username and password validation

[Eugene Anthony]

Is this method of validation for password and username considered to be
secured. In my previous post I was given a solution that uses command
object and the values are parsed by parameters. But the solution only
worked well for insert and delete, but not select.

<%
if Request.QueryString("Action") = 1 then
username = Trim(request.form("username"))
password = Trim(request.form("password"))
if username <> "" and password <> "" then
set conn = server.CreateObject("ADODB.Connection")
conn.connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data
Source=" & Server.MapPath("/db/upload/stelladb.mdb") & ";"
conn.open
set rs = server.CreateObject("ADODB.Recordset")
sql = "SELECT Count(*) FROM Account WHERE username='" &
username & "' AND password='" & password & "'"
rs.open sql,conn,3,3
if rs.Fields(0) = 1 then
session("boolean") = "true"
response.redirect "main.asp"
else
session("boolean") = "false"
response.write "<center><font class='error'>Error: Invalid
Authentication</font></center><br><br>"
end if
conn.close
Set conn = nothing
end if
end if
%>

Eugene Anthony

 

[Kyle Peterson]

well, your not requiring a case sensative password and I think your open to
SQL injection attacks even with using a count statement so probably no

 

[Mike Brind]

Is this method of validation for password and username considered to be
secured. In my previous post I was given a solution that uses command
object and the values are parsed by parameters. But the solution only
worked well for insert and delete, but not select.

<%
if Request.QueryString("Action") = 1 then
username = Trim(request.form("username"))
password = Trim(request.form("password"))
if username <> "" and password <> "" then
set conn = server.CreateObject("ADODB.Connection")
conn.connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data
Source=" & Server.MapPath("/db/upload/stelladb.mdb") & ";"
conn.open
set rs = server.CreateObject("ADODB.Recordset")
sql = "SELECT Count(*) FROM Account WHERE username='" &
username & "' AND password='" & password & "'"
rs.open sql,conn,3,3
if rs.Fields(0) = 1 then
session("boolean") = "true"
response.redirect "main.asp"
else
session("boolean") = "false"
response.write "<center><font class='error'>Error: Invalid
Authentication</font></center><br><br>"
end if
conn.close
Set conn = nothing
end if
end if
%>

If you are uncomfortable using the command object with parameters,
there is a much easier way to do this - use a saved parameter query.

Open your Access database, and go to the Query tab. Choose "Create
Query in Design View". A dialogue box appears offering you to select
tables. Close it. In the top left corner of your menus, you see
"SQL". Click that.

In the new pane that just opened, type (or copy and paste):

SELECT Count(*) FROM Account WHERE username=[p1] AND password=[p2]

Save it as qGetUser.

In your code do this:

<%
if Request.QueryString("Action") = 1 then
p1= Trim(request.form("username"))
p2= Trim(request.form("password"))
if p1<> "" and p2<> "" then
set conn = server.CreateObject("ADODB.Connection")
conn.connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data
Source=" & Server.MapPath("/db/upload/stelladb.mdb") & ";"
conn.open
set rs = server.CreateObject("ADODB.Recordset")
conn.qGetUser p1,p2,rs
If rs(0) = 1 Then
session("boolean") = "true"
.....
etc

Doing it this way means you still don't have to delimit values in
concatenated dynamic sql (same as the command and parameters), and you
are protected from sql injection in the same way. It's a lot less code
that the command object version, and if you ever feel the need to
change the name of one of your database fileds, you only have ot go to
the database to do it - you son't have ot chase around ASP code finding
all instances of the old field name.

Saved parameter queries work just as easily for inserts and updates
too.

 

[Eugene Anthony]

In asp I did this:

<%
if Request.QueryString("Action") = 1 then
on error resume next
p1 = Trim(request.form("username"))
p2 = Trim(request.form("password"))
if username <> "" and password <> "" then
set conn = Server.CreateObject("ADODB.Connection")
conn.open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" &
Server.MapPath("/db/upload/stelladb.mdb") & ";"
set rs = Server.CreateObject("ADODB.Recordset")
conn.qGetUser p1,p2,rs
if rs(0) = 1 then
session("boolean") = "true"
response.redirect "main.asp"
else
session("boolean") = "false"
response.write "<center><font class='error'>Error: Invalid
authentication</font></center><br><br>"
end if
if Err.number <> 0 then
Response.Write(Err.number & ":" & Err.Description & "<br>")
end if
on Error goto 0
conn.close
Set conn = nothing
end if
end if
%>


and in ms access I created the sql query:

SELECT Count(*) FROM Account WHERE username=[p1] AND password=[p2]


but when I access the page its going into a loop.

Eugene Anthony

 

[Eugene Anthony]

I did test qGetUser in MS Access, supplied the values and it works.
However using asp it is going into a loop.

Eugene Anthony

 

[Mike Brind]

I did test qGetUser in MS Access, supplied the values and it works.
However using asp it is going into a loop.

Get rid of on error resume next to see where it goes wrong. On Error
Resume Next has no place in code until it has been fully tested and is
working properly. It hides errors.

