(blockList, tables)) {
mPendingLookup->mBlocklistCount++;
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_LOCAL, BLOCK_LIST);
LOG(("Found principal %s on blocklist [this = %p]", mSpec.get(), this));
return mPendingLookup->OnComplete(true, NS_OK);
}
nsAutoCString allowList;
Preferences::GetCString(PREF_DOWNLOAD_ALLOW_TABLE, &allowList);
if (FindInReadable(allowList, tables)) {
mPendingLookup->mAllowlistCount++;
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_LOCAL, ALLOW_LIST);
LOG(("Found principal %s on allowlist [this = %p]", mSpec.get(), this));
// Don't call onComplete, since blocklisting trumps allowlisting
} else {
LOG(("Didn't find principal %s on any list [this = %p]", mSpec.get(),
this));
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_LOCAL, NO_LIST);
}
return mPendingLookup->LookupNext();
}
NS_IMPL_ISUPPORTS(PendingLookup,
nsIStreamListener,
nsIRequestObserver)
PendingLookup::PendingLookup(nsIApplicationReputationQuery* aQuery,
nsIApplicationReputationCallback* aCallback) :
mBlocklistCount(0),
mAllowlistCount(0),
mQuery(aQuery),
mCallback(aCallback)
{
LOG(("Created pending lookup [this = %p]", this));
}
PendingLookup::~PendingLookup()
{
LOG(("Destroying pending lookup [this = %p]", this));
}
bool
PendingLookup::IsBinaryFile()
{
nsString fileName;
nsresult rv = mQuery->GetSuggestedFileName(fileName);
if (NS_FAILED(rv)) {
LOG(("No suggested filename [this = %p]", this));
return false;
}
LOG(("Suggested filename: %s [this = %p]",
NS_ConvertUTF16toUTF8(fileName).get(), this));
return
// From https://code.google.com/p/chromium/codesearch#chromium/src/chrome/common/safe_browsing/download_protection_util.cc&l=14
// Archives _may_ contain binaries
#ifdef XP_WIN // disable on Mac/Linux, see 1167493
StringEndsWith(fileName, NS_LITERAL_STRING(".zip")) ||
#endif
// Android extensions
StringEndsWith(fileName, NS_LITERAL_STRING(".apk")) ||
// Windows extensions
StringEndsWith(fileName, NS_LITERAL_STRING(".bas")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".bat")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".cab")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".cmd")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".com")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".exe")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".hta")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".msi")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".pif")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".reg")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".scr")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".vb")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".vbs")) ||
// Mac extensions
StringEndsWith(fileName, NS_LITERAL_STRING(".app")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".dmg")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".osx")) ||
StringEndsWith(fileName, NS_LITERAL_STRING(".pkg"));
}
ClientDownloadRequest::DownloadType
PendingLookup::GetDownloadType(const nsAString& aFilename) {
MOZ_ASSERT(IsBinaryFile());
// From https://code.google.com/p/chromium/codesearch#chromium/src/chrome/common/safe_browsing/download_protection_util.cc&l=46
if (StringEndsWith(aFilename, NS_LITERAL_STRING(".zip"))) {
return ClientDownloadRequest::ZIPPED_EXECUTABLE;
} else if (StringEndsWith(aFilename, NS_LITERAL_STRING(".apk"))) {
return ClientDownloadRequest::ANDROID_APK;
} else if (StringEndsWith(aFilename, NS_LITERAL_STRING(".app")) ||
StringEndsWith(aFilename, NS_LITERAL_STRING(".dmg")) ||
StringEndsWith(aFilename, NS_LITERAL_STRING(".osx")) ||
StringEndsWith(aFilename, NS_LITERAL_STRING(".pkg"))) {
return ClientDownloadRequest::MAC_EXECUTABLE;
}
return ClientDownloadRequest::WIN_EXECUTABLE; // default to Windows binaries
}
nsresult
PendingLookup::LookupNext()
{
// We must call LookupNext or SendRemoteQuery upon return.
// Look up all of the URLs that could allow or block this download.
