JSP作为一种强大的动态网页制作工具，在安全方面的性能如何呢？在写JSP源码的时候，要提到MD5加密，它是什么？MD5加密很有用，而且用处很大，MD5几乎破解不了，所以提交过去的数据可以防止外泄。
JSP技术中也提供了这么强大的功能，这么说吧：***种，有人监听你的网络，直接获取你的用户名和密码。用MD5可以让他监听加密后的字符串，让他慢慢破解着去吧。
第二种，你的数据库被打开了，有人看到数据库里面的数据，你是希望他看到你数据库里的客户信息，还是一个个加过密的东西。
或许你会问加过密了自己怎么看，有些时候没必要自己看，比如说你要判断密码是否正确，如果你注册的时候给数据库中提交的是一个加过密的用户名和密码（你当然看不懂是什么），而当他再次登录的时候，你只需要判断是否和注册的md5值是否相等，而不必理睬是什么。
MD5很强的，别小看他了，那么在JSP源码中如何实现MD5加密。
JSP源码:
- /**
- * 类名： MD5Digest﹤br﹥
- * 说明： 用来进行密码加密的md5公用参数﹤br﹥
- * 编写日期： 2001/03/05﹤br﹥
- * 修改者： ﹤br﹥
- * 修改信息： ﹤br﹥
- * @author edgarlo edgarlo@china.com
- * @version 1.0﹤br﹥
- */
- import java.security.MessageDigest;
- import java.security.NoSuchAlgorithmException;
- public class MD5Digest
- {
- private MessageDigest __md5 = null;
- private StringBuffer __digestBuffer = null;
- public MD5Digest()
- throws NoSuchAlgorithmException
- {
- __md5 = MessageDigest.getInstance("MD5");
- __digestBuffer = new StringBuffer();
- }
- public String md5crypt(String s)
- {
- __digestBuffer.setLength(0);
- byte abyte0[] = __md5.digest(s.getBytes());
- for(int i = 0; i ﹤ abyte0.length; i++)
- __digestBuffer.append(toHex(abyte0[i]));
- return __digestBuffer.toString();
- }
- public String toHex(byte one){
- String HEX="0123456789ABCDEF";
- char[] result=new char[2];
- result[0]=HEX.charAt((one & 0xf0) ﹥﹥ 4);
- result[1]=HEX.charAt(one & 0x0f);
- String mm=new String(result);
- return mm;
- }
- }
- /************************************************
- MD5 算法的Java Bean
- @author:Topcat Tuppin
- Last Modified:10,Mar,2001
- *************************************************/
- package beartool;
- import java.lang.reflect.*;
- /*************************************************
- md5 类实现了RSA Data Security, Inc.在提交给IETF
- 的RFC1321中的MD5 message-digest 算法。
- *************************************************/
- public class MD5 {
- /* 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的，
- 这里把它们实现成为static final是表示了只读，切能在同一个进程空间内的多个
- Instance间共享*/
- static final int S11 = 7;
- static final int S12 = 12;
- static final int S13 = 17;
- static final int S14 = 22;
- static final int S21 = 5;
- static final int S22 = 9;
- static final int S23 = 14;
- static final int S24 = 20;
- static final int S31 = 4;
- static final int S32 = 11;
- static final int S33 = 16;
- static final int S34 = 23;
- static final int S41 = 6;
- static final int S42 = 10;
- static final int S43 = 15;
- static final int S44 = 21;
- static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
- /* 下面的三个成员是MD5计算过程中用到的3个核心数据，在原始的C实现中
- 被定义到MD5_CTX结构中
- */
- private long[] state = new long[4]; // state (ABCD)
- private long[] count = new long[2]; // number of bits, modulo 2^64 (lsb first)
- private byte[] buffer = new byte[64]; // input buffer
- /* digestHexStr是MD5的唯一一个公共成员，是***一次计算结果的
- 16进制ASCII表示.
- */
- public String digestHexStr;
- /* digest,是***一次计算结果的2进制内部表示，表示128bit的MD5值.
- */
- private byte[] digest = new byte[16];
- /*
- getMD5ofStr是类MD5最主要的公共方法，入口参数是你想要进行MD5变换的字符串
- 返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．
- */
- public String getMD5ofStr(String inbuf) {
- md5Init();
- md5Update(inbuf.getBytes(), inbuf.length());
- md5Final();
- digestHexStr = "";
- for (int i = 0; i ﹤ 16; i++) {
- digestHexStr += byteHEX(digest[i]);
- }
- return digestHexStr;
- }
- // 这是MD5这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数
- public MD5() {
- md5Init();
- return;
- }
- /* md5Init是一个初始化函数，初始化核心变量，装入标准的幻数 */
- private void md5Init() {
- count[0] = 0L;
- count[1] = 0L;
- ///* Load magic initialization constants.
