Java中常用的加密方式(附多个工具类)(二)
4.MD5加密
Message Digest Algorithm MD5（中文名为消息摘要算法第五版）为计算机安全领域广泛使用的一种散列函数，用以提供消息的完整性保护。该算法的文件号为RFC 1321（R.Rivest,MIT Laboratory for Computer Science and RSA Data Security Inc. April 1992）.
MD5的全称是Message-Digest Algorithm 5（信息-摘要算法），在90年代初由MIT Laboratory for Computer Science和RSA Data Security Inc的Ronald L. Rivest开发出来，经MD2、MD3和MD4发展而来。
MD5用于确保信息传输完整一致。是计算机广泛使用的杂凑算法之一（又译摘要算法、哈希算法），主流编程语言普遍已有MD5实现。将数据（如汉字）运算为另一固定长度值，是杂凑算法的基础原理，MD5的前身有MD2、MD3和MD4。
MD5的作用是让大容量信息在用数字签名软件签署私人密钥前被”压缩”成一种保密的格式（就是把一个任意长度的字节串变换成一定长的十六进制数字串）。
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
* Java消息摘要算法 MD5 工具类,其实其他摘要算法的实现也类似
*/
public class MD5Util {
/**
* 对文本执行 md5 摘要加密, 此算法与 mysql,JavaScript生成的md5摘要进行过一致性对比.
* @param plainText
* @return 返回值中的字母为小写
*/
public static String md5(String plainText) {
if (null == plainText) {
plainText = "";
}
String MD5Str = "";
try {
// JDK 6 支持以下6种消息摘要算法，不区分大小写
// md5,sha(sha-1),md2,sha-256,sha-384,sha-512
MessageDigest md = MessageDigest.getInstance("MD5");
md.update(plainText.getBytes());
byte b[] = md.digest();
int i;
StringBuilder builder = new StringBuilder(32);
for (int offset = 0; offset < b.length; offset++) {
i = b[offset];
if (i < 0)
i += 256;
if (i < 16)
builder.append("0");
builder.append(Integer.toHexString(i));
}
MD5Str = builder.toString();
// LogUtil.println("result: " + buf.toString());// 32位的加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return MD5Str;
}
// 一个简版测试
public static void main(String[] args) {
String m1 = md5("1");
String m2 = md5(m1);
/* 输出为
* m1=c4ca4238a0b923820dcc509a6f75849b
* m2=28c8edde3d61a0411511d3b1866f0636
*/
System.out.println("m1="+m1);
System.out.println("m2="+m2);
}
}
通常我们不直接使用上述MD5加密。通常将MD5产生的字节数组交给Base64再加密一把，得到相应的字符串。
5.数字签名算法
签名：就有安全性，抗否认性
数字签名：带有密钥（公钥，私钥）的消息摘要算法
作用：
1. 验证数据的完整性
2. 认证数据来源
3. 抗否认
数字签名遵循：私钥签名，公钥验证
常用的数字签名算法：RSA，DSA，ECDSA
RSA介绍：
是经典算法，是目前为止使用最广泛的数字签名算法。
RSA数字签名算法的密钥实现与RSA的加密算法是一样的，算法的名称都叫RSA。密钥的产生和转换都是一样的。
RSA数字签名算法主要包括MD和SHA两类。
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import org.apache.commons.codec.binary.Hex;
public class RSATest {
public static final String src = "hello world";
public static void main(String[] args) {
jdkRSA();
}
/**
* 说明： 用java的jdk里面相关方法实现rsa的签名及签名验证
*/
public static void jdkRSA() {
try {
// 1.初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator
.getInstance("RSA");
//设置KEY的长度
keyPairGenerator.initialize(512);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
//得到公钥
RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
//得到私钥
RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
// 2.进行签名
//用私钥进行签名
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(
rsaPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
//构造一个privateKey
PrivateKey privateKey = keyFactory
.generatePrivate(pkcs8EncodedKeySpec);
//声明签名的对象
Signature signature = Signature.getInstance("MD5withRSA");
signature.initSign(privateKey);
signature.update(src.getBytes());
//进行签名
byte[] result = signature.sign();
System.out.println("jdk rsa sign:" + Hex.encodeHexString(result));
// 3.验证签名
//用公钥进行验证签名
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(
rsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("RSA");
//构造一个publicKey
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
//声明签名对象
signature = Signature.getInstance("MD5withRSA");
signature.initVerify(publicKey);
signature.update(src.getBytes());
//验证签名
boolean bool = signature.verify(result);
System.out.println("jdk rsa verify:" + bool);
} catch (Exception e) {
System.out.println(e.toString());
}
}
}
四、应用场景
Base64应用场景：图片转码(应用于邮件，img标签，http加密)
MD5应用场景：密码加密、imei加密、文件校验
非对称加密：电商订单付款、银行相关业务
五、附多个工具类
AES
package com.hl.bluetooth.util;
import org.apache.commons.lang3.StringUtils;
import org.apache.tomcat.util.codec.binary.Base64;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class AesEncryptUtil {
//使用AES-128-CBC加密模式，key需要为16位,key和iv可以相同！
private final static String KEY = "ABCDEF1234432100";
private final static String IV = "43211234DCAB6789";
/**
* 加密方法
* @param data 要加密的数据
* @param key 加密key
* @param iv 加密iv
* @return 加密的结果
* @throws Exception
*/
public static String encrypt(String data, String key, String iv) throws Exception {
try {
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");//"算法/模式/补码方式"NoPadding PkcsPadding
int blockSize = cipher.getBlockSize();
byte[] dataBytes = data.getBytes();
int plaintextLength = dataBytes.length;
if (plaintextLength % blockSize != 0) {
plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
}
