Added Captcha to Registration Page

Author: Kishore kumar J

captcha/__init__.py

@@ -0,0 +1,12 @@
+VERSION = (0, 1, 7)
+
+def get_version(svn=False):
+    "Returns the version as a human-format string."
+    v = '.'.join([str(i) for i in VERSION])
+    if svn:
+        from django.utils.version import get_svn_revision
+        import os
+        svn_rev = get_svn_revision(os.path.dirname(__file__))
+        if svn_rev:
+            v = '%s-%s' % (v, svn_rev)
+    return v

captcha/conf/__init__.py

@@ -0,0 +1,49 @@
+import os
+from django.conf import settings
+
+CAPTCHA_FONT_PATH = getattr(settings,'CAPTCHA_FONT_PATH', os.path.normpath(os.path.join(os.path.dirname(__file__), '..', 'fonts/Vera.ttf'))) 
+CAPTCHA_FONT_SIZE = getattr(settings,'CAPTCHA_FONT_SIZE', 22)
+CAPTCHA_LETTER_ROTATION = getattr(settings, 'CAPTCHA_LETTER_ROTATION', (-35,35))
+CAPTCHA_BACKGROUND_COLOR = getattr(settings,'CAPTCHA_BACKGROUND_COLOR', '#ffffff')
+CAPTCHA_FOREGROUND_COLOR= getattr(settings,'CAPTCHA_FOREGROUND_COLOR', '#001100')
+CAPTCHA_CHALLENGE_FUNCT = getattr(settings,'CAPTCHA_CHALLENGE_FUNCT','captcha.helpers.random_char_challenge')
+CAPTCHA_NOISE_FUNCTIONS = getattr(settings,'CAPTCHA_NOISE_FUNCTIONS', ('captcha.helpers.noise_arcs','captcha.helpers.noise_dots',))
+CAPTCHA_FILTER_FUNCTIONS = getattr(settings,'CAPTCHA_FILTER_FUNCTIONS',('captcha.helpers.post_smooth',))
+CAPTCHA_WORDS_DICTIONARY = getattr(settings,'CAPTCHA_WORDS_DICTIONARY', '/usr/share/dict/words')
+CAPTCHA_FLITE_PATH = getattr(settings,'CAPTCHA_FLITE_PATH',None)
+CAPTCHA_TIMEOUT = getattr(settings, 'CAPTCHA_TIMEOUT', 5) # Minutes
+CAPTCHA_LENGTH = int(getattr(settings, 'CAPTCHA_LENGTH', 4)) # Chars
+CAPTCHA_IMAGE_BEFORE_FIELD = getattr(settings,'CAPTCHA_IMAGE_BEFORE_FIELD', True)
+CAPTCHA_DICTIONARY_MIN_LENGTH = getattr(settings,'CAPTCHA_DICTIONARY_MIN_LENGTH', 0)
+CAPTCHA_DICTIONARY_MAX_LENGTH = getattr(settings,'CAPTCHA_DICTIONARY_MAX_LENGTH', 99)
+if CAPTCHA_IMAGE_BEFORE_FIELD:
+    CAPTCHA_OUTPUT_FORMAT = getattr(settings,'CAPTCHA_OUTPUT_FORMAT', u'%(image)s %(hidden_field)s %(text_field)s')
+else:
+    CAPTCHA_OUTPUT_FORMAT = getattr(settings,'CAPTCHA_OUTPUT_FORMAT', u'%(hidden_field)s %(text_field)s %(image)s')
+
+
+# Failsafe
+if CAPTCHA_DICTIONARY_MIN_LENGTH > CAPTCHA_DICTIONARY_MAX_LENGTH:
+    CAPTCHA_DICTIONARY_MIN_LENGTH, CAPTCHA_DICTIONARY_MAX_LENGTH = CAPTCHA_DICTIONARY_MAX_LENGTH, CAPTCHA_DICTIONARY_MIN_LENGTH
+
+
+def _callable_from_string(string_or_callable):
+    if callable(string_or_callable):
+        return string_or_callable
+    else:
+        return getattr(__import__( '.'.join(string_or_callable.split('.')[:-1]), {}, {}, ['']), string_or_callable.split('.')[-1])
+    
+def get_challenge():
+    return _callable_from_string(CAPTCHA_CHALLENGE_FUNCT)
+
+
+def noise_functions():
+    if CAPTCHA_NOISE_FUNCTIONS:
+        return map(_callable_from_string, CAPTCHA_NOISE_FUNCTIONS)
+    return list()
+
+def filter_functions():
+    if CAPTCHA_FILTER_FUNCTIONS:
+        return map(_callable_from_string, CAPTCHA_FILTER_FUNCTIONS)
+    return list()
+

