Java使用3DES加密解密的流程
?、賯魅牍餐s定的密鑰(keyBytes)以及算法(Algorithm),來構(gòu)建SecretKey密鑰對象
SecretKey deskey = new SecretKeySpec(keyBytes, Algorithm);
?、诟鶕?jù)算法實(shí)例化Cipher對象。它負(fù)責(zé)加密/解密
Cipher c1 = Cipher.getInstance(Algorithm);
?、蹅魅爰用?解密模式以及SecretKey密鑰對象,實(shí)例化Cipher對象
c1.init(Cipher.ENCRYPT_MODE, deskey);
?、軅魅胱止?jié)數(shù)組,調(diào)用Cipher.doFinal()方法,實(shí)現(xiàn)加密/解密,并返回一個(gè)byte字節(jié)數(shù)組
c1.doFinal(src);
3DES案例
—SecretUtils.java(3DES加密解密的工具類)—
package my3des;
import java.io.UnsupportedEncodingException;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
/**
* SecretUtils {3DES加密解密的工具類 }
* @author William
* @date 2013-04-19
*/
public class SecretUtils {
//定義加密算法,有DES、DESede(即3DES)、Blowfish
private static final String Algorithm = “DESede”;
private static final String PASSWORD_CRYPT_KEY = “2012PinganVitality075522628888ForShenZhenBelter075561869839”;
/**
* 加密方法
* @param src 源數(shù)據(jù)的字節(jié)數(shù)組
* @return
*/
public static byte[] encryptMode(byte[] src) {
try {
SecretKey deskey = new SecretKeySpec(build3DesKey(PASSWORD_CRYPT_KEY), Algorithm); //生成密鑰
Cipher c1 = Cipher.getInstance(Algorithm); //實(shí)例化負(fù)責(zé)加密/解密的Cipher工具類
c1.init(Cipher.ENCRYPT_MODE, deskey); //初始化為加密模式
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;
}
/**
* 解密函數(shù)
* @param src 密文的字節(jié)數(shù)組
* @return
*/
public static byte[] decryptMode(byte[] src) {
try {
SecretKey deskey = new SecretKeySpec(build3DesKey(PASSWORD_CRYPT_KEY), Algorithm);
Cipher c1 = Cipher.getInstance(Algorithm);
c1.init(Cipher.DECRYPT_MODE, deskey); //初始化為解密模式
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;
}
/*
* 根據(jù)字符串生成密鑰字節(jié)數(shù)組
* @param keyStr 密鑰字符串
* @return
* @throws UnsupportedEncodingException
*/
public static byte[] build3DesKey(String keyStr) throws UnsupportedEncodingException{
byte[] key = new byte[24]; //聲明一個(gè)24位的字節(jié)數(shù)組,默認(rèn)里面都是0
byte[] temp = keyStr.getBytes(“UTF-8”); //將字符串轉(zhuǎn)成字節(jié)數(shù)組
/*
77 * 執(zhí)行數(shù)組拷貝
* System.arraycopy(源數(shù)組,從源數(shù)組哪里開始拷貝,目標(biāo)數(shù)組,拷貝多少位)
*/
if(key.length 》 temp.length){
//如果temp不夠24位,則拷貝temp數(shù)組整個(gè)長度的內(nèi)容到key數(shù)組中
System.arraycopy(temp, 0, key, 0, temp.length);
}else{
//如果temp大于24位,則拷貝temp數(shù)組24個(gè)長度的內(nèi)容到key數(shù)組中
System.arraycopy(temp, 0, key, 0, key.length);
}
return key;
}
}
—Main.java(測試類)—
package my3des;
public class Main {
/**
* @param args
*/
public static void main(String[] args) {
String msg = “3DES加密解密案例”;
System.out.println(“【加密前】:” + msg);
//加密
byte[] secretArr = SecretUtils.encryptMode(msg.getBytes());
System.out.println(“【加密后】:” + new String(secretArr));
//解密
byte[] myMsgArr = SecretUtils.decryptMode(secretArr);
System.out.println(“【解密后】:” + new String(myMsgArr));
}
}
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