Mcrypt from PHP to Go - encryption

Question

Im using a class to encrypt/decrypt strings in PHP.
How could I encrypt/decrypt the strings in Go?
The PHP class:
class Crypto {
private $encryptKey = 'xxxxxxxxxxxxxxxx';
private $iv = 'xxxxxxxxxxxxxxxx';
private $blocksize = 16;
public function decrypt($data)
{
return $this->unpad(mcrypt_decrypt(MCRYPT_RIJNDAEL_128,
$this->encryptKey,
hex2bin($data),
MCRYPT_MODE_CBC, $this->iv), $this->blocksize);
}
public function encrypt($data)
{
//don't use default php padding which is '\0'
$pad = $this->blocksize - (strlen($data) % $this->blocksize);
$data = $data . str_repeat(chr($pad), $pad);
return bin2hex(mcrypt_encrypt(MCRYPT_RIJNDAEL_128,
$this->encryptKey,
$data, MCRYPT_MODE_CBC, $this->iv));
}
private function unpad($str, $blocksize)
{
$len = strlen($str);
$pad = ord($str[$len - 1]);
if ($pad && $pad <= $blocksize) {
if (substr($str, -$pad) === str_repeat(chr($pad), $pad)) {
return substr($str, 0, $len - $pad);
}
}
return $str;
}
}
What to be able to encrypt/decrypt same string in both PHP and Go.

Answer 1

Here is an example:
package main
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"errors"
"fmt"
"io"
"log"
)
func main() {
key := []byte("xxxxxxxxxxxxxxxx") // 32 bytes
plaintext := []byte("TEST")
fmt.Printf("%s\n", plaintext)
ciphertext, err := encrypt(key, plaintext)
if err != nil {
log.Fatal(err)
}
fmt.Printf("%0x\n", ciphertext)
result, err := decrypt(key, ciphertext)
if err != nil {
log.Fatal(err)
}
fmt.Printf("%s\n", result)
}
func encrypt(key, text []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
b := base64.StdEncoding.EncodeToString(text)
ciphertext := make([]byte, aes.BlockSize+len(b))
iv := ciphertext[:aes.BlockSize]
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
return nil, err
}
cfb := cipher.NewCFBEncrypter(block, iv)
cfb.XORKeyStream(ciphertext[aes.BlockSize:], []byte(b))
return ciphertext, nil
}
func decrypt(key, text []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
if len(text) < aes.BlockSize {
return nil, errors.New("ciphertext too short")
}
iv := text[:aes.BlockSize]
text = text[aes.BlockSize:]
cfb := cipher.NewCFBDecrypter(block, iv)
cfb.XORKeyStream(text, text)
data, err := base64.StdEncoding.DecodeString(string(text))
if err != nil {
return nil, err
}
return data, nil
}
Mostly borrowed and adapted from: https://golang.org/src/crypto/cipher/example_test.go
// Input => TEST
// Output => 13360adba03733e11dd2702de441ff8bbb90676ad762fc83
UPDATE
To use a string as a parameter for decode function, you need to convert the string to byte using hex.Decodestring
data, _ := hex.DecodeString("1d6f12d3aa2353b23c6012dbc85816632129363d58a76063")
result, err := decrypt(key, data)
if err != nil {
log.Fatal(err)
}
fmt.Printf("%s\n", result)
Do not forget to include "encoding/hex" into package list.