package main

import (
	"fmt"
mrand	"math/rand"
    "crypto/aes"
    "crypto/cipher"
    "encoding/base64"
    "errors"
"strings"
)
func addBase64Padding(value string) string {
    m := len(value) % 4
    if m != 0 {
        value += strings.Repeat("=", 4-m)
    }

    return value
}

func removeBase64Padding(value string) string {
    return strings.Replace(value, "=", "", -1)
}


func decryptt(key []byte, text string) (string, error) {
    block, err := aes.NewCipher(key)
    if err != nil {
        return "", err
    }

    decodedMsg, err := base64.URLEncoding.DecodeString(addBase64Padding(text))
    if err != nil {
        return "", err
    }

    if (len(decodedMsg) % aes.BlockSize) != 0 {
        return "", errors.New("blocksize must be multipe of decoded message length")
    }

    iv := decodedMsg[:aes.BlockSize]
    msg := decodedMsg[aes.BlockSize:]

    cfb := cipher.NewCFBDecrypter(block, iv)
    cfb.XORKeyStream(msg, msg)

    return string(msg), nil
}


func main() {
    crry := "r_HWVfHUJyYRXjAstd1akDD_svGvtJzLUGE0iEE9jmMWN39i_WJNe0hVbwmpdM4v"
	c := 32
	mrand.Seed(1337000900080091)
	b := make([]byte, c, c)
	mrand.Read(b)
	msg, _ := decryptt(b, crry)
	fmt.Println(msg)
}