package com.duoduozb.constants;
import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.Cipher;
/**
* @author Created by deli
* @date 2018/9/21 08:14
* @description rsa加密工具
*/
public class RsaEncryptUtil {
/** */
/**
* 加密算法RSA
*/
public static final String KEY_ALGORITHM = "RSA";// RSA/NONE/NoPadding,RSA/NONE/PKCS1Padding
/**
* String to hold name of the encryption padding.
*/
public static final String PADDING = "RSA/NONE/PKCS1Padding";// RSA/NONE/NoPadding
/**
* String to hold name of the security provider.
*/
public static final String PROVIDER = "BC";
/** */
/**
* 签名算法
*/
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/** */
/**
* 获取公钥的key
*/
private static final String PUBLIC_KEY = "RSAPublicKey";
/** */
/**
* 获取私钥的key
*/
private static final String PRIVATE_KEY = "RSAPrivateKey";
/** */
/**
* RSA最大加密明文大小
*/
private static final int MAX_ENCRYPT_BLOCK = 117;
/** */
/**
* RSA最大解密密文大小
*/
private static final int MAX_DECRYPT_BLOCK = 128;
/*
* 公钥加密
*/
public static String encryptByPublicKey(String str) throws Exception {
Cipher cipher = Cipher.getInstance(PADDING, PROVIDER);
// 获得公钥
Key publicKey = getPublicKey();
// 用公钥加密
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
// 读数据源
byte[] data = str.getBytes("UTF-8");
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return Base64Util.encode(encryptedData);
}
/*
* 公钥解密
*/
public static String decryptByPublicKey(String str) throws Exception {
Cipher cipher = Cipher.getInstance(PADDING, PROVIDER);
// 获得公钥
Key publicKey = getPublicKey();
// 用公钥解密
cipher.init(Cipher.DECRYPT_MODE, publicKey);
// 读数据源
byte[] encryptedData = Base64Util.decode(str);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher
.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher
.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return new String(decryptedData, "UTF-8");
}
/**
* 读取公钥
*
* @return
* @throws Exception
* @comment
*/
private static Key getPublicKey() throws Exception {
String key = GlobalConstants.ras_public_key;
byte[] keyBytes;
keyBytes = Base64Util.decode(key);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey publicKey = keyFactory.generatePublic(keySpec);
return publicKey;
}
}
package com.duoduozb.constants;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import it.sauronsoftware.base64.Base64;
/**
* @author Created by deli
* @date 2018/9/21 08:17
* @description rsa 工具类
*/
public class Base64Util {
/** */
/**
* 文件读取缓冲区大小
*/
private static final int CACHE_SIZE = 1024;
/** */
/**
*
* BASE64字符串解码为二进制数据
*
*
* @param base64
* @return
* @throws Exception
*/
public static byte[] decode(String base64) throws Exception {
return Base64.decode(base64.getBytes());
}
/** */
/**
*
* 二进制数据编码为BASE64字符串
*
*
* @param bytes
* @return
* @throws Exception
*/
public static String encode(byte[] bytes) throws Exception {
return new String(Base64.encode(bytes));
}
/** */
/**
*
* 将文件编码为BASE64字符串
*
*
* 大文件慎用，可能会导致内存溢出
*
*
* @param filePath
* 文件绝对路径
* @return
* @throws Exception
*/
public static String encodeFile(String filePath) throws Exception {
byte[] bytes = fileToByte(filePath);
return encode(bytes);
}
/** */
/**
*
* BASE64字符串转回文件
*
*
* @param filePath
* 文件绝对路径
* @param base64
* 编码字符串
* @throws Exception
*/
public static void decodeToFile(String filePath, String base64)
throws Exception {
byte[] bytes = decode(base64);
byteArrayToFile(bytes, filePath);
}
/** */
/**
*
* 文件转换为二进制数组
*
*
* @param filePath
* 文件路径
* @return
* @throws Exception
*/
public static byte[] fileToByte(String filePath) throws Exception {
byte[] data = new byte[0];
File file = new File(filePath);
if (file.exists()) {
FileInputStream in = new FileInputStream(file);
ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
byte[] cache = new byte[CACHE_SIZE];
int nRead = 0;
while ((nRead = in.read(cache)) != -1) {
out.write(cache, 0, nRead);
out.flush();
}
out.close();
in.close();
data = out.toByteArray();
}
return data;
}
/** */
/**
*
* 二进制数据写文件
*
*
* @param bytes
* 二进制数据
* @param filePath
* 文件生成目录
*/
public static void byteArrayToFile(byte[] bytes, String filePath)
throws Exception {
InputStream in = new ByteArrayInputStream(bytes);
File destFile = new File(filePath);
if (!destFile.getParentFile().exists()) {
destFile.getParentFile().mkdirs();
}
destFile.createNewFile();
OutputStream out = new FileOutputStream(destFile);
byte[] cache = new byte[CACHE_SIZE];
int nRead = 0;
while ((nRead = in.read(cache)) != -1) {
out.write(cache, 0, nRead);
out.flush();
}
out.close();
in.close();
}
}
