在线用户    站点地图 技术论坛 文档中心 站点导航 资源下载 语言参考 教程专题 站点统计 业务项目 使用帮助
您的位置
MSDN参考新加了CSS2参考,全中文,制作精良。245k下载。           新加了sxf_sxf推荐的"动态网页专家指导" 下载!          新加了lsg2002lsg推荐的"ASP.NET高级编程(PDF)" 下载!          新加了DHTML代码预览!!,功能强大哦!欢迎试用          新加了网友lincong为大家提供的SQL Server 2000 程序员指南,有点大,但同时也就说明内容全咯!           新加了网友ibra为大家提供的北大的JAVA课件,很适合初学者入门           新加了一个java的连接缓冲池代码示例           新加了人月神话电子版下载!软件工程巨著哦~~           更新了评分标准,引入了“专家分”概念,相信可以更好的激励大家的学习!详情请看“使用帮助”           新加了由网友GGG提供的“IIS超级管理手册”,值得一看哦!(虽然我没看过 :P )           新加了“英雄榜”,欢迎测试!           “无组件上传·从原理剖析到实践”已经全部完成,源码全部开放,有兴趣的朋友请到文档中心一探究竟。  您的位置  首页>文档中心>ASP>文档A0000836 在同一窗口中打开页面中的链接 在新窗口中打开页面中的链接 将ASPCHINA设为首页 将ASPCHINA加入书签    
 LOGIN HERE
用户:
密码: 忘记密码
记住密码 用户注册 游客进入
相关文章

asp编码的转换

超漂亮后台完善企业代码V5.0

№ → 发布几个经典的ASP源码

利用asp连接远端Oracle数据库方法!

用ASP生成BMP图片

ASP与存储过程

ASP中对FoxPro自由表(DBF文件)的操作

优化asp数据访问代码

[原创]:DW+ASP.Net实战(五):留言板演示--大结局

[原创]:DW+ASP.Net实战(四):开发中应注意的一些小技巧
发表文章
验证码的程序及原理

原作者:     提交人:jammay     发布时间:04-10-29     文章类型:转贴     浏览量:1702
参考链结:http://    
关键字:asp
[本文档没有附件]
字体:    视力保护色: 杏仁黄  秋叶褐  胭脂红  芥末绿  天蓝  雪青  灰  银河白(默认色) [A0000836]

一共4个页面:form.asp; chk.asp; num.asp; count.asp
得到一个随即数字。加密!
解密后成成XBM图片
利用session 判断
form.asp
<%
’### To encrypt/decrypt include this code in your page 
’### strMyEncryptedString = EncryptString(strString)
’### strMyDecryptedString = DeCryptString(strMyEncryptedString)
’### You are free to use this code as long as credits remain in place
’### also if you improve this code let me know.

Private Function EncryptString(strString)
’####################################################################
’### Crypt Function (C) 2001 by Slavic Kozyuk grindkore@yahoo.com ###
’### Arguments: strString <--- String you wish to encrypt ###
’### Output: Encrypted HEX string ###
’####################################################################

Dim CharHexSet, intStringLen, strTemp, strRAW, i, intKey, intOffSet
Randomize Timer

intKey = Round((RND * 1000000) + 1000000) ’##### Key Bitsize
intOffSet = Round((RND * 1000000) + 1000000) ’##### KeyOffSet Bitsize

If IsNull(strString) = False Then
strRAW = strString
intStringLen = Len(strRAW)

For i = 0 to intStringLen - 1
strTemp = Left(strRAW, 1)
strRAW = Right(strRAW, Len(strRAW) - 1)
CharHexSet = CharHexSet & Hex(Asc(strTemp) * intKey)& Hex(intKey)
Next

EncryptString = CharHexSet & "|" & Hex(intOffSet + intKey) & "|" & Hex(intOffSet)
Else
EncryptString = ""
End If
End Function




