des.java

DES加密方法

byte[] encodeDES(byte[] data, int offset, int len, byte[] passwd) throws Exception 
{ 
	if (passwd.length != DESKeySpec.DES_KEY_LEN) 
		throw new Exception(“DES加密方法的密码位数为8，指定的密码位数为“ + passwd.length)；
	Security.addProvider (new com.sun.crypto.provider.SunJCE())； 
	try { 
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(“DES“)；
		DESKeySpec keySpec = new DESKeySpec(passwd)； 
		SecretKey deskey = keyFactory.generateSecret(keySpec)； 
		Cipher c = Cipher.getInstance(“DES“)； 
		c.init(Cipher.ENCRYPT_MODE, deskey)； 
		return c.doFinal(data, offset, len)； 
	} catch(Exception ex){ 
		throw new RuntimeException(“DES加密失败“, ex)； 
	} 
} 
byte[] decodeDES(byte[] data, int offset, int len, byte[] passwd) throws Exception
{ 
	if (passwd.length != DESKeySpec.DES_KEY_LEN) 
		throw new Exception(“DES加密方法的密码位数为8，指定的密码位数为“ + passwd.length)； 
	Security.addProvider(new com.sun.crypto.provider.SunJCE())； 
	try { 
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(“DES“)； 
		DESKeySpec keySpec = new DESKeySpec(passwd)； 
		SecretKey deskey = keyFactory.generateSecret(keySpec)； 
		Cipher c = Cipher.getInstance(“DES“)； 
		c.init(Cipher.DECRYPT_MODE, deskey)； 
		return c.doFinal(data, offset, len)； 
	} catch(Exception ex){ 
		throw new RuntimeException(“DES解密失败“, ex)； 
	} 
}