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ASP安全写入数据库操作，正常读出并显示在不同的场合
比如说有styledesc这个字段,数据要求的是50位,char形,可不可以只限制他50位,其它的不限制,输入什么字符都可以的.只要是char形,只要数据库允许就行
这样,安全写入数据库操作,正常读出并显示在不同的场合,应用.
应该是怎样做呢?
下面是我总结的几点.非常有可能不对,请指正.
如果对用户的输入是可以任意字符,(除了某字段特定的输入限制条件,如输入长度,输入类型==).就是输入尽可能不作限制.
对一字符串str,他输出的方向有以下几种:
1.输出至HTML中,Function fn_chk_to_html(Str)
2.输出至Script中(如javascript),Function fn_chk_to_script(Str)
3.输出至sql语句中,而且这条SQL语句是用@#@#两个单引括起字符串Str的.
Function fn_chk_to_sql_mark(Str)
4.输出至sql语句中,而且这条SQL语句是没有用单引括起Str的.Function fn_chk_to_sql_go(Str)
5.输出至URL .Function fn_chk_to_url(Str)
<%Function fn_chk_to_html(Str)
@#如<input text="<%=request("styledesc")%>">的情况下
If Isnull(Str) Then
ChkSql = ""
Exit Function
End If
Str = trim(Str)
Str = Replace(Str, Chr(0), "",1,-1,1)
Str = Replace(Str, """", """,1,-1,1)
Str = Replace(Str, "@#", "'",1,-1,1)
Str = Replace(Str, "<","<",1,-1,1)
Str = Replace(Str, ">",">",1,-1,1)
Str = Replace(Str, vbCrlf, "<br>",1,-1,1)
fn_chk_to_html = Str
End Function
%>
<%Function fn_chk_to_script(Str)
@#如 response.write "<script>alert(@#"&request("styledesc")&"@#);</script>"的情况下
If Isnull(Str) Then
ChkSql = ""
Exit Function
End If
Str = trim(Str)
Str = Replace(Str, "\", ")
Str = Replace(Str, """", "\""",1,-1,1)
Str = Replace(Str, "@#", "\@#",1,-1,1)
Str = Replace(Str,Chr(13),"\n",1,-1,1)
fn_chk_to_script = Str
End Function
%>
<%
Function fn_chk_to_sql_mark(Str)
@#如 sql="select * from style where styledesc like @#"&request("styledesc")&"@#"的情况下
If Isnull(Str) Then
ChkSql = ""
Exit Function
End If
Str = trim(Str)
Str = Replace(Str, "@#", "@#@#",1,-1,1)
fn_chk_to_sql_mark = Str
End Function
%>
<%Function fn_chk_to_sql_go(Str)
@#如sql = "select * from "&request("table")的情况下.??
If Isnull(Str) Then
ChkSql = ""
Exit Function
End If
Str = trim(Str)
Str = Replace(Str, Chr(0), "",1,-1,1)
Str = Replace(Str, """", """,1,-1,1)
Str = Replace(Str, "@#", "'",1,-1,1)
Str = Replace(Str, "<","<",1,-1,1)
Str = Replace(Str, ">",">",1,-1,1)
Str = Replace(Str, "[", "[",1,-1,1)
Str = Replace(Str, "]", "]",1,-1,1)
Str = Replace(Str, "\", "\",1,-1,1)
Str = Replace(Str, "*", "*",1,-1,1)
Str = Replace(Str, "%", "%",1,-1,1)
Str = Replace(Str, ";", ";",1,-1,1)
Str = Replace(Str, vbCrlf, "<br>",1,-1,1)
Str = Replace(Str, "--", "--")
fn_chk_to_sql_go = Str
End Function
%>
<%Function fn_chk_to_url(Str)
@#如 str="<img src=@#showimg.asp?id="&request("id")&"@#>"的情况下
If Isnull(Str) Then
ChkSql = ""
Exit Function
End If
Str = trim(Str)
Str = server.URLEncode(Str)
fn_chk_to_sql_mark = Str
End Function
%>
