Fixed #7723 - implemented a secure password reset form that uses a token and prompts user for new password.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8162 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/conf/global_settings.py

@@ -366,6 +366,9 @@ LOGOUT_URL = '/accounts/logout/'
 
 LOGIN_REDIRECT_URL = '/accounts/profile/'
 
+# The number of days a password reset link is valid for
+PASSWORD_RESET_TIMEOUT_DAYS = 3
+
 ###########
 # TESTING #
 ###########

django/contrib/admin/templates/registration/password_reset_complete.html

@@ -0,0 +1,14 @@
+{% extends "admin/base_site.html" %}
+{% load i18n %}
+
+{% block breadcrumbs %}<div class="breadcrumbs"><a href="../../">{% trans 'Home' %}</a> &rsaquo; {% trans 'Password reset' %}</div>{% endblock %}
+
+{% block title %}{% trans 'Password reset complete' %}{% endblock %}
+
+{% block content %}
+
+<h1>{% trans 'Password reset complete' %}</h1>
+
+<p>{% trans "Your password has been set.  You may go ahead and log in now." %}</p>
+
+{% endblock %}

django/contrib/admin/templates/registration/password_reset_confirm.html

@@ -0,0 +1,32 @@
+{% extends "admin/base_site.html" %}
+{% load i18n %}
+
+{% block breadcrumbs %}<div class="breadcrumbs"><a href="../">{% trans 'Home' %}</a> &rsaquo; {% trans 'Password reset confirmation' %}</div>{% endblock %}
+
+{% block title %}{% trans 'Password reset' %}{% endblock %}
+
+{% block content %}
+
+{% if validlink %}
+
+<h1>{% trans 'Enter new password' %}</h1>
+
+<p>{% trans "Please enter your new password twice so we can verify you typed it in correctly." %}</p>
+
+<form action="" method="post">
+{% if form.new_password1.errors %}{{ form.new_password1.errors }}{% endif %}
+<p class="aligned wide"><label for="id_new_password1">{% trans 'New password:' %}</label>{{ form.new_password1 }}</p>
+{% if form.new_password2.errors %}{{ form.new_password2.errors }}{% endif %}
+<p class="aligned wide"><label for="id_new_password2">{% trans 'Confirm password:' %}</label>{{ form.new_password2 }}</p>
+<p><input type="submit" value="{% trans 'Change my password' %}" /></p>
+</form>
+
+{% else %}
+
+<h1>{% trans 'Password reset unsuccessful' %}</h1>
+
+<p>{% trans "The password reset link was invalid, possibly because it has already been used.  Please request a new password reset." %}
+
+{% endif %}
+
+{% endblock %}

django/contrib/admin/templates/registration/password_reset_done.html

@@ -9,6 +9,6 @@
 
 <h1>{% trans 'Password reset successful' %}</h1>
 
-<p>{% trans "We've e-mailed a new password to the e-mail address you submitted. You should be receiving it shortly." %}</p>
+<p>{% trans "We've e-mailed you instructions for setting your password to the e-mail address you submitted. You should be receiving it shortly." %}</p>
 
 {% endblock %}

django/contrib/admin/templates/registration/password_reset_email.html

@@ -1,15 +1,15 @@
-{% load i18n %}
+{% load i18n %}{% autoescape off %}
 {% trans "You're receiving this e-mail because you requested a password reset" %}
 {% blocktrans %}for your user account at {{ site_name }}{% endblocktrans %}.
 
-{% blocktrans %}Your new password is: {{ new_password }}{% endblocktrans %}
+{% trans "Please go to the following page and choose a new password:" %}
-
+{% block reset_link %}
-{% trans "Feel free to change this password by going to this page:" %}
+{{ protocol }}://{{ domain }}/reset/{{ uid }}-{{ token }}/
-
+{% endblock %}
-http://{{ domain }}/password_change/
-
 {% trans "Your username, in case you've forgotten:" %} {{ user.username }}
 
