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Azazeal
10-22-2003, 09:31 PM
Hi Folks.
This is a log in page that I coded today. The concept behind the database is:
1. One database contains user names, passwords and a surveyID
2. The other database contains the URL to the survey.
Which the reason for the two queries.
I believe this works as it stands, but would like some opinions and ideas.
The only part I haven't completed would be an error message of sorts, if the username and pw is wrong.
For that I was thinking of using another switch on $result from the first query.

Thanks for any suggestions you may have.


<?php
$log_in = $_POST['Submit'];
$FormUserName = $_POST['FormUserName'];
$FormUserPass = $_POST['FormUserPass'];
//--Clean Data
$FormUserName = strip_tags($FormUserName);
$FormUserPass = strip_tags($FormUserPass);
$LFormUserName = strlen($FormUserName);
$LormUserPass = strlen($FormUserPass);
$authorized = '0';
//-Check for existence of input from user
if($log_in)
{
switch($log_in)
{
case !$FormUserName || !$FormUserPass:
$error = "Please fill out both fields";
break;
//--Leave commented out unless there is a length restriction on user input --//
//case $LuserName < 5:
// $error = "Your username is too short";
//break;
//case $LuserPass < 5:
// $error = "Your password is too short";
//break;
case $FormUserName && $FormUserPass:
require_once("dbincludes/db_connect.inc.php");
mysql_connect($db_server, $db_user, $db_password) or die("Cannot connect");
mysql_select_db($db_database) or die("Could not choose database");
$query = mysql_query("select * from $db_user_table where userName = '$FormUserName' and userPass = '$FormUserPass' ");
$result = mysql_num_rows($query);
while($userInfo=mysql_fetch_array($query))
{
$DBUserName = $userInfo['userName'];
$DBUserPass = $userInfo['userPass'];
$surveyID = $userInfo['surveyID'];
}

break;
}
}
if($authorized=='1')
{
$query = mysql_query("SELECT * from $db_survey_table WHERE surveyID = '$surveyID' ");
while($d=mysql_fetch_array($query))
{
$url = $d['URL'];
header("Location: $url");
}
//--Debug echo $url;
}
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> Log In: </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<link href="style.css" rel="stylesheet" type="text/css">
</HEAD>
<body>
<form name="" method="post" action='<?php $_SERVER['PHP_SELF']?>''>
<table width="200" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td><table width="200" border="0" cellspacing="0" cellpadding="0">
<tr>
<td><img src="images/top.gif" width="343" height="24"></td>
</tr>
</table></td>
</tr>
<tr>
<td><table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td class="boxborder"><table width="100%" border="0" cellspacing="0" cellpadding="2">
<tr align="center">
<td colspan="3">Please enter your login information.</td>
</tr>
<tr>
<td width="35%">&nbsp;</td>
<td width="65%" colspan="2">&nbsp;</td>
</tr>
<tr>
<td align="right" valign="middle">User Name:</td>
<td colspan="2"><input name="FormUserName" type="text" size="20" maxlength="20" value='<?php echo $FormUserName; ?>'></td>
</tr>
<tr>
<td align="right" valign="middle">Password:</td>
<td colspan="2"><input name="FormUserPass" type="password" size="20" maxlength="6"></td>
</tr>

<tr>
<td colspan="3"> <table width="100%" border="0" cellspacing="0" cellpadding="2">
<tr>
<td width="50%" align="right" valign="middle"><input type="reset" name="reset" value="Reset"></td>
<td width="50%" align="left" valign="middle"><input type="submit" name="Submit" value="Submit"></td>
</tr>
</table></td>
</tr>
</table></td>
</tr>
</table></td>
</tr>
<tr>
<td><table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td><img src="images/bottom.gif" width="343" height="24"></td>
</tr>
</table></td>
</tr>
</table>
<table align="center">
<tr>
<td align="center" class="error"><?php echo $error; ?></td>
</tr>
</table>

</form>
</body>
</html>
Weedpacket
10-22-2003, 11:11 PM
But what if (I claim) my username and password are ' OR ''='?
Azazeal
10-23-2003, 12:27 AM
Idea 1:

