ASP BASE64加解密(亲测可用)

核心代码：

<%
  ' option explicit
   const base_64_map_init = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789+/"
   dim newline
   dim base64encmap(63)
   dim base64decmap(127)
   '初始化函数
   public sub initcodecs()
     ' 初始化变量
     newline = "<p>" & chr(13) & chr(10)
     dim max, idx
       max = len(base_64_map_init)
     for idx = 0 to max - 1
        base64encmap(idx) = mid(base_64_map_init, idx + 1, 1)
     next
     for idx = 0 to max - 1
        base64decmap(asc(base64encmap(idx))) = idx
     next
   end sub
   'base64加密函数
   public function base64encode(plain)
     if len(plain) = 0 then
        base64encode = ""
        exit function
     end if
     dim ret, ndx, by3, first, second, third
     by3 = (len(plain) \ 3) * 3
     ndx = 1
     do while ndx <= by3
        first = asc(mid(plain, ndx+0, 1))
        second = asc(mid(plain, ndx+1, 1))
        third = asc(mid(plain, ndx+2, 1))
        ret = ret & base64encmap( (first \ 4) and 63 )
        ret = ret & base64encmap( ((first * 16) and 48) + ((second \ 16) and 15 ) )
        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
   'base64解密函数
   public 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)))
          ret = ret & chr( ((second * 16) and 255) + ((third \ 4) and 15))
        end if
     end if
     base64decode = ret
   end function

%>

使用方法：

' 初始化
 call initcodecs
response.write(base64encode("之我要加密的字符串"))
response.write(base64decode("bwfycziwmtawmjiw0"))