 {% trans "Thanks for using our site!" %}
 
 {% blocktrans %}The {{ site_name }} team{% endblocktrans %}
+
+{% endautoescape %}

django/contrib/admin/templates/registration/password_reset_form.html

@@ -9,7 +9,7 @@
 
 <h1>{% trans "Password reset" %}</h1>
 
-<p>{% trans "Forgotten your password? Enter your e-mail address below, and we'll reset your password and e-mail the new one to you." %}</p>
+<p>{% trans "Forgotten your password? Enter your e-mail address below, and we'll e-mail instructions for setting a new one." %}</p>
 
 <form action="" method="post">
 {% if form.email.errors %}{{ form.email.errors }}{% endif %}

django/contrib/auth/forms.py

@@ -1,9 +1,11 @@
 from django.contrib.auth.models import User
 from django.contrib.auth import authenticate
+from django.contrib.auth.tokens import default_token_generator
 from django.contrib.sites.models import Site
 from django.template import Context, loader
 from django import forms
 from django.utils.translation import ugettext_lazy as _
+from django.utils.http import int_to_base36
 
 class UserCreationForm(forms.ModelForm):
     """
@@ -98,15 +100,13 @@ class PasswordResetForm(forms.Form):
         if len(self.users_cache) == 0:
             raise forms.ValidationError(_("That e-mail address doesn't have an associated user account. Are you sure you've registered?"))
 
-    def save(self, domain_override=None, email_template_name='registration/password_reset_email.html'):
+    def save(self, domain_override=None, email_template_name='registration/password_reset_email.html',
+             use_https=False, token_generator=default_token_generator):
         """
-        Calculates a new password randomly and sends it to the user.
+        Generates a one-use only link for restting password and sends to the user
         """
         from django.core.mail import send_mail
         for user in self.users_cache:
-            new_pass = User.objects.make_random_password()
-            user.set_password(new_pass)
-            user.save()
             if not domain_override:
                 current_site = Site.objects.get_current()
                 site_name = current_site.name
@@ -115,35 +115,28 @@ class PasswordResetForm(forms.Form):
                 site_name = domain = domain_override
             t = loader.get_template(email_template_name)
             c = {
-                'new_password': new_pass,
                 'email': user.email,
                 'domain': domain,
                 'site_name': site_name,
+                'uid': int_to_base36(user.id),
                 'user': user,
+                'token': token_generator.make_token(user),
+                'protocol': use_https and 'https' or 'http',
             }
             send_mail(_("Password reset on %s") % site_name,
                 t.render(Context(c)), None, [user.email])
 
-class PasswordChangeForm(forms.Form):
+class SetPasswordForm(forms.Form):
     """
-    A form that lets a user change his/her password.
+    A form that lets a user change set his/her password without
+    entering the old password
     """
-    old_password = forms.CharField(label=_("Old password"), max_length=30, widget=forms.PasswordInput)
+    new_password1 = forms.CharField(label=_("New password"), max_length=60, widget=forms.PasswordInput)
-    new_password1 = forms.CharField(label=_("New password"), max_length=30, widget=forms.PasswordInput)
+    new_password2 = forms.CharField(label=_("New password confirmation"), max_length=60, widget=forms.PasswordInput)
-    new_password2 = forms.CharField(label=_("New password confirmation"), max_length=30, widget=forms.PasswordInput)
 
     def __init__(self, user, *args, **kwargs):
         self.user = user
-        super(PasswordChangeForm, self).__init__(*args, **kwargs)
+        super(SetPasswordForm, self).__init__(*args, **kwargs)
-    
-    def clean_old_password(self):
-        """
-        Validates that the old_password field is correct.
-        """
-        old_password = self.cleaned_data["old_password"]
-        if not self.user.check_password(old_password):
-            raise forms.ValidationError(_("Your old password was entered incorrectly. Please enter it again."))
-        return old_password
 
     def clean_new_password2(self):
         password1 = self.cleaned_data.get('new_password1')
@@ -159,6 +152,23 @@ class PasswordChangeForm(forms.Form):
             self.user.save()
         return self.user
     
+class PasswordChangeForm(SetPasswordForm):
+    """
+    A form that lets a user change his/her password by entering
+    their old password.
+    """
+    old_password = forms.CharField(label=_("Old password"), max_length=60, widget=forms.PasswordInput)
+    
+    def clean_old_password(self):
+        """
+        Validates that the old_password field is correct.
+        """
+        old_password = self.cleaned_data["old_password"]
+        if not self.user.check_password(old_password):
+            raise forms.ValidationError(_("Your old password was entered incorrectly. Please enter it again."))
+        return old_password
+PasswordChangeForm.base_fields.keyOrder = ['old_password', 'new_password1', 'new_password2']
+    
 class AdminPasswordChangeForm(forms.Form):
     """
     A form used to change the password of a user in the admin interface.

