Java使用RSA加密算法对内容进行加密
什么是RSA加密算法
RSA是一种典型的非对称性加密算法，具体介绍可参考阮一峰的日志 RSA算法原理
下面是使用RSA算法对传输内容进行加密的一个简要Java案例，主要用到了三个类，大体实现如下：
对内容进行RSA加密和解密校验的类
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
public class RSASignature {
/**
* 签名算法
*/
public static final String SIGN_ALGORITHMS = "SHA1withRSA";
/**
* 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( Base64.decode(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 Base64.encode(signed);
}
catch (Exception e)
{
e.printStackTrace();
}
return null;
}
public static String sign(String content, String privateKey)
{
try
{
PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec( Base64.decode(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 Base64.encode(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
* @return 布尔值
*/
public static boolean doCheck(String content, String sign, String publicKey)
{
try
{
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
byte[] encodedKey = Base64.decode(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( Base64.decode(sign) );
return bverify;
}
catch (Exception e)
{
e.printStackTrace();
}
return false;
}
}
Base64基础类
public class Base64 {
static private final int BASELENGTH = 128;
static private final int LOOKUPLENGTH = 64;
static private final int TWENTYFOURBITGROUP = 24;
static private final int EIGHTBIT = 8;
static private final int SIXTEENBIT = 16;
static private final int FOURBYTE = 4;
static private final int SIGN = -128;
static private final char PAD = '=';
static private final boolean fDebug = false;
static final private byte[] base64Alphabet = new byte[BASELENGTH];
static final private char[] lookUpBase64Alphabet = new char[LOOKUPLENGTH];
static {
for (int i = 0; i < BASELENGTH; ++i) {
base64Alphabet[i] = -1;
}
for (int i = 'Z'; i >= 'A'; i--) {
base64Alphabet[i] = (byte) (i - 'A');
}
for (int i = 'z'; i >= 'a'; i--) {
base64Alphabet[i] = (byte) (i - 'a' + 26);
}
for (int i = '9'; i >= '0'; i--) {
base64Alphabet[i] = (byte) (i - '0' + 52);
}
base64Alphabet['+'] = 62;
base64Alphabet['/'] = 63;
for (int i = 0; i <= 25; i++) {
lookUpBase64Alphabet[i] = (char) ('A' + i);
}
for (int i = 26, j = 0; i <= 51; i++, j++) {
lookUpBase64Alphabet[i] = (char) ('a' + j);
}
for (int i = 52, j = 0; i <= 61; i++, j++) {
lookUpBase64Alphabet[i] = (char) ('0' + j);
}
lookUpBase64Alphabet[62] = (char) '+';
lookUpBase64Alphabet[63] = (char) '/';
}
private static boolean isWhiteSpace(char octect) {
return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);
}
private static boolean isPad(char octect) {
return (octect == PAD);
}
private static boolean isData(char octect) {
return (octect < BASELENGTH && base64Alphabet[octect] != -1);
}
/**
* Encodes hex octects into Base64
*
* @param binaryData Array containing binaryData
* @return Encoded Base64 array
*/
public static String encode(byte[] binaryData) {
if (binaryData == null) {
return null;
}
int lengthDataBits = binaryData.length * EIGHTBIT;
if (lengthDataBits == 0) {
return "";
}
int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
int numberQuartet = fewerThan24bits != 0 ? numberTriplets + 1 : numberTriplets;
char encodedData[] = null;
encodedData = new char[numberQuartet * 4];
byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;
int encodedIndex = 0;
int dataIndex = 0;
if (fDebug) {
System.out.println("number of triplets = " + numberTriplets);
}
for (int i = 0; i < numberTriplets; i++) {
b1 = binaryData[dataIndex++];
b2 = binaryData[dataIndex++];
b3 = binaryData[dataIndex++];
if (fDebug) {
