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@c0nrad /ecb.go Secret
Created Jul 3, 2016

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package main
import (
"bytes"
"crypto/aes"
"encoding/hex"
"fmt"
"net"
)
const (
BlockSize = 16
)
func main() {
ln, err := net.Listen("tcp", ":8080")
if err != nil {
// handle error
}
fmt.Println("Server listening on :8080")
for {
conn, err := ln.Accept()
if err != nil {
// handle error
continue
}
go HandleConnection(conn)
}
}
func HandleConnection(conn net.Conn) {
secret := []byte("SECRET")
key := []byte("ENCRYPTIONKEY123")
for {
buffer := make([]byte, 4048)
count, err := conn.Read(buffer)
if err != nil {
fmt.Println("Error", err)
return
}
buffer = bytes.TrimSpace(buffer[:count])
buffer = append(buffer, secret...)
buffer = pad(buffer)
fmt.Println("Encrypting", buffer)
ciphertext := encrypt(buffer, key)
encoded := encode(ciphertext)
conn.Write(encoded)
}
}
func pad(in []byte) []byte {
extra := BlockSize - (len(in) % BlockSize)
out := append(in, bytes.Repeat([]byte{0}, extra)...)
return out
}
func encode(in []byte) []byte {
size := hex.EncodedLen(len(in))
out := make([]byte, size)
hex.Encode(out, in)
return out
}
func encrypt(buffer, key []byte) []byte {
c, err := aes.NewCipher(key)
if err != nil {
panic(err)
}
if len(buffer)%16 != 0 {
panic("Invalid buffer length")
}
out := make([]byte, len(buffer))
for x := 0; x < len(buffer)/16; x += 1 {
c.Encrypt(out[x*16:(x+1)*16], buffer[x*16:(x+1)*16])
}
return out
}
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c0nrad Jul 3, 2016

go run ecb.go
telnet localhost 8080

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c0nrad commented Jul 3, 2016

go run ecb.go
telnet localhost 8080

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