RSA加密、解密、加签、验签以及生成公私钥

﹏ヽ暗。殇╰゛Y 2022-05-31 12:21 825阅读 0赞

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"}