byte[] plaintext = new byte[plaintextLength];
System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);
SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());
cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
byte[] encrypted = cipher.doFinal(plaintext);
return new Base64().encodeToString(encrypted);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 解密方法
* @param data 要解密的数据
* @param key 解密key
* @param iv 解密iv
* @return 解密的结果
* @throws Exception
*/
public static String desEncrypt(String data, String key, String iv) throws Exception {
try {
// byte[] encrypted1 = new Base64().decode(data);
byte[] encrypted1 = parseHexStr2Byte(data);
// Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());
cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);
byte[] original = cipher.doFinal(encrypted1);
String originalString = new String(original);
return originalString;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 使用默认的key和iv加密
* @param data
* @return
* @throws Exception
*/
public static String encrypt(String data) throws Exception {
return encrypt(data, KEY, IV);
}
/**
* 使用默认的key和iv解密
* @param data
* @return
* @throws Exception
*/
public static String desEncrypt(String data) throws Exception {
if (StringUtils.isEmpty(data)) {
return null;
}
return desEncrypt(data, KEY, IV);
}
/**
* @Author wdc
* @Description 16进制转byte数组
* @Date 2021/4/19 11:14
* @Param [hexStr]
* @return byte[]
**/
public 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;
}
public static void main(String[] args) {
// String test = "{'admin','admin'}";
//// String test =new String(test1.getBytes(),"UTF-8");
// String data = null;
// data = AesEncryptUtil.encrypt(test);
// System.out.println("数据："+test);
// System.out.println("加密："+data);
// String jiemi = AesEncryptUtil.desEncrypt(data);
// System.out.println("解密："+jiemi);
}
}
base64
package com.sgitg.util;
import java.io.UnsupportedEncodingException;
import org.springframework.util.Base64Utils;
public class Base64Util {
/**
* 解码base64编码的字符串
*
* @param source
* @return
* @throws UnsupportedEncodingException
*/
public static String decodeFromString(String source) {
String str = "";
try {
byte[] bt = Base64Utils.decodeFromString(source);
str = new String(bt, "utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace(); // To change body of catch statement use File |
// Settings | File Templates.
}
return str;
}
/**
* 对字符串进行base64编码
*
* @param source
* @return
* @throws UnsupportedEncodingException
*/
public static String encodeToString(String source) {
byte[] bt = new byte[0];
try {
bt = source.getBytes("utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace(); // To change body of catch statement use File |
// Settings | File Templates.
}
return Base64Utils.encodeToString(bt);
}
}
EncryptUtils (编码集合)
* 1、Base64编码
* 1、AES、DES可逆算法
* 2、md5,Hex,Sha不可逆算法加密
package com.sgitg.util;
import org.apache.commons.codec.digest.DigestUtils;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Base64;
import java.util.zip.CRC32;
/**
* 数据加密
* 继承org.apache.commons.codec.digest.DigestUtils
* 1、Base64编码
* 1、AES、DES可逆算法
* 2、md5,Hex,Sha不可逆算法加密
*
* @author liuyadu
*/
public class EncryptUtils extends DigestUtils {
/**
* 计算大文件 md5获取getMD5(); SHA1获取getSha1() CRC32获取 getCRC32()
*/
private static char[] hexDigits = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e',
'f'};
// 测试
public static void main(String[] args) {
String en = encryptDES("hahahaha", "yaer");
String de = decryptDES("kzWPLLyAsDeBr84lL2COsA==", "yaer");
System.out.println(de);
System.out.println(en);
en = encryptAES("hahahaha", "yaer");
de = decryptAES("FBC82B89BAA1FBBDF3AE086A09D57E7C", "yaer");
System.out.println(de);
System.out.println(en);
}
/**
* AES加密(可逆)
*
* @param plainText 明文
* @param privateKey 密钥
* @return
* @throws NoSuchAlgorithmException
*/
public static String encryptAES(String plainText, String privateKey) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
random.setSeed(privateKey.getBytes());
kgen.init(128, random);
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");
byte[] byteContent = plainText.getBytes("utf-8");
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
byte[] byteRresult = cipher.doFinal(byteContent);
String sb = new String("");
for (int i = 0; i < byteRresult.length; i++) {
String hex = Integer.toHexString(byteRresult[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
sb = sb.concat(hex.toUpperCase());
}
return sb;
} catch (Exception e) {
return null;
}
}
/**
* AES解密
*
