Encryption & Decryption method for C#

EncryptDecrypt.cs

public static string Encrypt(string data, string key)
{
    RijndaelManaged rijndaelCipher = new RijndaelManaged();
    rijndaelCipher.Mode = CipherMode.CBC;
    rijndaelCipher.Padding = PaddingMode.PKCS7;
    
    rijndaelCipher.KeySize = 0x80;
    rijndaelCipher.BlockSize = 0x80;
    byte[] pwdBytes = Encoding.UTF8.GetBytes(key);
    byte[] keyBytes = new byte[0x10];
    int len = pwdBytes.Length;
    
    if (len > keyBytes.Length)
    {
        len = keyBytes.Length;
    }
    
    Array.Copy(pwdBytes, keyBytes, len);
    rijndaelCipher.Key = keyBytes;
    rijndaelCipher.IV = keyBytes;
    ICryptoTransform transform = rijndaelCipher.CreateEncryptor();
    byte[] plainText = Encoding.UTF8.GetBytes(data);
    
    return Convert.ToBase64String
    (transform.TransformFinalBlock(plainText, 0, plainText.Length));
}

public static string Decrypt(string data, string key)
{
    RijndaelManaged rijndaelCipher = new RijndaelManaged();
    rijndaelCipher.Mode = CipherMode.CBC;
    rijndaelCipher.Padding = PaddingMode.PKCS7;
    
    rijndaelCipher.KeySize = 0x80;
    rijndaelCipher.BlockSize = 0x80;
    byte[] encryptedData = Convert.FromBase64String(data);
    byte[] pwdBytes = Encoding.UTF8.GetBytes(key);
    byte[] keyBytes = new byte[0x10];
    int len = pwdBytes.Length;
    
    if (len > keyBytes.Length)
    {
        len = keyBytes.Length;
    }
    
    Array.Copy(pwdBytes, keyBytes, len);
    rijndaelCipher.Key = keyBytes;
    rijndaelCipher.IV = keyBytes;
    byte[] plainText = rijndaelCipher.CreateDecryptor().TransformFinalBlock
    (encryptedData, 0, encryptedData.Length);
    
    return Encoding.UTF8.GetString(plainText);
}

I need to decrypt from dart as android side . How to do it?