chromeos/tpm/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_TPM_TOKEN_INFO_GETTER_H_
   6 #define CHROMEOS_TPM_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 // For invalid token |token_name| and |user_pin| will be empty, while
  29 // |token_slot_id| will be set to -1.
  30 struct TPMTokenInfo {
  31   // Default constructor creates token info for disabled TPM.
  32   TPMTokenInfo();
  33   ~TPMTokenInfo();
  34
  35   bool tpm_is_enabled;
  36   std::string token_name;
  37   std::string user_pin;
  38   int token_slot_id;
  39 };
  40
  41 // Class for getting a user or the system TPM token info from cryptohome during
  42 // TPM token loading.
  43 class CHROMEOS_EXPORT TPMTokenInfoGetter {
  44  public:
  45   using TPMTokenInfoCallback = base::Callback<void(const TPMTokenInfo& info)>;
  46
  47   // Factory method for TPMTokenInfoGetter for a user token.
  48   static scoped_ptr<TPMTokenInfoGetter> CreateForUserToken(
  49       const std::string& user_id,
  50       CryptohomeClient* cryptohome_client,
  51       const scoped_refptr<base::TaskRunner>& delayed_task_runner);
  52
  53   // Factory method for TPMTokenGetter for the system token.
  54   static scoped_ptr<TPMTokenInfoGetter> CreateForSystemToken(
  55       CryptohomeClient* cryptohome_client,
  56       const scoped_refptr<base::TaskRunner>& delayed_task_runner);
  57
  58   ~TPMTokenInfoGetter();
  59
  60   // Starts getting TPM token info. Should be called at most once.
  61   // |callback| will be called when all the info is fetched.
  62   // The object may get deleted before |callback| is called, which is equivalent
  63   // to cancelling the info getting (in which case |callback| will never get
  64   // called).
  65   void Start(const TPMTokenInfoCallback& callback);
  66
  67  private:
  68   enum Type {
  69     TYPE_SYSTEM,
  70     TYPE_USER
  71   };
  72
  73   enum State {
  74     STATE_INITIAL,
  75     STATE_STARTED,
  76     STATE_TPM_ENABLED,
  77     STATE_DONE
  78   };
  79
  80   TPMTokenInfoGetter(
  81       Type type,
  82       const std::string& user_id,
  83       CryptohomeClient* cryptohome_client,
  84       const scoped_refptr<base::TaskRunner>& delayed_task_runner);
  85
  86   // Continues TPM token info getting procedure by starting the task associated
  87   // with the current TPMTokenInfoGetter state.
  88   void Continue();
  89
  90   // If token initialization step fails (e.g. if tpm token is not yet ready)
  91   // schedules the initialization step retry attempt after a timeout.
  92   void RetryLater();
  93
  94   // Cryptohome methods callbacks.
  95   void OnTpmIsEnabled(DBusMethodCallStatus call_status,
  96                       bool tpm_is_enabled);
  97   void OnPkcs11GetTpmTokenInfo(DBusMethodCallStatus call_status,
  98                                const std::string& token_name,
  99                                const std::string& user_pin,
 100                                int token_slot_id);
 101
 102   // The task runner used to run delayed tasks when retrying failed Cryptohome
 103   // calls.
 104   scoped_refptr<base::TaskRunner> delayed_task_runner_;
 105
 106   Type type_;
 107   State state_;
 108
 109   // The user id associated with the TPMTokenInfoGetter. Empty for system token.
 110   std::string user_id_;
 111
 112   TPMTokenInfoCallback callback_;
 113
 114   // The current request delay before the next attempt to initialize the
 115   // TPM. Will be adapted after each attempt.
 116   base::TimeDelta tpm_request_delay_;
 117
 118   CryptohomeClient* cryptohome_client_;
 119
 120   base::WeakPtrFactory<TPMTokenInfoGetter> weak_factory_;
 121
 122   DISALLOW_COPY_AND_ASSIGN(TPMTokenInfoGetter);
 123 };
 124
 125 }  // namespace chromeos
 126
 127 #endif  // CHROMEOS_TPM_TPM_TOKEN_INFO_GETTER_H_