crypto/nss_crypto_module_delegate.h

   1 // Copyright 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 #ifndef CRYPTO_NSS_CRYPTO_MODULE_DELEGATE_H_
   6 #define CRYPTO_NSS_CRYPTO_MODULE_DELEGATE_H_
   7
   8 #include <string>
   9
  10 #include "base/callback_forward.h"
  11 #include "crypto/scoped_nss_types.h"
  12
  13 namespace crypto {
  14
  15 // PK11_SetPasswordFunc is a global setting.  An implementation of
  16 // CryptoModuleBlockingPasswordDelegate should be passed using wincx() as the
  17 // user data argument (|wincx|) to relevant NSS functions, which the global
  18 // password handler will call to do the actual work. This delegate should only
  19 // be used in NSS calls on worker threads due to the blocking nature.
  20 class CryptoModuleBlockingPasswordDelegate {
  21  public:
  22   virtual ~CryptoModuleBlockingPasswordDelegate() {}
  23
  24   // Return a value suitable for passing to the |wincx| argument of relevant NSS
  25   // functions. This should be used instead of passing the object pointer
  26   // directly to avoid accidentally casting a pointer to a subclass to void* and
  27   // then casting back to a pointer of the base class
  28   void* wincx() { return this; }
  29
  30   // Requests a password to unlock |slot_name|. The interface is synchronous
  31   // because NSS cannot issue an asynchronous request. |retry| is true if this
  32   // is a request for the retry and we previously returned the wrong password.
  33   // The implementation should set |*cancelled| to true if the user cancelled
  34   // instead of entering a password, otherwise it should return the password the
  35   // user entered.
  36   virtual std::string RequestPassword(const std::string& slot_name, bool retry,
  37                                       bool* cancelled) = 0;
  38
  39 };
  40
  41 // Extends CryptoModuleBlockingPasswordDelegate with the ability to return a
  42 // slot in which to act. (Eg, which slot to store a generated key in.)
  43 class NSSCryptoModuleDelegate : public CryptoModuleBlockingPasswordDelegate {
  44  public:
  45   virtual ~NSSCryptoModuleDelegate() {}
  46
  47   // Get the slot to store the generated key.
  48   virtual ScopedPK11Slot RequestSlot() = 0;
  49 };
  50
  51 }  // namespace crypto
  52
  53 #endif  // CRYPTO_NSS_CRYPTO_MODULE_DELEGATE_H_