django/contrib/auth/tests/__init__.py

@@ -1,8 +1,11 @@
-from django.contrib.auth.tests.basic import BASIC_TESTS, PasswordResetTest
+from django.contrib.auth.tests.basic import BASIC_TESTS
+from django.contrib.auth.tests.views import PasswordResetTest
 from django.contrib.auth.tests.forms import FORM_TESTS
+from django.contrib.auth.tests.tokens import TOKEN_GENERATOR_TESTS
 
 __test__ = {
     'BASIC_TESTS': BASIC_TESTS,
     'PASSWORDRESET_TESTS': PasswordResetTest,
     'FORM_TESTS': FORM_TESTS,
+    'TOKEN_GENERATOR_TESTS': TOKEN_GENERATOR_TESTS
 }

django/contrib/auth/tests/basic.py

@@ -54,24 +54,3 @@ u'joe@somewhere.org'
 >>> u.password
 u'!'
 """
-
-from django.test import TestCase
-from django.core import mail
-
-class PasswordResetTest(TestCase):
-    fixtures = ['authtestdata.json']
-    urls = 'django.contrib.auth.urls'
-    
-    def test_email_not_found(self):
-        "Error is raised if the provided email address isn't currently registered"
-        response = self.client.get('/password_reset/')
-        self.assertEquals(response.status_code, 200)
-        response = self.client.post('/password_reset/', {'email': 'not_a_real_email@email.com'})
-        self.assertContains(response, "That e-mail address doesn't have an associated user account")
-        self.assertEquals(len(mail.outbox), 0)
-    
-    def test_email_found(self):
-        "Email is sent if a valid email address is provided for password reset"
-        response = self.client.post('/password_reset/', {'email': 'staffmember@example.com'})
-        self.assertEquals(response.status_code, 302)
-        self.assertEquals(len(mail.outbox), 1)

django/contrib/auth/tests/forms.py

@@ -2,7 +2,7 @@
 FORM_TESTS = """
 >>> from django.contrib.auth.models import User
 >>> from django.contrib.auth.forms import UserCreationForm, AuthenticationForm
->>> from django.contrib.auth.forms import PasswordChangeForm
+>>> from django.contrib.auth.forms import PasswordChangeForm, SetPasswordForm
 
 The user already exists.
 
@@ -95,6 +95,32 @@ True
 >>> form.non_field_errors()
 []
 
+SetPasswordForm:
+
+The two new passwords do not match.
+
+>>> data = {
+...     'new_password1': 'abc123',
+...     'new_password2': 'abc',
+... }
+>>> form = SetPasswordForm(user, data)
+>>> form.is_valid()
+False
+>>> form["new_password2"].errors
+[u"The two password fields didn't match."]
+
+The success case.
+
+>>> data = {
+...     'new_password1': 'abc123',
+...     'new_password2': 'abc123',
+... }
+>>> form = SetPasswordForm(user, data)
+>>> form.is_valid()
+True
+
+PasswordChangeForm:
+
 The old password is incorrect.
 
 >>> data = {
@@ -132,4 +158,9 @@ The success case.
 >>> form.is_valid()
 True
 
+Regression test - check the order of fields:
+
+>>> PasswordChangeForm(user, {}).fields.keys()
+['old_password', 'new_password1', 'new_password2']
+
 """

