52 lines
1.1 KiB
Go
52 lines
1.1 KiB
Go
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package main
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import (
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"fmt"
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"log"
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"net"
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"os"
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"time"
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"deadbeef.codes/steven/hyp/otphyp"
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)
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// MaxNetworkLatency specifies the number of milliseconds
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// A packet-switched network... more like "race condition factory"
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const MaxNetworkLatency = 500
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func main() {
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// validate number of input arguments
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if len(os.Args) < 2 {
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usage()
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os.Exit(1)
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}
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// load secret and generate ports using secret and current time
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secretBytes, err := os.ReadFile("hyp.secret")
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if err != nil {
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log.Fatalf("failed to read file 'hyp.secret': %v", err)
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}
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sharedSecret := string(secretBytes)
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ports, err := otphyp.GeneratePorts(sharedSecret, time.Now())
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if err != nil {
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log.Fatalf("failed to generate ports from shared secret: %v", err)
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}
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// Transmit
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fmt.Println("Transmitting knock sequence:", ports)
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for _, port := range ports {
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conn, _ := net.Dial("udp", fmt.Sprintf("%s:%d", os.Args[1], port))
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conn.Write([]byte{0})
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conn.Close()
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time.Sleep(time.Millisecond * MaxNetworkLatency)
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}
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}
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func usage() {
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fmt.Println(os.Args[0], "usage")
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fmt.Println("Supply an ordered list of ports to knock")
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fmt.Println(os.Args[0], "server")
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}
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