反SPAM新思路—换Z-BLOG的验证码！


            最近我们一些Z-BLOGGER都在想做个什么插件拦住SPAM，当然解决方法也不是没有，就是弄个超强的服务器，可惜搞不起。那……我们只好从SPAMMER的角度来想了。 　　懂一些的人可能知道，SPAM软件的基本原理是[搜索目标]-进入网站-扫描验证码-OCR-[填写表单]-POST。每一步我们都可以加以防范，比较现实的是防止SPAM软件成功的OCR出验证码。Z-BLOG自带的验证码实在有点弱，干扰点等于没有，感觉可以轻易的分析出验证码里的数字。解决方法就是——换一个验证码程序。 　　这个验证码程序（就是我现在用的）是从月光留言本里挖出来的，稍加修改，以便适应Z-BLOG。个人认为要编出软件OCR这个验证码是有点难度的，应该可以换取片刻的安宁。当然，这只是权宜之计，如果广泛使用，势必还会有高手来破解的。所以啊……最好官方能弄个服务器，有时候，我觉得商业化或是适当引进投资也是不错的~ 目前还在测试效果，3-28晚开始。到目前（07-03-30）为止共收到1个SPAM（包括被拦截的。），内容和别的SPAM不一样，应该不是那个垃圾SEO网站的作品（很大胆的加了2个链接），而且不是提交在在一般搜索引擎搜索进来的《google加了一个网页恶意软件检测？》，而是在我的留言本。根据REFERER的结果应该是从主页过去的（也不排除从别的地方进去而没有执行脚本或提交refer信息），怀疑为人工SPAM（UPDATE:Haphic也收到了一个同样的。到底是不是人工的？他用的验证码是原版的……），换验证码的效果还需继续观察…… c_validcode.asp代码复制代码 代码如下:<%@ CODEPAGE=65001 %> <% Option Explicit %> <%  'On Error Resume Next  %> <!-- #include file="../c_option.asp" --> <!-- #include file="../function/c_function.asp" --> <% Response.buffer=true Call Com_CreatValidCode("CheckCode") Rem 生成验证码图片 Sub Com_CreatValidCode(pSN)     Const codeLenMin = 5                '验证码位数范围     Const codeLenMax = 5                '验证码位数范围     Const cOdds = 2                         '杂点出现的机率     Const dbtTimes = 1                    '干扰次数     Const posX = 3                            '位置随机范围X     Const posY = 2                            '位置随机范围Y     ImgWidth = 60                            '图像宽(要为4的倍数)     ImgHeight = 20                            '图像高     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 = 15                '字高     Const DotsLimit = 10                '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     '-----------     Randomize     Dim i,ii,iii,flag,ActUnitWidth,ImgYuWidth,codeLen,ImgWidth,ImgHeight     codeLen = codeLenMin + cint(Rnd*(codeLenMax-codeLenMin))     If ImgWidth Mod 4 <> 0 Or ImgWidth < codeLen*UnitWidth Then ImgWidth = codeLen*UnitWidth     If ImgHeight < UnitHeight Then ImgHeight = UnitHeight     ' 禁止缓存     Response.Expires = -9999     Response.AddHeader "Pragma","no-cache"     Response.AddHeader "cache-ctrol","no-cache"     Response.ContentType = "Image/BMP"     ' 颜色的数据(字符，背景)     Dim vColorData(1)     vColorData(0) = ChrB(0) & ChrB(0) & ChrB(0)  ' 蓝0，绿0，红0（黑色）前景色     vColorData(1) = ChrB(255) & ChrB(255) & ChrB(255) ' 蓝250，绿236，红211（浅蓝色）背景色     ' 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) = "111111111111111111110000000011111110000000000111111001111110011111100111111001111110011111100111111001111110011111100111111001111110011111100111111001111110011111100111111001111110011111100111111000000000011111110000000011111111111111111111"     vNumberData(1) = "111111111111111111111100011111111111000001111111111000000111111111001100011111111111110001111111111111000111111111111100011111111111110001111111111111000111111111111100011111111111110001111111111000000000111111100000000011111111111111111111"     vNumberData(2) = "111111111111111111111100000111111111100000001111111100011100111111100011110011111111111110011111111111110011111111111110011111111111110011111111111110011111111111110011110011111110011111001111111000000000111111100000000011111111111111111111"     vNumberData(3) = "111111111111111111111000000111111111000000001111111001111110011111100111110011111111111110011111111111100011111111111110001111111111111110011111111111111100111111100111111001111110011111100111111100000000111111111000000111111111111111111111"     vNumberData(4) = "111111111111111111111111001111111111101100111111111100110011111111110011001111111110011100111111110011110011111110000000000000111000000000000011111111110011111111111111001111111111111100111111111111110011111111111111001111111111111111111111"     