captcha/conf/settings.py

@@ -0,0 +1,81 @@
+from django.forms.fields import CharField, MultiValueField
+from django.forms import ValidationError
+from django.forms.widgets import TextInput, MultiWidget, HiddenInput
+from django.utils.safestring import mark_safe
+from django.utils.translation import ugettext_lazy as _
+from django.core.urlresolvers import reverse
+from captcha.models import CaptchaStore
+from captcha.conf import settings
+from captcha.helpers import *
+import datetime
+
+class CaptchaTextInput(MultiWidget):
+    def __init__(self,attrs=None):
+        widgets = (
+            HiddenInput(attrs),
+            TextInput(attrs),
+        )
+        
+        for key in ('image','hidden_field','text_field'):
+            if '%%(%s)s'%key not in settings.CAPTCHA_OUTPUT_FORMAT:
+                raise KeyError('All of %s must be present in your CAPTCHA_OUTPUT_FORMAT setting. Could not find %s' %(
+                    ', '.join(['%%(%s)s'%k for k in ('image','hidden_field','text_field')]),
+                    '%%(%s)s'%key
+                ))
+                
+        super(CaptchaTextInput,self).__init__(widgets,attrs)
+    
+    def decompress(self,value):
+        if value:
+            return value.split(',')
+        return [None,None]
+    
+    def format_output(self, rendered_widgets):
+        hidden_field, text_field = rendered_widgets
+        return settings.CAPTCHA_OUTPUT_FORMAT %dict(image=self.image_and_audio, hidden_field=hidden_field, text_field=text_field)
+        
+    def render(self, name, value, attrs=None):
+        challenge,response= settings.get_challenge()()
+        
+        store = CaptchaStore.objects.create(challenge=challenge,response=response)
+        key = store.hashkey
+        value = [key, u'']
+        
+        self.image_and_audio = '<img src="%s" alt="captcha" class="captcha" />' %reverse('captcha-image',kwargs=dict(key=key))
+        if settings.CAPTCHA_FLITE_PATH:
+            self.image_and_audio = '<a href="%s" title="%s">%s</a>' %( reverse('captcha-audio', kwargs=dict(key=key)), unicode(_('Play captcha as audio file')), self.image_and_audio)
+        #fields = super(CaptchaTextInput, self).render(name, value, attrs=attrs)
+        
+        return super(CaptchaTextInput, self).render(name, value, attrs=attrs)
+
+class CaptchaField(MultiValueField):
+    widget=CaptchaTextInput
+    
+    def __init__(self, *args,**kwargs):
+        fields = (
+            CharField(show_hidden_initial=True), 
+            CharField(),
+        )
+        if 'error_messages' not in kwargs or 'invalid' not in kwargs.get('error_messages'):
+            if 'error_messages' not in kwargs:
+                kwargs['error_messages'] = dict()
+            kwargs['error_messages'].update(dict(invalid=_('Invalid CAPTCHA')))
+
+            
+        super(CaptchaField,self).__init__(fields=fields, *args, **kwargs)
+    
+    def compress(self,data_list):
+        if data_list:
+            return ','.join(data_list)
+        return None
+        
+    def clean(self, value):
+        super(CaptchaField, self).clean(value)
+        response, value[1] = value[1].strip().lower(), ''
+        CaptchaStore.remove_expired()
+        try:
+            store = CaptchaStore.objects.get(response=response, hashkey=value[0], expiration__gt=datetime.datetime.now())
+            store.delete()
+        except Exception:
+            raise ValidationError(getattr(self,'error_messages',dict()).get('invalid', _('Invalid CAPTCHA')))
+        return value

