decrypt

internal static string Decrypt(byte[] key,string input)
        {
            if (input == null || input.Length <= 0)
                throw new ArgumentNullException("input");
            if (key == null || key.Length <= 0)
                throw new ArgumentNullException("Key");

            var un64byte = Convert.FromBase64String(input);
            if (un64byte.Length < 16)
                return ""; // Too short

	    //Pluck out the IV bytes (first 16 bytes)
            var IV = un64byte.Take(16).ToArray();
            //All that remains is the actual data
            var cipherText = un64byte.Skip(16).Take(un64byte.Length - 16).ToArray();
         
            using (RijndaelManaged aes = new RijndaelManaged())
            {
                aes.Key = Key;
                aes.IV = IV;
                aes.Mode = CipherMode.CBC;
                
                //!!!Note that you have to have knowledge of the original length to strip padding
                aes.Padding = PaddingMode.Zeros;

                ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);
		
		string plaintext = "";
                using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {
                            plaintext = srDecrypt.ReadToEnd();
                        }
                    }
                }
            }

            return plaintext;
        }

encrypt

func encrypt(key []byte, text string) string {

	blockSize := aes.BlockSize
	if len(text)%blockSize != 0 {
		text += strings.Repeat("0", blockSize-len(text)%blockSize)
	}

	plaintext := []byte(text)

	block, err := aes.NewCipher(key)
	if err != nil {
		panic(err)
	}
	ciphertext := make([]byte, aes.BlockSize+len(plaintext))
	iv := ciphertext[:aes.BlockSize]
	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
		panic(err)
	}
	mode := cipher.NewCBCEncrypter(block, iv)
	mode.CryptBlocks(ciphertext[aes.BlockSize:], plaintext)
	return base64.StdEncoding.EncodeToString(ciphertext)
}