前端登录数据js加密后端解密（DES）-基于角色的权限管理系统

        在用户注册登录时，为了安全需要，有时候需要前端对数据进行加密后传输，后端对加密的数据进行解密，然后去数据库对比。因为要解密所以采用对称加密算法。不讨论哪个对称加密算法好，这里采用DES，在实现的过程中发现要找一个js版本的DES加密，并且java能DES解密的还真不容易。

加解密思路

        由于是对称加密，所以加解密的密钥就非常重要。这里采用uuid作为加解密的密钥，而且每次请求页面时生成的uuid都不一样，保证每次的密钥都不知道是什么。

看后端生成密钥的过程

@RequestMapping(value = "/login.html", method = RequestMethod.GET)public String login(Model model, HttpSession session) {    logger.info("登录页面");    session.setAttribute(SessionParam.LOGIN_KEY, UUIDGenerator.getUUID());    model.addAttribute("title", "用户登录");    return "admin/login";}

在进入login页面的时候将生成的uuid放进session中。

// 密码进行两次md5var passwordMd5 = CryptoJS.MD5(password);passwordMd5 = CryptoJS.MD5(passwordMd5);// console.info("md5:" + passwordMd5);$(this).val("正在登录...");$(this).attr("disabled", true);// 用户名des加密username = encryptByDES(username, key);// 填充表单并提交表单$("#postUsername").val(username);$('#postPassword').val(passwordMd5);$('#postForm').submit();// DES加密function encryptByDES(message, key) {    var keyHex = CryptoJS.enc.Utf8.parse(key);    var encrypted = CryptoJS.DES.encrypt(message, keyHex, {        mode : CryptoJS.mode.ECB,        padding : CryptoJS.pad.Pkcs7    });    return encrypted.toString();}

当表单准备好之后，对密码进行两次MD5，用户名则采用DES加密，加密的密钥就是session中保存的那个uuid。

后端再对传过来的用户名进行解密，因为数据库本来就存的是密码的两次MD5的值，所以只对用户名进行加密，因为即使密码被获取到，也不知道是什么。

后端过程：

// 得到加密密钥logger.info("-----原始数据：username:{} password:{}-----", username, password);String key = session.getAttribute(SessionParam.LOGIN_KEY) + "";logger.info("-----加解密key:{}-----", key);try {    username = DESUtil.decryption(username, key);} catch (Exception e) {    logger.info("-----解密出错：{}-----", e.getMessage());}logger.info("解密后：username:{} password:{}", username, password);

