RSA加密、解密、加签、验签以及生成公私钥

RSA加解密、加验签、生成公私钥代码如下：

package util;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Signature;
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.Cipher;

/**
 * RSA使用X509EncodedKeySpec、PKCS8EncodedKeySpec生成公钥和私钥
 * 加密数据大小不能超过127 bytes
 * @Description：加签、验签、加密、解密、生成公钥、私钥
 * @date：2018年2月24日
 */
public class RSAUtil
{
    public static void main(String[] args) throws Exception
    {
        //生成公私钥文件
        //RSAUtil.getKeyPair("E:/");

        String publicKey = RSAUtil.readKeyFromFile("E:/publicKey.keystore");
        String privateKey = RSAUtil.readKeyFromFile("E:/privateKey.keystore");
        System.out.println("publicKey："+publicKey);
        System.out.println("privateKey："+privateKey);

        System.out.println("---------------------------------------------");

        String sign = RSAUtil.signByPrivateKey("测试加签", privateKey);
        System.out.println("sign："+sign);
        System.out.println("验签："+RSAUtil.verifySignByPublicKey("测试加签", publicKey, sign));

        System.out.println("---------------------------------------------");

        String cipherText = RSAUtil.encryptByPublicKey("测试加密明文数据", RSAUtil.readPublicKeyFromString(publicKey));
        System.out.println("cipherText："+cipherText);
        String plainText = RSAUtil.decryptByPrivateKey(cipherText, RSAUtil.readPrivateKeyFromString(privateKey));
        System.out.println("plainText："+plainText);
    }


    /**
     * 生成公私钥对
     * @param filePath 生成文件路径
     */
    @SuppressWarnings("static-access")
    public static void getKeyPair(String filePath)
    {
        KeyPairGenerator keyPairGenerator = null;
        try
        {
            keyPairGenerator = keyPairGenerator.getInstance("RSA");
        }
        catch (NoSuchAlgorithmException e)
        {
            e.printStackTrace();
        }
        keyPairGenerator.initialize(1024, new SecureRandom());
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

        String publicKeyString = Base64.encode(publicKey.getEncoded());
        String privateKeyString = Base64.encode(privateKey.getEncoded());
        try
        {
            BufferedWriter publicbw = new BufferedWriter(new FileWriter(new File(filePath+"/publicKey.keystore")));
            BufferedWriter privatebw = new BufferedWriter(new FileWriter(new File(filePath+"/privateKey.keystore")));
            publicbw.write(publicKeyString);
            privatebw.write(privateKeyString);
            publicbw.flush();
            publicbw.close();
            privatebw.flush();
            privatebw.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }

    }

    /**
     * 从文件中读取公钥或私钥
     * @param filePath 文件路径
     * @return 公钥或私钥
     */
    public static String readKeyFromFile(String filePath)
    {
        try
        {
            BufferedReader br = new BufferedReader(new FileReader(new File(filePath)));
            String readLine = null;
            StringBuilder sb = new StringBuilder();
            while((readLine = br.readLine()) != null)
            {
                sb.append(readLine);
            }
            br.close();
            return sb.toString();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 从字符串中加载公钥
     * @return 公钥
     */
    public static RSAPublicKey readPublicKeyFromString(String publicKeyStr)
    {
        try
        {
            byte[] bt = Base64.decode(publicKeyStr);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(bt);
            return (RSAPublicKey) keyFactory.generatePublic(x509EncodedKeySpec);
        }
        catch (NoSuchAlgorithmException e)
        {
            e.printStackTrace();
        }
        catch (InvalidKeySpecException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 从字符串中加载私钥
     * @return 私钥
     */
    public static RSAPrivateKey readPrivateKeyFromString(String privateKeyStr)
    {
        try
        {
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.decode(privateKeyStr));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            return (RSAPrivateKey) keyFactory.generatePrivate(pkcs8EncodedKeySpec);
        }
        catch (NoSuchAlgorithmException e)
        {
            e.printStackTrace();
        }
        catch (InvalidKeySpecException e)
        {
            e.printStackTrace();
        }
        return null;
    }


    /**
     * 私钥加签
     * @param content 报文
     * @param privateKey 私钥
     * @return 签名值
     */
    public static String signByPrivateKey(String content,String privateKey)
    {
        try
        {
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.decode(privateKey));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey priKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
            Signature signature = Signature.getInstance("SHA256withRSA");//MD5withRSA
            signature.initSign(priKey);
            signature.update(content.getBytes());
            byte[] sign = signature.sign();
            return Base64.encode(sign);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 公钥验签
     * @param content 报文
     * @param publicKey 公钥
     * @param sign 签名值
     * @return 验签是否通过
     */
    public static boolean verifySignByPublicKey(String content,String publicKey,String sign)
    {
        try
        {
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(Base64.decode(publicKey));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PublicKey pubKey = keyFactory.generatePublic(x509EncodedKeySpec);
            Signature signature = Signature.getInstance("SHA256withRSA");//MD5withRSA
            signature.initVerify(pubKey);
            signature.update(content.getBytes());
            return signature.verify(Base64.decode(sign));
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return false;
    }