//--Clean Data
//--Strip HTML tags
$FormUserName = strip_tags($FormUserName);
$FormUserPass = strip_tags($FormUserPass);
//--Replace Quotes
$FormUserName = str_replace("'", "", $FormUserName);
$FormUserName = str_replace(""", "", $FormUserName);
$FormUserName = trim($FormUserName);
$FormUserName = trim($FormUserPass);


$LFormUserName = strlen($FormUserName);
$LFormUserPass = strlen($FormUserPass);


Idea 2:

//--Clean Data
//--Strip HTML tags and strip white space from beg. and end.
$FormUserName = strip_tags($FormUserName);
$FormUserPass = strip_tags($FormUserPass);
$FormUserName = trim($FormUserName);
$FormUserName = trim($FormUserPass);
$FormUserName = ltrim($FormUserName);
$FormUserName = ltrim($FormUserPass);

$LFormUserName = strlen($FormUserName);
$LFormUserPass = strlen($FormUserPass);
if(ereg('^[A-Za-z]' , $FormUserName)
{
$error = "some message here"
}



While researching, I noticed that idea 1 would not be practical.

Thanks for not giving a direct answer, I enjoy trying to figure it out.
And thanks for the direction.

Does this code seem more appropriate?

Would running the ereg() function be suitable for spitting out an error if HTML tags are used as a username or pw?
I know it wouldn't strip them out, but I don't think it would be good to accept anything if it had an HTML tag.
~Az
Azazeal
10-23-2003, 10:11 AM
After even more research, my ereg() is incorrect.
I need to search the string for illegal characters and then spit an error out.

Is that correct?
tekky
10-23-2003, 10:44 AM
Originally posted by Azazeal
After even more research, my ereg() is incorrect.
I need to search the string for illegal characters and then spit an error out.

Is that correct?

searching for NOT legal chars works too ;)
BuzzLY
10-23-2003, 06:46 PM
Wow... a newb that researches. I'm impressed! You are a rare animal :D
Merve
10-23-2003, 07:43 PM
Belongs in the ranting thread...good newbs...cool code there AZ!
Weedpacket
10-23-2003, 08:54 PM
Huzzah! We need to recognise the good ones out there more often!

Re: the code. It only works for things like passwords, but it's pretty good to md5() whatever they enter before storing it in the database. Buncha reasons:
(Assuming the conventional representation of an MD5 hash) the field fixed at char(32); people can enter pretty much whatever ****e they like into the password field and the resulting hash will be safe to go into the query Someone gets ahold of your user database they still have work ahead of them to get the users' passwords

Obviously it's only good for passwords and the like where you don't ever need to see the things yourself.
Azazeal
10-23-2003, 09:57 PM
Hey hey...no stereotyping!!!
So.........can you write it for me?





...just kidding.

Thanks for the comments.
I didn't have much time to work on this today, as I am trying to get a cron job to run an .sh backup script.

But I had something in mind:

ereg('[!@#$%^&*()_+-=[]\{}|;':",./<>?]', $FormUserName)


That was from memory, so it may be off a little.
I tried using it in the switch($log_in), but it gave some unexpected results.

switch($log_in)
{
case !$FormUserName || !$FormUserPass:
$error = "Please fill out both fields";
break;
case ereg('[!@#$%^&*()_+-=[]\{}|;':",./<>?]', $FormUserName):
$error = "Please enter your user name again."
}


I believe is close to what I tried. I have the code at work.

Regarding the md5(), I plan to use that, but I am just taking it step-by-step. I figure I would get the standard validation working, then move to the query again.

The real fun will be coding the admin page, where the admin can add, delete or modify users and survey URL's.

Any suggestions on the above code?

Thanks again.
~Az
Weedpacket
10-23-2003, 11:47 PM
It may be better to rewrite the validity check to make sure that users only use characters they are allowed to use, and let them use only safe characters; phrase the validation task as "Have you followed these rules? NO? Then go and try again." and phrase the rules in a positive fashion: "Passwords are to be at least five characters and may use upper- or lowercase letters (a-z), digits (0-9), spaces, or underscores (_)". The test for that would be

if(preg_match("/[^a-z0-9_ ]/i",$userName))
{ //Invalid characters found
}

or
if(eregi("[^a-z0-9_ ]",$userName))
{ //Invalid characters found
}


Limit your exposure to what you know is safe, and don't allow anything through that doesn't pass muster; instead of exposing yourself to everything and then trying to second-guess every possible exploit.

