I'm not able to decrypt a string encrypted with CSharp using Golang, because I think CSharp uses a CFB8 and Golang CFB128 (Feedback Size). But if I use CSharp with FeedbackSize=128 then I need to use Padding that as a result I will have it also in the encrypted text (that Golang doesn't have), viceversa I cannot use FeedbackSize=8 in Golang because is not implemented.

Any idea?

CSharp code:

static void Main(string[] args)
    {
        byte[] msg = Encoding.UTF8.GetBytes("Message to encrypt");
        byte[] k = Encoding.UTF8.GetBytes("0123456789abcdef");
        byte[] iv = Encoding.UTF8.GetBytes("0123456789abcdef");
        using (RijndaelManaged Aes128 = new RijndaelManaged())
        {
            Aes128.BlockSize = 128;
            Aes128.KeySize = 128;
            Aes128.Mode = CipherMode.CFB;
            Aes128.FeedbackSize = 8;
            Aes128.Padding = PaddingMode.Zeros;
            Aes128.Key = k;
            Aes128.IV = iv;

            using (var encryptor = Aes128.CreateEncryptor())
            using (var msEncrypt = new MemoryStream())
            using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))

            using (var bw = new BinaryWriter(csEncrypt, Encoding.UTF8))
            {
                bw.Write(msg);
                bw.Close();
                msg = msEncrypt.ToArray();
                Console.WriteLine("Encrypted " + BitConverter.ToString(msg));
            }
        }
    }

Result:

Encrypted 3F-D6-AD-8E-D5-34-E6-2D-38-7B-38-4E-DE-72-E8-B1-42-1C

Golang code:

    package main
import (
    "crypto/aes"
    "crypto/cipher"
    "fmt"
)
func main() {
    msg := []byte("Message to encrypt")
    k := []byte("0123456789abcdef")
    iv := []byte("0123456789abcdef")
    {
        block, _ := aes.NewCipher(k)
        stream := cipher.NewCFBEncrypter(block, iv)
        stream.XORKeyStream(msg, msg)
        fmt.Printf("Encrypted %x
", msg)
    }
}

Result:

Encrypted 3f170dfb7fbb982174c8380d176ac71c89ac

Note: if I change to Aes128.FeedbackSize = 128, then I got an error because I don't use padding, if I use padding I have the following result:

Encrypted 3F-17-0D-FB-7F-BB-98-21-74-C8-38-0D-17-6A-C7-1C-89-AC-F2-4F-9A-1D-E8-0B-D4-40-21-60-AF-48-36-5F

Many thanks in advance.