chromeos/cert_loader.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chromeos/cert_loader.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/location.h"
  11 #include "base/message_loop/message_loop_proxy.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/task_runner_util.h"
  14 #include "base/threading/worker_pool.h"
  15 #include "crypto/nss_util.h"
  16 #include "crypto/scoped_nss_types.h"
  17 #include "net/cert/nss_cert_database.h"
  18 #include "net/cert/nss_cert_database_chromeos.h"
  19 #include "net/cert/x509_certificate.h"
  20
  21 namespace chromeos {
  22
  23 static CertLoader* g_cert_loader = NULL;
  24
  25 // static
  26 void CertLoader::Initialize() {
  27   CHECK(!g_cert_loader);
  28   g_cert_loader = new CertLoader();
  29 }
  30
  31 // static
  32 void CertLoader::Shutdown() {
  33   CHECK(g_cert_loader);
  34   delete g_cert_loader;
  35   g_cert_loader = NULL;
  36 }
  37
  38 // static
  39 CertLoader* CertLoader::Get() {
  40   CHECK(g_cert_loader) << "CertLoader::Get() called before Initialize()";
  41   return g_cert_loader;
  42 }
  43
  44 // static
  45 bool CertLoader::IsInitialized() {
  46   return g_cert_loader;
  47 }
  48
  49 CertLoader::CertLoader()
  50     : certificates_loaded_(false),
  51       certificates_update_required_(false),
  52       certificates_update_running_(false),
  53       database_(NULL),
  54       force_hardware_backed_for_test_(false),
  55       cert_list_(new net::CertificateList),
  56       weak_factory_(this) {
  57 }
  58
  59 CertLoader::~CertLoader() {
  60   net::CertDatabase::GetInstance()->RemoveObserver(this);
  61 }
  62
  63 void CertLoader::StartWithNSSDB(net::NSSCertDatabase* database) {
  64   CHECK(!database_);
  65   database_ = database;
  66
  67   // Start observing cert database for changes.
  68   // Observing net::CertDatabase is preferred over observing |database_|
  69   // directly, as |database_| observers receive only events generated directly
  70   // by |database_|, so they may miss a few relevant ones.
  71   // TODO(tbarzic): Once singleton NSSCertDatabase is removed, investigate if
  72   // it would be OK to observe |database_| directly; or change NSSCertDatabase
  73   // to send notification on all relevant changes.
  74   net::CertDatabase::GetInstance()->AddObserver(this);
  75
  76   LoadCertificates();
  77 }
  78
  79 void CertLoader::AddObserver(CertLoader::Observer* observer) {
  80   observers_.AddObserver(observer);
  81 }
  82
  83 void CertLoader::RemoveObserver(CertLoader::Observer* observer) {
  84   observers_.RemoveObserver(observer);
  85 }
  86
  87 int CertLoader::TPMTokenSlotID() const {
  88   if (!database_)
  89     return -1;
  90   crypto::ScopedPK11Slot slot(database_->GetPrivateSlot());
  91   if (!slot)
  92     return -1;
  93   return static_cast<int>(PK11_GetSlotID(slot.get()));
  94 }
  95
  96 bool CertLoader::IsHardwareBacked() const {
  97   if (force_hardware_backed_for_test_)
  98     return true;
  99   if (!database_)
 100     return false;
 101   crypto::ScopedPK11Slot slot(database_->GetPrivateSlot());
 102   if (!slot)
 103     return false;
 104   return PK11_IsHW(slot.get());
 105 }
 106
 107 bool CertLoader::IsCertificateHardwareBacked(
 108     const net::X509Certificate* cert) const {
 109   if (!database_)
 110     return false;
 111   return database_->IsHardwareBacked(cert);
 112 }
 113
 114 bool CertLoader::CertificatesLoading() const {
 115   return database_ && !certificates_loaded_;
 116 }
 117
 118 // static
 119 //
 120 // For background see this discussion on dev-tech-crypto.lists.mozilla.org:
 121 // http://web.archiveorange.com/archive/v/6JJW7E40sypfZGtbkzxX
 122 //
 123 // NOTE: This function relies on the convention that the same PKCS#11 ID
 124 // is shared between a certificate and its associated private and public
 125 // keys.  I tried to implement this with PK11_GetLowLevelKeyIDForCert(),
 126 // but that always returns NULL on Chrome OS for me.
 127 std::string CertLoader::GetPkcs11IdForCert(const net::X509Certificate& cert) {
 128   CERTCertificateStr* cert_handle = cert.os_cert_handle();
 129   SECKEYPrivateKey *priv_key =
 130       PK11_FindKeyByAnyCert(cert_handle, NULL /* wincx */);
 131   if (!priv_key)
 132     return std::string();
 133
 134   // Get the CKA_ID attribute for a key.
 135   SECItem* sec_item = PK11_GetLowLevelKeyIDForPrivateKey(priv_key);
 136   std::string pkcs11_id;
 137   if (sec_item) {
 138     pkcs11_id = base::HexEncode(sec_item->data, sec_item->len);
 139     SECITEM_FreeItem(sec_item, PR_TRUE);
 140   }
 141   SECKEY_DestroyPrivateKey(priv_key);
 142
 143   return pkcs11_id;
 144 }
 145
 146 void CertLoader::LoadCertificates() {
 147   CHECK(thread_checker_.CalledOnValidThread());
 148   VLOG(1) << "LoadCertificates: " << certificates_update_running_;
 149
 150   if (certificates_update_running_) {
 151     certificates_update_required_ = true;
 152     return;
 153   }
 154
 155   certificates_update_running_ = true;
 156   certificates_update_required_ = false;
 157
 158   database_->ListCerts(
 159       base::Bind(&CertLoader::UpdateCertificates, weak_factory_.GetWeakPtr()));
 160 }
 161
 162 void CertLoader::UpdateCertificates(
 163     scoped_ptr<net::CertificateList> cert_list) {
 164   CHECK(thread_checker_.CalledOnValidThread());
 165   DCHECK(certificates_update_running_);
 166   VLOG(1) << "UpdateCertificates: " << cert_list->size();
 167
 168   // Ignore any existing certificates.
 169   cert_list_ = cert_list.Pass();
 170
 171   bool initial_load = !certificates_loaded_;
 172   certificates_loaded_ = true;
 173   NotifyCertificatesLoaded(initial_load);
 174
 175   certificates_update_running_ = false;
 176   if (certificates_update_required_)
 177     LoadCertificates();
 178 }
 179
 180 void CertLoader::NotifyCertificatesLoaded(bool initial_load) {
 181   FOR_EACH_OBSERVER(Observer, observers_,
 182                     OnCertificatesLoaded(*cert_list_, initial_load));
 183 }
 184
 185 void CertLoader::OnCACertChanged(const net::X509Certificate* cert) {
 186   // This is triggered when a CA certificate is modified.
 187   VLOG(1) << "OnCACertChanged";
 188   LoadCertificates();
 189 }
 190
 191 void CertLoader::OnCertAdded(const net::X509Certificate* cert) {
 192   // This is triggered when a client certificate is added.
 193   VLOG(1) << "OnCertAdded";
 194   LoadCertificates();
 195 }
 196
 197 void CertLoader::OnCertRemoved(const net::X509Certificate* cert) {
 198   VLOG(1) << "OnCertRemoved";
 199   LoadCertificates();
 200 }
 201
 202 }  // namespace chromeos