des3.go

package main

import (
	"crypto/cipher"
	"crypto/des"
	"encoding/binary"
	"fmt"
)

var des3 cipher.Block

func init() {
var err error
	des3, err = des.NewTripleDESCipher([]byte("dummy testing cipher key"))
	if err != nil {
		panic(err)
	}
}

func main() {
	fmt.Println(encrypt(42))
	fmt.Println(decrypt(encrypt(42)))
}

func encrypt(i uint64) uint64 {
	bb := make([]byte, 8)
	binary.LittleEndian.PutUint64(bb, i)
	des3.Encrypt(bb, bb)
	return binary.LittleEndian.Uint64(bb)
}

func decrypt(i uint64) uint64 {
	bb := make([]byte, 8)
	binary.LittleEndian.PutUint64(bb, i)
	des3.Decrypt(bb, bb)
	return binary.LittleEndian.Uint64(bb)
}