基于RSA非对称加密,属于轻量型加密,加密数据的大小有严格限制,我们可以通过对分段加密方式,实现对大量数据的非对称加密,本文在参考非对称的加密的资料基础之上,实现了大数据的非对称加密,因此少量数据于大量数据都可以实现加密处理,如果仅想实现这个非对称加密功能代码可直接使用。
代码实现:
package com.company.test;
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 java.util.Arrays;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import sun.misc.BASE64Decoder;
public class RSAEncrypt {
//一次能够加密的最大数据长度
private static final Integer MAX_LENGTH_STR=128;
//这里可以通过调用密钥对进行生成公钥;
private static final String DEFAULT_PUBLIC_KEY=
"MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQChDzcjw/rWgFwnxunbKp7/4e8w" + "\r" +
"/UmXx2jk6qEEn69t6N2R1i/LmcyDT1xr/T2AHGOiXNQ5V8W4iCaaeNawi7aJaRht" + "\r" +
"Vx1uOH/2U378fscEESEG8XDqll0GCfB1/TjKI2aitVSzXOtRs8kYgGU78f7VmDNg" + "\r" +
"XIlk3gdhnzh+uoEQywIDAQAB" + "\r";
//这里可以通过调用密钥对进行生成私钥;
private static final String DEFAULT_PRIVATE_KEY=
"MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBAKEPNyPD+taAXCfG" + "\r" +
"6dsqnv/h7zD9SZfHaOTqoQSfr23o3ZHWL8uZzINPXGv9PYAcY6Jc1DlXxbiIJpp4" + "\r" +
"1rCLtolpGG1XHW44f/ZTfvx+xwQRIQbxcOqWXQYJ8HX9OMojZqK1VLNc61GzyRiA" + "\r" +
"ZTvx/tWYM2BciWTeB2GfOH66gRDLAgMBAAECgYBp4qTvoJKynuT3SbDJY/XwaEtm" + "\r" +
"u768SF9P0GlXrtwYuDWjAVue0VhBI9WxMWZTaVafkcP8hxX4QZqPh84td0zjcq3j" + "\r" +
"DLOegAFJkIorGzq5FyK7ydBoU1TLjFV459c8dTZMTu+LgsOTD11/V/Jr4NJxIudo" + "\r" +
"MBQ3c4cHmOoYv4uzkQJBANR+7Fc3e6oZgqTOesqPSPqljbsdF9E4x4eDFuOecCkJ" + "\r" +
"DvVLOOoAzvtHfAiUp+H3fk4hXRpALiNBEHiIdhIuX2UCQQDCCHiPHFd4gC58yyCM" + "\r" +
"6Leqkmoa+6YpfRb3oxykLBXcWx7DtbX+ayKy5OQmnkEG+MW8XB8wAdiUl0/tb6cQ" + "\r" +
"FaRvAkBhvP94Hk0DMDinFVHlWYJ3xy4pongSA8vCyMj+aSGtvjzjFnZXK4gIjBjA" + "\r" +
"2Z9ekDfIOBBawqp2DLdGuX2VXz8BAkByMuIh+KBSv76cnEDwLhfLQJlKgEnvqTvX" + "\r" +
"TB0TUw8avlaBAXW34/5sI+NUB1hmbgyTK/T/IFcEPXpBWLGO+e3pAkAGWLpnH0Zh" + "\r" +
"Fae7oAqkMAd3xCNY6ec180tAe57hZ6kS+SYLKwb4gGzYaCxc22vMtYksXHtUeamo" + "\r" +
"1NMLzI2ZfUoX" + "\r";
/**
* 私钥
*/
private RSAPrivateKey privateKey;
/**
* 公钥
*/
private RSAPublicKey publicKey;
/**
* 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'};
/**
* 获取私钥
* @return 当前的私钥对象
*/
public RSAPrivateKey getPrivateKey() {
return privateKey;
}
/**
* 获取公钥
* @return 当前的公钥对象
*/
public RSAPublicKey getPublicKey() {
return publicKey;
}
/**
* 随机生成密钥对
*/
public void genKeyPair(){
KeyPairGenerator keyPairGen= null;
try {
keyPairGen= KeyPairGenerator.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
keyPairGen.initialize(1024, new SecureRandom());
KeyPair keyPair= keyPairGen.generateKeyPair();
this.privateKey= (RSAPrivateKey) keyPair.getPrivate();
this.publicKey= (RSAPublicKey) keyPair.getPublic();
}
/**
* 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 void loadPublicKey(String publicKeyStr) throws Exception{
try {
BASE64Decoder base64Decoder= new BASE64Decoder();
byte[] buffer= base64Decoder.decodeBuffer(publicKeyStr);
KeyFactory keyFactory= KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec= new X509EncodedKeySpec(buffer);
this.publicKey= (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 (IOException e) {
throw new Exception("公钥数据内容读取错误");
} catch (NullPointerException e) {
throw new Exception("公钥数据为空");