- state[0] = 0x67452301L;
- state[1] = 0xefcdab89L;
- state[2] = 0x98badcfeL;
- state[3] = 0x10325476L;
- return;
- }
- /* F, G, H ,I 是4个基本的MD5函数，在原始的MD5的C实现中，由于它们是
- 简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们
- 实现成了private方法，名字保持了原来C中的。 */
- private long F(long x, long y, long z) {
- return (x & y) | ((~x) & z);
- }
- private long G(long x, long y, long z) {
- return (x & z) | (y & (~z));
- }
- private long H(long x, long y, long z) {
- return x ^ y ^ z;
- }
- private long I(long x, long y, long z) {
- return y ^ (x | (~z));
- }
- /*
- FF,GG,HH和II将调用F,G,H,I进行近一步变换
- FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
- Rotation is separate from addition to prevent recomputation.
- */
- private long FF(long a, long b, long c, long d, long x, long s,
- long ac) {
- a += F (b, c, d) + x + ac;
- a = ((int) a ﹤﹤ s) | ((int) a ﹥﹥﹥ (32 - s));
- a += b;
- return a;
- }
- private long GG(long a, long b, long c, long d, long x, long s,
- long ac) {
- a += G (b, c, d) + x + ac;
- a = ((int) a ﹤﹤ s) | ((int) a ﹥﹥﹥ (32 - s));
- a += b;
- return a;
- }
- private long HH(long a, long b, long c, long d, long x, long s,
- long ac) {
- a += H (b, c, d) + x + ac;
- a = ((int) a ﹤﹤ s) | ((int) a ﹥﹥﹥ (32 - s));
- a += b;
- return a;
- }
- private long II(long a, long b, long c, long d, long x, long s,
- long ac) {
- a += I (b, c, d) + x + ac;
- a = ((int) a ﹤﹤ s) | ((int) a ﹥﹥﹥ (32 - s));
- a += b;
- return a;
- }
- /*
- md5Update是MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
- 函数由getMD5ofStr调用，调用之前需要调用md5init，因此把它设计成private的
- */
- private void md5Update(byte[] inbuf, int inputLen) {
- int i, index, partLen;
- byte[] block = new byte[64];
- index = (int)(count[0] ﹥﹥﹥ 3) & 0x3F;
- // /* Update number of bits */
- if ((count[0] += (inputLen ﹤﹤ 3)) ﹤ (inputLen ﹤﹤ 3))
- count[1]++;
- count[1] += (inputLen ﹥﹥﹥ 29);
- partLen = 64 - index;
- // Transform as many times as possible.
- if (inputLen ﹥= partLen) {
- md5Memcpy(buffer, inbuf, index, 0, partLen);
- md5Transform(buffer);
- for (i = partLen; i + 63 ﹤ inputLen; i += 64) {
- md5Memcpy(block, inbuf, 0, i, 64);
- md5Transform (block);
- }
- index = 0;
- } else
- i = 0;
- ///* Buffer remaining input */
- md5Memcpy(buffer, inbuf, index, i, inputLen - i);
- }
- /*
- md5Final整理和填写输出结果
- */
- private void md5Final () {
- byte[] bits = new byte[8];
- int index, padLen;
- ///* Save number of bits */
- Encode (bits, count, 8);
- ///* Pad out to 56 mod 64.
- index = (int)(count[0] ﹥﹥﹥ 3) & 0x3f;
- padLen = (index ﹤ 56) ? (56 - index) : (120 - index);
- md5Update (PADDING, padLen);
- ///* Append length (before padding) */
- md5Update(bits, 8);
- ///* Store state in digest */
- Encode (digest, state, 16);
- }
- /* md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的
- 字节拷贝到output的outpos位置开始
- */
- private void md5Memcpy (byte[] output, byte[] input,
- int outpos, int inpos, int len)
- {
- int i;
- for (i = 0; i ﹤ len; i++)
- output[outpos + i] = input[inpos + i];
- }
- /*
- md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节
- */
- private void md5Transform (byte block[]) {
- long a = state[0], b = state[1], c = state[2], d = state[3];
- long[] x = new long[16];
- Decode (x, block, 64);
- /* Round 1 */
- a = FF (a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
- d = FF (d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
- c = FF (c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
- b = FF (b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
- a = FF (a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
- d = FF (d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
- c = FF (c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
- b = FF (b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
- a = FF (a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
- d = FF (d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
- c = FF (c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
- b = FF (b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
- a = FF (a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
- d = FF (d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
- c = FF (c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
- b = FF (b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */
- /* Round 2 */
- a = GG (a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
- d = GG (d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
- c = GG (c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
- b = GG (b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
- a = GG (a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
- d = GG (d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
- c = GG (c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
- b = GG (b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
- a = GG (a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
- d = GG (d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
- c = GG (c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
- b = GG (b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
- a = GG (a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
- d = GG (d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
- c = GG (c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
- b = GG (b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */
- /* Round 3 */
