ASP验证码代码下载

1、<%'-'图片验证码'netdust'05-8-29 发布'以前的图片验证码很容易被破解，所以在其基础上进行改进，即使知道源代码'也很难破解。'干扰次数每加一   ->   穷举法的代价提高约100*100倍'适当设定杂点几率可以有效降低软件识别正确率'05-12-20 修正了一个错误'- Option Explicit Call Com_CreatValidCode("GetCode") Rem 生成验

2、证码图片Sub Com_CreatValidCode(pSN)Const codeLen = 4 '验证码位数Const cOdds = 3 '杂点出现的机率Const dbtTimes = 1 '干扰次数（安全考虑，最好不要小于3） Const cAmount = 10 '字库数量Const cCode = "0123456789" '字库对应的字符Const UnitWidth = 16 '字宽(要为4的倍数)Const UnitHeight = 13 '字高Const DotsLimit = 5 

3、9;每次删除有效点的上限(避免无法人为识别)Const tryCount = 5 '避免删除有效点超过上限的尝试次数限制 '- RandomizeDim i, ii, iii ' 禁止缓存Response.Expires = -9999Response.AddHeader "Pragma","no-cache"Response.AddHeader "cache-ctrol","no-cache"Response.ContentType = "Image

4、/BMP" ' 颜色的数?字符，背景)Dim vColorData(1)vColorData(0) = ChrB(0) & ChrB(0) & ChrB(0)   ' 蓝0，绿0，红0（黑色）vColorData(1) = ChrB(255) & ChrB(255) & ChrB(255) ' 蓝250，绿236，红211（浅蓝色） ' 字符的数据(可以自己修改，如果修改了尺寸，记得把前面的设定也改了)Dim vNumberData(9)vNumberData(0) =

5、"1111000000001111111000000000011111100111111001111110011111100111111001111110011111100111111001111110011111100111111001111110011111100111111001111110011111100111111001111110011111100000000001111111000000001111"vNumberData(1) = "111111000111111111110000011111111110000001111111110011000

6、1111111111111000111111111111100011111111111110001111111111111000111111111111100011111111111110001111111111111000111111111100000000011111110000000001111"vNumberData(2) = "111111000001111111111000000011111111000111001111111000111100111111111111100111111111111100111111111111100111111111111100

7、1111111111111001111111111111001111001111111001111100111111100000000011111110000000001111"vNumberData(3) = "111110000001111111110000000011111110011111100111111001111100111111111111100111111111111000111111111111100011111111111111100111111111111111001111111001111110011111100111111001111111000

8、0000011111111100000011111"vNumberData(4) = "1111111100111111111110110011111111110011001111111111001100111111111001110011111111001111001111111000000000000011100000000000001111111111001111111111111100111111111111110011111111111111001111111111111100111111"vNumberData(5) = "111000000

9、0000111110011111111111111001111111111111100111111111111110011111111111111001100000011111100000111100111111111111110011111111111111001111111111111100111110011111110011111001111111001111110000000001111"vNumberData(6) = "111111000001111111111000000011111111001111100111111001111111111111100111

10、1111111111100100000111111110000000001111111000111110011111100111111001111110011111100111111001111110011111110000000011111111100000011111"vNumberData(7) = "111000000000011111100000000001111110011111100111111001111110011111111111110011111111111111001111111111111001111111111111001111111111111

11、1001111111111111100111111111111110011111111111111001111111111111100111111"vNumberData(8) = "111110000001111111110000000011111110011111100111111001111110011111100111111001111111000000001111111100000000111111110011110011111110011111100111111001111110011111100111111001111111000000001111111110

12、0000011111"vNumberData(9) = "1111100000011111111100000000111111100111111001111110011111100111111001111110011111110000000001111111000000100111111111111110011111111111111001111111111111100111111001111100111111110000000011111111100000011111" ' 随机产生字符Dim vCodesReDim vCode(codeLen

13、-1)For i = 0 To codeLen-1   vCode(i) = Int(Rnd * cAmount)   vCodes = vCodes & Mid(cCode, vCode(i) + 1, 1)   vCode(i) = pcd_doubter(vNumberData(vCode(i),UnitWidth,UnitHeight,DotsLimit,tryCount,dbtTimes)Next Session(pSN) = vCodes   '记录入Session 

14、' 输出图像文件头Response.BinaryWrite ChrB(66) & ChrB(77) & Num2ChrB(54+UnitWidth*UnitHeight*CodeLen*3,4) & ChrB(0) & ChrB(0) &_   ChrB(0) & ChrB(0) & ChrB(54) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(40) & ChrB(0) &_   ChrB(0) & Ch

15、rB(0) & Num2ChrB(UnitWidth*CodeLen,4) & Num2ChrB(UnitHeight,4) &_   ChrB(1) & ChrB(0) ' 输出图像信息头Response.BinaryWrite ChrB(24) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & Num2ChrB(UnitWidth*UnitHeight*CodeLen*3,4) &_   Ch

16、rB(18) & ChrB(11) & ChrB(0) & ChrB(0) & ChrB(18) & ChrB(11) &_   ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) &_   ChrB(0) & ChrB(0) For i = UnitHeight-1 To 0 Step -1   

17、9; 历经所有行   For ii = 0 To codeLen-1   ' 历经所有字   For iii = 1 To UnitWidth ' 历经所有像素       If Rnd * 99 + 1 >= cOdds Then ' 逐行、逐字、逐像素地输出图像数据      Response.BinaryWrite vColorData(Mid(vCo

