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// Copyright (c) 2013 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.
#ifndef CHROMEOS_CERT_LOADER_H_
#define CHROMEOS_CERT_LOADER_H_
#include <string>
#include <vector>
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/threading/thread_checker.h"
#include "chromeos/chromeos_export.h"
#include "net/cert/x509_certificate.h"
namespace net {
class NSSCertDatabase;
typedef std::vector<scoped_refptr<X509Certificate> > CertificateList;
}
namespace chromeos {
// This class is responsible for loading certificates once the TPM is
// initialized. It is expected to be constructed on the UI thread and public
// methods should all be called from the UI thread.
// When certificates have been loaded (after login completes and tpm token is
// initialized), or the cert database changes, observers are called with
// OnCertificatesLoaded().
// This class supports using one or two cert databases. The expected usage is
// that CertLoader is used with a NSSCertDatabase backed by the system token
// before user sign-in, and additionally with a user-specific NSSCertDatabase
// after user sign-in. When both NSSCertDatabase are used, CertLoader combines
// certificates from both into |all_certs()|.
class CHROMEOS_EXPORT CertLoader {
public:
class Observer {
public:
// Called when the certificates, passed for convenience as |all_certs|,
// have completed loading. |initial_load| is true the first time this
// is called. It will be false if this is called because another slot has
// been added to CertLoader's data sources.
virtual void OnCertificatesLoaded(const net::CertificateList& all_certs,
bool initial_load) = 0;
protected:
virtual ~Observer() {}
};
// Sets the global instance. Must be called before any calls to Get().
static void Initialize();
// Destroys the global instance.
static void Shutdown();
// Gets the global instance. Initialize() must be called first.
static CertLoader* Get();
// Returns true if the global instance has been initialized.
static bool IsInitialized();
// Returns the PKCS#11 attribute CKA_ID for a certificate as an upper-case
// hex string and sets |slot_id| to the id of the containing slot, or returns
// an empty string and doesn't modify |slot_id| if the PKCS#11 id could not be
// determined.
static std::string GetPkcs11IdAndSlotForCert(const net::X509Certificate& cert,
int* slot_id);
// Sets the NSS cert database which CertLoader should use to access system
// slot certificates. The CertLoader will _not_ take ownership of the database
// - see comment on SetUserNSSDB. CertLoader supports working with only one
// database or with both (system and user) databases.
void SetSystemNSSDB(net::NSSCertDatabase* system_slot_database);
// Sets the NSS cert database which CertLoader should use to access user slot
// certificates. CertLoader understands the edge case that this database could
// also give access to system slot certificates (e.g. for affiliated users).
// The CertLoader will _not_ take the ownership of the database, but it
// expects it to stay alive at least until the shutdown starts on the main
// thread. This assumes that SetUserNSSDB and other methods directly using
// |database_| are not called during shutdown. CertLoader supports working
// with only one database or with both (system and user) databases.
void SetUserNSSDB(net::NSSCertDatabase* user_database);
void AddObserver(CertLoader::Observer* observer);
void RemoveObserver(CertLoader::Observer* observer);
// Returns true if |cert| is hardware backed. See also
// ForceHardwareBackedForTesting().
static bool IsCertificateHardwareBacked(const net::X509Certificate* cert);
// Returns true when the certificate list has been requested but not loaded.
// When two databases are in use (SetSystemNSSDB and SetUserNSSDB have both
// been called), this returns true when at least one of them is currently
// loading certificates.
// Note that this method poses an exception in the CertLoader interface:
// While most of CertLoader's interface treats the initial load of a second
// database the same way as an update in the first database, this method does
// not. The reason is that it's targeted at displaying a message in the GUI,
// so the user knows that (more) certificates will be available soon.
bool initial_load_of_any_database_running() const;
// Returns true if any certificates have been loaded. If CertLoader uses a
// system and a user NSS database, this returns true after the certificates
// from the first (usually system) database have been loaded.
bool initial_load_finished() const;
// Returns all certificates. This will be empty until certificates_loaded() is
// true.
const net::CertificateList& all_certs() const {
DCHECK(thread_checker_.CalledOnValidThread());
return all_certs_;
}
// Returns certificates from the system token. This will be empty until
// certificates_loaded() is true.
const net::CertificateList& system_certs() const {
DCHECK(thread_checker_.CalledOnValidThread());
return system_certs_;
}
// Called in tests if |IsCertificateHardwareBacked()| should always return
// true.
static void ForceHardwareBackedForTesting();
private:
class CertCache;
CertLoader();
~CertLoader();
// Called by |system_cert_cache_| or |user_cert_cache| when these had an
// update.
void CacheUpdated();
// Called if a certificate load task is finished.
void UpdateCertificates(net::CertificateList all_certs,
net::CertificateList system_certs);
void NotifyCertificatesLoaded(bool initial_load);
// True if the initial load of CertLoader is still pending. This is used to
// set the |initial_load| parameter when calling Observers.
bool pending_initial_load_;
base::ObserverList<Observer> observers_;
// Cache for certificates from the system-token NSSCertDatabase.
std::unique_ptr<CertCache> system_cert_cache_;
// Cache for certificates from the user-specific NSSCertDatabase.
std::unique_ptr<CertCache> user_cert_cache_;
// Cached certificates loaded from the database(s).
net::CertificateList all_certs_;
// Cached certificates from system token.
net::CertificateList system_certs_;
base::ThreadChecker thread_checker_;
base::WeakPtrFactory<CertLoader> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(CertLoader);
};
} // namespace chromeos
#endif // CHROMEOS_CERT_LOADER_H_