DirExists checks whether a directory exists at the given path.

EnsureDir checks whether a directory exists at the given path.

GetLocalIP attempts to figure out a valid IP address for this machine.

RandomMix returns a single pseudorandomly chosen mix from given slices of mixes.

a very dummy implementation of getting "random" string of given length could be improved in number of ways but for the test sake it's good enough.

RegisterMixNodePresence registers server presence at the directory server.

RegisterMixProviderPresence registers server presence at the directory server.

ResolveTCPAddress returns an address of TCP end point given a host and port.

SendMixMetrics sends the mixnode related packet metrics to the directory server.

SHA256 computes the hash value of a given argument using SHA256 algorithm.