Look, the easiest way I find to produce ASP pages is the following:

1. Add Option Explicit statement to the top of a page.
2. Produce ASP code without any html
3. Test and debug
4. Once it's working as it should, add error handling
5. Test and debug
6. Add html (or move tested code to html page already constructed)
7. Test and debug.
8. Once working and ready for deployment, remove Option Explicit
statement

What's the name of the page you have put this code in? Is it main.asp?
Where is the loop? On the Redirect?

 

[Eugene Anthony]

This is the complete code for login.asp. inc_Common.asp contains all the
variable.


<%Option Explicit%>
<!--#INCLUDE FILE="inc_Common.asp" -->
<%
if Request.QueryString("Action") = 1 then
'on error resume next
p1 = Trim(request.form("username"))
p2 = Trim(request.form("password"))
if username <> "" and password <> "" then
set conn = Server.CreateObject("ADODB.Connection")
conn.open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" &
Server.MapPath("/db/upload/stelladb.mdb") & ";"
set rs = Server.CreateObject("ADODB.Recordset")
conn.qGetUser p1,p2,rs
if rs(0) = 1 then
session("boolean") = "true"
response.redirect "main.asp"
else
session("boolean") = "false"
response.write "<center><font class='error'>Error: Invalid
authentication</font></center><br><br>"
end if
' if Err.number <> 0 then
' Response.Write(Err.number & ":" & Err.Description & "<br>")
' end if
'on Error goto 0
conn.close
Set conn = nothing
end if
end if
%>
<html>
<head>
<title>Login</title>
</head>
<body bgcolor="#FFFFFF">
<center>
<table width="291" border="0" cellpadding="0" cellspacing="0"
height="20">
<tr>
<td class="header" width="420"><font
class="PopTitle"><center>Login</center></font></td>
</tr>
<tr>
<td height="50">
<br>
<center>
<form name="form1" method="post" action="login.asp?Action=1">
<table border="0" cellpadding="2" cellspacing="0" width="223">
<tr>
<td width="150">Username</td>
<td width="148">
<input type="text" name="username"
style="background:FFFFF9; border:1px solid; size="20" size="20">
</td>
</tr>
<tr>
<td width="150">Password</td>
<td width="148">
<input type="password" name="password"
style="background:FFFFF9; border:1px solid; size="20" size="20">
</td>
</tr>
<tr>
<td width="298" colspan="2">
<table border="0" cellpadding="2" cellspacing="0"
width="100%">
<tr>
<td width="25%"></td>
<td width="25%">
<input type="Submit" style="background:EEEEEE;
border:1px solid; " value="Submit" name="Submit">
</td>
<td width="22%">
<input type="Reset" value="Reset"
style="background:EEEEEE; border:1px solid; " size="20" name="Reset">
</td>
<td width="28%"></td>
</tr>
</table>
</td>
</tr>
</table>
</form>
</center>
</td>
</tr>
</table>
</center>
</body>
</html>


Eugene Anthony

 

[Eugene Anthony]

I found the error:

In my <!--#INCLUDE FILE="inc_Common.asp" -->

I have this code

<%
if session("boolean") = "false" or session("boolean") = "" then
response.redirect "login.asp"
end if
%>

and this caused the problem.

Eugene Anthony

 

[Bob Barrows [MVP]]

By directly embedding the values of the ``username`` and ``password``
variables in your SQL statement, you are effectively executing
arbitrary code supplied by the client. Instead, you should use the
ADO Command object to pass arguments to a query.

Set cmd = CreateObject("ADODB.Command")
With cmd
Set .ActiveConnection = conn
.CommandType = adCmdText
.CommandText = "SELECT COUNT(*) FROM Account WHERE username=?
AND password=?"
.Parameters.Append cmd.CreateParameter("username", adVarChar,
adParamInput, 50, username)
.Parameters.Append cmd.CreateParameter("password", adVarChar,
adParamInput, 50, password)
Set rst = .Execute()
End With

It can be done more simply than this, especially with Jet which does not
support output or return parameters:
http://groups-beta.google.com/group/microsoft.public.inetserver.asp.db/msg/72e36562fee7804e

 

[Dave Anderson]

I've never heard such advice. What do you gain by doing this?

A few CPU cycles. And probably a bad habit.

As Eric Lippert has written[1], VBScript performance is vastly improved when
variables are explicitly declared. I have seen suggestions[2] that removing
Option Explicit from your code eliminates one parsing step during script
execution and does not harm performance as long as the script would function
with the declaration intact.

IMO, if you are that desperate for performance improvement, VBScript is the
wrong language for you anyway.




[1] http://groups.google.com/groups?oi=djq&selm=an_558784968
[2] Among others,
http://groups.google.com/group/microsoft.public.scripting.vbscript/msg/3ec1546e3958ec80?hl=en

 

[Dave Anderson]

I can't even see how it would work. If omitting Option
Explicit causes the parser to skip the pass where it checks
for declared variables, then it wouldn't have an opportunity
to build the name tables Eric describes, and it would have
to fall back on the hunt-all-over-everywhere strategy. It
sounds like complete bunk to me.

I don't think it's possible for the parser to not parse the script, Option
Explicit or not. I have read Lippert's post carefully, and I don't see
anything to suggest that. And I believe this sentence suggests the opposite:

"By forcing you to declare locals, Option Explicit makes you write
faster code."

Lippert seems to be saying that it is the variable declaration, and not the
Option Explicit directive, that matters.