package main import ( "crypto/rsa" "encoding/gob" "github.com/rs/zerolog" "github.com/rs/zerolog/log" "net" "os" ) // Exchange keys with sender func ReceiverKeyExchange(key *rsa.PublicKey) string { // Use ConsoleWriter logger log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr}) // Create TCP listener on port 9797 listener, err := net.Listen("tcp", ":9797") if err != nil { log.Fatal().Err(err).Msg("Error starting listener") } // Create string for sender address var senderAddr string // Create channel to send break signal breakChannel := make(chan bool) for { // Accept connection on listener connection, err := listener.Accept() // Get sender address and store it in senderAddr senderAddr = connection.RemoteAddr().String() if err != nil { log.Fatal().Err(err).Msg("Error accepting connections") } // Concurrently handle connection go func(conn net.Conn) { // Create gob encoder with connection as io.Writer encoder := gob.NewEncoder(conn) // Encode key into connection err := encoder.Encode(key) if err != nil { log.Fatal().Err(err).Msg("Error encoding key") } // Send signal to breakChannel breakChannel <- true }(connection) // Wait for break signal select { // When break signal arrives case _ = <-breakChannel: // Return sender address return senderAddr } } } // Exchange keys with receiver func SenderKeyExchange(receiverIP string) *rsa.PublicKey { // Use ConsoleWriter logger log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr}) // Connect to TCP socket on receiver IP port 9797 connection, err := net.Dial("tcp", receiverIP + ":9797") if err != nil { log.Fatal().Err(err).Msg("Error connecting to sender") } // Create gob decoder decoder := gob.NewDecoder(connection) // Instantiate rsa.PublicKey struct recvPubKey := &rsa.PublicKey{} // Decode key err = decoder.Decode(recvPubKey) if err != nil { log.Fatal().Err(err).Msg("Error decoding key") } // Return received key return recvPubKey }