mydes.java

这是一个加密程序

 
import java.security.*; 
import javax.crypto.*; 
import javax.crypto.spec.SecretKeySpec; 

public class MyDes { 

private static final String Algorithm = "DESede"; //定义 加密算法,可用 DES,DESede,Blowfish 

//keybyte为加密密钥，长度为24字节 
//src为被加密的数据缓冲区（源） 
public static byte[] encryptMode(byte[] keybyte, byte[] src) { 
try { 
//生成密钥 
SecretKey deskey = new SecretKeySpec(keybyte, Algorithm); 

//加密 
Cipher c1 = Cipher.getInstance(Algorithm); 
c1.init(Cipher.ENCRYPT_MODE, deskey); 
return c1.doFinal(src); 
} catch (java.security.NoSuchAlgorithmException e1) { 
e1.printStackTrace(); 
} catch (javax.crypto.NoSuchPaddingException e2) { 
e2.printStackTrace(); 
} catch (java.lang.Exception e3) { 
e3.printStackTrace(); 
} 
return null; 
} 

//keybyte为加密密钥，长度为24字节 
//src为加密后的缓冲区 
public static byte[] decryptMode(byte[] keybyte, byte[] src) { 
try { 
//生成密钥 
SecretKey deskey = new SecretKeySpec(keybyte, Algorithm); 

//解密 
Cipher c1 = Cipher.getInstance(Algorithm); 
c1.init(Cipher.DECRYPT_MODE, deskey); 
return c1.doFinal(src); 
} catch (java.security.NoSuchAlgorithmException e1) { 
e1.printStackTrace(); 
} catch (javax.crypto.NoSuchPaddingException e2) { 
e2.printStackTrace(); 
} catch (java.lang.Exception e3) { 
e3.printStackTrace(); 
} 
return null; 
} 

//转换成十六进制字符串 
public static String byte2hex(byte[] b) { 
String hs=""; 
String stmp=""; 

for (int n=0;n<b.length;n++) { 
stmp=(java.lang.Integer.toHexString(b[n] & 0XFF)); 
if (stmp.length()==1) hs=hs+"0"+stmp; 
else hs=hs+stmp; 
if (n<b.length-1) hs=hs+":"; 
} 
return hs.toUpperCase(); 
} 

public static void main(String[] args) 
{ 
//添加新安全算法,如果用JCE就要把它添加进去 
Security.addProvider(new com.sun.crypto.provider.SunJCE()); 

final byte[] keyBytes = {0x11, 0x11, 0x11, 0x11, (byte)0x11, 0x11, 0x11, 0x11 
, 0x11, 0x11, 0x11, 0x11, (byte)0x11, (byte)0x11, 0x11, 0x11 
, 0x11, 0x11, 0x11, (byte)0x11, 0x11, 0x11, 0x11, (byte)0x11}; //24字节的密钥 
String szSrc = "aaa aaa aaa."; 

System.out.println("加密前的字符串:" + szSrc); 

byte[] encoded = encryptMode(keyBytes, szSrc.getBytes()); 
System.out.println("加密后的字符串:" + new String(encoded)); 

byte[] srcBytes = decryptMode(keyBytes, encoded); 
System.out.println("解密后的字符串:" + (new String(srcBytes))); 
} 
}