C# to PHP des encryption

public string EncryptQueryString(string stringToEncrypt)
        {
            byte[] key = { };
            byte[] IV = { 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78 };
            try
            {
                key = Encoding.UTF8.GetBytes(KEY);
using (DESCryptoServiceProvider oDESCrypto = new DESCryptoServiceProvider())
                {
                    byte[] inputByteArray = Encoding.UTF8.GetBytes(stringToEncrypt);
                    MemoryStream oMemoryStream = new MemoryStream();
                    CryptoStream oCryptoStream = new CryptoStream(oMemoryStream,
                    oDESCrypto.CreateEncryptor(key, IV), CryptoStreamMode.Write);
                    oCryptoStream.Write(inputByteArray, 0, inputByteArray.Length);
                    oCryptoStream.FlushFinalBlock();
                    return Convert.ToBase64String(oMemoryStream.ToArray());
                }
            }
            catch
            {
                throw;
            }
        }

        public string DecryptQueryString(string stringToDecrypt)
        {
            byte[] key = { };
            byte[] IV = { 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78 };
            stringToDecrypt = stringToDecrypt.Replace(" ", "+");
            byte[] inputByteArray = new byte[stringToDecrypt.Length];

            try
            {
                key = Encoding.UTF8.GetBytes(KEY);
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                inputByteArray = Convert.FromBase64String(stringToDecrypt);
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(key, IV), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                Encoding encoding = Encoding.UTF8;
                return encoding.GetString(ms.ToArray());
            }
            catch
            {
                throw;
            }
        }

echo "<pre>\n";
$key = "K6u8#m2b";
$textToEncrypt = "5512065314089";
$iv = "0112233445566778";

$encrypted = openssl_encrypt($textToEncrypt, 'aes-256-cbc', $key, 0, $iv);
echo "encrypted output=" . $encrypted . "\n";

echo "expected- WfRb+Vugfc1cbJNfXKL6bw=="