captcha/fields.py

@@ -0,0 +1,124 @@
+Bitstream Vera Fonts Copyright
+
+The fonts have a generous copyright, allowing derivative works (as
+long as "Bitstream" or "Vera" are not in the names), and full
+redistribution (so long as they are not *sold* by themselves). They
+can be be bundled, redistributed and sold with any software.
+
+The fonts are distributed under the following copyright:
+
+Copyright
+=========
+
+Copyright (c) 2003 by Bitstream, Inc. All Rights Reserved. Bitstream
+Vera is a trademark of Bitstream, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the fonts accompanying this license ("Fonts") and associated
+documentation files (the "Font Software"), to reproduce and distribute
+the Font Software, including without limitation the rights to use,
+copy, merge, publish, distribute, and/or sell copies of the Font
+Software, and to permit persons to whom the Font Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright and trademark notices and this permission notice
+shall be included in all copies of one or more of the Font Software
+typefaces.
+
+The Font Software may be modified, altered, or added to, and in
+particular the designs of glyphs or characters in the Fonts may be
+modified and additional glyphs or characters may be added to the
+Fonts, only if the fonts are renamed to names not containing either
+the words "Bitstream" or the word "Vera".
+
+This License becomes null and void to the extent applicable to Fonts
+or Font Software that has been modified and is distributed under the
+"Bitstream Vera" names.
+
+The Font Software may be sold as part of a larger software package but
+no copy of one or more of the Font Software typefaces may be sold by
+itself.
+
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL
+BITSTREAM OR THE GNOME FOUNDATION BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL,
+OR CONSEQUENTIAL DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+OTHERWISE, ARISING FROM, OUT OF THE USE OR INABILITY TO USE THE FONT
+SOFTWARE OR FROM OTHER DEALINGS IN THE FONT SOFTWARE.
+
+Except as contained in this notice, the names of Gnome, the Gnome
+Foundation, and Bitstream Inc., shall not be used in advertising or
+otherwise to promote the sale, use or other dealings in this Font
+Software without prior written authorization from the Gnome Foundation
+or Bitstream Inc., respectively. For further information, contact:
+fonts at gnome dot org.
+
+Copyright FAQ
+=============
+
+   1. I don't understand the resale restriction... What gives?
+
+      Bitstream is giving away these fonts, but wishes to ensure its
+      competitors can't just drop the fonts as is into a font sale system
+      and sell them as is. It seems fair that if Bitstream can't make money
+      from the Bitstream Vera fonts, their competitors should not be able to
+      do so either. You can sell the fonts as part of any software package,
+      however.
+
+   2. I want to package these fonts separately for distribution and
+      sale as part of a larger software package or system.  Can I do so?
+
+      Yes. A RPM or Debian package is a "larger software package" to begin 
+      with, and you aren't selling them independently by themselves. 
+      See 1. above.
+
+   3. Are derivative works allowed?
+      Yes!
+
+   4. Can I change or add to the font(s)?
+      Yes, but you must change the name(s) of the font(s).
+
+   5. Under what terms are derivative works allowed?
+
+      You must change the name(s) of the fonts. This is to ensure the
+      quality of the fonts, both to protect Bitstream and Gnome. We want to
+      ensure that if an application has opened a font specifically of these
+      names, it gets what it expects (though of course, using fontconfig,
+      substitutions could still could have occurred during font
+      opening). You must include the Bitstream copyright. Additional
+      copyrights can be added, as per copyright law. Happy Font Hacking!
+
+   6. If I have improvements for Bitstream Vera, is it possible they might get 
+       adopted in future versions?
+
+      Yes. The contract between the Gnome Foundation and Bitstream has
+      provisions for working with Bitstream to ensure quality additions to
+      the Bitstream Vera font family. Please contact us if you have such
+      additions. Note, that in general, we will want such additions for the
+      entire family, not just a single font, and that you'll have to keep
+      both Gnome and Jim Lyles, Vera's designer, happy! To make sense to add
+      glyphs to the font, they must be stylistically in keeping with Vera's
+      design. Vera cannot become a "ransom note" font. Jim Lyles will be
+      providing a document describing the design elements used in Vera, as a
+      guide and aid for people interested in contributing to Vera.
+
+   7. I want to sell a software package that uses these fonts: Can I do so?
+
+      Sure. Bundle the fonts with your software and sell your software
+      with the fonts. That is the intent of the copyright.
+
+   8. If applications have built the names "Bitstream Vera" into them, 
+      can I override this somehow to use fonts of my choosing?
+
+      This depends on exact details of the software. Most open source
+      systems and software (e.g., Gnome, KDE, etc.) are now converting to
+      use fontconfig (see www.fontconfig.org) to handle font configuration,
+      selection and substitution; it has provisions for overriding font
+      names and subsituting alternatives. An example is provided by the
+      supplied local.conf file, which chooses the family Bitstream Vera for
+      "sans", "serif" and "monospace".  Other software (e.g., the XFree86
+      core server) has other mechanisms for font substitution.
+

