encryption - ruby, python and golang with AES-256-CFB and

enc_dec.go

package main

import (
    "fmt"
    "io"
    "encoding/base64"
    "crypto/rand"
    "crypto/cipher"
    "crypto/aes"
    "crypto/md5"
    "golang.org/x/crypto/pbkdf2"
)


const saltlen = 8
const keylen = 32
const iterations = 10002

func encrypt(plaintext string, password string) string {
    header := make([]byte, saltlen + aes.BlockSize)

    salt := header[:saltlen]
    if _, err := io.ReadFull(rand.Reader, salt); err != nil {
        panic(err)
    }

    iv := header[saltlen:aes.BlockSize+saltlen]
    if _, err := io.ReadFull(rand.Reader, iv); err != nil {
        panic(err)
    }

    key := pbkdf2.Key([]byte(password), salt, iterations, keylen, md5.New)

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

    ciphertext := make([]byte, len(header) + len(plaintext))
    copy(ciphertext, header)

    stream := cipher.NewCFBEncrypter(block, iv)
    stream.XORKeyStream(ciphertext[aes.BlockSize+saltlen:], []byte(plaintext))
    return base64Encode(ciphertext)
}

func decrypt(encrypted string, password string) string {
    a, err := base64Decode([]byte(encrypted))
    if err != nil {
      panic(err)
    }
    ciphertext := a
    salt := ciphertext[:saltlen]
    iv := ciphertext[saltlen:aes.BlockSize+saltlen]
    key := pbkdf2.Key([]byte(password), salt, iterations, keylen, md5.New)

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

    if len(ciphertext) < aes.BlockSize {
        return ""
    }

    decrypted := ciphertext[saltlen+aes.BlockSize:]
    stream := cipher.NewCFBDecrypter(block, iv)
    stream.XORKeyStream(decrypted, decrypted)

    return string(decrypted)
}


func base64Encode(src []byte) string {
  return base64.StdEncoding.EncodeToString(src)
}

func base64Decode(src []byte) ([]byte, error) {
  return base64.StdEncoding.DecodeString(string(src))
}

func main() {
  text := "maeno"
  password := "pass"
  enc_text := encrypt(text, password)
  fmt.Println(enc_text)
  fmt.Println(decrypt(enc_text,password))
  fmt.Println(decrypt("yzFQOv38nMY3bfY17mhDjtMlKqcK0gEJHHdON9k=\n",password))
}

enc_dec.py

import hashlib
import base64
import Crypto.Random
import M2Crypto.EVP

PASSWORD = b"pass"
SALTLEN = 8
KEYLEN = 32
IVLEN = 16
ITERATIONS = 10002
ENCRYPT = 1
DECRYPT = 0


def encrypt(text):
    salt = Crypto.Random.get_random_bytes(SALTLEN)
    dk = hashlib.pbkdf2_hmac("md5", PASSWORD, salt, ITERATIONS, IVLEN+KEYLEN)
    key = dk[:KEYLEN]
    iv = dk[KEYLEN:]

    cipher = M2Crypto.EVP.Cipher('aes_256_cfb', key, iv, ENCRYPT)
    encrypted = cipher.update(text) + cipher.final()
    return base64.b64encode(salt+iv+encrypted)


def decrypt(encrypted):
    data = base64.b64decode(encrypted)
    salt = data[:SALTLEN]
    data = data[SALTLEN:]
    dk = hashlib.pbkdf2_hmac("md5", PASSWORD, salt, ITERATIONS, IVLEN+KEYLEN)
    key = dk[:KEYLEN]
    iv = dk[KEYLEN:]

    cipher = M2Crypto.EVP.Cipher('aes_256_cfb', key, iv, DECRYPT)
    text = cipher.update(data) + cipher.final()
    return text[IVLEN:]

if __name__ == '__main__':
    a = encrypt("maeno")
    print a
    print decrypt(a)
    print decrypt("ZRYc5tvMdbO7jdyygwLGythQ5+d4ts+laesOnhA=\n")
    print decrypt("yaZNBg2XcOkQrIv4EfOeeujL9XG3QEd2RrujivU=")

enc_dec.rb

require 'openssl'
require 'base64'

$password = "pass"
$saltlen = 8
$keylen = 32
$iterations = 10002

def aes256_encrypt(text)
  cipher = OpenSSL::Cipher::Cipher.new("AES-256-CFB")
  salt = OpenSSL::Random.random_bytes($saltlen)
  key_iv = OpenSSL::PKCS5.pbkdf2_hmac($password, salt, $iterations, $keylen+cipher.iv_len, "md5")
  cipher.key = key_iv[0, cipher.key_len]
  cipher.iv = key_iv[cipher.key_len, cipher.iv_len]
  cipher.encrypt
  text = cipher.update(text) + cipher.final
  text = salt + key_iv[cipher.key_len, cipher.iv_len] + text
  Base64.encode64(text)
end


def aes256_decrypt(encrypted)
  data = Base64.decode64(encrypted)
  salt = data[0,$saltlen]
  data = data[$saltlen, data.size]
  cipher = OpenSSL::Cipher::Cipher.new("AES-256-CFB")
  key_iv = OpenSSL::PKCS5.pbkdf2_hmac($password, salt, $iterations, $keylen+cipher.iv_len, "md5")
  cipher.key = key_iv[0, cipher.key_len]
  cipher.iv = key_iv[cipher.key_len, cipher.iv_len]
  cipher.decrypt
  data = cipher.update(data) + cipher.final
  data[cipher.iv_len, data.size]
end

a = aes256_encrypt("maeno")
p a
p aes256_decrypt(a)
p aes256_decrypt("PBg3yu4a5Hh//HN1qUHHHiIiVgjUlMAbCw2mf6Y=")