// Blocklist first.
if (mBlocklistCount > 0) {
return OnComplete(true, NS_OK);
}
int index = mAnylistSpecs.Length() - 1;
nsCString spec;
if (index >= 0) {
// Check the source URI, referrer and redirect chain.
spec = mAnylistSpecs[index];
mAnylistSpecs.RemoveElementAt(index);
nsRefPtr<PendingDBLookup> lookup(new PendingDBLookup(this));
return lookup->LookupSpec(spec, false);
}
// If any of mAnylistSpecs matched the blocklist, go ahead and block.
if (mBlocklistCount > 0) {
return OnComplete(true, NS_OK);
}
// If any of mAnylistSpecs matched the allowlist, go ahead and pass.
if (mAllowlistCount > 0) {
return OnComplete(false, NS_OK);
}
// Only binary signatures remain.
index = mAllowlistSpecs.Length() - 1;
if (index >= 0) {
spec = mAllowlistSpecs[index];
LOG(("PendingLookup::LookupNext: checking %s on allowlist", spec.get()));
mAllowlistSpecs.RemoveElementAt(index);
nsRefPtr<PendingDBLookup> lookup(new PendingDBLookup(this));
return lookup->LookupSpec(spec, true);
}
// There are no more URIs to check against local list. If the file is
// not eligible for remote lookup, bail.
if (!IsBinaryFile()) {
LOG(("Not eligible for remote lookups [this=%x]", this));
return OnComplete(false, NS_OK);
}
nsresult rv = SendRemoteQuery();
if (NS_FAILED(rv)) {
return OnComplete(false, rv);
}
return NS_OK;
}
nsCString
PendingLookup::EscapeCertificateAttribute(const nsACString& aAttribute)
{
// Escape '/' because it's a field separator, and '%' because Chrome does
nsCString escaped;
escaped.SetCapacity(aAttribute.Length());
for (unsigned int i = 0; i < aAttribute.Length(); ++i) {
if (aAttribute.Data()[i] == '%') {
escaped.AppendLiteral("%25");
} else if (aAttribute.Data()[i] == '/') {
escaped.AppendLiteral("%2F");
} else if (aAttribute.Data()[i] == ' ') {
escaped.AppendLiteral("%20");
} else {
escaped.Append(aAttribute.Data()[i]);
}
}
return escaped;
}
nsCString
PendingLookup::EscapeFingerprint(const nsACString& aFingerprint)
{
// Google's fingerprint doesn't have colons
nsCString escaped;
escaped.SetCapacity(aFingerprint.Length());
for (unsigned int i = 0; i < aFingerprint.Length(); ++i) {
if (aFingerprint.Data()[i] != ':') {
escaped.Append(aFingerprint.Data()[i]);
}
}
return escaped;
}
nsresult
PendingLookup::GenerateWhitelistStringsForPair(
nsIX509Cert* certificate,
nsIX509Cert* issuer)
{
// The whitelist paths have format:
// http://sb-ssl.google.com/safebrowsing/csd/certificate/<issuer_cert_fingerprint>[/CN=<cn>][/O=<org>][/OU=<unit>]
// Any of CN, O, or OU may be omitted from the whitelist entry. Unfortunately
// this is not publicly documented, but the Chrome implementation can be found
// here:
// https://code.google.com/p/chromium/codesearch#search/&q=GetCertificateWhitelistStrings
nsCString whitelistString(
"http://sb-ssl.google.com/safebrowsing/csd/certificate/");
nsString fingerprint;
nsresult rv = issuer->GetSha1Fingerprint(fingerprint);
NS_ENSURE_SUCCESS(rv, rv);
whitelistString.Append(
EscapeFingerprint(NS_ConvertUTF16toUTF8(fingerprint)));
nsString commonName;
rv = certificate->GetCommonName(commonName);
NS_ENSURE_SUCCESS(rv, rv);
if (!commonName.IsEmpty()) {
whitelistString.AppendLiteral("/CN=");
whitelistString.Append(
EscapeCertificateAttribute(NS_ConvertUTF16toUTF8(commonName)));
}
nsString organization;
rv = certificate->GetOrganization(organization);
NS_ENSURE_SUCCESS(rv, rv);
if (!organization.IsEmpty()) {
whitelistString.AppendLiteral("/O=");
whitelistString.Append(
EscapeCertificateAttribute(NS_ConvertUTF16toUTF8(organization)));
}
nsString organizationalUnit;
rv = certificate->GetOrganizationalUnit(organizationalUnit);
NS_ENSURE_SUCCESS(rv, rv);
if (!organizationalUnit.IsEmpty()) {
whitelistString.AppendLiteral("/OU=");
whitelistString.Append(
EscapeCertificateAttribute(NS_ConvertUTF16toUTF8(organizationalUnit)));
}
LOG(("Whitelisting %s", whitelistString.get()));
mAllowlistSpecs.AppendElement(whitelistString);
return NS_OK;
}
nsresult
PendingLookup::GenerateWhitelistStringsForChain(
const safe_browsing::ClientDownloadRequest_CertificateChain& aChain)
{
// We need a signing certificate and an issuer to construct a whitelist
// entry.
