using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Windows.Forms;
namespace AES_2
{
public partial class Form5 : Form
{
public Form5()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
textBox2.Text = EncryptString(textBox1.Text, textBox3.Text);
string file = "";
OpenFileDialog dialog = new OpenFileDialog();
dialog.Multiselect = false; //該值確定是否可以選擇多個檔案
dialog.Title = "請選擇圖片";
dialog.Filter = "圖片檔案(*.bmp)|*.bmp;*.jpg";
if (dialog.ShowDialog() == DialogResult.OK)
{
file = dialog.FileName;
textBox4.Text = file;
}
else
{
return;
}
Bitmap enBit = new Bitmap(file);
enBit = MixStringIntoImage(textBox2.Text, enBit);
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.Title = "另存圖片";
saveFileDialog1.Filter = "圖片檔案(*.bmp)|*.bmp;*.jpg";
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
PictureBox PB1 = new PictureBox();
PB1.Image = enBit;
try
{
PB1.Image.Save(saveFileDialog1.FileName, System.Drawing.Imaging.ImageFormat.Bmp);
}
catch {
MessageBox.Show("發生錯誤，請重啟程式");
Application.Restart();
}
pictureBox1.Image = enBit;
}
}
private void button2_Click(object sender, EventArgs e)
{
string file = "";
OpenFileDialog dialog = new OpenFileDialog();
dialog.Multiselect = false; //該值確定是否可以選擇多個檔案
dialog.Title = "請選擇圖片";
dialog.Filter = "圖片檔案(*.bmp)|*.bmp;*.jpg";
if (dialog.ShowDialog() == DialogResult.OK)
{
file = dialog.FileName;
textBox4.Text = file;
}
else
{
return;
}
Bitmap enBit = new Bitmap(file);
pictureBox1.Image = enBit;
try
{
textBox2.Text = GetStringFromMixedImage(enBit);
textBox1.Text = DecryptString(textBox2.Text, textBox3.Text);
}
catch(Exception ex) {
MessageBox.Show(ex.Message);
}
}
public static string EncryptString(string message, string key)
{
key = Get_SHA256_Hash(key).Substring(0, 32);
var keyBytes = Encoding.UTF8.GetBytes(key);
var aes = new AesCryptoServiceProvider();
aes.GenerateIV();
var iv = aes.IV;
using (var memStream = new System.IO.MemoryStream())
{
memStream.Write(iv, 0, iv.Length); // Add the IV to the first 16 bytes of the encrypted value
using (var cryptStream = new CryptoStream(memStream, aes.CreateEncryptor(keyBytes, aes.IV), CryptoStreamMode.Write))
{
using (var writer = new System.IO.StreamWriter(cryptStream))
{
writer.Write(message);
}
}
var buf = memStream.ToArray();
return Convert.ToBase64String(buf);
}
}
public static string DecryptString(string encryptedValue, string key)
{
key = Get_SHA256_Hash(key).Substring(0, 32);
var bytes = Convert.FromBase64String(encryptedValue);
var keyBytes = Encoding.UTF8.GetBytes(key);
var aes = new AesCryptoServiceProvider();
using (var memStream = new System.IO.MemoryStream(bytes))
{
var iv = new byte[16];
memStream.Read(iv, 0, 16); // Pull the IV from the first 16 bytes of the encrypted value
using (var cryptStream = new CryptoStream(memStream, aes.CreateDecryptor(keyBytes, iv), CryptoStreamMode.Read))
{
using (var reader = new System.IO.StreamReader(cryptStream))
{
return reader.ReadToEnd();
}
}
}
}
public static string Get_SHA256_Hash(string str)
{
byte[] sha256Bytes = Encoding.UTF8.GetBytes(str);
SHA256Managed sha256 = new SHA256Managed();
byte[] bytes = sha256.ComputeHash(sha256Bytes);
return BitConverter.ToString(bytes).Replace("-", "").ToUpper();
}
public Bitmap MixStringIntoImage(string s, Bitmap img)
{
int i, x, y;
i = 0;
x = 0;
y = 0;
while (i <= s.Length)
{
Color pixelColor = img.GetPixel(x, y);
if (i == 0) //紀錄暗文字數
{
int num = s.Length;
int sR, sG, sB;
sB = num % 256;
num /= 256;
sG = num % 256;
num /= 256;
sR = num % 256;
pixelColor = Color.FromArgb(sR, sG, sB);
}
else
{
pixelColor = Color.FromArgb(pixelColor.R, pixelColor.G, (int)s[i - 1]); //將暗文寫入該像素的藍色(B)
}
img.SetPixel(x, y, pixelColor);
i++;
x++;
if (x == img.Width)
{
x = 0;
y++;
if (y == img.Height) throw new Exception("String is too long for this image!!!");
}
}
return img;
}
public string GetStringFromMixedImage(Bitmap img)
{
string s = "";
int i, x, y;
int stringLength = 1;
i = 0;
x = 0;
y = 0;
while (i <= stringLength)
{
if (i == 0) //獲得暗文字數
{
int sR, sG, sB;
sR = img.GetPixel(0, 0).R;
sG = img.GetPixel(0, 0).G;
sB = img.GetPixel(0, 0).B;
stringLength = sR * Convert.ToInt32(Math.Pow(256, 2)) + sG * 256 + sB;
}
else
{
s = s + (char)(img.GetPixel(x, y).B); //該像素的藍色(B) = 暗文
}
i++;
x++;
if (x == img.Width)
{
x = 0;
y++;
if (y == img.Height) throw new Exception("String is too long for this image!!!");
}
}
return s;
}
}
}
