JAVA RSA加解密和数字签名、DES加解密 在项目中的实际使用
RSA：
输出结果：
demo下载：http://download.csdn.net/detail/q908555281/9671119
1、生成随机秘钥对
2、用公钥加密私钥解密
客户端：RSA用公钥加密之后，需要对加密后的数据在进行Base64加密， 以便在HTTP协议之间传输（兼容各语言的差异性）。
服务端：以JAVA端为列，接受到数据流（InputStream）之后，将流转化为字符串，先用Base64解密，将解密后的结果，在用RSA的私钥解密。
PS：公钥保存在客户端，私钥保存在服务器端。
如果需要加解密的，采用公钥加密，私钥解密的流程。
私钥加密，一般用来做数字签名，然后用公钥来验证改数字签名。
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class RSAEncrypt {
/**
* 字节数据转字符串专用集合
*/
private static final char[] HEX_CHAR = { '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
/**
* 随机生成密钥对
*/
public static void genKeyPair(String filePath) {
// KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
KeyPairGenerator keyPairGen = null;
try {
keyPairGen = KeyPairGenerator.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// 初始化密钥对生成器，密钥大小为96-1024位
keyPairGen.initialize(1024,new SecureRandom());
// 生成一个密钥对，保存在keyPair中
KeyPair keyPair = keyPairGen.generateKeyPair();
// 得到私钥
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
// 得到公钥
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
try {
// 得到公钥字符串
String publicKeyString = new String(encryptBASE64(publicKey.getEncoded()));
// 得到私钥字符串
String privateKeyString =new String(encryptBASE64(privateKey.getEncoded()));
// 将密钥对写入到文件
FileWriter pubfw = new FileWriter(filePath + "/publicKey.keystore");
FileWriter prifw = new FileWriter(filePath + "/privateKey.keystore");
BufferedWriter pubbw = new BufferedWriter(pubfw);
BufferedWriter pribw = new BufferedWriter(prifw);
pubbw.write(publicKeyString);
pribw.write(privateKeyString);
pubbw.flush();
pubbw.close();
pubfw.close();
pribw.flush();
pribw.close();
prifw.close();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 从文件中输入流中加载公钥
*
* @param in
* 公钥输入流
* @throws Exception
* 加载公钥时产生的异常
*/
public static String loadPublicKeyByFile(String path) throws Exception {
try {
BufferedReader br = new BufferedReader(new FileReader(path
+ "/publicKey.keystore"));
String readLine = null;
StringBuilder sb = new StringBuilder();
while ((readLine = br.readLine()) != null) {
sb.append(readLine);
}
br.close();
return sb.toString();
} catch (IOException e) {
throw new Exception("公钥数据流读取错误");
} catch (NullPointerException e) {
throw new Exception("公钥输入流为空");
}
}
/**
* 从字符串中加载公钥
*
* @param publicKeyStr
* 公钥数据字符串
* @throws Exception
* 加载公钥时产生的异常
*/
public static RSAPublicKey loadPublicKeyByStr(String publicKeyStr)
throws Exception {
try {
byte[] buffer = decryptBASE64(publicKeyStr);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
return (RSAPublicKey) keyFactory.generatePublic(keySpec);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此算法");
} catch (InvalidKeySpecException e) {
throw new Exception("公钥非法");
} catch (NullPointerException e) {
throw new Exception("公钥数据为空");
}
}
/**
* 从文件中加载私钥
*
* @param keyFileName
* 私钥文件名
* @return 是否成功
* @throws Exception
*/
public static String loadPrivateKeyByFile(String path) throws Exception {
try {
BufferedReader br = new BufferedReader(new FileReader(path
+ "/privateKey.keystore"));
String readLine = null;
StringBuilder sb = new StringBuilder();
while ((readLine = br.readLine()) != null) {
sb.append(readLine);
}
br.close();
return sb.toString();
} catch (IOException e) {
throw new Exception("私钥数据读取错误");
} catch (NullPointerException e) {
throw new Exception("私钥输入流为空");
}
}
public static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr)
throws Exception {
try {
byte[] buffer = decryptBASE64(privateKeyStr);
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此算法");
} catch (InvalidKeySpecException e) {
throw new Exception("私钥非法");
} catch (NullPointerException e) {
throw new Exception("私钥数据为空");
}
}
/**
* 公钥加密过程
*
* @param publicKey
* 公钥
* @param plainTextData
* 明文数据
* @return
* @throws Exception
* 加密过程中的异常信息
*/
public static byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData)
throws Exception {
if (publicKey == null) {
throw new Exception("加密公钥为空, 请设置");
}
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] output = cipher.doFinal(plainTextData);
return output;
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此加密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("加密公钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("明文长度非法");
} catch (BadPaddingException e) {
throw new Exception("明文数据已损坏");
}
}
/**
* 私钥加密过程
*
* @param privateKey
* 私钥
* @param plainTextData
* 明文数据
* @return
* @throws Exception
* 加密过程中的异常信息