}
}
/**
* 从字符串中加载私钥
* @param privateKeyStr
* @throws Exception
*/
public void loadPrivateKey(String privateKeyStr) throws Exception{
try {
BASE64Decoder base64Decoder= new BASE64Decoder();
byte[] buffer= base64Decoder.decodeBuffer(privateKeyStr);
PKCS8EncodedKeySpec keySpec= new PKCS8EncodedKeySpec(buffer);
KeyFactory keyFactory= KeyFactory.getInstance("RSA");
this.privateKey= (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 (IOException e) {
throw new Exception("私钥数据内容读取错误");
} catch (NullPointerException e) {
throw new Exception("私钥数据为空");
}
}
/**
* 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 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 {
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");
}
}
/**
* 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 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 {
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");
}
}
/**
* 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 void main(String[] args){
RSAEncrypt rsaEncrypt= new RSAEncrypt();
//加载公钥
try {
rsaEncrypt.loadPublicKey(RSAEncrypt.DEFAULT_PUBLIC_KEY);
System.out.println("加载公钥成功");
} catch (Exception e) {
System.err.println(e.getMessage());
System.err.println("加载公钥失败");
}
//加载私钥
try {
rsaEncrypt.loadPrivateKey(RSAEncrypt.DEFAULT_PRIVATE_KEY);
System.out.println("加载私钥成功");
} catch (Exception e) {
System.err.println(e.getMessage());
System.err.println("加载私钥失败");
}
//测试字符串
String encryptStr= "TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTestttttttttttttttttttttttttttttttttttttttttttttttyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy";
System.out.println("输入的字符串长度"+encryptStr.length());
int all = encryptStr.length();
//把String分成多个子字符串数组
//子字符串长度
int start=0;
int strsLen;
int i = all /RSAEncrypt.MAX_LENGTH_STR ;//有bug这行(bug已经修复)
strsLen = i != 0 ? i + 1 : 1;
String[] strs=new String[strsLen];
for (int j = 0; j < strsLen; j++) {
if (j<strsLen-1){
strs[j]=encryptStr.substring(start,start+=RSAEncrypt.MAX_LENGTH_STR);//顾首不顾尾
}else {
strs[j]=encryptStr.substring(start,all);
}
}
System.out.println(Arrays.toString(strs));
//定义StringBuffer进行数组拼接
StringBuffer cipherText = new StringBuffer();
StringBuffer lightText = new StringBuffer();
//遍历分段的字符
Arrays.stream(strs).forEach(str -> {
try {
//加密
byte[] cipher = rsaEncrypt.encrypt(rsaEncrypt.getPublicKey(), str.getBytes());
cipherText.append(RSAEncrypt.byteArrayToString(cipher));
//解密
byte[] plainText = rsaEncrypt.decrypt(rsaEncrypt.getPrivateKey(), cipher);
lightText.append(new String(plainText));
} catch (Exception e) {
System.err.println(e.getMessage());
}
}
);
System.out.println("返回的密文:"+cipherText);
System.out.println("拼接回来的明文"+lightText.toString());
System.out.println(encryptStr.equals(lightText.toString()));//与原来的明文比较
}
}
PS:这里是通过读取代码中字符串公私钥的方式进行实现的,还可以将公私存储在文件中,利用流的方式进行读取。
可参考:
RSA介绍：RSA算法_百度百科
OpenSSL介绍：openssl_百度百科
链接：https://blog.csdn.net/chaijunkun/article/details/7275632
密钥对生成：http://www.howforge.com/how-to-generate-key-pair-using-openssl
私钥编码格式转换：http://shuany.iteye.com/blog/730910
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