Private Function DeCryptString(strCryptString)
’####################################################################
’### Crypt Function (C) 2001 by Slavic Kozyuk grindkore@yahoo.com ###
’### Arguments: Encrypted HEX stringt ###
’### Output: Decrypted ASCII string ###
’####################################################################
’### Note this function uses HexConv() and get_hxno() functions ###
’### so make sure they are not removed ###
’####################################################################

Dim strRAW, arHexCharSet, i, intKey, intOffSet, strRawKey, strHexCrypData


strRawKey = Right(strCryptString, Len(strCryptString) - InStr(strCryptString, "|"))
intOffSet = Right(strRawKey, Len(strRawKey) - InStr(strRawKey,"|"))
intKey = HexConv(Left(strRawKey, InStr(strRawKey, "|") - 1)) - HexConv(intOffSet)
strHexCrypData = Left(strCryptString, Len(strCryptString) - (Len(strRawKey) + 1))

arHexCharSet = Split(strHexCrypData, Hex(intKey))

For i=0 to UBound(arHexCharSet)
strRAW = strRAW & Chr(HexConv(arHexCharSet(i))/intKey)
Next

DeCryptString = strRAW
End Function

Private Function HexConv(hexVar)
Dim hxx, hxx_var, multiply 
IF hexVar <> "" THEN
hexVar = UCASE(hexVar)
hexVar = StrReverse(hexVar)
DIM hx()
REDIM hx(LEN(hexVar))
hxx = 0
hxx_var = 0
FOR hxx = 1 TO LEN(hexVar)
IF multiply = "" THEN multiply = 1
hx(hxx) = mid(hexVar,hxx,1)
hxx_var = (get_hxno(hx(hxx)) * multiply) + hxx_var
multiply = (multiply * 16)
NEXT
hexVar = hxx_var
HexConv = hexVar
END IF
End Function

Private Function get_hxno(ghx)
If ghx = "A" Then
ghx = 10
ElseIf ghx = "B" Then
ghx = 11
ElseIf ghx = "C" Then
ghx = 12
ElseIf ghx = "D" Then
ghx = 13
ElseIf ghx = "E" Then
ghx = 14
ElseIf ghx = "F" Then
ghx = 15
End If
get_hxno = ghx
End Function
%>
<%
randomize
num = int(7999*rnd+2000) ’计数器的值
num2 = EncryptString(num)
session("pwdt")=num
%>
<form action="chk.asp" method=post>
请输入验证码: <input type="text" name="pwds">
<img src="count.asp?sksid=<%=num2%>"> <input type=submit value=提交>
</form>

chk.asp
<%
if trim(request.form("pwds"))<>trim(session("pwdt")) then
%>
输入错误: 应该为:<%=session("pwdt")%>,可你输入的是:<%=request.form("pwds")%>
<%
else
%>
输入正确
<%end if%>

count.asp

<!--#include file="num.asp"-->

<%
’### To encrypt/decrypt include this code in your page 
’### strMyEncryptedString = EncryptString(strString)
’### strMyDecryptedString = DeCryptString(strMyEncryptedString)
’### You are free to use this code as long as credits remain in place
’### also if you improve this code let me know.

Private Function EncryptString(strString)
’####################################################################
’### Crypt Function (C) 2001 by Slavic Kozyuk grindkore@yahoo.com ###
’### Arguments: strString <--- String you wish to encrypt ###
’### Output: Encrypted HEX string ###
’####################################################################

Dim CharHexSet, intStringLen, strTemp, strRAW, i, intKey, intOffSet
Randomize Timer

intKey = Round((RND * 1000000) + 1000000) ’##### Key Bitsize
intOffSet = Round((RND * 1000000) + 1000000) ’##### KeyOffSet Bitsize

If IsNull(strString) = False Then
strRAW = strString
intStringLen = Len(strRAW)

For i = 0 to intStringLen - 1
strTemp = Left(strRAW, 1)
strRAW = Right(strRAW, Len(strRAW) - 1)
CharHexSet = CharHexSet & Hex(Asc(strTemp) * intKey)& Hex(intKey)
Next