*/
public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData)
throws Exception {
if (privateKey == null) {
throw new Exception("加密私钥为空, 请设置");
}
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
byte[] output = cipher.doFinal(plainTextData);
return output;
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此加密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("加密私钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("明文长度非法");
} catch (BadPaddingException e) {
throw new Exception("明文数据已损坏");
}
}
/**
* 私钥解密过程
*
* @param privateKey
* 私钥
* @param cipherData
* 密文数据
* @return 明文
* @throws Exception
* 解密过程中的异常信息
*/
public static byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData)
throws Exception {
if (privateKey == null) {
throw new Exception("解密私钥为空, 请设置");
}
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] output = cipher.doFinal(cipherData);
return output;
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此解密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("解密私钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("密文长度非法");
} catch (BadPaddingException e) {
throw new Exception("密文数据已损坏");
}
}
/**
* 公钥解密过程
*
* @param publicKey
* 公钥
* @param cipherData
* 密文数据
* @return 明文
* @throws Exception
* 解密过程中的异常信息
*/
public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData)
throws Exception {
if (publicKey == null) {
throw new Exception("解密公钥为空, 请设置");
}
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
cipher.init(Cipher.DECRYPT_MODE, publicKey);
byte[] output = cipher.doFinal(cipherData);
return output;
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此解密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("解密公钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("密文长度非法");
} catch (BadPaddingException e) {
throw new Exception("密文数据已损坏");
}
}
/**
* 字节数据转十六进制字符串
*
* @param data
* 输入数据
* @return 十六进制内容
*/
public static String byteArrayToString(byte[] data) {
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < data.length; i++) {
// 取出字节的高四位 作为索引得到相应的十六进制标识符 注意无符号右移
stringBuilder.append(HEX_CHAR[(data[i] & 0xf0) >>> 4]);
// 取出字节的低四位 作为索引得到相应的十六进制标识符
stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);
if (i < data.length - 1) {
stringBuilder.append(' ');
}
}
return stringBuilder.toString();
}
public static String encryptBASE64(byte[] key) throws Exception {
return (new BASE64Encoder()).encodeBuffer(key);
}
public static byte[] decryptBASE64(String key) throws Exception {
return (new BASE64Decoder()).decodeBuffer(key);
}
}
上面代码中，利用
genKeyPair （）方法来生成钥匙对。
加密：
RSAEncrypt.
encryptBASE64
(RSAEncrypt.
encrypt
(RSAEncrypt.
loadPublicKeyByStr
(RSAEncrypt.
loadPublicKeyByFile
(filepath)),"要加密的字符串".getBytes()))
解密：
RSAEncrypt.
decrypt
(RSAEncrypt.
loadPrivateKeyByStr
(RSAEncrypt.
loadPrivateKeyByFile
(filepath)), RSAEncrypt.
decryptBASE64
("要解密的字符串"))
下面用 私钥加密（数字签名），用公钥进行验证
System. out.println( "---------------私钥签名过程------------------" );
String content= "ihep_这是用于签名的原始数据" ;
String signstr=RSASignature.encryptBASE64(RSASignature. sign(content,RSAEncrypt.loadPrivateKeyByFile(filepath)));
System. out.println( "签名原串：" +content);
System. out.println( "签名串："+signstr);
System. out.println();
//
System. out.println( "---------------公钥校验签名------------------" );
System. out.println( "签名原串：" +content);
System. out.println( "签名串："+signstr);
System. out. println("验签结果："+RSASignature. doCheck(content, signstr, RSAEncrypt.loadPublicKeyByFile(filepath)));
输出结果：
附上签名的class:
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
/**
* RSA签名验签类
*/
public class RSASignature{
/**
* 签名算法
*/
public static final String SIGN_ALGORITHMS = "SHA1WithRSA";
// public static final String SIGN_ALGORITHMS = "sha1WithRSAEncryption";
/**
* RSA签名
* @param content 待签名数据
* @param privateKey 商户私钥
* @param encode 字符集编码
* @return 签名值
*/
public static String sign(String content, String privateKey, String encode)
{
try
{
PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(decryptBASE64(privateKey) );
KeyFactory keyf = KeyFactory.getInstance("RSA");
PrivateKey priKey = keyf.generatePrivate(priPKCS8);
java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
signature.initSign(priKey);
signature.update( content.getBytes(encode));
byte[] signed = signature.sign();
return new String( encryptBASE64(signed));
}
catch (Exception e)
{
e.printStackTrace();
}
return null;
}
public static byte[] sign(String content, String privateKey)