    /**
     * 公钥加密
     * @param plainText 明文
     * @param publicKey 公钥
     * @return 密文
     * @throws Exception 
     */
    public static String encryptByPublicKey(String plainText,RSAPublicKey publicKey) throws Exception
    {
        if(publicKey == null)
        {
            throw new Exception("公钥为空！");
        }
        Cipher cipher = null;
        try
        {
            cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            byte[] output = cipher.doFinal(plainText.getBytes());
            return Base64.encode(output);
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        return null;        
    }


    /**
     * 私钥解密
     * @param cipherText 密文
     * @param privateKey 私钥
     * @return 明文
     * @throws Exception
     */
    public static String decryptByPrivateKey(String cipherText,RSAPrivateKey privateKey) throws Exception
    {
        if(privateKey == null)
        {
            throw new Exception("私钥为空！");
        }
        Cipher cipher = null;
        try
        {
            cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] output = cipher.doFinal(Base64.decode(cipherText));
            return new String(output);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }

}

    

package util;

public final 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;
    }
}

   

运行结果如下：

publicKey：MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCMLDV2a6Ci7hC9MTARF6S4MWyktZmqGcOFuW53pf3YZW1C7PmCIlesIrsloRRzs9eqh17/oCBNacnuXwlpukVG+tUJUU3T5uVI3+kQvP8p9fM+0kW+IOyOWOoIincVaFzDpBUOIuEnuKeaDB2COToQfSrz+U+g2/CQ2N/yJD+BDwIDAQAB
privateKey：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
---------------------------------------------
sign：VOyW13g3yg/mu+v2hvYI4ri7oewZamp6jiXt0y0PW1PREhWxTbgCcF6TMBFtKxayPt1QcwTpSUPSR0lpAkXoQPms+WMtZQvSfNPBvz+aNrTq9LtDWvCBAdMZA/7ZlnzwcvRRkFfcSya1jjPwY/7Qx3tbJ5PWgUKKLYV93zA6PaA=
验签：true
---------------------------------------------
cipherText：TCYWTSqJyetaS/g67CN9Ik8qBrADAXMGt0cSB2lJ3yHIQrE7LVDwkYZ+XHTr2EYufPPRONvSwcNc/hcNaOhgKruWVKUaOn2qGrLLsmTU8xDDGJf/zsQKrcKPVYfruHdmfXdIhwhWh+bNYVrcr5bGvDjtgJYjzYL485PKJUcPD88=
plainText：测试加密明文数据

写一个Socket通信测试加签、加密传输：

package util;

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.Map;

import com.alibaba.fastjson.JSONObject;

public class TCPClient
{
    private static String url = "21.131.4.33";
    private static int port = 10000;
    private static String publicKey = RSAUtil.readKeyFromFile("E:/publicKey.keystore");
    private static String privateKey = RSAUtil.readKeyFromFile("E:/privateKey.keystore");
    public static void main(String[] args) throws Exception
    {
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("name", "张三");
        map.put("age", "23");
        map.put("address", "北京市");
        map.put("message", "测试数据");
        String data = JSONObject.toJSONString(map);
        //加签
        String sign = RSAUtil.signByPrivateKey(data, privateKey);
        //加密
        String cipherText = RSAUtil.encryptByPublicKey(data, RSAUtil.readPublicKeyFromString(publicKey));
        TCPClient tcpClient = new TCPClient();
        tcpClient.sendMessage(url, port, sign+","+cipherText);
    }

    public void sendMessage(String url,int port,String message) throws UnknownHostException, IOException
    {
        Socket socket = new Socket(url,port);
        OutputStream outputStream = socket.getOutputStream();
        outputStream.write(message.getBytes());
        socket.close();
        outputStream.close();
    }
}

package util;

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class TCPServer
{
    private static int port = 10000;
    private static String publicKey = RSAUtil.readKeyFromFile("E:/publicKey.keystore");
    private static String privateKey = RSAUtil.readKeyFromFile("E:/privateKey.keystore");
    public static void main(String[] args) throws Exception
    {
        TCPServer tcpServer = new TCPServer();
        String message = tcpServer.getMessage(port);
        //message = sign+cipherText
        //System.out.println("message："+message);
        String sign = message.split(",")[0];
        String cipherText = message.split(",")[1];
        String plainText = RSAUtil.decryptByPrivateKey(cipherText, RSAUtil.readPrivateKeyFromString(privateKey));
        if(RSAUtil.verifySignByPublicKey(plainText, publicKey, sign))
        {
            System.out.println("验签成功！");
            System.out.println(plainText);
        }
        else 
        {
            System.out.println("验签失败！");
        }
    }

    public String getMessage(int port) throws IOException
    {
        String message = "";
        ServerSocket serverSocket = new ServerSocket(port);
        Socket socket = serverSocket.accept();
        InputStream inputStream = socket.getInputStream();
        byte[] bs = new byte[1024];
        int len = inputStream.read(bs);
        message = new String(bs, 0, len);
        socket.close();
        serverSocket.close();
        return message;
    }
}

先启动Server端，再启动Client端，传输过程中使用密文传输，加签防止内容被篡改，运行结果如下：

验签成功！
{"message":"测试数据","address":"北京市","age":"23","name":"张三"}