截图

JAVA DES

分享一个js前端加密，java后端加密的小程序


package com.jrbac.util;import java.security.InvalidKeyException;import java.security.NoSuchAlgorithmException;import java.security.spec.InvalidKeySpecException;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.NoSuchPaddingException;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;/** * DES加解密工具类 *  * @author 程高伟 * * @date 2016年6月15日 上午10:02:50 */public class DESUtil {    private static final String DES_ALGORITHM = "DES";    /**     * DES加密     *      * @param plainData     *            原始字符串     * @param secretKey     *            加密密钥     * @return 加密后的字符串     * @throws Exception     */    public static String encryption(String plainData, String secretKey) throws Exception {        Cipher cipher = null;        try {            cipher = Cipher.getInstance(DES_ALGORITHM);            cipher.init(Cipher.ENCRYPT_MODE, generateKey(secretKey));        } catch (NoSuchAlgorithmException e) {            e.printStackTrace();        } catch (NoSuchPaddingException e) {            e.printStackTrace();        } catch (InvalidKeyException e) {        }        try {            // 为了防止解密时报javax.crypto.IllegalBlockSizeException: Input length must            // be multiple of 8 when decrypting with padded cipher异常，            // 不能把加密后的字节数组直接转换成字符串            byte[] buf = cipher.doFinal(plainData.getBytes());            return Base64Utils.encode(buf);        } catch (IllegalBlockSizeException e) {            e.printStackTrace();            throw new Exception("IllegalBlockSizeException", e);        } catch (BadPaddingException e) {            e.printStackTrace();            throw new Exception("BadPaddingException", e);        }    }    /**     * DES解密     *      * @param secretData     *            密码字符串     * @param secretKey     *            解密密钥     * @return 原始字符串     * @throws Exception     */    public static String decryption(String secretData, String secretKey) throws Exception {        Cipher cipher = null;        try {            cipher = Cipher.getInstance(DES_ALGORITHM);            cipher.init(Cipher.DECRYPT_MODE, generateKey(secretKey));        } catch (NoSuchAlgorithmException e) {            e.printStackTrace();            throw new Exception("NoSuchAlgorithmException", e);        } catch (NoSuchPaddingException e) {            e.printStackTrace();            throw new Exception("NoSuchPaddingException", e);        } catch (InvalidKeyException e) {            e.printStackTrace();            throw new Exception("InvalidKeyException", e);        }        try {            byte[] buf = cipher.doFinal(Base64Utils.decode(secretData.toCharArray()));            return new String(buf);        } catch (IllegalBlockSizeException e) {            e.printStackTrace();            throw new Exception("IllegalBlockSizeException", e);        } catch (BadPaddingException e) {            e.printStackTrace();            throw new Exception("BadPaddingException", e);        }    }    /**     * 获得秘密密钥     *      * @param secretKey     * @return     * @throws NoSuchAlgorithmException     * @throws InvalidKeySpecException     * @throws InvalidKeyException     */    private static SecretKey generateKey(String secretKey)            throws NoSuchAlgorithmException, InvalidKeySpecException, InvalidKeyException {        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES_ALGORITHM);        DESKeySpec keySpec = new DESKeySpec(secretKey.getBytes());        keyFactory.generateSecret(keySpec);        return keyFactory.generateSecret(keySpec);    }    static private class Base64Utils {        static private char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="                .toCharArray();        static private byte[] codes = new byte[256];        static {            for (int i = 0; i < 256; i++)                codes[i] = -1;            for (int i = 'A'; i <= 'Z'; i++)                codes[i] = (byte) (i - 'A');            for (int i = 'a'; i <= 'z'; i++)                codes[i] = (byte) (26 + i - 'a');            for (int i = '0'; i <= '9'; i++)                codes[i] = (byte) (52 + i - '0');            codes['+'] = 62;            codes['/'] = 63;        }        /**         * 将原始数据编码为base64编码         */        static private String encode(byte[] data) {            char[] out = new char[((data.length + 2) / 3) * 4];            for (int i = 0, index = 0; i < data.length; i += 3, index += 4) {                boolean quad = false;                boolean trip = false;                int val = (0xFF & (int) data[i]);                val <<= 8;                if ((i + 1) < data.length) {                    val |= (0xFF & (int) data[i + 1]);                    trip = true;                }                val <<= 8;                if ((i + 2) < data.length) {                    val |= (0xFF & (int) data[i + 2]);                    quad = true;                }                out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];                val >>= 6;                out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];                val >>= 6;                out[index + 1] = alphabet[val & 0x3F];                val >>= 6;                out[index + 0] = alphabet[val & 0x3F];            }            return new String(out);        }        /**         * 将base64编码的数据解码成原始数据         */        static private byte[] decode(char[] data) {            int len = ((data.length + 3) / 4) * 3;            if (data.length > 0 && data[data.length - 1] == '=')                --len;            if (data.length > 1 && data[data.length - 2] == '=')                --len;            byte[] out = new byte[len];            int shift = 0;            int accum = 0;            int index = 0;            for (int ix = 0; ix < data.length; ix++) {                int value = codes[data[ix] & 0xFF];                if (value >= 0) {                    accum <<= 6;                    shift += 6;                    accum |= value;                    if (shift >= 8) {                        shift -= 8;                        out[index++] = (byte) ((accum >> shift) & 0xff);                    }                }            }            if (index != out.length)                throw new Error("miscalculated data length!");            return out;        }    }}

CryptoJS DES和MD5

点此下载源代码