if (aChain.element_size() < 2) {
return NS_OK;
}
// Get the signer.
nsresult rv;
nsCOMPtr<nsIX509CertDB> certDB = do_GetService(NS_X509CERTDB_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIX509Cert> signer;
rv = certDB->ConstructX509(
const_cast<char *>(aChain.element(0).certificate().data()),
aChain.element(0).certificate().size(), getter_AddRefs(signer));
NS_ENSURE_SUCCESS(rv, rv);
for (int i = 1; i < aChain.element_size(); ++i) {
// Get the issuer.
nsCOMPtr<nsIX509Cert> issuer;
rv = certDB->ConstructX509(
const_cast<char *>(aChain.element(i).certificate().data()),
aChain.element(i).certificate().size(), getter_AddRefs(issuer));
NS_ENSURE_SUCCESS(rv, rv);
nsresult rv = GenerateWhitelistStringsForPair(signer, issuer);
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
nsresult
PendingLookup::GenerateWhitelistStrings()
{
for (int i = 0; i < mRequest.signature().certificate_chain_size(); ++i) {
nsresult rv = GenerateWhitelistStringsForChain(
mRequest.signature().certificate_chain(i));
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
nsresult
PendingLookup::AddRedirects(nsIArray* aRedirects)
{
uint32_t length = 0;
aRedirects->GetLength(&length);
LOG(("ApplicationReputation: Got %u redirects", length));
nsCOMPtr<nsISimpleEnumerator> iter;
nsresult rv = aRedirects->Enumerate(getter_AddRefs(iter));
NS_ENSURE_SUCCESS(rv, rv);
bool hasMoreRedirects = false;
rv = iter->HasMoreElements(&hasMoreRedirects);
NS_ENSURE_SUCCESS(rv, rv);
while (hasMoreRedirects) {
nsCOMPtr<nsISupports> supports;
rv = iter->GetNext(getter_AddRefs(supports));
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIPrincipal> principal = do_QueryInterface(supports, &rv);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIURI> uri;
rv = principal->GetURI(getter_AddRefs(uri));
NS_ENSURE_SUCCESS(rv, rv);
// Add the spec to our list of local lookups. The most recent redirect is
// the last element.
nsCString spec;
rv = GetStrippedSpec(uri, spec);
NS_ENSURE_SUCCESS(rv, rv);
mAnylistSpecs.AppendElement(spec);
LOG(("ApplicationReputation: Appending redirect %s\n", spec.get()));
// Store the redirect information in the remote request.
ClientDownloadRequest_Resource* resource = mRequest.add_resources();
resource->set_url(spec.get());
resource->set_type(ClientDownloadRequest::DOWNLOAD_REDIRECT);
rv = iter->HasMoreElements(&hasMoreRedirects);
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
nsresult
PendingLookup::StartLookup()
{
mStartTime = TimeStamp::Now();
nsresult rv = DoLookupInternal();
if (NS_FAILED(rv)) {
return OnComplete(false, NS_OK);
};
return rv;
}
nsresult
PendingLookup::GetStrippedSpec(nsIURI* aUri, nsACString& escaped)
{
// If aURI is not an nsIURL, we do not want to check the lists or send a
// remote query.
nsresult rv;
nsCOMPtr<nsIURL> url = do_QueryInterface(aUri, &rv);
NS_ENSURE_SUCCESS(rv, rv);
rv = url->GetScheme(escaped);
NS_ENSURE_SUCCESS(rv, rv);
nsCString temp;
rv = url->GetHostPort(temp);
NS_ENSURE_SUCCESS(rv, rv);
escaped.Append("://");
escaped.Append(temp);
rv = url->GetFilePath(temp);
NS_ENSURE_SUCCESS(rv, rv);
// nsIUrl.filePath starts with '/'
escaped.Append(temp);
return NS_OK;
}
nsresult
PendingLookup::DoLookupInternal()
{
// We want to check the target URI, its referrer, and associated redirects
// against the local lists.