System.out.println("b1= " + b1 + ", b2= " + b2 + ", b3= " + b3);
}
l = (byte) (b2 & 0x0f);
k = (byte) (b1 & 0x03);
byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);
if (fDebug) {
System.out.println("val2 = " + val2);
System.out.println("k4 = " + (k << 4));
System.out.println("vak = " + (val2 | (k << 4)));
}
encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
encodedData[encodedIndex++] = lookUpBase64Alphabet[(l << 2) | val3];
encodedData[encodedIndex++] = lookUpBase64Alphabet[b3 & 0x3f];
}
// form integral number of 6-bit groups
if (fewerThan24bits == EIGHTBIT) {
b1 = binaryData[dataIndex];
k = (byte) (b1 & 0x03);
if (fDebug) {
System.out.println("b1=" + b1);
System.out.println("b1<<2 = " + (b1 >> 2));
}
byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
encodedData[encodedIndex++] = lookUpBase64Alphabet[k << 4];
encodedData[encodedIndex++] = PAD;
encodedData[encodedIndex++] = PAD;
} else if (fewerThan24bits == SIXTEENBIT) {
b1 = binaryData[dataIndex];
b2 = binaryData[dataIndex + 1];
l = (byte) (b2 & 0x0f);
k = (byte) (b1 & 0x03);
byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];
encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];
encodedData[encodedIndex++] = lookUpBase64Alphabet[l << 2];
encodedData[encodedIndex++] = PAD;
}
return new String(encodedData);
}
/**
* Decodes Base64 data into octects
*
* @param encoded string containing Base64 data
* @return Array containind decoded data.
*/
public static byte[] decode(String encoded) {
if (encoded == null) {
return null;
}
char[] base64Data = encoded.toCharArray();
// remove white spaces
int len = removeWhiteSpace(base64Data);
if (len % FOURBYTE != 0) {
return null;//should be divisible by four
}
int numberQuadruple = (len / FOURBYTE);
if (numberQuadruple == 0) {
return new byte[0];
}
byte decodedData[] = null;
byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;
char d1 = 0, d2 = 0, d3 = 0, d4 = 0;
int i = 0;
int encodedIndex = 0;
int dataIndex = 0;
decodedData = new byte[(numberQuadruple) * 3];
for (; i < numberQuadruple - 1; i++) {
if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))
|| !isData((d3 = base64Data[dataIndex++]))
|| !isData((d4 = base64Data[dataIndex++]))) {
return null;
}//if found "no data" just return null
b1 = base64Alphabet[d1];
b2 = base64Alphabet[d2];
b3 = base64Alphabet[d3];
b4 = base64Alphabet[d4];
decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);
}
if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))) {
return null;//if found "no data" just return null
}
b1 = base64Alphabet[d1];
b2 = base64Alphabet[d2];
d3 = base64Data[dataIndex++];
d4 = base64Data[dataIndex++];
if (!isData((d3)) || !isData((d4))) {//Check if they are PAD characters
if (isPad(d3) && isPad(d4)) {
if ((b2 & 0xf) != 0)//last 4 bits should be zero
{
return null;
}
byte[] tmp = new byte[i * 3 + 1];
System.arraycopy(decodedData, 0, tmp, 0, i * 3);
tmp[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
return tmp;
} else if (!isPad(d3) && isPad(d4)) {
b3 = base64Alphabet[d3];
if ((b3 & 0x3) != 0)//last 2 bits should be zero
{
return null;
}
byte[] tmp = new byte[i * 3 + 2];
System.arraycopy(decodedData, 0, tmp, 0, i * 3);
tmp[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
tmp[encodedIndex] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
return tmp;
} else {
return null;
}
} else { //No PAD e.g 3cQl
b3 = base64Alphabet[d3];
b4 = base64Alphabet[d4];
decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);
}
return decodedData;
}
/**
* remove WhiteSpace from MIME containing encoded Base64 data.
