Java 中用于加密和解密文本文件的密钥
Key for Encrypting and Decrypting a Text File in Java
我正在 Java 开发一个 Encryption/Decryption 程序。我正在使用一个名为 "secret1234" 的密钥来加密和解密文本文件中的消息。该程序使用字符串作为密钥。但是,我对使用数字(整数)作为密钥感兴趣,这样我就可以生成随机数。那么,如何修改这个程序,让密钥是一个整数,而不是一个用于加密和解密消息的字符串呢?
这是程序:
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
public class Program {
public static void main(String[] args) {
try {
String key = "secret1234";// This is the key
FileInputStream fis = new FileInputStream("text.txt");//text.txt is a text file with a short message
FileOutputStream fos = new FileOutputStream("encryptedText.txt");
encrypt(key, fis, fos);
FileInputStream fis2 = new FileInputStream("encryptedText.txt");
FileOutputStream fos2 = new FileOutputStream("decryptedText.txt");
decrypt(key, fis2, fos2);
} catch (Throwable e) {
e.printStackTrace();
}
}
public static void encrypt(String key, InputStream is, OutputStream os) throws Throwable {
encryptOrDecrypt(key, Cipher.ENCRYPT_MODE, is, os);
}
public static void decrypt(String key, InputStream is, OutputStream os) throws Throwable {
encryptOrDecrypt(key, Cipher.DECRYPT_MODE, is, os);
}
public static void encryptOrDecrypt(String key, int mode, InputStream is, OutputStream os) throws Throwable {
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
SecretKey desKey = skf.generateSecret(dks);
Cipher cipher = Cipher.getInstance("DES");
if (mode == Cipher.ENCRYPT_MODE) {
cipher.init(Cipher.ENCRYPT_MODE, desKey);
CipherInputStream cis = new CipherInputStream(is, cipher);
doCopy(cis, os);
} else if (mode == Cipher.DECRYPT_MODE) {
cipher.init(Cipher.DECRYPT_MODE, desKey);
CipherOutputStream cos = new CipherOutputStream(os, cipher);
doCopy(is, cos);
}
}
public static void doCopy(InputStream is, OutputStream os) throws IOException {
byte[] bytes = new byte[64];
int numBytes;
while ((numBytes = is.read(bytes)) != -1) {
os.write(bytes, 0, numBytes);
}
os.flush();
os.close();
is.close();
}
}
在您的代码中使用它来生成密钥:
String key = String.valueOf(SecureRandom.getInstance("SHA1PRNG").nextInt());
我正在 Java 开发一个 Encryption/Decryption 程序。我正在使用一个名为 "secret1234" 的密钥来加密和解密文本文件中的消息。该程序使用字符串作为密钥。但是,我对使用数字(整数)作为密钥感兴趣,这样我就可以生成随机数。那么,如何修改这个程序,让密钥是一个整数,而不是一个用于加密和解密消息的字符串呢?
这是程序:
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
public class Program {
public static void main(String[] args) {
try {
String key = "secret1234";// This is the key
FileInputStream fis = new FileInputStream("text.txt");//text.txt is a text file with a short message
FileOutputStream fos = new FileOutputStream("encryptedText.txt");
encrypt(key, fis, fos);
FileInputStream fis2 = new FileInputStream("encryptedText.txt");
FileOutputStream fos2 = new FileOutputStream("decryptedText.txt");
decrypt(key, fis2, fos2);
} catch (Throwable e) {
e.printStackTrace();
}
}
public static void encrypt(String key, InputStream is, OutputStream os) throws Throwable {
encryptOrDecrypt(key, Cipher.ENCRYPT_MODE, is, os);
}
public static void decrypt(String key, InputStream is, OutputStream os) throws Throwable {
encryptOrDecrypt(key, Cipher.DECRYPT_MODE, is, os);
}
public static void encryptOrDecrypt(String key, int mode, InputStream is, OutputStream os) throws Throwable {
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
SecretKey desKey = skf.generateSecret(dks);
Cipher cipher = Cipher.getInstance("DES");
if (mode == Cipher.ENCRYPT_MODE) {
cipher.init(Cipher.ENCRYPT_MODE, desKey);
CipherInputStream cis = new CipherInputStream(is, cipher);
doCopy(cis, os);
} else if (mode == Cipher.DECRYPT_MODE) {
cipher.init(Cipher.DECRYPT_MODE, desKey);
CipherOutputStream cos = new CipherOutputStream(os, cipher);
doCopy(is, cos);
}
}
public static void doCopy(InputStream is, OutputStream os) throws IOException {
byte[] bytes = new byte[64];
int numBytes;
while ((numBytes = is.read(bytes)) != -1) {
os.write(bytes, 0, numBytes);
}
os.flush();
os.close();
is.close();
}
}
在您的代码中使用它来生成密钥:
String key = String.valueOf(SecureRandom.getInstance("SHA1PRNG").nextInt());