chromeos/tpm_token_info_getter.h

   1 // Copyright 2014 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 #ifndef CHROMEOS_TPM_TOKEN_INFO_GETTER_H_
   6 #define CHROMEOS_TPM_TOKEN_INFO_GETTER_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/time/time.h"
  14 #include "chromeos/chromeos_export.h"
  15 #include "chromeos/dbus/dbus_method_call_status.h"
  16
  17 namespace base {
  18 class TaskRunner;
  19 }
  20
  21 namespace chromeos {
  22 class CryptohomeClient;
  23 }
  24
  25 namespace chromeos {
  26
  27 // Information retrieved from cryptohome by TPMTokenInfoGetter.
  28 struct TPMTokenInfo {
  29   // Default constructor creates token info for disabled TPM.
  30   TPMTokenInfo();
  31   ~TPMTokenInfo();
  32
  33   bool tpm_is_enabled;
  34   std::string token_name;
  35   std::string user_pin;
  36   int token_slot_id;
  37 };
  38
  39 // Class for getting a user or the system TPM token info from cryptohome during
  40 // TPM token loading.
  41 class CHROMEOS_EXPORT TPMTokenInfoGetter {
  42  public:
  43   using TPMTokenInfoCallback = base::Callback<void(const TPMTokenInfo& info)>;
  44
  45   // Factory method for TPMTokenInfoGetter for a user token.
  46   static scoped_ptr<TPMTokenInfoGetter> CreateForUserToken(
  47       const std::string& user_id,
  48       CryptohomeClient* cryptohome_client,
  49       const scoped_refptr<base::TaskRunner>& delayed_task_runner);
  50
  51   // Factory method for TPMTokenGetter for the system token.
  52   static scoped_ptr<TPMTokenInfoGetter> CreateForSystemToken(
  53       CryptohomeClient* cryptohome_client,
  54       const scoped_refptr<base::TaskRunner>& delayed_task_runner);
  55
  56   ~TPMTokenInfoGetter();
  57
  58   // Starts getting TPM token info. Should be called at most once.
  59   // |callback| will be called when all the info is fetched.
  60   // The object may get deleted before |callback| is called, which is equivalent
  61   // to cancelling the info getting (in which case |callback| will never get
  62   // called).
  63   void Start(const TPMTokenInfoCallback& callback);
  64
  65  private:
  66   enum Type {
  67     TYPE_SYSTEM,
  68     TYPE_USER
  69   };
  70
  71   enum State {
  72     STATE_INITIAL,
  73     STATE_STARTED,
  74     STATE_TPM_ENABLED,
  75     STATE_DONE
  76   };
  77
  78   TPMTokenInfoGetter(
  79       Type type,
  80       const std::string& user_id,
  81       CryptohomeClient* cryptohome_client,
  82       const scoped_refptr<base::TaskRunner>& delayed_task_runner);
  83
  84   // Continues TPM token info getting procedure by starting the task associated
  85   // with the current TPMTokenInfoGetter state.
  86   void Continue();
  87
  88   // If token initialization step fails (e.g. if tpm token is not yet ready)
  89   // schedules the initialization step retry attempt after a timeout.
  90   void RetryLater();
  91
  92   // Cryptohome methods callbacks.
  93   void OnTpmIsEnabled(DBusMethodCallStatus call_status,
  94                       bool tpm_is_enabled);
  95   void OnPkcs11GetTpmTokenInfo(DBusMethodCallStatus call_status,
  96                                const std::string& token_name,
  97                                const std::string& user_pin,
  98                                int token_slot_id);
  99
 100   // The task runner used to run delayed tasks when retrying failed Cryptohome
 101   // calls.
 102   scoped_refptr<base::TaskRunner> delayed_task_runner_;
 103
 104   Type type_;
 105   State state_;
 106
 107   // The user id associated with the TPMTokenInfoGetter. Empty for system token.
 108   std::string user_id_;
 109
 110   TPMTokenInfoCallback callback_;
 111
 112   // The current request delay before the next attempt to initialize the
 113   // TPM. Will be adapted after each attempt.
 114   base::TimeDelta tpm_request_delay_;
 115
 116   CryptohomeClient* cryptohome_client_;
 117
 118   base::WeakPtrFactory<TPMTokenInfoGetter> weak_factory_;
 119
 120   DISALLOW_COPY_AND_ASSIGN(TPMTokenInfoGetter);
 121 };
 122
 123 }  // namespace chromeos
 124
 125 #endif  // CHROMEOS_TPM_TOKEN_INFO_GETTER_H_