com.xiongyingqi.util.RsaUtils Maven / Gradle / Ivy
package com.xiongyingqi.util;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
import javax.crypto.Cipher;
import java.io.*;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
public class RsaUtils {
/**
* 指定加密算法为RSA
*/
public static final String ALGORITHM = "RSA";
/**
* 密钥长度，用来初始化
*/
private static final int KEYSIZE = 1024;
/**
* 指定公钥存放文件
*/
private static String PUBLIC_KEY_FILE = "PublicKey";
/**
* 指定私钥存放文件
*/
private static String PRIVATE_KEY_FILE = "PrivateKey";
/**
* 生成密钥对
*
* @throws Exception
*/
private static void generateKeyPair() throws Exception {
// /** RSA算法要求有一个可信任的随机数源 */
// SecureRandom secureRandom = new SecureRandom();
/** 为RSA算法创建一个KeyPairGenerator对象 */
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(ALGORITHM);
/** 利用上面的随机数据源初始化这个KeyPairGenerator对象 */
// keyPairGenerator.initialize(KEYSIZE, secureRandom);
keyPairGenerator.initialize(KEYSIZE);
/** 生成密匙对 */
KeyPair keyPair = keyPairGenerator.generateKeyPair();
/** 得到公钥 */
Key publicKey = keyPair.getPublic();
/** 得到私钥 */
Key privateKey = keyPair.getPrivate();
ObjectOutputStream oos1 = null;
ObjectOutputStream oos2 = null;
try {
/** 用对象流将生成的密钥写入文件 */
oos1 = new ObjectOutputStream(new FileOutputStream(PUBLIC_KEY_FILE));
oos2 = new ObjectOutputStream(new FileOutputStream(PRIVATE_KEY_FILE));
oos1.writeObject(publicKey);
oos2.writeObject(privateKey);
} catch (Exception e) {
throw e;
} finally {
/** 清空缓存，关闭文件输出流 */
oos1.close();
oos2.close();
}
}
/**
* 加密方法
*
* @param source 源数据
* @return
* @throws Exception
* @deprecated
*/
private static String encrypt(String source) throws Exception {
generateKeyPair();
Key publicKey;
ObjectInputStream ois = null;
try {
/** 将文件中的公钥对象读出 */
ois = new ObjectInputStream(new FileInputStream(
PUBLIC_KEY_FILE));
publicKey = (Key) ois.readObject();
} catch (Exception e) {
throw e;
} finally {
ois.close();
}
/** 得到Cipher对象来实现对源数据的RSA加密 */
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] b = source.getBytes();
/** 执行加密操作 */
byte[] b1 = cipher.doFinal(b);
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(b1);
}
/**
* 解密算法
*
* @param cryptograph 密文
* @return
* @throws Exception
*/
private static String decrypt(String cryptograph) throws Exception {
Key privateKey;
ObjectInputStream ois = null;
try {
/** 将文件中的私钥对象读出 */
ois = new ObjectInputStream(new FileInputStream(
PRIVATE_KEY_FILE));
privateKey = (Key) ois.readObject();
} catch (Exception e) {
throw e;
} finally {
ois.close();
}
/** 得到Cipher对象对已用公钥加密的数据进行RSA解密 */
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
BASE64Decoder decoder = new BASE64Decoder();
byte[] b1 = decoder.decodeBuffer(cryptograph);
/** 执行解密操作 */
byte[] b = cipher.doFinal(b1);
return new String(b);
}
/**
* 生成密钥对
*
* @throws Exception
*/
public KeyPair generatorKeyPair() throws NoSuchAlgorithmException {
return generatorKeyPair(ALGORITHM, KEYSIZE);
}
/**
* 生成密钥对
*
* @param algorithm
* @param keySize
* @return
* @throws java.security.NoSuchAlgorithmException
*/
public KeyPair generatorKeyPair(String algorithm, int keySize) throws NoSuchAlgorithmException {
/** 为RSA算法创建一个KeyPairGenerator对象 */
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(algorithm);
/** 利用上面的随机数据源初始化这个KeyPairGenerator对象 */
// keyPairGenerator.initialize(KEYSIZE, secureRandom);
keyPairGenerator.initialize(keySize);
/** 生成密匙对 */
KeyPair keyPair = keyPairGenerator.generateKeyPair();
return keyPair;
}
public String encrypt(String source, Key publicKey) throws Exception {
return encrypt(source, publicKey, ALGORITHM);
}
public String encrypt(String source, Key publicKey, String algorithm) throws Exception {
/** 得到Cipher对象来实现对源数据的RSA加密 */
Cipher cipher = Cipher.getInstance(algorithm);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] b = source.getBytes();
/** 执行加密操作 */
byte[] b1 = cipher.doFinal(b);
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(b1);
}
public String encrypt(String source, KeyPair keyPair) throws Exception {
return encrypt(source, keyPair.getPublic());
}
public String decrypt(String cryptograph, Key privateKey) throws Exception {
return decrypt(cryptograph, privateKey, ALGORITHM);
}
public String decrypt(String cryptograph, Key privateKey, String algorithm) throws Exception {
/** 得到Cipher对象对已用公钥加密的数据进行RSA解密 */
Cipher cipher = Cipher.getInstance(algorithm);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
BASE64Decoder decoder = new BASE64Decoder();
byte[] b1 = decoder.decodeBuffer(cryptograph);
/** 执行解密操作 */
byte[] b = cipher.doFinal(b1);
return new String(b);
}
/**
* 解密算法
*
* @param cryptograph 密文
* @return
* @throws Exception
*/
public String decrypt(String cryptograph, KeyPair keyPair) throws Exception {
return decrypt(cryptograph, keyPair.getPrivate());
}
public static void main(String[] args) throws Exception {
// String source = "恭喜发财!";// 要加密的字符串
// System.out.println("准备用公钥加密的字符串为：" + source);
//
// String cryptograph = encrypt(source);// 生成的密文
// System.out.print("用公钥加密后的结果为:" + cryptograph);
// System.out.println();
//
// String target = decrypt(cryptograph);// 解密密文
// System.out.println("用私钥解密后的字符串为：" + target);
// System.out.println();
RsaUtils rsaUtils = new RsaUtils();
KeyPair keyPair = rsaUtils.generatorKeyPair();
String secret = rsaUtils.encrypt(StringUtil.randomString(117), keyPair);
String message = rsaUtils.decrypt(secret, keyPair);
ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();
ObjectOutputStream outputStream = new ObjectOutputStream(arrayOutputStream);
outputStream.writeObject(keyPair.getPrivate());
outputStream.flush();
outputStream.close();
arrayOutputStream.flush();
arrayOutputStream.close();
EntityHelper.print(arrayOutputStream.toString().length());
System.out.println(message);
System.out.println(keyPair.getPrivate());
System.out.println(keyPair.getPublic());
System.out.println(secret);
}
}
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