nsCOMPtr<nsIURI> uri;
nsresult rv = mQuery->GetSourceURI(getter_AddRefs(uri));
NS_ENSURE_SUCCESS(rv, rv);
nsCString spec;
rv = GetStrippedSpec(uri, spec);
NS_ENSURE_SUCCESS(rv, rv);
mAnylistSpecs.AppendElement(spec);
ClientDownloadRequest_Resource* resource = mRequest.add_resources();
resource->set_url(spec.get());
resource->set_type(ClientDownloadRequest::DOWNLOAD_URL);
nsCOMPtr<nsIURI> referrer = nullptr;
rv = mQuery->GetReferrerURI(getter_AddRefs(referrer));
if (referrer) {
nsCString spec;
rv = GetStrippedSpec(referrer, spec);
NS_ENSURE_SUCCESS(rv, rv);
mAnylistSpecs.AppendElement(spec);
resource->set_referrer(spec.get());
}
nsCOMPtr<nsIArray> redirects;
rv = mQuery->GetRedirects(getter_AddRefs(redirects));
if (redirects) {
AddRedirects(redirects);
} else {
LOG(("ApplicationReputation: Got no redirects [this=%p]", this));
}
// Extract the signature and parse certificates so we can use it to check
// whitelists.
nsCOMPtr<nsIArray> sigArray;
rv = mQuery->GetSignatureInfo(getter_AddRefs(sigArray));
NS_ENSURE_SUCCESS(rv, rv);
if (sigArray) {
rv = ParseCertificates(sigArray);
NS_ENSURE_SUCCESS(rv, rv);
}
rv = GenerateWhitelistStrings();
NS_ENSURE_SUCCESS(rv, rv);
// Start the call chain.
return LookupNext();
}
nsresult
PendingLookup::OnComplete(bool shouldBlock, nsresult rv)
{
if (mTimeoutTimer) {
mTimeoutTimer->Cancel();
mTimeoutTimer = nullptr;
}
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SHOULD_BLOCK,
shouldBlock);
double t = (TimeStamp::Now() - mStartTime).ToMilliseconds();
if (shouldBlock) {
LOG(("Application Reputation check failed, blocking bad binary in %f ms "
"[this = %p]", t, this));
} else {
LOG(("Application Reputation check passed in %f ms [this = %p]", t, this));
}
nsresult res = mCallback->OnComplete(shouldBlock, rv);
return res;
}
nsresult
PendingLookup::ParseCertificates(nsIArray* aSigArray)
{
// If we haven't been set for any reason, bail.
NS_ENSURE_ARG_POINTER(aSigArray);
// Binaries may be signed by multiple chains of certificates. If there are no
// chains, the binary is unsigned (or we were unable to extract signature
// information on a non-Windows platform)
nsCOMPtr<nsISimpleEnumerator> chains;
nsresult rv = aSigArray->Enumerate(getter_AddRefs(chains));
NS_ENSURE_SUCCESS(rv, rv);
bool hasMoreChains = false;
rv = chains->HasMoreElements(&hasMoreChains);
NS_ENSURE_SUCCESS(rv, rv);
while (hasMoreChains) {
nsCOMPtr<nsISupports> supports;
rv = chains->GetNext(getter_AddRefs(supports));
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIX509CertList> certList = do_QueryInterface(supports, &rv);
NS_ENSURE_SUCCESS(rv, rv);
safe_browsing::ClientDownloadRequest_CertificateChain* certChain =
mRequest.mutable_signature()->add_certificate_chain();
nsCOMPtr<nsISimpleEnumerator> chainElt;
rv = certList->GetEnumerator(getter_AddRefs(chainElt));
NS_ENSURE_SUCCESS(rv, rv);
// Each chain may have multiple certificates.
bool hasMoreCerts = false;
rv = chainElt->HasMoreElements(&hasMoreCerts);
while (hasMoreCerts) {
nsCOMPtr<nsISupports> supports;
rv = chainElt->GetNext(getter_AddRefs(supports));
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIX509Cert> cert = do_QueryInterface(supports, &rv);
NS_ENSURE_SUCCESS(rv, rv);
uint8_t* data = nullptr;
uint32_t len = 0;
rv = cert->GetRawDER(&len, &data);
NS_ENSURE_SUCCESS(rv, rv);
// Add this certificate to the protobuf to send remotely.
