java前后端密碼加密

貼上工具類

package com.common.utils;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.util.HashMap;
import java.util.Map;

/**
 * RSA 工具類。提供加密，解密，生成密鑰對等方法。
 * 需要到    下載bcprov-jdk14-123.jar。
 *
 */



public class RSAUtils {
    private static final int MAX_ENCRYPT_BLOCK = 117; // RSA最大加密明文大小
    private static final int MAX_DECRYPT_BLOCK = 128; // RSA最大解密密文大小

    /**
     * 生成公鑰和私鑰
     *
     * @throws NoSuchAlgorithmException
     */
    public static KeyPair genRSAKeyPair() throws NoSuchAlgorithmException {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
        keyPairGen.initialize(1024);
        return keyPairGen.generateKeyPair();
    }

    /**
     * 使用模和指數生成RSA公鑰
     * 注意：【此代碼用了默認補位方式，為RSA/None/PKCS1Padding，不同JDK默認的補位方式可能不同，如Android默認是RSA
     * /None/NoPadding】
     *
     * @param modulus  模
     * @param exponent 指數
     * @return
     */
    public static RSAPublicKey getPublicKey(String modulus, String exponent) {
        try {
            BigInteger b1 = new BigInteger(modulus, 16);
            BigInteger b2 = new BigInteger(exponent, 16);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            RSAPublicKeySpec keySpec = new RSAPublicKeySpec(b1, b2);
            return (RSAPublicKey) keyFactory.generatePublic(keySpec);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 使用模和指數生成RSA私鑰
     * 注意：【此代碼用了默認補位方式，為RSA/None/PKCS1Padding，不同JDK默認的補位方式可能不同，如Android默認是RSA
     * /None/NoPadding】
     *
     * @param modulus  模
     * @param exponent 指數
     * @return
     */
    public static RSAPrivateKey getPrivateKey(String modulus, String exponent) {
        try {
            BigInteger b1 = new BigInteger(modulus, 16);
            BigInteger b2 = new BigInteger(exponent, 16);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            RSAPrivateKeySpec keySpec = new RSAPrivateKeySpec(b1, b2);
            return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 公鑰加密
     */
    public static byte[] encryptByPublicKey(byte[] data, RSAPublicKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        int inputLen = data.length;

        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
            int offSet = 0;
            byte[] cache;
            int i = 0;
            // 對數據分段加密
            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;
            }
            return out.toByteArray();
        }
    }

    /**
     * 私鑰解密
     */
    public static String decryptByPrivateKey(byte[] encryptedData, RSAPrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        int inputLen = encryptedData.length;

        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {

            int offSet = 0;
            byte[] cache;
            int i = 0;

            // 對數據分段解密
            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;
            }

            return new String(out.toByteArray(), "utf-8");
        }
    }

    /**
     * ASCII碼轉BCD碼
     */
    public static byte[] ASCII_To_BCD(byte[] ascii, int asc_len) {
        byte[] bcd = new byte[asc_len / 2];
        int j = 0;
        for (int i = 0; i < (asc_len + 1) / 2; i++) {
            bcd[i] = asc_to_bcd(ascii[j++]);
            bcd[i] = (byte) (((j >= asc_len) ? 0x00 : asc_to_bcd(ascii[j++])) + (bcd[i] << 4));
        }
        return bcd;
    }

    public static byte asc_to_bcd(byte asc) {
        byte bcd;

        if ((asc >= '0') && (asc <= '9'))
            bcd = (byte) (asc - '0');
        else if ((asc >= 'A') && (asc <= 'F'))
            bcd = (byte) (asc - 'A' + 10);
        else if ((asc >= 'a') && (asc <= 'f'))
            bcd = (byte) (asc - 'a' + 10);
        else
            bcd = (byte) (asc - 48);
        return bcd;
    }

    /**
     * BCD轉字符串
     */
    public static String bcd2Str(byte[] bytes) {
        char temp[] = new char[bytes.length * 2], val;

        for (int i = 0; i < bytes.length; i++) {
            val = (char) (((bytes[i] & 0xf0) >> 4) & 0x0f);
            temp[i * 2] = (char) (val > 9 ? val + 'A' - 10 : val + '0');

            val = (char) (bytes[i] & 0x0f);
            temp[i * 2 + 1] = (char) (val > 9 ? val + 'A' - 10 : val + '0');
        }
        return new String(temp);
    }

