在JSP中如何实现MD5加密的方法

在各种应用系统的开发中,经常需要存储用户信息,很多地方都要存储用户密码,而将用户密码直接存储在服务器上显然是不安全的,本文简要介绍在JSP中如何实现MD5加密的方法,希望能抛砖引玉。

(一)消息摘要简介
一个消息摘要就是一个数据块的数字指纹。即对一个任意长度的一个数据块进行计算,产生一个唯一指印(对于SHA1是产生一个20字节的二进制数组)。消息摘要是一种与消息认证码结合使用以确保消息完整性的技术。主要使用单向散列函数算法,可用于检验消息的完整性,和通过散列密码直接以文本形式保存等,目前广泛使用的算法有MD4、MD5、SHA-1。

消息摘要有两个基本属性:

两个不同的报文难以生成相同的摘要

难以对指定的摘要生成一个报文,而可以由该报文反推算出该指定的摘要。

Java源码

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,是最新一次计算结果的     16进制ASCII表示.   */   public String digestHexStr;   /* digest,是最新一次计算结果的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

-------------------------------------------------------------------------------

内容版权声明:除非注明,否则皆为本站原创文章。

转载注明出处:https://www.heiqu.com/wzggxd.html