EncryptString = CharHexSet & "|" & Hex(intOffSet + intKey) & "|" & Hex(intOffSet)
Else
EncryptString = ""
End If
End Function

Private Function DeCryptString(strCryptString)
’####################################################################
’### Crypt Function (C) 2001 by Slavic Kozyuk grindkore@yahoo.com ###
’### Arguments: Encrypted HEX stringt ###
’### Output: Decrypted ASCII string ###
’####################################################################
’### Note this function uses HexConv() and get_hxno() functions ###
’### so make sure they are not removed ###
’####################################################################

Dim strRAW, arHexCharSet, i, intKey, intOffSet, strRawKey, strHexCrypData

strRawKey = Right(strCryptString, Len(strCryptString) - InStr(strCryptString, "|"))
intOffSet = Right(strRawKey, Len(strRawKey) - InStr(strRawKey,"|"))
intKey = HexConv(Left(strRawKey, InStr(strRawKey, "|") - 1)) - HexConv(intOffSet)
strHexCrypData = Left(strCryptString, Len(strCryptString) - (Len(strRawKey) + 1))

arHexCharSet = Split(strHexCrypData, Hex(intKey))

For i=0 to UBound(arHexCharSet)
strRAW = strRAW & Chr(HexConv(arHexCharSet(i))/intKey)
Next

DeCryptString = strRAW
End Function

Private Function HexConv(hexVar)
Dim hxx, hxx_var, multiply 
IF hexVar <> "" THEN
hexVar = UCASE(hexVar)
hexVar = StrReverse(hexVar)
DIM hx()
REDIM hx(LEN(hexVar))
hxx = 0
hxx_var = 0
FOR hxx = 1 TO LEN(hexVar)
IF multiply = "" THEN multiply = 1
hx(hxx) = mid(hexVar,hxx,1)
hxx_var = (get_hxno(hx(hxx)) * multiply) + hxx_var
multiply = (multiply * 16)
NEXT
hexVar = hxx_var
HexConv = hexVar
END IF
End Function

Private Function get_hxno(ghx)
If ghx = "A" Then
ghx = 10
ElseIf ghx = "B" Then
ghx = 11
ElseIf ghx = "C" Then
ghx = 12
ElseIf ghx = "D" Then
ghx = 13
ElseIf ghx = "E" Then
ghx = 14
ElseIf ghx = "F" Then
ghx = 15
End If
get_hxno = ghx
End Function

%>

<%
Dim Image
Dim Width, Height
Dim num
Dim digtal
Dim Length
Dim sort
Length = 4 ’自定计数器长度

Redim sort( Length )

num=cint(DeCryptString(request.querystring("sksid")))
digital = ""
For I = 1 To Length -Len( num ) ’补0
digital = digital & "0"
Next
For I = 1 To Len( num )
digital = digital & Mid( num, I, 1 )
Next
For I = 1 To Len( digital )
sort(I) = Mid( digital, I, 1 )
Next
Width = 8 * Len( digital ) ’图像的宽度
Height = 10 ’图像的高度,在本例中为固定值

Response.ContentType="image/x-xbitmap"

hc=chr(13) & chr(10) 

Image = "#define counter_width " & Width & hc
Image = Image & "#define counter_height " & Height & hc
Image = Image & "static unsigned char counter_bits[]={" & hc

For I = 1 To Height
For J = 1 To Length
Image = Image & a(sort(J),I) & ","
Next
Next
Image = Left( Image, Len( Image ) - 1 ) ’去掉最后一个逗号
Image = Image & "};" & hc
%>
<%
Response.Write Image
%>

num.asp
<%
Dim a(10,10)

a(0,1) = "0x3c" ’数字0
a(0,2) = "0x66"
a(0,3) = "0xc3"
a(0,4) = "0xc3"
a(0,5) = "0xc3"
a(0,6) = "0xc3"
a(0,7) = "0xc3"
a(0,8) = "0xc3"
a(0,9) = "0x66"
a(0,10)= "0x3c"