certChain->add_element()->set_certificate(data, len);
free(data);
rv = chainElt->HasMoreElements(&hasMoreCerts);
NS_ENSURE_SUCCESS(rv, rv);
}
rv = chains->HasMoreElements(&hasMoreChains);
NS_ENSURE_SUCCESS(rv, rv);
}
if (mRequest.signature().certificate_chain_size() > 0) {
mRequest.mutable_signature()->set_trusted(true);
}
return NS_OK;
}
nsresult
PendingLookup::SendRemoteQuery()
{
nsresult rv = SendRemoteQueryInternal();
if (NS_FAILED(rv)) {
LOG(("Failed sending remote query for application reputation "
"[this = %p]", this));
return OnComplete(false, rv);
}
// SendRemoteQueryInternal has fired off the query and we call OnComplete in
// the nsIStreamListener.onStopRequest.
return rv;
}
nsresult
PendingLookup::SendRemoteQueryInternal()
{
// If we aren't supposed to do remote lookups, bail.
if (!Preferences::GetBool(PREF_SB_DOWNLOADS_REMOTE_ENABLED, false)) {
LOG(("Remote lookups are disabled [this = %p]", this));
return NS_ERROR_NOT_AVAILABLE;
}
// If the remote lookup URL is empty or absent, bail.
nsCString serviceUrl;
NS_ENSURE_SUCCESS(Preferences::GetCString(PREF_SB_APP_REP_URL, &serviceUrl),
NS_ERROR_NOT_AVAILABLE);
if (serviceUrl.EqualsLiteral("")) {
LOG(("Remote lookup URL is empty [this = %p]", this));
return NS_ERROR_NOT_AVAILABLE;
}
// If the blocklist or allowlist is empty (so we couldn't do local lookups),
// bail
nsCString table;
NS_ENSURE_SUCCESS(Preferences::GetCString(PREF_DOWNLOAD_BLOCK_TABLE, &table),
NS_ERROR_NOT_AVAILABLE);
if (table.EqualsLiteral("")) {
LOG(("Blocklist is empty [this = %p]", this));
return NS_ERROR_NOT_AVAILABLE;
}
#ifdef XP_WIN
// The allowlist is only needed to do signature verification on Windows
NS_ENSURE_SUCCESS(Preferences::GetCString(PREF_DOWNLOAD_ALLOW_TABLE, &table),
NS_ERROR_NOT_AVAILABLE);
if (table.EqualsLiteral("")) {
LOG(("Allowlist is empty [this = %p]", this));
return NS_ERROR_NOT_AVAILABLE;
}
#endif
LOG(("Sending remote query for application reputation [this = %p]",
this));
// We did not find a local result, so fire off the query to the
// application reputation service.
nsCOMPtr<nsIURI> uri;
nsresult rv;
rv = mQuery->GetSourceURI(getter_AddRefs(uri));
NS_ENSURE_SUCCESS(rv, rv);
nsCString spec;
rv = GetStrippedSpec(uri, spec);
NS_ENSURE_SUCCESS(rv, rv);
mRequest.set_url(spec.get());
uint32_t fileSize;
rv = mQuery->GetFileSize(&fileSize);
NS_ENSURE_SUCCESS(rv, rv);
mRequest.set_length(fileSize);
// We have no way of knowing whether or not a user initiated the
// download. Set it to true to lessen the chance of false positives.
mRequest.set_user_initiated(true);
nsCString locale;
NS_ENSURE_SUCCESS(Preferences::GetCString(PREF_GENERAL_LOCALE, &locale),
NS_ERROR_NOT_AVAILABLE);
mRequest.set_locale(locale.get());
nsCString sha256Hash;
rv = mQuery->GetSha256Hash(sha256Hash);
NS_ENSURE_SUCCESS(rv, rv);
mRequest.mutable_digests()->set_sha256(sha256Hash.Data());
nsString fileName;
rv = mQuery->GetSuggestedFileName(fileName);
NS_ENSURE_SUCCESS(rv, rv);
mRequest.set_file_basename(NS_ConvertUTF16toUTF8(fileName).get());
mRequest.set_download_type(GetDownloadType(fileName));
if (mRequest.signature().trusted()) {
LOG(("Got signed binary for remote application reputation check "
"[this = %p]", this));
} else {
LOG(("Got unsigned binary for remote application reputation check "
"[this = %p]", this));
}
// Serialize the protocol buffer to a string. This can only fail if we are
// out of memory, or if the protocol buffer req is missing required fields
// (only the URL for now).