- a = HH (a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
- d = HH (d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
- c = HH (c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
- b = HH (b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
- a = HH (a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
- d = HH (d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
- c = HH (c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
- b = HH (b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
- a = HH (a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
- d = HH (d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
- c = HH (c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
- b = HH (b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
- a = HH (a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
- d = HH (d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
- c = HH (c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
- b = HH (b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */
- /* Round 4 */
- a = II (a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
- d = II (d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
- c = II (c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
- b = II (b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
- a = II (a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
- d = II (d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
- c = II (c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
- b = II (b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
- a = II (a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
- d = II (d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
- c = II (c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
- b = II (b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
- a = II (a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
- d = II (d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
- c = II (c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
- b = II (b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */
- state[0] += a;
- state[1] += b;
- state[2] += c;
- state[3] += d;
- }
- /*Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的，
- 只拆低32bit，以适应原始C实现的用途
- */
- private void Encode (byte[] output, long[] input, int len) {
- int i, j;
- for (i = 0, j = 0; j ﹤ len; i++, j += 4) {
- output[j] = (byte)(input[i] & 0xffL);
- output[j + 1] = (byte)((input[i] ﹥﹥﹥ 8) & 0xffL);
- output[j + 2] = (byte)((input[i] ﹥﹥﹥ 16) & 0xffL);
- output[j + 3] = (byte)((input[i] ﹥﹥﹥ 24) & 0xffL);
- }
- }
- /*Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
- 只合成低32bit，高32bit清零，以适应原始C实现的用途
- */
- private void Decode (long[] output, byte[] input, int len) {
- int i, j;
- for (i = 0, j = 0; j ﹤ len; i++, j += 4)
- output[i] = b2iu(input[j]) |
- (b2iu(input[j + 1]) ﹤﹤ 8) |
- (b2iu(input[j + 2]) ﹤﹤ 16) |
- (b2iu(input[j + 3]) ﹤﹤ 24);
- return;
- }
- /*
- b2iu是我写的一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算
- */
- public static long b2iu(byte b) {
- return b ﹤ 0 ? b & 0x7F + 128 : b;
- }
- /*byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
- 因为java中的byte的toString无法实现这一点，我们又没有C语言中的
- sprintf(outbuf,"%02X",ib)
- */
- public static String byteHEX(byte ib) {
- char[] Digit = { '0','1','2','3','4','5','6','7','8','9',
- 'A','B','C','D','E','F' };
- char [] ob = new char[2];
- ob[0] = Digit[(ib ﹥﹥﹥ 4) & 0X0F];
- ob[1] = Digit[ib & 0X0F];
- String s = new String(ob);
- return s;
- }
- public static void main(String args[]) {
- MD5 m = new MD5();
- if (Array.getLength(args) == 0) { //如果没有参数，执行标准的Test Suite
- System.out.println("MD5 Test suite:");
- System.out.println("MD5(\"\"):"+m.getMD5ofStr(""));
- System.out.println("MD5(\"a\"):"+m.getMD5ofStr("a"));
- System.out.println("MD5(\"abc\"):"+m.getMD5ofStr("abc"));
- System.out.println("MD5(\"message digest\"):"+m.getMD5ofStr("message digest"));
- System.out.println("MD5(\"abcdefghijklmnopqrstuvwxyz\"):"+
- m.getMD5ofStr("abcdefghijklmnopqrstuvwxyz"));
- System.out.println("MD5(\"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789\"):"+
- m.getMD5ofStr("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"));
- }
- else
- System.out.println("MD5(" + args[0] + ")=" + m.getMD5ofStr(args[0]));
- }
- }
- JSP中的使用方法
- -------------------------------------------------------------------------------
- ﹤%@ page language='java' %﹥
- ﹤jsp:useBean id='oMD5' scope='request' class='beartool.MD5'/﹥
- ﹤%@ page import='java.util.*'%﹥
- ﹤%@ page import='java.sql.*'%﹥
- ﹤html﹥
- ﹤body﹥
- ﹤%
- String userid = request.getParameter("UserID"); //获取用户输入UserID
- String password = request.getParameter("Password"); //获取用户输入的Password
- String pwdmd5 = oMD5.getMD5ofStr(password); //计算MD5的值
- PrintWriter rp = response.getWriter();
- Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
- Connection con = DriverManager.getConnection("jdbc:odbc:community", "", "");
- Statement stmt = con.createStatement();
- ResultSet rs = stmt.executeQuery("select * from users where userID ='"+userid+"' and pwdmd5= '" + pwdmd5+"'" );
- if (rs.next())
- {
- rp.print("Login OK");
- }
- else
- {
- rp.print("Login Fail");
- }
- stmt.close();
- con.close();
- %﹥
- ﹤/body﹥
- ﹤/html﹥
关于这么强大的实现MD5加密的JSP源码，是不是想立即实现呢？赶紧动手尝试吧！
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