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