std::string serialized;
if (!mRequest.SerializeToString(&serialized)) {
return NS_ERROR_UNEXPECTED;
}
LOG(("Serialized protocol buffer [this = %p]: (length=%d) %s", this,
serialized.length(), serialized.c_str()));
// Set the input stream to the serialized protocol buffer
nsCOMPtr<nsIStringInputStream> sstream =
do_CreateInstance("@mozilla.org/io/string-input-stream;1", &rv);
NS_ENSURE_SUCCESS(rv, rv);
rv = sstream->SetData(serialized.c_str(), serialized.length());
NS_ENSURE_SUCCESS(rv, rv);
// Set up the channel to transmit the request to the service.
nsCOMPtr<nsIIOService> ios = do_GetService(NS_IOSERVICE_CONTRACTID, &rv);
rv = ios->NewChannel2(serviceUrl,
nullptr,
nullptr,
nullptr, // aLoadingNode
nsContentUtils::GetSystemPrincipal(),
nullptr, // aTriggeringPrincipal
nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
nsIContentPolicy::TYPE_OTHER,
getter_AddRefs(mChannel));
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(mChannel, &rv));
NS_ENSURE_SUCCESS(rv, rv);
// Upload the protobuf to the application reputation service.
nsCOMPtr<nsIUploadChannel2> uploadChannel = do_QueryInterface(mChannel, &rv);
NS_ENSURE_SUCCESS(rv, rv);
rv = uploadChannel->ExplicitSetUploadStream(sstream,
NS_LITERAL_CSTRING("application/octet-stream"), serialized.size(),
NS_LITERAL_CSTRING("POST"), false);
NS_ENSURE_SUCCESS(rv, rv);
// Set the Safebrowsing cookie jar, so that the regular Google cookie is not
// sent with this request. See bug 897516.
nsCOMPtr<nsIInterfaceRequestor> loadContext =
new mozilla::LoadContext(NECKO_SAFEBROWSING_APP_ID);
rv = mChannel->SetNotificationCallbacks(loadContext);
NS_ENSURE_SUCCESS(rv, rv);
uint32_t timeoutMs = Preferences::GetUint(PREF_SB_DOWNLOADS_REMOTE_TIMEOUT, 10000);
mTimeoutTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
mTimeoutTimer->InitWithCallback(this, timeoutMs, nsITimer::TYPE_ONE_SHOT);
rv = mChannel->AsyncOpen2(this);
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
NS_IMETHODIMP
PendingLookup::Notify(nsITimer* aTimer)
{
LOG(("Remote lookup timed out [this = %p]", this));
MOZ_ASSERT(aTimer == mTimeoutTimer);
mChannel->Cancel(NS_ERROR_NET_TIMEOUT);
mTimeoutTimer->Cancel();
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
//// nsIStreamListener
static NS_METHOD
AppendSegmentToString(nsIInputStream* inputStream,
void *closure,
const char *rawSegment,
uint32_t toOffset,
uint32_t count,
uint32_t *writeCount) {
nsAutoCString* decodedData = static_cast<nsAutoCString*>(closure);
decodedData->Append(rawSegment, count);
*writeCount = count;
return NS_OK;
}
NS_IMETHODIMP
PendingLookup::OnDataAvailable(nsIRequest *aRequest,
nsISupports *aContext,
nsIInputStream *aStream,
uint64_t offset,
uint32_t count) {
uint32_t read;
return aStream->ReadSegments(AppendSegmentToString, &mResponse, count, &read);
}
NS_IMETHODIMP
PendingLookup::OnStartRequest(nsIRequest *aRequest,
nsISupports *aContext) {
return NS_OK;
}
NS_IMETHODIMP
PendingLookup::OnStopRequest(nsIRequest *aRequest,
nsISupports *aContext,
nsresult aResult) {
NS_ENSURE_STATE(mCallback);
bool shouldBlock = false;
nsresult rv = OnStopRequestInternal(aRequest, aContext, aResult,
&shouldBlock);
OnComplete(shouldBlock, rv);
return rv;
}
nsresult
PendingLookup::OnStopRequestInternal(nsIRequest *aRequest,
nsISupports *aContext,
nsresult aResult,
bool* aShouldBlock) {
if (NS_FAILED(aResult)) {
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SERVER,
SERVER_RESPONSE_FAILED);
return aResult;
}
*aShouldBlock = false;
nsresult rv;
nsCOMPtr<nsIHttpChannel> channel = do_QueryInterface(aRequest, &rv);
if (NS_FAILED(rv)) {
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SERVER,
SERVER_RESPONSE_FAILED);
return rv;
}
uint32_t status = 0;
rv = channel->GetResponseStatus(&status);
if (NS_FAILED(rv)) {
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SERVER,
SERVER_RESPONSE_FAILED);
return rv;
}
if (status != 200) {
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SERVER,
SERVER_RESPONSE_FAILED);
return NS_ERROR_NOT_AVAILABLE;
}
std::string buf(mResponse.Data(), mResponse.Length());
safe_browsing::ClientDownloadResponse response;
if (!response.ParseFromString(buf)) {
LOG(("Invalid protocol buffer response [this = %p]: %s", this, buf.c_str()));
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SERVER,
SERVER_RESPONSE_INVALID);
return NS_ERROR_CANNOT_CONVERT_DATA;
}
// There are several more verdicts, but we only respect DANGEROUS and
// DANGEROUS_HOST for now and treat everything else as SAFE.