It's a general security principle, and one that Microsoft would be well-advised to take on board....(I mean, who actually uses that Indexing Services thingy?)
Azazeal
10-24-2003, 12:17 AM
Interesting.

ereg('^[A-Za-z]' , $FormUserName)
{
$error = "some message here"
}


I believe I tried the above, which I assume is the same as the eregi() that you posted.
However, when I tried a username like ' !az ', it was allowed through, since the string contained 'az' in it.

It probably was the coding, so I will give it a go tomorrow.
Thanks for the suggestion.

~Az
tekky
10-24-2003, 01:07 AM
Originally posted by Azazeal
Interesting.

ereg('^[A-Za-z]' , $FormUserName)
{
$error = "some message here"
}


I believe I tried the above, which I assume is the same as the eregi() that you posted.
However, when I tried a username like ' !az ', it was allowed through, since the string contained 'az' in it.

It probably was the coding, so I will give it a go tomorrow.
Thanks for the suggestion.

~Az

notice the placement of your []'s as opposed to Weedspackets []'s

in regexp, [text here] designates a list of characters... to cocmbine in 1 type of check.. ie [^A-Z0-9] means a range of text thats NOT A-Z (all uppers) or 0-9 (numerics) where as....

^[A-Z0-9] means any line STARTING with A-Z (all uppers) or 0-9 (numerics)

2 totally different contexts for that flag in regexps ;)

(Weed, correct me if I'm wrong... but I feel fairly confident in my understanding of that atleast :D)

[edit -- handy regexp reference (http://etext.lib.virginia.edu/helpsheets/regex.html) --]
Azazeal
10-27-2003, 11:56 AM
$LFormUserName = strlen($FormUserName);
$LFormUserPass = strlen($FormUserPass);
$UserNameLength = '5';
$UserPassLength = '5';
$authorized = '0';
//***************************NOTHING BELOW THIS LINE SHOULD BE CHANGED********

//-Check for existence of input from user
if($log_in)
{
if(ereg('[^a-z0-9_ ]', $FormUserName))
{
$error = "You have used an invalid character in your user name.<br> Valid characters consist of upper or lower case letters (a-z), numbers (0-9), spaces or underscores (_).";
}

//--Validate Data
switch($log_in)
{
case $FormUserName && !$FormUserPass:
$error = "Please enter your password";
break;
case !$FormUserName && $FormUserPass:
$error = "Please enter your username.<br>Your password has been cleared for security reasons.";
break;
case !$FormUserName || !$FormUserPass:
$error = "Please fill out both fields";
break;
//--Leave commented out unless there is a length restriction on user input --//
//case $LFormUserName < $UserNameLength:
// $error = "Your username is too short";
//break;
case $LFormUserPass < $UserPassLength:
$error = "Your password is too short.<br>The required length is five characters.";
break;
case $FormUserName && $FormUserPass:
require_once("dbincludes/db_connect.inc.php");
mysql_connect($db_server, $db_user, $db_password) or die("Cannot connect");
mysql_select_db($db_database) or die("Could not choose database");
$query = mysql_query("SELECT * FROM $db_user_table
WHERE userName = '$FormUserName'
AND userPass = '$FormUserPass' ");
$result = mysql_num_rows($query);
while($userInfo=mysql_fetch_array($query))
{
$DBUserName = $userInfo['userName'];
$DBUserPass = $userInfo['userPass'];
$surveyID = $userInfo['surveyID'];
}
$authorized='1';
}
}
if($authorized=='1')
{
$query = mysql_query("SELECT * from $db_survey_table
WHERE surveyID = '$surveyID' ");
while($d=mysql_fetch_array($query))
{
$url = $d['URL'];
header("Location: $url");
}
}



Here is the latest code.
Thanks for the help, it works a charm.

Could you still review what I have here, as any other suggestions would be useful?

Thanks.

~Az