网站安全之ASP程序加密解密方法全面解析

　　ret = ret & Base64EncMap( ((second * 4) AND 60) + ((third \ 64) AND 3 ) )
　　ret = ret & Base64EncMap( third AND 63)
　　ndx = ndx + 3
　　loop
　　if by3 < len(plain) then
　　first = asc(mid(plain, ndx+0, 1))
　　ret = ret & Base64EncMap( (first \ 4) AND 63 )
　　if (len(plain) MOD 3 ) = 2 then
　　second = asc(mid(plain, ndx+1, 1))
　　ret = ret & Base64EncMap( ((first * 16) AND 48) + ((second \ 16) AND 15 ) )
　　ret = ret & Base64EncMap( ((second * 4) AND 60) )
　　else
　　ret = ret & Base64EncMap( (first * 16) AND 48)
　　ret = ret '& "="
　　end if
　　ret = ret '& "="
　　end if
　　base64Encode = ret
　　END FUNCTION

3)重新改写要保护的asp文件

　　改写原来的asp文件，在文件中增加UnEncode 和base64Decode函数，全部代码如下：

以下是引用片段：
　　Dim Hu,Hu2
　　'拷贝“欲保护asp代码”的密文 将之存放到Hu变量中
　　Hu=”c2V0IHJzPXNlcnZlci5jcmVhdGVvYmplY3Qo12Fkb2RiLnJlY29yZHNldOMpICAgICDuc3FsPeNzZWxlY3QgKiBmcm9tIGdxICB3aGVyZSB4cz0xIG9yZGVyIGJ5IGRhdGUgYXNj1yAgICAgsnJzLm9wZW4gc3FsLGNvbm4sMSwxICAgICDuaWYgcnMuZW9mIGFuZCBycy5ib2YgdGhlbiDucmVzcG9uc2Uud3JpdGUTvSD7INAg5iAgILUgvyAFILITsmVsc2UgsiAgICAgUmVzcG9uc2UuV3JpdGUg1zxBIEhSRUY9bmV3MC5hc3A/bGJpZD0TJnJlcXVlc3Qo12xiaWQTKSAmIOM+PC9BPuPuZW5kIGlmICAgIL5zZXQgcnM9bm90aGluZyAgICAgICAgsmNvbm4uY2xvc2UgICAgICDuc2V0IGNvbm49bm90aGluZyAgIL4”
　　Hu2= base64Decode(hu) '还原要保护的ASP代码
　　execute(UnEncode(Hu2)) '还原单引号、回车换行，并执行原代码
　　’解密函数base64Decode
　　FUNCTION base64Decode(scrambled)
　　if len(scrambled) = 0 then
　　base64Decode = ""
　　exit function
　　end if
　　dim realLen
　　realLen = len(scrambled)
　　do while mid(scrambled, realLen, 1) = "="
　　realLen = realLen - 1
　　loop
　　dim ret, ndx, by4, first, second, third, fourth
　　ret = ""
　　by4 = (realLen \ 4) * 4
　　ndx = 1
　　do while ndx <= by4
　　first = Base64DecMap(asc(mid(scrambled, ndx+0, 1)))
　　second = Base64DecMap(asc(mid(scrambled, ndx+1, 1)))
　　third = Base64DecMap(asc(mid(scrambled, ndx+2, 1)))
　　fourth = Base64DecMap(asc(mid(scrambled, ndx+3, 1)))
　　ret = ret & chr( ((first * 4) AND 255) + ((second \ 16) AND 3))
　　ret = ret & chr( ((second * 16) AND 255) + ((third \ 4) AND 15))
　　ret = ret & chr( ((third * 64) AND 255) + (fourth AND 63))
　　ndx = ndx + 4
　　loop
　　if ndx < realLen then
　　first = Base64DecMap(asc(mid(scrambled, ndx+0, 1)))
　　second = Base64DecMap(asc(mid(scrambled, ndx+1, 1)))
　　ret = ret & chr( ((first * 4) AND 255) + ((second \ 16) AND 3))
　　if realLen MOD 4 = 3 then
　　third = Base64DecMap(asc(mid(scrambled,ndx+2,1)))