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Saturday 2 September 2017

Encryption and Decryption of image file in C#.


Simple example of image encryption and decryption in c# and save to different server.
////////////////////////////// Form Code ///////////////////////////////////////////////////////////////////
public partial class Form1 : Form
    {

        public Form1()
        {
            InitializeComponent();
        }

        //define in web.config file 
        string BaseAddress = ConfigurationManager.AppSettings["BaseAddress"];
        string SyncPathConfigurationManager.AppSettings["SyncPath"];
       
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {

                btnSavePic.Enabled = false;
                button1.Enabled = false;
                HttpClient client = new HttpClient();
                client.BaseAddress = new Uri(BaseAddress);
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                HttpResponseMessage response = new HttpResponseMessage();
                byte[] mybytearray = null;
                response = client.GetAsync("api/employee?EmployeeNo=" + textBox1.Text.Trim() + "&SyncPath=" + SyncPath).Result;
                if (response.IsSuccessStatusCode)
                {
                    mybytearray = response.Content.ReadAsAsync<byte[]>().Result;

                    if (mybytearray.Count() > 0)
                    {
                        byte[] DecryPic = DecryptBytes(mybytearray, "2BeMy", "EmpPicUpdate");
                        Image img1 = byteArrayToImage(DecryPic);
                        pictureBox1.Image = img1;
                    }
                }
                btnSavePic.Enabled = true;
                button1.Enabled = true;
            }
            catch
            {
                btnSavePic.Enabled = true;
                button1.Enabled = true;
            }
        }
        public Image byteArrayToImage(byte[] byteArrayIn)
        {
            using (MemoryStream mStream = new MemoryStream(byteArrayIn))
            {
                return Image.FromStream(mStream);
            }
        }
        public static byte[] DecryptBytes(byte[] encryptedBytes, string passPhrase, string saltValue)
        {
            RijndaelManaged RijndaelCipher = new RijndaelManaged();

            RijndaelCipher.Mode = CipherMode.CBC;
            byte[] salt = Encoding.ASCII.GetBytes(saltValue);
            PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, salt, "SHA1", 2);

            ICryptoTransform Decryptor = RijndaelCipher.CreateDecryptor(password.GetBytes(32), password.GetBytes(16));

            MemoryStream memoryStream = new MemoryStream(encryptedBytes);
            CryptoStream cryptoStream = new CryptoStream(memoryStream, Decryptor, CryptoStreamMode.Read);
            byte[] plainBytes = new byte[encryptedBytes.Length];

            int DecryptedCount = cryptoStream.Read(plainBytes, 0, plainBytes.Length);

            memoryStream.Close();
            cryptoStream.Close();

            return plainBytes;
        }
        public static byte[] EncryptBytes(byte[] inputBytes, string passPhrase, string saltValue)
        {
            RijndaelManaged RijndaelCipher = new RijndaelManaged();

            RijndaelCipher.Mode = CipherMode.CBC;
            byte[] salt = Encoding.ASCII.GetBytes(saltValue);
            PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, salt, "SHA1", 2);
            ICryptoTransform Encryptor = RijndaelCipher.CreateEncryptor(password.GetBytes(32), password.GetBytes(16));

            MemoryStream memoryStream = new MemoryStream();
            CryptoStream cryptoStream = new CryptoStream(memoryStream, Encryptor, CryptoStreamMode.Write);
            cryptoStream.Write(inputBytes, 0, inputBytes.Length);
            cryptoStream.FlushFinalBlock();
            byte[] CipherBytes = memoryStream.ToArray();

            memoryStream.Close();
            cryptoStream.Close();

            return CipherBytes;
        }
        public class Param
        {
            public byte[] EmpPic { get; set; }
            public int EmpId { get; set; }
            public string SyncParam { get; set; }
        }
        private void btnSavePic_Click(object sender, EventArgs e)
        {
          
          
            int employeeNo = 0;
            if (!string.IsNullOrEmpty(textBox1.Text.Trim()))
            {
                employeeNo = Convert.ToInt32(textBox1.Text.Trim());
            }
            if (employeeNo > 0)
            {
                HttpClient client = new HttpClient();

                client.BaseAddress = new Uri(BaseAddress);
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                HttpResponseMessage response = new HttpResponseMessage();

                Stream myStream = null;
                OpenFileDialog openFileDialog1 = new OpenFileDialog(); 


                openFileDialog1.InitialDirectory = "c:\\";
                openFileDialog1.Filter = "Images (*.BMP;*.JPG;*.GIF,*.PNG,*.TIFF)|*.BMP;*.JPG;*.GIF;*.PNG;*.TIFF| All files (*.*)|*.*";
                openFileDialog1.FilterIndex = 2;
                openFileDialog1.RestoreDirectory = true;

                if (openFileDialog1.ShowDialog() == DialogResult.OK)
                {
                    try
                    {
                        if ((myStream = openFileDialog1.OpenFile()) != null)
                        {
                            btnSavePic.Enabled = false;
                            button1.Enabled = false;
                            using (myStream)
                            {
                                // Insert code to read the stream here.
                                byte[] buffer = new byte[16 * 1024];
                                using (MemoryStream ms = new MemoryStream())
                                {
                                    int read;
                                    while ((read = myStream.Read(buffer, 0, buffer.Length)) > 0)
                                    {
                                        ms.Write(buffer, 0, read);
                                    }
                                    byte[] EncyPic = EncryptBytes(ms.ToArray(), "2BeMy", "EmpPicUpdate");
                                    Param prm = new Param();
                                    prm.EmpPic = EncyPic;
                                    prm.EmpId = employeeNo;
                                    prm.SyncParam = SyncPath;
                                    response = client.PostAsJsonAsync("api/employee", prm).Result;
                                   
                                    if (response.IsSuccessStatusCode)
                                    {
                                       
                                        Image img1 = byteArrayToImage(ms.ToArray());
                                        pictureBox1.Image = img1;
                                    }
                                    btnSavePic.Enabled = true;
                                    button1.Enabled = true;
                                }
                            }
                        }
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
                    }
                }
            }
            else
            {
                MessageBox.Show("EmployeeNo is Required");
            }
        }

    }
 ///////////////////////////////////////////// End Form Code /////////////////////////////////////////////////
///////////////////////////////////EmployeeController : ApiController/////////////////////////////////////
        [HttpPost]
        public bool SaveEmployeeImage(Param ms)
        {
            SQL obj = new SQL();
            DataSet ds = new DataSet();
            try
            {
                byte[] DecryPic = DecryptBytes(ms.EmpPic, "2BeMy", "EmpPicUpdate");
                MemoryStream ms1 = new MemoryStream(DecryPic);             
                SaveFileOnDisk(ms1, ms.EmpId.ToString(),ms.SyncParam);

            }
            catch (Exception s)
            { throw (s); }

            return true;
        }
////////////////////////////////End////////////////////////////////////////////////

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