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SERVER,
SERVER_RESPONSE_VALID);
// Clamp responses 0-7, we only know about 0-4 for now.
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SERVER_VERDICT,
std::min<uint32_t>(response.verdict(), 7));
switch(response.verdict()) {
case safe_browsing::ClientDownloadResponse::DANGEROUS:
case safe_browsing::ClientDownloadResponse::DANGEROUS_HOST:
*aShouldBlock = true;
break;
default:
break;
}
return NS_OK;
}
NS_IMPL_ISUPPORTS(ApplicationReputationService,
nsIApplicationReputationService)
ApplicationReputationService*
ApplicationReputationService::gApplicationReputationService = nullptr;
ApplicationReputationService*
ApplicationReputationService::GetSingleton()
{
if (gApplicationReputationService) {
NS_ADDREF(gApplicationReputationService);
return gApplicationReputationService;
}
// We're not initialized yet.
gApplicationReputationService = new ApplicationReputationService();
if (gApplicationReputationService) {
NS_ADDREF(gApplicationReputationService);
}
return gApplicationReputationService;
}
ApplicationReputationService::ApplicationReputationService()
{
if (!prlog) {
prlog = PR_NewLogModule("ApplicationReputation");
}
LOG(("Application reputation service started up"));
}
ApplicationReputationService::~ApplicationReputationService() {
LOG(("Application reputation service shutting down"));
}
NS_IMETHODIMP
ApplicationReputationService::QueryReputation(
nsIApplicationReputationQuery* aQuery,
nsIApplicationReputationCallback* aCallback) {
LOG(("Starting application reputation check [query=%p]", aQuery));
NS_ENSURE_ARG_POINTER(aQuery);
NS_ENSURE_ARG_POINTER(aCallback);
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_COUNT, true);
nsresult rv = QueryReputationInternal(aQuery, aCallback);
if (NS_FAILED(rv)) {
Accumulate(mozilla::Telemetry::APPLICATION_REPUTATION_SHOULD_BLOCK,
false);
aCallback->OnComplete(false, rv);
}
return NS_OK;
}
nsresult ApplicationReputationService::QueryReputationInternal(
nsIApplicationReputationQuery* aQuery,
nsIApplicationReputationCallback* aCallback) {
nsresult rv;
// If malware checks aren't enabled, don't query application reputation.
if (!Preferences::GetBool(PREF_SB_MALWARE_ENABLED, false)) {
return NS_ERROR_NOT_AVAILABLE;
}
if (!Preferences::GetBool(PREF_SB_DOWNLOADS_ENABLED, false)) {
return NS_ERROR_NOT_AVAILABLE;
}
nsCOMPtr<nsIURI> uri;
rv = aQuery->GetSourceURI(getter_AddRefs(uri));
NS_ENSURE_SUCCESS(rv, rv);
// Bail if the URI hasn't been set.
NS_ENSURE_STATE(uri);
// Create a new pending lookup and start the call chain.
nsRefPtr<PendingLookup> lookup(new PendingLookup(aQuery, aCallback));
NS_ENSURE_STATE(lookup);
return lookup->StartLookup();
}
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