a(1,1) = "0x18" ’数字1
a(1,2) = "0x1c"
a(1,3) = "0x18"
a(1,4) = "0x18"
a(1,5) = "0x18"
a(1,6) = "0x18"
a(1,7) = "0x18"
a(1,8) = "0x18"
a(1,9) = "0x18"
a(0,10)= "0x7e"


a(2,1) = "0x3c" ’数字2
a(2,2) = "0x66"
a(2,3) = "0x60"
a(2,4) = "0x60"
a(2,5) = "0x30"
a(2,6) = "0x18"
a(2,7) = "0x0c"
a(2,8) = "0x06"
a(2,9) = "0x06"
a(2,10)= "0x7e"

a(3,1) = "0x3c" ’数字3
a(3,2) = "0x66"
a(3,3) = "0xc0"
a(3,4) = "0x60"
a(3,5) = "0x1c"
a(3,6) = "0x60"
a(3,7) = "0xc0"
a(3,8) = "0xc0"
a(3,9) = "0x66"
a(3,10)= "0x38"

a(4,1) = "0x38" ’数字4
a(4,2) = "0x3c"
a(4,3) = "0x36"
a(4,4) = "0x33"
a(4,5) = "0x33"
a(4,6) = "0x33"
a(4,7) = "0xff"
a(4,8) = "0x30"
a(4,9) = "0x30"
a(4,10)= "0xfe"

a(5,1) = "0xfe" ’数字5
a(5,2) = "0xfe"
a(5,3) = "0x06"
a(5,4) = "0x06"
a(5,5) = "0x3e"
a(5,6) = "0x60"
a(5,7) = "0xc0"
a(5,8) = "0xc3"
a(5,9) = "0x66"
a(5,10)= "0x3c"

a(6,1) = "0x60" ’数字6
a(6,2) = "0x30"
a(6,3) = "0x18"
a(6,4) = "0x0c"
a(6,5) = "0x3e"
a(6,6) = "0x63"
a(6,7) = "0xc3"
a(6,8) = "0xc3"
a(6,9) = "0x66"
a(6,10) ="0x3c"

a(7,1) = "0xff" ’数字7
a(7,2) = "0xc0"
a(7,3) = "0x60"
a(7,4) = "0x30"
a(7,5) = "0x18"
a(7,6) = "0x18"
a(7,7) = "0x18"
a(7,8) = "0x18"
a(7,9) = "0x18"
a(7,10)= "0x18"

a(8,1) = "0x3c" ’数字8
a(8,2) = "0x66"
a(8,3) = "0xc3"
a(8,4) = "0x66"
a(8,5) = "0x3c"
a(8,6) = "0x66"
a(8,7) = "0xc3"
a(8,8) = "0xc3"
a(8,9) = "0x66"
a(8,10)= "0x3c"

a(9,1) = "0x3c" ’数字9
a(9,2) = "0x66"
a(9,3) = "0xc3"
a(9,4) = "0xc3"
a(9,5) = "0x66"
a(9,6) = "0x3c"
a(9,7) = "0x18"
a(9,8) = "0x0c"
a(9,9) = "0x06"
a(9,10)= "0x03"

%>

关于这篇文章的评论 [注意:这里仅仅是给大家提供了一个发表对文章本身看法的地方,如果有疑问,请到论坛提出] 我要提问!
datoudatou        2006/8/5 11:47:00
:)
验证码可以防止恶意提交,因为每次都不一样,这样搞破坏的人写了个循环提交的程序就会被阻止。
刑天        2005/11/3 15:11:00
:)
我是新手也有同感
验证码到底做什么用的啊
hywhy        2005/7/7 20:56:00
:)
可是我一直不明白,验证吗是干什么用的
标题
内容
发言
*您尚未以注册用户身份登录,不能发表评论。这里登录
您的位置
  (c)2000-2019 Yup Studio, all rights reserved.  
664.0625