在JSP中如何实现MD5加密

来源：作者：出处：巧巧读书 2007-12-16 进入讨论组

关键词：
update
word
html
java
c语言

/*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>