将加密的图像字节保存到文件中，并在java中恢复为原始图像 [英] Save encrypted image bytes to file and recover to original image in java
问题描述
我有一个图像的加密和解密问题，原因是现在确定的，但我不能弄清楚解决方案。
i have a problem with encryption and decryption of an image the reason is identified now but I couldn't figureout the solution.
我试图实现项目
但问题是加密图像字节不能恢复后使用rasterclass和ImageIO类
but the problem is encrypted image bytes are not recovered after written to an image file using rasterclass and ImageIO class
写入图像文件后，尝试的代码和解释是
< a href =http://stackoverflow.com/questions/28383811/reading-encrypted-bytes-from-an-image-in-java> 在此处提交
my problem,tried code and explanations are submitted here
我必须在加密的图像（Stegnography）中嵌入文本。我googled，并找到了在图像中嵌入文本的代码。但我必须首先加密图像，并在这个加密的图像嵌入文本。我的尝试如下。
I have to embed text in an encrypted image(Stegnography). I googled and found codes for embedding text in an image. But I have to encrypt image at first and embed text in this encrypted image. My tries are as follows.
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package tbn;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.ComponentColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.io.File;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.imageio.ImageIO;
/**
*
* @author user
*/
public class DbtClass {
public static void main(String[] args) {
try {
BufferedImage orgnlimage = ImageIO.read(new File("parrruuuuu.png"));
orgnlimage = user_space(orgnlimage);
byte[] orgnlimagebytes = get_byte_data(orgnlimage);
byte[] encryptedbytes = encrypt(orgnlimagebytes, "abc");
BufferedImage encryptedimage = toImage(encryptedbytes, orgnlimage.getWidth(), orgnlimage.getHeight());
ImageIO.write(encryptedimage, "png", new File("encrypted.png"));
/////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////
byte[] encryptedbytes2 = get_byte_data(encryptedimage);
System.out.println("encryptedbytes before writing: "+encryptedbytes2.length);
BufferedImage encryptedimage3 = ImageIO.read(new File("encrypted.png"));
byte[] encryptedbyte3 = get_byte_data(encryptedimage3);
System.out.println("encryptedbytes after writing: "+encryptedbyte3.length);
} catch (IOException ex) {
Logger.getLogger(DbtClass.class.getName()).log(Level.SEVERE, null, ex);
}
}
public static BufferedImage user_space(BufferedImage image) {
//create new_img with the attributes of image
BufferedImage new_img = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
Graphics2D graphics = new_img.createGraphics();
graphics.drawRenderedImage(image, null);
graphics.dispose(); //release all allocated memory for this image
return new_img;
}
public static byte[] get_byte_data(BufferedImage image) {
WritableRaster raster = image.getRaster();
DataBufferByte buffer = (DataBufferByte) raster.getDataBuffer();
return buffer.getData();
}
public static byte[] encrypt(byte[] orgnlbytes, String key) {
byte[] encbytes = null;
try {
Cipher cipher = Cipher.getInstance("AES");
KeyGenerator keyGen = KeyGenerator.getInstance("AES");
SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
// cryptograph. secure random
random.setSeed(key.getBytes());
keyGen.init(128, random);
// for example
SecretKey secretKey = keyGen.generateKey();
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
encbytes = cipher.doFinal(orgnlbytes);
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(DbtClass.class.getName()).log(Level.SEVERE, null, ex);
} catch (NoSuchPaddingException ex) {
Logger.getLogger(DbtClass.class.getName()).log(Level.SEVERE, null, ex);
} catch (InvalidKeyException ex) {
Logger.getLogger(DbtClass.class.getName()).log(Level.SEVERE, null, ex);
} catch (IllegalBlockSizeException ex) {
Logger.getLogger(DbtClass.class.getName()).log(Level.SEVERE, null, ex);
} catch (BadPaddingException ex) {
Logger.getLogger(DbtClass.class.getName()).log(Level.SEVERE, null, ex);
}
return encbytes;
}
public static BufferedImage toImage(byte[] imagebytes, int width, int height) {
DataBuffer buffer = new DataBufferByte(imagebytes, imagebytes.length);
WritableRaster raster = Raster.createInterleavedRaster(buffer, width, height, 3 * width, 3, new int[]{2, 1, 0}, (Point) null);
ColorModel cm = new ComponentColorModel(ColorModel.getRGBdefault().getColorSpace(), false, true, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
return new BufferedImage(cm, raster, true, null);
}
}
这里我使用栅格类编写了加密图像， ImageIO.write（）。然后从文件中读取这个加密的字节使用ImageIO.read（）在写图像之前加密的字节[]和读取图像后的字节[]是不同的
Here I was written the encrypted image using raster class and ImageIO.write().Then read this encrypted bytes from file Using ImageIO.read().The encrypted byte[] before writing the image and the byte[] after reading the image are totaly different
我有理由为此这里但我不知道该在这里做什么来克服
I got reason for this here but I don't know what to do here to overcome
推荐答案
我有一个解决方案， XOR加密
这将永远不会导致数据丢失通过写入加密的图像字节到图像文件
I got a solution by replacing AES encryption by XOR encryption this will never cause the data loss by writing encrypted image bytes to image file
所以谢谢你的反应在thids和previuos问题
so thank you for your responses in every time in thids and previuos question
这篇关于将加密的图像字节保存到文件中，并在java中恢复为原始图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
