Add ability to pass decryption key id to CreateSecureMessage method

chromeos/dbus/easy_unlock_client.h

 // Copyright 2014 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_DBUS_EASY_UNLOCK_CLIENT_H_
 #define CHROMEOS_DBUS_EASY_UNLOCK_CLIENT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 44 matching lines @@
   //     encryption is required, the key must be symetric.
   // |associated_data|: Data associated with the message. The data will not
   //     actually be added to the message, but it will be used while
   //     signing the message (the receiver will use the same data to
   //     authenticate the signature).
   // |public_metadata|: Metadata added to the message header.
   // |verification_key_id|: The key id added to the message header. Has to be
   //     set if the message is signed with private asymetric key. This value
   //     is used by the receiver to identify the public key that should be used
   //     to verify the signature.
+  // |decryption_key_id|: Key id added to the message header. Used by the
+  //     message receiver to identify the key that should be used to decrypt
+  //     the message.
   // |encryption_type|: The encryption algorithm to use for encrypting the
   //     message. (May be set to none).
   // |signature_type|: The algorithm to use to sign the message.
   // |callback|: Called with the created message. On failure, the message will
   //     be empty.
   virtual void CreateSecureMessage(const std::string& payload,
                                    const std::string& secret_key,
                                    const std::string& associated_data,
                                    const std::string& public_metadata,
                                    const std::string& verification_key_id,
+                                   const std::string& decryption_key_id,
                                    const std::string& encryption_type,
                                    const std::string& signature_type,
                                    const DataCallback& callback) = 0;

[stevenjb, 2014/09/02 16:09:25]

nit: For future consideration, passing this many arguments to a function is
confusing, we should  define a struct instead and pass that. Not necessary for
this CL.

 
   // Authenticates and, if specified, decrypts a secure message.
   // |message|: The message to unwrap. It is in the same format as the message
   //     returned by |CreateSecureMessage|.
   // |key|: The key used to authenticate message signature and, if needed,
   //     decrypt the message. If the message is encrypted, only symetric key
   //     can be used.
   // |associated_data|: Data associated with the message. Message
   //     authentication will succeed only if the message was created with the
   //     associated data.
@@ skipping 18 matching lines @@
   // Create() should be used instead.
   EasyUnlockClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(EasyUnlockClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_EASY_UNLOCK_CLIENT_H_