vNumberData(5) = "111111111111111111100000000001111100000000000111110011111111111111001111111111111100111111111111110011000000111111000001111001111111111111100111111111111110011111111111111001111100111111100111110011111110011111100000000011111111111111111111"     vNumberData(6) = "111111111111111111111100000111111111100000001111111100111110011111100111111111111110011111111111111001000001111111100000000011111110001111100111111001111110011111100111111001111110011111100111111100000000111111111000000111111111111111111111"     vNumberData(7) = "111111111111111111100000000001111110000000000111111001111110011111100111111001111111111111001111111111111100111111111111100111111111111100111111111111110011111111111111001111111111111100111111111111110011111111111111001111111111111111111111"     vNumberData(8) = "111111111111111111111000000111111111000000001111111001111110011111100111111001111110011111100111111100000000111111110000000011111111001111001111111001111110011111100111111001111110011111100111111100000000111111111000000111111111111111111111"     vNumberData(9) = "111111111111111111111000000111111111000000001111111001111110011111100111111001111110011111100111111100000000011111110000001001111111111111100111111111111110011111111111111001111110011111001111111100000000111111111000000111111111111111111111"     ' 随机产生字符     Dim vCode(), vCodes     ReDim vCode(codeLen-1)     vCodes = GetVerifyNumber     For i = 0 To 4         vCode(i) = cint(mid(vCodes,i+1,1))         vCode(i) = pcd_doubter(vNumberData(vCode(i)),UnitWidth,UnitHeight,DotsLimit,tryCount,dbtTimes)     Next     ' 随机产生字符     'Dim vCodes     'ReDim vCode(codeLen-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     ' 输出图像文件头     Response.BinaryWrite ChrB(66) & ChrB(77) & Num2ChrB(54+ImgWidth*ImgHeight*3,4) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(54) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(40) & ChrB(0) & ChrB(0) & ChrB(0) & Num2ChrB(ImgWidth,4) & Num2ChrB(ImgHeight,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(ImgWidth*ImgHeight*3,4) & ChrB(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)     ' 生成干扰线     ReDim noiseLine(1,-1)     Call makeNoise(noiseLine,ImgWidth,ImgHeight)     Call makeNoise(noiseLine,ImgWidth,ImgHeight)     ' 如果想多画几条直接复制就可以     ' Call makeNoise(noiseLine,ImgWidth,ImgHeight)     ' 位置随机     ActUnitWidth = Int(ImgWidth / codeLen)     ImgYuWidth = ImgWidth - ActUnitWidth * codeLen     ReDim posAry(1,codeLen-1)     posAry(0,0) = Int((Rnd)*(posX+(ActUnitWidth-UnitWidth)/2))     posAry(1,0) = Int((ImgHeight-UnitHeight)/2+(1-2*Rnd)*posY)     For i=1 To codeLen-2         posAry(0,i) = Int((1-2*Rnd)*(posX+(ActUnitWidth-UnitWidth)/2))         posAry(1,i) = Int((ImgHeight-UnitHeight)/2+(1-2*Rnd)*posY)     Next     If codeLen > 1 Then         posAry(0,codeLen-1) = Int((Rnd)*(posX+(ActUnitWidth-UnitWidth)/2))         posAry(1,codeLen-1) = Int((ImgHeight-UnitHeight)/2+(-Rnd)*posY)     End If     ' 输出图像数据     For i = ImgHeight-1 To 0 Step -1    '行       For ii = 0 To codeLen-1                    '字           For iii = 0 To ActUnitWidth-1         '字宽               flag = 0               If onNoiseLine(noiseLine,ii*ActUnitWidth+iii,i) Then ' 干扰线                    flag = 1             ElseIf getUnitDot(posAry,vCode,ii,iii,i,UnitWidth,UnitHeight) = "0" Then                 flag = 1             ElseIf getUnitDot(posAry,vCode,ii-1,iii+ActUnitWidth,i,UnitWidth,UnitHeight) = "0" Then                 flag = 1             ElseIf getUnitDot(posAry,vCode,ii+1,iii-ActUnitWidth,i,UnitWidth,UnitHeight) = "0" Then                 