captcha/fonts/COPYRIGHT.TXT

@@ -0,0 +1,11 @@
+Contained herin is the Bitstream Vera font family.
+
+The Copyright information is found in the COPYRIGHT.TXT file (along
+with being incoporated into the fonts themselves).
+
+The releases notes are found in the file "RELEASENOTES.TXT".
+
+We hope you enjoy Vera!
+
+                        Bitstream, Inc.
+			The Gnome Project

captcha/fonts/README.TXT

@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+import random
+from captcha.conf import settings
+
+def math_challenge():
+    operators = ('+','*','-',)
+    operands = (random.randint(1,10),random.randint(1,10))
+    operator = random.choice(operators)
+    if operands[0] < operands[1] and '-' == operator:
+        operands = (operands[1],operands[0])
+    challenge = '%d%s%d' %(operands[0],operator,operands[1])
+    return u'%s=' %(challenge), unicode(eval(challenge))
+    
+def random_char_challenge():
+    chars,ret = u'abcdefghijklmnopqrstuvwxyz', u''
+    for i in range(settings.CAPTCHA_LENGTH):
+        ret += random.choice(chars)
+    return ret.upper(),ret
+
+def unicode_challenge():
+    chars,ret = u'äàáëéèïíîöóòüúù', u''
+    for i in range(settings.CAPTCHA_LENGTH):
+        ret += random.choice(chars)
+    return ret.upper(), ret
+        
+def word_challenge():
+    fd = file(settings.CAPTCHA_WORDS_DICTIONARY,'rb')
+    l = fd.readlines()
+    fd.close()
+    while True:
+        word = random.choice(l).strip()
+        if len(word) >= settings.CAPTCHA_DICTIONARY_MIN_LENGTH and len(word) <= settings.CAPTCHA_DICTIONARY_MAX_LENGTH:
+            break
+    return word.upper(), word.lower()
+    
+def noise_arcs(draw,image):
+    size = image.size
+    draw.arc([-20,-20, size[0],20], 0, 295, fill=settings.CAPTCHA_FOREGROUND_COLOR)
+    draw.line([-20,20, size[0]+20,size[1]-20], fill=settings.CAPTCHA_FOREGROUND_COLOR)
+    draw.line([-20,0, size[0]+20,size[1]], fill=settings.CAPTCHA_FOREGROUND_COLOR)
+    return draw
+
+def noise_dots(draw,image):
+    size = image.size
+    for p in range(int(size[0]*size[1]*0.1)):
+        draw.point((random.randint(0, size[0]),random.randint(0, size[1])), fill=settings.CAPTCHA_FOREGROUND_COLOR )
+    return draw
+
+def post_smooth(image):
+    import ImageFilter
+    return image.filter(ImageFilter.SMOOTH)

captcha/fonts/Vera.ttf

@@ -0,0 +1,28 @@
+from django.core.management.base import BaseCommand, CommandError
+import sys
+
+from optparse import make_option
+
+class Command(BaseCommand):
+    help = "Clean up expired captcha hashkeys."
+    
+    def handle(self, **options):
+        from captcha.models import CaptchaStore
+        import datetime
+        verbose = int(options.get('verbosity'))
+        expired_keys = CaptchaStore.objects.filter(expiration__lte=datetime.datetime.now()).count()
+        if verbose >= 1:
+            print "Currently %s expired hashkeys" % expired_keys
+        try:
+            CaptchaStore.remove_expired()
+        except:
+            if verbose >= 1 :
+                print "Unable to delete expired hashkeys."
+            sys.exit(1)
+        if verbose >= 1:
+            if expired_keys > 0:
+                print "Expired hashkeys removed."
+            else:
+                print "No keys to remove."
+        
+