将base64String保存为FTP服务器上的图像，保存损坏的文件

Question

将base64String保存为FTP服务器上的图像将其保存为损坏的文件。 我正在做一些事情

1. 将base64String转换为byte []。
2. 在上一步中转换了字节的初始化MemoryStream。
3. 从FTP打开流
4. 在ftp上写流。

以下是代码

public bool WriteFromBase64ToFile(string base64, string path, string fileName)
    {
        bool result = false;

        using (FtpClient ftp = new FtpClient())
        {

            // setting ftp properties with required values.
            ftp.ReadTimeout = 999999999;
            ftp.Host = host;
            ftp.Credentials = new System.Net.NetworkCredential(username, password);
            ftp.Port = Convert.ToInt32(port);
            ftp.DataConnectionType = FtpDataConnectionType.AutoPassive;
            ftp.Connect();
            ftp.ConnectTimeout = 1000000;

            // converting base64String into byte array.
            byte[] file = Convert.FromBase64String(base64);



            if (ftp.IsConnected)
            {
                int BUFFER_SIZE = file.Length; // 64KB buffer
                byte[] buffer = new byte[file.Length];

                // Initializing MemoryStream with byte converted from base64String.
                MemoryStream ms = new MemoryStream(buffer);

                using (Stream readStream = ms)
                {
                    fileName = fileName.ReplacingSpecialCharacterswithEntities();

                    // Getting stream from ftp and then writing it on FTP server.
                    using (Stream writeStream = ftp.OpenWrite(path + "/" + fileName+".jpg", FtpDataType.Binary))
                    {

                        while (readStream.Position < readStream.Length)
                        {
                            buffer.Initialize();

                            // Reading stream
                            int bytesRead = readStream.Read(buffer, 0, BUFFER_SIZE);
                            // Writing stream
                            writeStream.Write(buffer, 0, bytesRead);
                        }

                        // flushing stream.
                        writeStream.Flush();
                    }
                }
            }
        }
        result = true;
        return result;
    }