flag = 1             End If             ' 随机生成杂点             If Rnd * 99 + 1 < cOdds Then flag = 1 - flag             Response.BinaryWrite vColorData(1-flag)              Next         Next          For ii = 0 To ImgYuWidth-1              Response.BinaryWrite vColorData(1)          Next     Next End Sub Rem 获取单元的点（考虑位移） Function getUnitDot(ByRef posAry,ByRef vCode,i,ByVal x,ByVal y,UnitWidth,UnitHeight)     getUnitDot = "1"     If i < 0 Or i > UBound(vCode) Then Exit Function     x = x - posAry(0,i)     If x < 0 Or x >= UnitWidth Then Exit Function     y = y - posAry(1,i)     If y < 0 Or y >= UnitHeight Then Exit Function     getUnitDot = Mid(vCode(i),y*UnitWidth+x+1,1) End Function Rem 生成干扰线 Sub makeNoise(ByRef nl,imgW,UnitHeight)     Dim i,l,x1,y1,x2,y2,dx,dy,deltaT     x1 = Int(Rnd*imgW)     y1 = Int(Rnd*UnitHeight)     x2 = Int(Rnd*imgW)     y2 = Int(Rnd*UnitHeight)     dx = X2 - X1     dy = Y2 - Y1     If Abs(dx) > Abs(dy) Then deltaT = Abs(dx) Else deltaT = Abs(dy)     If deltaT = 0 Then Exit Sub     l = UBound(nl,2)     ReDim Preserve nl(1,l+deltaT+1)     l = l + 1     For i = 0 To deltaT         nl(0,l+i) = x1 + dx * i \ deltaT         nl(1,l+i) = y1 + dy * i \ deltaT     Next End Sub Rem 判断是否为干扰线上的点 Function onNoiseLine(ByRef nl,x,y)     onNoiseLine = False     Dim i     For i=0 To UBound(nl,2)         If x = nl(0,i) And y = nl(1,i) Then             onNoiseLine = True             Exit For         End If     Next End Function Rem 对单个字的点阵进行干扰 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)     Randomize     Dim x1,x2,y1,y2,dx,dy,deltaT,i,ii,way,f1,f2     For f1=1 To dbtTimes    '干扰次数         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)             dx = X2 - X1             dy = Y2 - Y1             If Abs(dx) > Abs(dy) Then deltaT = Abs(dx) Else deltaT = Abs(dy)             ReDim ary(1,deltaT)    '存储连线的点             If deltaT = 0 Then                 ary(0,0) = x1                 ary(1,0) = y1             Else                 ii = 0                 For i = 0 To deltaT                     ary(0,i) = x1 + dx * i \ deltaT                     ary(1,i) = y1 + dy * i \ deltaT                     If pcd_getDot(ary(0,i),ary(1,i),str,UnitWidth) = "0" Then ii = ii + 1                 Next                 ' 统计连线上有效点的数量,如未超过有效点上限则跳出循环，执行干扰                 If ii <= DotsLimit Then Exit For             End If         Next         ' 执行干扰(dx,dy改作不同的方向标记用)         If Abs(dx) > Abs(dy) Then dx = 1 Else dx = 0         If dx = 1 Then             If Int(Rnd*10) > 4 Then                 dy = 1                 way = -1             Else                 dy = UnitHeight - 2                 way = 1             End If         Else             If Int(Rnd*10) > 4 Then                 dy = 1                 way = -1             Else                 dy = UnitWidth - 2                 way = 1             End If         End If         For i=0 To deltaT             For ii=ary(dx,i) To dy Step way                 Call pcd_setDot(ary(0,i)*dx+ii*(1-dx),ary(1,i)*(1-dx)+ii*(dx),str,pcd_getDot(ary(0,i)*dx+(ii+way)*(1-dx),ary(1,i)*(1-dx)+(ii+way)*(dx),str,UnitWidth),UnitWidth)             Next             '添补空白             Call pcd_setDot(ary(0,i)*dx+(dy+way)*(1-dx),ary(1,i)*(1-dx)+(dy+way)*(dx),str,"1",UnitWidth)         Next     Next     pcd_doubter = str End 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(ByVal num,lens)     Dim ret,i     ret = ""     While (num>0)         ret = ret & ChrB(num mod 256)         num = num \ 256     WEnd     For i=Lenb(ret) To lens-1         ret = ret & chrB(0)     Next     Num2ChrB = ret End Function %>