I'm trying to create an anti-automation feature to prevent scripts
from running reports on our website by requiring users to enter a code
from an image (like Yahoo e-mail sign-up, or Network Solutions WHOIS
search).
I'm using Python as the scripting language in the ASP page, and using
PIL to generate the image. The code is stored into a session variable,
which is used to check the user's entry. It works fine the first time
around, but the problem I'm running into is that the page doesn't
refresh properly if the user returns to it. It just returns a blank
page.
Any help would be greatly appreciated. See code below:
<%@ LANGUAGE=Python %>
<html>
<head>
<title>Python ASP Page</title>
<%
import random
import PIL
import Image, ImageDraw, ImageFont
def password(n):
"""Returns a pseudo-random number of length n."""
# initialize empty string
s = ""
# generate random number, convert to string and append to s
for x in range(n):
i = random.randint( 1,9)
s = s + str(i)
return s
def passwordImg(p):
"""Generate s an image with text p."""
# open existing image
img = Image.open('C:\ \Inetpub\\wwwro ot\\BegASPFiles \\images\\tempp assword.gif')
# create new image
imgsize = (150,20) # image size
blue = (102,102,255) # image color
white = (255,255,255) # font color
newimg = Image.new("RGB" ,imgsize,blue)
# set font
arial = ImageFont.load( 'C:\\PythonScri pts\\PILtest\\f onts\\Arial
Bold_14_100.pil ')
# create ImageDraw object to write text
draw = ImageDraw.Draw( newimg)
draw.text((40,-1),p, fill=white,font =arial)
# paste new image with password over old image
img.paste(newim g)
# save image and return true if successful
# Note: img.save returns None
imgPath = 'C:\\Inetpub\\w wwroot\\BegASPF iles\\images\\p assword.gif'
if img.save(imgPat h):
return 0
else:
return 1
%>
</head>
<body>
<%
p = password(7)
Session.SetValu e("key",p)
Response.Write( "<p>")
//*************** ********
// check to see session variable has been written - remove for
production
//*************** ********
Response.Write( Session("key"))
Response.Write( "</p>")
Response.Write( "<p>test password:</p>")
if(passwordImg( p)):
Response.Write( "<p><img src='images/password.gif' width='150'
height='20' alt='password'> </p>")
else:
Response.Write( "<p>Passwor d image could not be generated.</p>")
Response.Write( "<form action='pythonh andler.asp' method='POST'>" )
Response.Write( "<input type='text' name='pwd' size='10'><br>" )
Response.Write( "<input type='submit' value='Submit'> ")
Response.Write( "</form>")
%>
</p>
</body>
</html>