django/contrib/auth/tests/tokens.py

@@ -0,0 +1,29 @@
+TOKEN_GENERATOR_TESTS = """
+>>> from django.contrib.auth.models import User, AnonymousUser
+>>> from django.contrib.auth.tokens import PasswordResetTokenGenerator
+>>> from django.conf import settings
+>>> u = User.objects.create_user('tokentestuser', 'test2@example.com', 'testpw')
+>>> p0 = PasswordResetTokenGenerator()
+>>> tk1 = p0.make_token(u)
+>>> p0.check_token(u, tk1)
+True
+
+Tests to ensure we can use the token after n days, but no greater.
+Use a mocked version of PasswordResetTokenGenerator so we can change
+the value of 'today'
+
+>>> class Mocked(PasswordResetTokenGenerator):
+...     def __init__(self, today):
+...         self._today_val = today
+...     def _today(self):
+...         return self._today_val
+
+>>> from datetime import date, timedelta
+>>> p1 = Mocked(date.today() + timedelta(settings.PASSWORD_RESET_TIMEOUT_DAYS))
+>>> p1.check_token(u, tk1)
+True
+>>> p2 = Mocked(date.today() + timedelta(settings.PASSWORD_RESET_TIMEOUT_DAYS + 1))
+>>> p2.check_token(u, tk1)
+False
+
+"""

django/contrib/auth/tests/views.py

@@ -0,0 +1,88 @@
+
+import re
+from django.contrib.auth.models import User
+from django.test import TestCase
+from django.core import mail
+
+class PasswordResetTest(TestCase):
+    fixtures = ['authtestdata.json']
+    urls = 'django.contrib.auth.urls'
+    
+    def test_email_not_found(self):
+        "Error is raised if the provided email address isn't currently registered"
+        response = self.client.get('/password_reset/')
+        self.assertEquals(response.status_code, 200)
+        response = self.client.post('/password_reset/', {'email': 'not_a_real_email@email.com'})
+        self.assertContains(response, "That e-mail address doesn't have an associated user account")
+        self.assertEquals(len(mail.outbox), 0)
+    
+    def test_email_found(self):
+        "Email is sent if a valid email address is provided for password reset"
+        response = self.client.post('/password_reset/', {'email': 'staffmember@example.com'})
+        self.assertEquals(response.status_code, 302)
+        self.assertEquals(len(mail.outbox), 1)
+        self.assert_("http://" in mail.outbox[0].body)
+
+    def _test_confirm_start(self):
+        # Start by creating the email
+        response = self.client.post('/password_reset/', {'email': 'staffmember@example.com'})
+        self.assertEquals(response.status_code, 302)
+        self.assertEquals(len(mail.outbox), 1)
+        return self._read_signup_email(mail.outbox[0])
+
+    def _read_signup_email(self, email):
+        urlmatch = re.search(r"https?://[^/]*(/.*reset/\S*)", email.body)
+        self.assert_(urlmatch is not None, "No URL found in sent email")
+        return urlmatch.group(), urlmatch.groups()[0]
+
+    def test_confirm_valid(self):
+        url, path = self._test_confirm_start()
+        response = self.client.get(path)
+        # redirect to a 'complete' page:
+        self.assertEquals(response.status_code, 200) 
+        self.assert_("Please enter your new password" in response.content)
+
+    def test_confirm_invalid(self):
+        url, path = self._test_confirm_start()
+        # Lets munge the token in the path, but keep the same length,
+        # in case the URL conf will reject a different length
+        path = path[:-5] + ("0"*4) + path[-1]
+
+        response = self.client.get(path)
+        self.assertEquals(response.status_code, 200) 
+        self.assert_("The password reset link was invalid" in response.content)
+
+    def test_confirm_invalid_post(self):
+        # Same as test_confirm_invalid, but trying
+        # to do a POST instead.
+        url, path = self._test_confirm_start()
+        path = path[:-5] + ("0"*4) + path[-1]
+
+        response = self.client.post(path, {'new_password1': 'anewpassword',
+                                           'new_password2':' anewpassword'})
+        # Check the password has not been changed 
+        u = User.objects.get(email='staffmember@example.com')
+        self.assert_(not u.check_password("anewpassword"))
+
+    def test_confirm_complete(self):
+        url, path = self._test_confirm_start()
+        response = self.client.post(path, {'new_password1': 'anewpassword',
+                                           'new_password2': 'anewpassword'})
+        # It redirects us to a 'complete' page:
+        self.assertEquals(response.status_code, 302) 
+        # Check the password has been changed 
+        u = User.objects.get(email='staffmember@example.com')
+        self.assert_(u.check_password("anewpassword"))
+
+        # Check we can't use the link again
+        response = self.client.get(path)
+        self.assertEquals(response.status_code, 200) 
+        self.assert_("The password reset link was invalid" in response.content)
+
+    def test_confirm_different_passwords(self):
+        url, path = self._test_confirm_start()
+        response = self.client.post(path, {'new_password1': 'anewpassword',
+                                           'new_password2':' x'})
+        self.assertEquals(response.status_code, 200)
+        self.assert_("The two password fields didn't match" in response.content)
+