    /**
     * 拆分字符串
     */
    public static String[] splitString(String string, int len) {
        int x = string.length() / len;
        int y = string.length() % len;
        int z = 0;
        if (y != 0) {
            z = 1;
        }
        String[] strings = new String[x + z];
        String str = "";
        for (int i = 0; i < x + z; i++) {
            if (i == x + z - 1 && y != 0) {
                str = string.substring(i * len, i * len + y);
            } else {
                str = string.substring(i * len, i * len + len);
            }
            strings[i] = str;
        }
        return strings;
    }

    /**
     * 拆分數組
     */
    public static byte[][] splitArray(byte[] data, int len) {
        int x = data.length / len;
        int y = data.length % len;
        int z = 0;
        if (y != 0) {
            z = 1;
        }
        byte[][] arrays = new byte[x + z][];
        byte[] arr;
        for (int i = 0; i < x + z; i++) {
            arr = new byte[len];
            if (i == x + z - 1 && y != 0) {
                System.arraycopy(data, i * len, arr, 0, y);
            } else {
                System.arraycopy(data, i * len, arr, 0, len);
            }
            arrays[i] = arr;
        }
        return arrays;
    }
    //String 解密
    public static String Decrypt(String str,String mou,String m) throws Exception{
        //模hex
        String modulus =mou;
        //私鑰指數hex
        String private_exponent = m;

        RSAPrivateKey priKey = getPrivateKey(modulus, private_exponent);

        return decryptByPrivateKey(HexUtil.hexStringToBytes(str), priKey);
    }
    //獲取模塊信息
    public static Map getModulus () throws NoSuchAlgorithmException{
        KeyPair keyPair = genRSAKeyPair();
        Map map = new HashMap();
        //生成公鑰和私鑰
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        //模hex
        String modulus = publicKey.getModulus().toString(16);
        //公鑰指數hex
        String public_exponent = publicKey.getPublicExponent().toString(16);
        //私鑰指數hex
        String private_exponent = privateKey.getPrivateExponent().toString(16);
        map.put("g", public_exponent);
        map.put("m", private_exponent);
        map.put("modu", modulus);
        return map;
    }
    public static void main(String[] args) throws Exception {
        KeyPair keyPair = genRSAKeyPair();

        //生成公鑰和私鑰
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();


        //模hex
        String modulus = publicKey.getModulus().toString(16);
        //公鑰指數hex
        String public_exponent = publicKey.getPublicExponent().toString(16);
        //私鑰指數hex
        String private_exponent = privateKey.getPrivateExponent().toString(16);

        System.out.println("public_modulus: " + modulus);
        System.out.println("public_exponent: " + public_exponent);
        System.out.println("private_exponent: " + private_exponent);

        //明文
        String plaintStr = "123456";
        System.out.println("plaintStr: " + plaintStr);

        //使用模和指數生成公鑰和私鑰
        RSAPublicKey pubKey = getPublicKey(modulus, public_exponent);
        RSAPrivateKey priKey = getPrivateKey(modulus, private_exponent);
        //公鑰加密后的密文
        byte[] encryptStr = encryptByPublicKey(plaintStr.getBytes("utf-8"), pubKey);
        System.out.println("encryptStr: " + HexUtil.bytesToHexString(encryptStr));
        String jmh = HexUtil.bytesToHexString(encryptStr);
        System.out.println("start");
        //私鑰解密后的明文
        System.out.println("decryptStr: " + decryptByPrivateKey(HexUtil.hexStringToBytes(jmh), priKey));
    }

}

package com.common.utils;

public class HexUtil {

    /**
     * 二進制byte數組轉十六進制byte數組
     * byte array to hex
     *
     * @param b byte array
     * @return hex string
     */
    public static String byte2hex(byte[] b) {
        StringBuilder hs = new StringBuilder();
        String stmp;
        for (int i = 0; i < b.length; i++) {
            stmp = Integer.toHexString(b[i] & 0xFF).toUpperCase();
            if (stmp.length() == 1) {
                hs.append("0").append(stmp);
            } else {
                hs.append(stmp);
            }
        }
        return hs.toString();
    }

