GoLang Encrypt string to base64 and vice versa using AES encryption.

main.go

package main

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"encoding/base64"
	"fmt"
	"io"
)

func main() {
	originalText := "encrypt this golang"
	fmt.Println(originalText)

	key := []byte("example key 1234")

	// encrypt value to base64
	cryptoText := encrypt(key, originalText)
	fmt.Println(cryptoText)

	// encrypt base64 crypto to original value
	text := decrypt(key, cryptoText)
	fmt.Printf(text)
}

// encrypt string to base64 crypto using AES
func encrypt(key []byte, text string) string {
	// key := []byte(keyText)
	plaintext := []byte(text)

	block, err := aes.NewCipher(key)
	if err != nil {
		panic(err)
	}

	// The IV needs to be unique, but not secure. Therefore it's common to
	// include it at the beginning of the ciphertext.
	ciphertext := make([]byte, aes.BlockSize+len(plaintext))
	iv := ciphertext[:aes.BlockSize]
	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
		panic(err)
	}

	stream := cipher.NewCFBEncrypter(block, iv)
	stream.XORKeyStream(ciphertext[aes.BlockSize:], plaintext)

	// convert to base64
	return base64.URLEncoding.EncodeToString(ciphertext)
}

// decrypt from base64 to decrypted string
func decrypt(key []byte, cryptoText string) string {
	ciphertext, _ := base64.URLEncoding.DecodeString(cryptoText)

	block, err := aes.NewCipher(key)
	if err != nil {
		panic(err)
	}

	// The IV needs to be unique, but not secure. Therefore it's common to
	// include it at the beginning of the ciphertext.
	if len(ciphertext) < aes.BlockSize {
		panic("ciphertext too short")
	}
	iv := ciphertext[:aes.BlockSize]
	ciphertext = ciphertext[aes.BlockSize:]

	stream := cipher.NewCFBDecrypter(block, iv)

	// XORKeyStream can work in-place if the two arguments are the same.
	stream.XORKeyStream(ciphertext, ciphertext)

	return fmt.Sprintf("%s", ciphertext)
}

Updated to use UrlEncoding instead of StdEncoding. I see that UrlEncoding has broader usage, atleast i need it.

how can I decrypt from node.js ? any suggestions ?

I would move from using AES directly to using the Cipher package similar to what's done in https://gist.github.com/kkirsche/e28da6754c39d5e7ea10 based on feedback from the Golang team when I proposed including an example of proper AES encryption in the examples.

A note: the key (line 30) should be 16, 24 or 32 byte when creating new cipher (line 32), as reported in https://golang.org/src/crypto/aes/cipher.go

Thank you for this package, helped me a lot!

Thank you for the code!

I wrapped this code in a package if anyone cares to use it or help contribute: https://github.com/blaskovicz/go-cryptkeeper.

It provides types.Encrypt(), types.Decrypt(), and a types.CryptStringstruct that can be used for databaseScan()/Value()andMarshalJSON()` operations.

how to GoLang Encrypt string to base64 and vice versa using AES encryption with javascript

This package is wrong, don't use this anywhere!

I wouldn't recommend using URL encoding as it will replace / with _ for example which will not work across different systems.
base64.StdEncoding.EncodeToString is much better for cross system encoding.