18、de(ii), i * UnitWidth + iii, 1)       Else ' 随机生成杂点      Response.BinaryWrite vColorData(1-CInt(Mid(vCode(ii), i * UnitWidth + iii, 1)       End If   Next   NextNextEnd Sub Rem 对单个字

19、的点阵进行干扰Rem 干扰思想：在点阵范围内随机产生2个端点，进行连线，以位移较大的一方做横轴，先将连线上的点删除，再将被删除点的纵轴方向上方或下方的点（随机确定）移向被删除点，移动后的空白用背景色补充Function pcd_doubter(ByVal str,UnitWidth,UnitHeight,DotsLimit,tryCount,dbtTimes)RandomizeDim x1,x2,y1,y2,xOffSet,yOffSet,direction,flag,rows,step,yu,yuStr,i,ii,iii,f1,f2For f1=1 To dbtTimes '干扰次数

20、For f2=1 To tryCount '避免删除有效点超过上限的尝试次数限制'随机确定2个端点x1 = int(Rnd*UnitWidth)x2 = int(Rnd*UnitWidth)y1 = int(Rnd*UnitHeight)y2 = int(Rnd*UnitHeight)'x,y位移量xOffSet = Abs(x2-x1)yOffSet = Abs(y2-y1)If xOffSet >= yOffSet Then '以位移量较大方做横轴direction = "x"ReDim ary(xOffSet) '用来记录

21、连线各点y值'x2,y2存储x值较大的点If x2 < x1 Theni = x1x1 = x2x2 = ii = y1y1 = y2y2 = iEnd If'判断从x1->x2在纵轴方向上是增是减If y2 >= y1 Thenflag = 1Elseflag = -1End If'下面计算连线上点的分布（先是平均分配各行的点，然后随机分配剩余的点到各行）rows = yOffSet + 1 '所占行数step = (xOffSet+1) rows '各行平均分配的点yu = (xOffSet+1) Mod rows '剩余的

22、点数ReDim ary2(rows-1) '用来记录剩余点的随机分配While yu > 0i = int(Rnd*rows)ary2(i) = ary2(i)&"." '被分配到的行则加一个字符"."yu = yu - 1WEndiii = 0'将连线的点信息记录到数组For i=0 To rows-1For ii=1 To step+Len(ary2(i)ary(iii) = y1 + i*flagiii = iii + 1NextNextii = 0'统计连线上有效点的数量For i=0 To xOff

23、SetIf pcd_getDot(x1+i,ary(i),str,UnitWidth) = "0" Then ii = ii + 1NextElse'这里是以y为横轴，原理与x时相同direction = "y"ReDim ary(yOffSet)If y2 < y1 Theni = x1x1 = x2x2 = ii = y1y1 = y2y2 = iEnd IfIf x2 >= x1 Thenflag = 1Elseflag = -1End Ifrows = xOffSet + 1step = (yOffSet+1) rowsyu

24、= (yOffSet+1) Mod rowsReDim ary2(rows-1)While yu > 0i = int(Rnd*10)If i < rows Thenary2(i) = ary2(i)&"."yu = yu - 1End IfWEndiii = 0For i=0 To rows-1For ii=1 To step+Len(ary2(i)ary(iii) = x1 + i*flagiii = iii + 1NextNextii = 0For i=0 To yOffSetIf pcd_getDot(ary(i),y1+i,str,UnitWi

25、dth) = "0" Then ii = ii + 1NextEnd If'如未超过有效点上限则跳出循环，执行干扰If ii <= DotsLimit Then Exit ForNext If direction = "x" Then'随机确定在纵轴方向上或下进行移动If int(Rnd*10) > 4 Then'变量连线上的点For i=0 To xOffSet'遍历移动For ii=ary(i) To 1 Step -1Call pcd_setDot(x1+i,ii,str,pcd_getDot(

26、x1+i,ii-1,str,UnitWidth),UnitWidth)Next'添补空白Call pcd_setDot(x1+i,0,str,"1",UnitWidth)NextElseFor i=0 To xOffSetFor ii=ary(i) To UnitHeight-2Call pcd_setDot(x1+i,ii,str,pcd_getDot(x1+i,ii+1,str,UnitWidth),UnitWidth)NextCall pcd_setDot(x1+i,UnitHeight-1,str,"1",UnitWidth)NextEn

27、d IfElseIf int(Rnd*10) > 4 ThenFor i=0 To yOffSetFor ii=ary(i) To 1 Step -1Call pcd_setDot(ii,y1+i,str,pcd_getDot(ii-1,y1+i,str,UnitWidth),UnitWidth)NextCall pcd_setDot(0,y1+i,str,"1",UnitWidth)NextElseFor i=0 To yOffSetFor ii=ary(i) To UnitWidth-2Call pcd_setDot(ii,y1+i,str,pcd_getDot(

28、ii+1,y1+i,str,UnitWidth),UnitWidth)NextCall pcd_setDot(UnitWidth-1,y1+i,str,"1",UnitWidth)NextEnd IfEnd IfNextpcd_doubter = strEnd Function Rem 得到某点的字符Function pcd_getDot(x,y,str,UnitWidth)pcd_getDot = Mid(str,x+1+y*UnitWidth,1)End Function Rem 设置某点的字符Sub pcd_setDot(x,y,ByRef str,newDot,UnitWidth)str = Left(str,x+y*UnitWidth) & newDot & Right(str,Len(str)-x-y*UnitWidth-1)End Sub Rem 将数字转为bmp需要的格式 lens是目标字节长度Function Num2ChrB(num,lens)Dim ret,iret = ""While (num>0)ret = ret & ChrB(num mod 256)num = num 256WEndFor i=Lenb(ret) To