Encrypt and Decrypt Image .net

Question

Can anyone give me an example for encrypt and decrypt an image using .net with asp.net

I want this encryption to the image when I save it into sql server as binary data.

Answer 1

Include these name spaces

using System.IO;
using System.Security.Cryptography;

For Encryption create below function:

private void EncryptFile(string inputFile, string outputFile)
{

    try
    {
        string password = @"myKey123"; // Your Key Here
        UnicodeEncoding UE = new UnicodeEncoding();
        byte[] key = UE.GetBytes(password);

        string cryptFile = outputFile;
        FileStream fsCrypt = new FileStream(cryptFile, FileMode.Create);

        RijndaelManaged RMCrypto = new RijndaelManaged();

        CryptoStream cs = new CryptoStream(fsCrypt,
            RMCrypto.CreateEncryptor(key, key),
            CryptoStreamMode.Write);

        FileStream fsIn = new FileStream(inputFile, FileMode.Open);

        int data;
        while ((data = fsIn.ReadByte()) != -1)
            cs.WriteByte((byte)data);


        fsIn.Close();
        cs.Close();
        fsCrypt.Close();
    }
    catch
    {
        MessageBox.Show("Encryption failed!", "Error");
    }
}

For Decryption create below function :

private void DecryptFile(string inputFile, string outputFile)
{

    {
        string password = @"myKey123"; // Your Key Here

        UnicodeEncoding UE = new UnicodeEncoding();
        byte[] key = UE.GetBytes(password);

        FileStream fsCrypt = new FileStream(inputFile, FileMode.Open);

        RijndaelManaged RMCrypto = new RijndaelManaged();

        CryptoStream cs = new CryptoStream(fsCrypt,
            RMCrypto.CreateDecryptor(key, key),
            CryptoStreamMode.Read);

        FileStream fsOut = new FileStream(outputFile, FileMode.Create);

        int data;
        while ((data = cs.ReadByte()) != -1)
            fsOut.WriteByte((byte)data);

        fsOut.Close();
        cs.Close();
        fsCrypt.Close();

    }
}

You can call like this

   EncryptFile(@"D:\OriginalImage.png", @"D:\VizioEncrypted.png"); //To Encrypt

   DecryptFile(@"D:\VizioEncrypted.png", @"D:\VizioDecrypted.png"); //To Decrypt

This will help

Answer 2

Finally I found the solution for this problem. I will add the code for helping who need that.

Encryption method:

    Public Function EncryptStream(ByVal input As Byte()) As Byte()
    Dim rijn As New RijndaelManaged()
    Dim encrypted As Byte()
    Dim key As Byte() = New Byte() {&H22, &HC0, &H6D, &HCB, &H23, &HA6, _
     &H3, &H1B, &H5A, &H1D, &HD3, &H9F, _
     &H85, &HD, &HC1, &H72, &HED, &HF4, _
     &H54, &HE6, &HBA, &H65, &HC, &H22, _
     &H62, &HBE, &HF3, &HEC, &H14, &H81, _
     &HA8, &HA}
    '32
    Dim IV As Byte() = New Byte() {&H43, &HB1, &H93, &HB, &H1A, &H87, _
     &H52, &H62, &HFB, &H8, &HD, &HC0, _
     &HCA, &H40, &HC2, &HDB}
    '16
    'Get an encryptor.
    Dim encryptor As ICryptoTransform = rijn.CreateEncryptor(key, IV)

    'Encrypt the data.
    Dim msEncrypt As New MemoryStream()
    Dim csEncrypt As New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)


    'Write all data to the crypto stream and flush it.
    csEncrypt.Write(input, 0, input.Length)
    csEncrypt.FlushFinalBlock()

    'Get encrypted array of bytes.
    encrypted = msEncrypt.ToArray()

    Return encrypted

End Function

Decryption Method:

    Public Function DecryptStream(ByVal input As Byte()) As Byte()
    Dim rijn As New RijndaelManaged()
    Dim decrypted As Byte()
    Dim key As Byte() = New Byte() {&H22, &HC0, &H6D, &HCB, &H23, &HA6, _
     &H3, &H1B, &H5A, &H1D, &HD3, &H9F, _
     &H85, &HD, &HC1, &H72, &HED, &HF4, _
     &H54, &HE6, &HBA, &H65, &HC, &H22, _
     &H62, &HBE, &HF3, &HEC, &H14, &H81, _
     &HA8, &HA}
    '32
    Dim IV As Byte() = New Byte() {&H43, &HB1, &H93, &HB, &H1A, &H87, _
     &H52, &H62, &HFB, &H8, &HD, &HC0, _
     &HCA, &H40, &HC2, &HDB}
    '16 


    'Get a decryptor that uses the same key and IV as the encryptor.
    Dim decryptor As ICryptoTransform = rijn.CreateDecryptor(key, IV)

    'Now decrypt the previously encrypted message using the decryptor
    ' obtained in the above step.
    Dim msDecrypt As New MemoryStream(input)
    Dim csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)

    decrypted = New Byte(input.Length - 1) {}

    'Read the data out of the crypto stream.
    csDecrypt.Read(decrypted, 0, decrypted.Length)

    Return decrypted
End Function