    /**
     * 十六進制byte數組轉二進制byte數組
     * hex to byte array
     *
     * @param hex hex string
     * @return byte array
     */
    public static byte[] hex2byte(String hex)
            throws IllegalArgumentException{
        if (hex.length() % 2 != 0) {
            throw new IllegalArgumentException ("invalid hex string");
        }
        char[] arr = hex.toCharArray();
        byte[] b = new byte[hex.length() / 2];
        for (int i = 0, j = 0, l = hex.length(); i < l; i++, j++) {
            String swap = "" + arr[i++] + arr[i];
            int byteint = Integer.parseInt(swap, 16) & 0xFF;
            b[j] = new Integer(byteint).byteValue();
        }
        return b;
    }


    public static String bytesToHexString(byte[] src){
        StringBuilder stringBuilder = new StringBuilder("");
        if (src == null || src.length <= 0) {
            return null;
        }
        for (int i = 0; i < src.length; i++) {
            int v = src[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }
    private static byte charToByte(char c) {
        return (byte) "0123456789ABCDEF".indexOf(c);
    }
    public static byte[] hexStringToBytes(String hexString) {
        if (hexString == null || hexString.equals("")) {
            return null;
        }
        hexString = hexString.toUpperCase();
        int length = hexString.length() / 2;
        char[] hexChars = hexString.toCharArray();
        byte[] d = new byte[length];
        for (int i = 0; i < length; i++) {
            int pos = i * 2;
            d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
        }
        return d;
    }

}

前端調用

<!-- js必要 -->
<script language="JavaScript" type="text/javascript" src="http://www-cs-students.stanford.edu/~tjw/jsbn/jsbn.js"></script>
<script language="JavaScript" type="text/javascript" src="http://www-cs-students.stanford.edu/~tjw/jsbn/jsbn2.js"></script>
<script language="JavaScript" type="text/javascript" src="http://www-cs-students.stanford.edu/~tjw/jsbn/prng4.js"></script>
<script language="JavaScript" type="text/javascript" src="http://www-cs-students.stanford.edu/~tjw/jsbn/rng.js"></script>
<script language="JavaScript" type="text/javascript" src="http://www-cs-students.stanford.edu/~tjw/jsbn/rsa.js"></script>
<script language="JavaScript" type="text/javascript" src="http://www-cs-students.stanford.edu/~tjw/jsbn/rsa2.js"></script>

//2獲取加密信息
    function getModule() {
        var that = this;
        $.ajax("${ctx}/wechat/reader/getMoudle.do", {
            dataType: 'json', //服務器返回json格式數據
            async: false,
            type: 'post', //HTTP請求類型
            timeout: 10000, //超時時間設置為10秒；
            success: function (data) {
                that.RSADo.modulus = data.modu;
                that.RSADo.publicExponent = data.g;
            },
            error: function (xhr, type, errorThrown) {
            }
        });
    }

    //公鑰加密方法
    function encryption(str) {
        // 實例化js的RSA對象生成
        var rsa = new RSAKey()
        rsa.setPublic(this.RSADo.modulus, this.RSADo.publicExponent)
        var encryptStr = rsa.encrypt(str);
        return encryptStr;
    }

    //調用
    var password = this.encryption(this.password);

后端方法實現及解密調用

//聲明加密秘鑰
    private static String m;
    //聲明加密模塊
    private static String mou;

    //調用RSA工具類的getModulus方法獲取配套的公鑰，秘鑰，和加密模塊信息，並將公鑰和加密模塊傳送到前台，秘鑰和加密模塊
    //保存到后台
    @ResponseBody
    @RequestMapping(value = "/getMoudle", method = RequestMethod.POST)
    public Object getMoudle() throws NoSuchAlgorithmException {
        Map jmInfo = RSAUtils.getModulus();
        String my = jmInfo.get("m").toString();
        m = my;
        mou = jmInfo.get("modu").toString();
        return jmInfo;
    }

        //解密調用
        String password = RSAUtils.Decrypt(password,mou,m);