Golang : Encrypt and decrypt data with TripleDES

In this tutorial we will learn how to encrypt and decrypt data with Golang's DES crypto package.

Triple DES (3DES) is the common name for the Triple Data Encryption Algorithm (TDEA or Triple DEA) symmetric-key block cipher, which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block.

Here is the source code for encrypting and decrypting a 8 bytes string message with TripleDES :

 package main

 import (
 "fmt"
 "crypto/des"
 "crypto/cipher"
 "os"
 )

 func main() {
 // because we are going to use TripleDES... therefore we Triple it!
 triplekey := "12345678" + "12345678" + "12345678" 
 // you can use append as well if you want



 // plaintext will cause panic: crypto/cipher: input not full blocks
 // IF it is not the correct BlockSize. ( des.BlockSize = 8 bytes )
 // to fix this issue, plaintext may need to be padded to the whole block
 // ( 8 bytes ) for the simplicity of this tutorial, we will just keep 
 // the plaintext input to 8 bytes
 plaintext := []byte("Hello Wo") // Hello Wo = 8 bytes.



 block,err := des.NewTripleDESCipher([]byte(triplekey))

 if err != nil {
 fmt.Printf("%s \n", err.Error())
 os.Exit(1)
 }

 fmt.Printf("%d bytes NewTripleDESCipher key with block size of %d bytes\n", len(triplekey), block.BlockSize)


 ciphertext := []byte("abcdef1234567890")
 iv := ciphertext[:des.BlockSize] // const BlockSize = 8

 // encrypt

 mode := cipher.NewCBCEncrypter(block, iv)
 encrypted := make([]byte, len(plaintext))
 //mode.CryptBlocks(ciphertext[des.BlockSize:], plaintext)
 mode.CryptBlocks(encrypted, plaintext)
 fmt.Printf("%s encrypt to %x \n", plaintext, encrypted)


 //decrypt
 decrypter := cipher.NewCBCDecrypter(block, iv)
 decrypted := make([]byte, len(plaintext))
 decrypter.CryptBlocks(decrypted, encrypted)
 fmt.Printf("%x decrypt to %s\n", encrypted, decrypted)

 }

Executing the above code will produce the following result :

go run tripledescrypto.go

24 bytes NewTripleDESCipher key with block size of 10144 bytes

Hello Wo encrypt to 5fe6b99beabfbb25

5fe6b99beabfbb25 decrypt to Hello Wo

Reference :

http://golang.org/pkg/crypto/des/#NewTripleDESCipher

http://en.wikipedia.org/wiki/Triple_DES

http://golang.org/pkg/crypto/cipher/#NewCBCEncrypter