*
* @param data the byte array of base64 data (with WS)
* @return the new length
*/
private static int removeWhiteSpace(char[] data) {
if (data == null) {
return 0;
}
// count characters that's not whitespace
int newSize = 0;
int len = data.length;
for (int i = 0; i < len; i++) {
if (!isWhiteSpace(data[i])) {
data[newSize++] = data[i];
}
}
return newSize;
}
}
在过滤器的Request中对加签的请求进行验签，在Response中对返回的参数加签。
import java.nio.charset.Charset;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import com.alibaba.fastjson.JSONObject;
public class ChannelSignature implements ServletChannelInterceptor{
private final static Logger logger = (Logger) LoggerFactory.getLogger(ChannelSignature.class);
private static final String DEFAULT_CHARSET = "UTF-8";
/是否签名验签，true:验签 ,false:不进行验签/
private boolean verifySignFlag;
/私钥路径/
@Value("${privateKey}")
private String privateKey;
/公钥路径/
@Value("${publicKey}")
private String publicKey;
@Override
public void onRequest(ChannelContext<HttpServletRequest, HttpServletResponse> channelContext, ContextEx contextEx)
throws FcsiException{
if(!verifySignFlag){logger.debug("don't need verif");return;}
Object object = channelContext.getRequestPayload();
String json = new String((byte[])object,Charset.forName(DEFAULT_CHARSET));
JSONObject jsonObject = JSONObject.parseObject(json);
String requestParamStr = jsonObject.getString("requestData");
String vSign = jsonObject.getString("sign");
logger.debug("verif sign begin ... ... requestParamStr:{} signStr:{}",requestParamStr,vSign);
Boolean verifResult = RSASignature.doCheck(requestParamStr, vSign, publicKey);
if(!verifResult){throw new SignatureException(MsgConstants.IFP_230002,"验签异常");}
logger.debug("verif sign end ... ... signResult:{}",verifResult);
}
@Override
public void onResponse(ChannelContext<HttpServletRequest, HttpServletResponse> channelContext, ContextEx contextEx,
Throwable ex) {
JSONObject jsonObject = null;
if(ex instanceof SignatureException ){jsonObject = getSignatureExceptionRespData(ex); sign(channelContext,jsonObject);return;}
Object object = channelContext.getResponsePalyload();
if(null == object){logger.debug("responsePalyload is null");return;}
String json = new String((byte[])object,Charset.forName("UTF8"));
jsonObject = JSONObject.parseObject(json);
sign(channelContext,jsonObject);
}
/**
* 对响应数据进行签名，并将响应结果放至ResponsePayload
* @param channelContext
* @param jsonObject
*/
private void sign(ChannelContext<HttpServletRequest, HttpServletResponse> channelContext, JSONObject jsonObject) {
String responseParamStr = jsonObject.getString("responseData");
logger.debug("generate sign begin ... ... signParamStr:{}",responseParamStr);
String sign=RSASignature.sign(responseParamStr,privateKey); //对原始报文进行签名
logger.debug("generate sign end ... ... signStr:{}",sign);
jsonObject.put("sign", sign); String str = jsonObject.toString();
channelContext.setResponsePayload((Object)str.getBytes(Charset.forName(DEFAULT_CHARSET)));
}
/**
* 组装签名异常响应数据
* @param ex
* @return
*/
private JSONObject getSignatureExceptionRespData(Throwable ex) {
String code = ((SignatureException) ex).getCode();
String defaultMessage = ((SignatureException) ex).getMessage();
String[] errMessageStr= defaultMessage.split("]"); String msg = errMessageStr[1];
JSONObject jsonObject = new JSONObject();jsonObject.put("code", code); jsonObject.put("msg", msg);
JSONObject respJsonObject = new JSONObject(); respJsonObject.put("responseData", jsonObject);
return respJsonObject;
}
public boolean isVerifySignFlag() {
return verifySignFlag;
}
public void setVerifySignFlag(boolean verifySignFlag) {
this.verifySignFlag = verifySignFlag;
}
}
