Distributed secure configuration exchange betweem multiple Linux devices

A number of devices running on Linux are connected with a TCP/IP network. All devices run the same software, but their function in the network is different dependent on their configuration. If one device fails, it can be removed from the network and replaced with another device. The new device should replace the removed device and take over its function. Therefore the configuration for this device must be downloaded from the other still functioning devices in the network. Both the method of intercommunication of the devices must be designed, and implemented. A number of constraints exist for this software. 1) The required programming language is C because this software has to be integrated in an existing program. Proposals in other languages will not be considered. 2) All communications between the devices must be encrypted. In your design you have to explain how proper encryption is performed. 3) If a device configuration changes, that changed configuration must be distributed to all other devices in order to have a current backup of the configuration of each device at any time. Device configuration changes can be initiated from the main software program running on each device. 4) A replacement device which is added to the network must have a method to authenticate itself to the other devices and request the configuration data for that node. Please design and implement a method for this which takes only a small amount of basic information which must be entered manually to the new device in order to receive all other information from the other nodes. 5) New devices with new functions can be flexibly added to the network. Design and implement a method which makes this possible. 6) The definition of "configuration data" was left explicitly abstract in this project proposal because the definition of it may change over time, and the configuration exchange protocol must be stable independent of the actual data exchanged. Please keep that in mind when designing and implementing this project. 7) The program is delivered in source code, and contains well written and documented code. For the testing and implementation phase a Makefile and possibly other configuration files are provided which guarantee easy compiling. Inline comments and documentation are in English. The intellectual rights on the code written by the freelancer are transferred to us. In case partially existing code is used, that code may not have been published with a license which prohibits commercial use. The app may also not use any existing code which has been published with a license which forces viral publishing of the code, like for example the GPL license. 8) In case you have reason to bid with a price which is outside the proposed budget, please be sure to add justification for the higher price. Although budget is a concern, quality and other aspects are taken into account when making the final choice of the partner to develop this work.