{
try
{
PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec( decryptBASE64(privateKey) );
KeyFactory keyf = KeyFactory.getInstance("RSA");
PrivateKey priKey = keyf.generatePrivate(priPKCS8);
java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
signature.initSign(priKey);
signature.update( content.getBytes());
byte[] signed = signature.sign();
return signed;
}
catch (Exception e)
{
e.printStackTrace();
}
return null;
}
/**
* RSA验签名检查
* @param content 待签名数据
* @param sign 签名值
* @param publicKey 分配给开发商公钥
* @param encode 字符集编码
* @return 布尔值
*/
public static boolean doCheck(String content, String sign, String publicKey,String encode)
{
try
{
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
byte[] encodedKey =decryptBASE64(publicKey);
PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));
java.security.Signature signature = java.security.Signature
.getInstance(SIGN_ALGORITHMS);
signature.initVerify(pubKey);
signature.update( content.getBytes(encode) );
boolean bverify = signature.verify( decryptBASE64(sign) );
return bverify;
}
catch (Exception e)
{
e.printStackTrace();
}
return false;
}
public static boolean doCheck(String content, String sign, String publicKey)
{
try
{
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
byte[] encodedKey =decryptBASE64(publicKey);
PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));
java.security.Signature signature = java.security.Signature
.getInstance(SIGN_ALGORITHMS);
signature.initVerify(pubKey);
signature.update( content.getBytes() );
boolean bverify = signature.verify(decryptBASE64(sign) );
return bverify;
}
catch (Exception e)
{
e.printStackTrace();
}
return false;
}
public static String encryptBASE64(byte[] key) throws Exception {
return (new BASE64Encoder()).encodeBuffer(key);
}
public static byte[] decryptBASE64(String key) throws Exception {
return (new BASE64Decoder()).decodeBuffer(key);
}
}
DES加解密：
1、客户端：首先进行DES加密，再将加密后的结果进行BASE64加密。
2、服务端：将得到的流转化为字符串，在进行BASE64解密， 将解密之后的结果再进行DES解密。
DES加解密的KEY必须一致！
package des;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import com.alibaba.fastjson.JSONObject;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class EncryptUtil {
public static final String DES_KEY="@Wx^t)V#";
/**
*
* 解密
*
* @param src
* 数据源
* @param key
* 密钥，长度必须是8的倍数
* @return 返回解密后的原始数据
* @throws Exception
*/
public static byte[] decrypt(byte[] src, byte[] key) throws Exception {
// DES算法要求有一个可信任的随机数源
SecureRandom sr = new SecureRandom();
// 从原始密匙数据创建一个DESKeySpec对象
DESKeySpec dks = new DESKeySpec(key);
// 创建一个密匙工厂，然后用它把DESKeySpec对象转换成
// 一个SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey securekey = keyFactory.generateSecret(dks);
// Cipher对象实际完成解密操作
Cipher cipher = Cipher.getInstance("DES");
// 用密匙初始化Cipher对象
cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
// 现在，获取数据并解密
// 正式执行解密操作
return cipher.doFinal(src);
}
/**
*
* 加密
*
* @param src
* 数据源
*
* @param key
* 密钥，长度必须是8的倍数
*
* @return 返回加密后的数据
*
* @throws Exception
*
*/
public static byte[] encrypt(byte[] src, byte[] key) throws Exception {
// DES算法要求有一个可信任的随机数源
SecureRandom sr = new SecureRandom();
// 从原始密匙数据创建DESKeySpec对象
DESKeySpec dks = new DESKeySpec(key);
// 创建一个密匙工厂，然后用它把DESKeySpec转换成
// 一个SecretKey对象
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey securekey = keyFactory.generateSecret(dks);
// Cipher对象实际完成加密操作
Cipher cipher = Cipher.getInstance("DES");
// 用密匙初始化Cipher对象
cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
// 现在，获取数据并加密
// 正式执行加密操作
return cipher.doFinal(src);
}
public static String encryptBASE64(byte[] key) throws Exception {
return (new BASE64Encoder()).encodeBuffer(key);
}
public static byte[] decryptBASE64(String key) throws Exception {
return (new BASE64Decoder()).decodeBuffer(key);
}
@SuppressWarnings("deprecation")
public static void main(String[] args) throws Exception {
JSONObject obj= new JSONObject();
obj.put("name", "张三");
System.out.println("加密前的数据："+obj.toString());
System.out.println("DES开始加密......");
String enData=encryptBASE64(encrypt(obj.toString().getBytes(), DES_KEY.getBytes()));
System.out.println("加密后的数据"+enData);
System.out.println("DES开始解密.....");
String deData=new String(decrypt(decryptBASE64(enData), DES_KEY.getBytes()));
System.out.println("DES解密后的数据:"+deData);
}
}
输入结果：
加密前的数据：{"name":"张三"}
DES开始加密......
加密后的数据cOOCD8/CXRmjaBYA5K7KYA==
DES开始解密.....
DES解密后的数据:{"name":"张三"}