主要包括base64,AES,RSA,SHA和MD5等加密方式
未使用任何第三方工具,直接运行main方法即可
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
public class TestSecu {
public static void main(String[] args) {
try {
//base64();
//aes();
//sm();
rsa();
//sing();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* RSA加密
* 非对称加密,加密密钥分为公钥和私钥。可以使用公钥加密私钥解密,也可以使用私钥加密公钥解密
* 数字签名是带有密钥(公钥、私钥)的消息摘要算法。主要作用是验证数据的完整性、认证数据来源、抗否认。在数字签名的实现中我们使用私钥签名、公钥验证。常用的数字签名算法包括RSA、DSA、ECDSA。
*/
static void rsa() throws Exception {
String src = "hello rsa";
//1.初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(1024);//密钥长度为64的整数倍,最大是65536
KeyPair keyPair = keyPairGenerator.generateKeyPair();
RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
byte[] pk = rsaPublicKey.getEncoded();
byte[] sk = rsaPrivateKey.getEncoded();
System.out.println("RSA公钥:" + parseByte2HexStr(pk));
System.out.println("RSA私钥:" + parseByte2HexStr(sk));//可以将其保存到本地文件中
//2.1私钥加密,公钥解密【加密】
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
byte[] result = cipher.doFinal(src.getBytes());
System.out.println("RSA私钥加密:" + parseByte2HexStr(result));
//2.2私钥加密,公钥解密【解密】
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("RSA");
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
cipher.init(Cipher.DECRYPT_MODE, publicKey);
result = cipher.doFinal(result);
System.out.println("RSA公钥解密:" + new String(result));
//3.1公钥加密,私钥解密【加密】
x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("RSA");
publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
result = cipher.doFinal(src.getBytes());
System.out.println("RSA公钥加密:" + parseByte2HexStr(result));
//3.2公约加密,私钥解密【解密】
pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
keyFactory = KeyFactory.getInstance("RSA");
privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
result = cipher.doFinal(result);
System.out.println("RSA私钥解密:" + new String(result));
}
/**
* 数字签名-rsa
* 数字签名是带有密钥(公钥、私钥)的消息摘要算法。主要作用是验证数据的完整性、认证数据来源、抗否认。在数字签名的实现中我们使用私钥签名、公钥验证。常用的数字签名算法包括RSA、DSA、ECDSA。n
*/
static void sing() throws Exception {
String src = "hello rsa";
//1.初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(1024);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
//2.执行数字签名【私钥签名】
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Signature signature = Signature.getInstance("MD5WithRSA");
signature.initSign(privateKey);
signature.update(src.getBytes());
byte[] result = signature.sign();
System.out.println("RSA签名:" + parseByte2HexStr(result));
//3.验证签名【公钥验证】
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("RSA");
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
signature = Signature.getInstance("MD5WithRSA");
signature.initVerify(publicKey);
signature.update(src.getBytes());
boolean bool = signature.verify(result);
System.out.println("数字签名是否有效?" + bool);
}
/**
* Base64
* Base64并不是一种加密/解密算法,而是一种编码方式。Base64不生成密钥,通过Base64编码后的密文就可以直接“翻译”为明文,但是可以通过向明文中添加混淆字符来达到加密的效果。
* 注意,都是基于字节的
*/
static void base64() throws IOException {
String src = "www.xxx.com?title=你好";
//加密
BASE64Encoder encoder = new BASE64Encoder();
String encode = encoder.encode(src.getBytes());
System.out.println("加密后:"+encode);
//解密
BASE64Decoder decoder = new BASE64Decoder();
byte[] decode = decoder.decodeBuffer(encode);
System.out.println("解密后:"+new String(decode));
}
/**
* AES
* AES是现在对称加密算法中最流行的算法之一。加密密钥和解密密钥相同,加密运算和解密运算互为逆运算。是一种初等的加密算法。主要的算法有DES(3DES)、AES、PBE、IDEA。
*/
static void aes() throws Exception {
String src = "name=张三";//加密内容
String pkey = "123";//秘钥
//配置--加密与解密公用的
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom(pkey.getBytes()));
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
//加密
byte[] byteContent = src.getBytes("utf-8");
cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化加密器
byte[] result = cipher.doFinal(byteContent);
String p = parseByte2HexStr(result);//不可直接转成字符串
System.out.println("密文:" + p);
//解密
cipher.init(Cipher.DECRYPT_MODE, key);// 初始化解密器
byte[] decryptFrom = parseHexStr2Byte(p);
byte[] result1 = cipher.doFinal(decryptFrom);
System.out.println("原文:" + new String(result1));
}
/**
* SHA与MD5
* 不可逆的加密方式,是为了防止消息在传输过程中的篡改。验证信息等。
*/
static void sm() throws Exception {
String src = "abcd";
//加密
MessageDigest messageDigest = MessageDigest.getInstance("MD5");// 构建加密类型/SHA-512
messageDigest.update(src.getBytes());// 传入要加密的字符串
byte[] b = messageDigest.digest();
String p = parseByte2HexStr(b);
System.out.println("加密后"+p);
}
/**
* 二进制转换成16进制,加密后的字节数组不能直接转换为字符串
*/
static String parseByte2HexStr(byte buf[]) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < buf.length; i++) {
String hex = Integer.toHexString(buf[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
sb.append(hex.toUpperCase());
}
return sb.toString();
}
/**
* 16进制转换成二进制
*/
static byte[] parseHexStr2Byte(String hexStr) {
if (hexStr.length() < 1)
return null;
byte[] result = new byte[hexStr.length() / 2];
for (int i = 0; i < hexStr.length() / 2; i++) {
int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
result[i] = (byte) (high * 16 + low);
}
return result;
}
}