* @param cipherText 密文
* @param privateKey 密钥
* @return
* @throws Exception
*/
public static String decryptAES(String cipherText, String privateKey) {
try {
if (cipherText.length() < 1) {
return null;
}
byte[] byteRresult = new byte[cipherText.length() / 2];
for (int i = 0; i < cipherText.length() / 2; i++) {
int high = Integer.parseInt(cipherText.substring(i * 2, i * 2 + 1), 16);
int low = Integer.parseInt(cipherText.substring(i * 2 + 1, i * 2 + 2), 16);
byteRresult[i] = (byte) (high * 16 + low);
}
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
random.setSeed(privateKey.getBytes());
kgen.init(128, random);
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
byte[] result = cipher.doFinal(byteRresult);
return new String(result);
} catch (Exception e) {
return null;
}
}
/**
* 加密DES(可逆)
*
* @param plainText 明文
* @param privateKey 密钥
* @return
*/
public static String encryptDES(String plainText, String privateKey) {
try {
KeyGenerator keygen = KeyGenerator.getInstance("DES");
SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
secureRandom.setSeed(privateKey.getBytes());
keygen.init(56, secureRandom);
SecretKey secretKey = keygen.generateKey();
Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
byte[] cipherBytes = cipher.doFinal(plainText.getBytes("utf-8"));
byte[] plainTextBytes = Base64.getEncoder().encode(cipherBytes);
return new String(plainTextBytes, "utf-8");
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 解密DES
*
* @param cipherText 密文
* @param privateKey 密钥
* @return
*/
public static String decryptDES(String cipherText, String privateKey) {
try {
KeyGenerator keygen = KeyGenerator.getInstance("DES");
SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
secureRandom.setSeed(privateKey.getBytes());
keygen.init(56, secureRandom);
SecretKey secretKey = keygen.generateKey();
Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, secretKey);
byte[] cipherTextBytes = Base64.getDecoder().decode(cipherText.getBytes("utf-8"));
byte[] cipherBytes = cipher.doFinal(cipherTextBytes);
return new String(cipherBytes, "utf-8");
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 获取文件md5值
*
* @return md5串
*/
public static String md5(File file) {
try {
//encrypt
MessageDigest messagedigest = MessageDigest.getInstance("MD5");
FileInputStream in = new FileInputStream(file);
FileChannel ch = in.getChannel();
MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
messagedigest.update(byteBuffer);
return bufferToHex(messagedigest.digest());
} catch (Exception e) {
return null;
}
}
/***
* 获取文件SHA1值
*
* @return String 适用于上G大的文件
*/
public static String sha1(File file) {
try {
MessageDigest messagedigest = MessageDigest.getInstance("SHA-1");
FileInputStream in = new FileInputStream(file);
FileChannel ch = in.getChannel();
MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
messagedigest.update(byteBuffer);
return bufferToHex(messagedigest.digest());
} catch (Exception e) {
return null;
}
}
/**
* 获取文件SHA256值
*
* @return String
*/
public static String sha256(File file) {
try {
MessageDigest messagedigest = MessageDigest.getInstance("SHA-256");
FileInputStream in = new FileInputStream(file);
FileChannel ch = in.getChannel();
MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
messagedigest.update(byteBuffer);
return bufferToHex(messagedigest.digest());
} catch (Exception e) {
return null;
}
}
/**
* 获取文件CRC32码
*
* @return String
*/
public static String crc32(File file) {
CRC32 crc32 = new CRC32();
// MessageDigest.get
FileInputStream fileInputStream = null;
try {
fileInputStream = new FileInputStream(file);
byte[] buffer = new byte[8192];
int length;
while ((length = fileInputStream.read(buffer)) != -1) {
crc32.update(buffer, 0, length);
}
return crc32.getValue() + "";
} catch (FileNotFoundException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
} finally {
try {
if (fileInputStream != null) {
fileInputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 计算二进制数据
*
* @return
*/
private static String bufferToHex(byte bytes[]) {
return bufferToHex(bytes, 0, bytes.length);
}
private static String bufferToHex(byte bytes[], int m, int n) {
StringBuffer stringbuffer = new StringBuffer(2 * n);
int k = m + n;
for (int l = m; l < k; l++) {
appendHexPair(bytes[l], stringbuffer);
}
return stringbuffer.toString();
}
private static void appendHexPair(byte bt, StringBuffer stringbuffer) {
char c0 = hexDigits[(bt & 0xf0) >> 4];
char c1 = hexDigits[bt & 0xf];
stringbuffer.append(c0);
stringbuffer.append(c1);
}
}