django/contrib/auth/tokens.py

@@ -0,0 +1,66 @@
+from datetime import date
+from django.conf import settings
+from django.utils.http import int_to_base36, base36_to_int
+
+class PasswordResetTokenGenerator(object):
+    """
+    Stratgy object used to generate and check tokens for the password
+    reset mechanism.
+    """
+    def make_token(self, user):
+        """
+        Returns a token that can be used once to do a password reset
+        for the given user.
+        """
+        return self._make_token_with_timestamp(user, self._num_days(self._today()))
+
+    def check_token(self, user, token):
+        """
+        Check that a password reset token is correct for a given user.
+        """
+        # Parse the tokem
+        try:
+            ts_b36, hash = token.split("-")
+        except ValueError:
+            return False
+
+        try:
+            ts = base36_to_int(ts_b36)
+        except ValueError:
+            return False
+
+        # Check that the timestamp/uid has not been tampered with
+        if self._make_token_with_timestamp(user, ts) != token:
+            return False
+
+        # Check the timestamp is within limit
+        if (self._num_days(self._today()) - ts) > settings.PASSWORD_RESET_TIMEOUT_DAYS:
+            return False
+
+        return True
+
+    def _make_token_with_timestamp(self, user, timestamp):
+        # timestamp is number of days since 2001-1-1.  Converted to
+        # base 36, this gives us a 3 digit string until about 2121
+        ts_b36 = int_to_base36(timestamp)
+
+        # By hashing on the internal state of the user and using state
+        # that is sure to change (the password salt will change as soon as
+        # the password is set, at least for current Django auth, and
+        # last_login will also change), we produce a hash that will be
+        # invalid as soon as it is used.
+        # We limit the hash to 20 chars to keep URL short
+        import sha
+        hash = sha.new(settings.SECRET_KEY + unicode(user.id) + 
+                       user.password + unicode(user.last_login) + 
+                       unicode(timestamp)).hexdigest()[::2]
+        return "%s-%s" % (ts_b36, hash)
+
+    def _num_days(self, dt):
+        return (dt - date(2001,1,1)).days 
+
+    def _today(self):
+        # Used for mocking in tests
+        return date.today()        
+
+default_token_generator = PasswordResetTokenGenerator()

django/contrib/auth/urls.py

@@ -8,6 +8,9 @@ urlpatterns = patterns('',
     ('^logout/$', 'django.contrib.auth.views.logout'),
     ('^password_change/$', 'django.contrib.auth.views.password_change'),
     ('^password_change/done/$', 'django.contrib.auth.views.password_change_done'),
-    ('^password_reset/$', 'django.contrib.auth.views.password_reset')
+    ('^password_reset/$', 'django.contrib.auth.views.password_reset'),
+    ('^password_reset/done/$', 'django.contrib.auth.views.password_reset_done'),
+    ('^reset/(?P<uidb36>[0-9A-Za-z]+)-(?P<token>.+)/$', 'django.contrib.auth.views.password_reset_confirm'),
+    ('^reset/done/$', 'django.contrib.auth.views.password_reset_complete'),
 )
 

django/contrib/auth/views.py

@@ -1,13 +1,14 @@
 from django.contrib.auth import REDIRECT_FIELD_NAME
 from django.contrib.auth.decorators import login_required
 from django.contrib.auth.forms import AuthenticationForm
-from django.contrib.auth.forms import PasswordResetForm, PasswordChangeForm, AdminPasswordChangeForm
+from django.contrib.auth.forms import PasswordResetForm, SetPasswordForm, PasswordChangeForm, AdminPasswordChangeForm
+from django.contrib.auth.tokens import default_token_generator
 from django.core.exceptions import PermissionDenied
 from django.shortcuts import render_to_response, get_object_or_404
 from django.contrib.sites.models import Site, RequestSite
-from django.http import HttpResponseRedirect
+from django.http import HttpResponseRedirect, Http404
 from django.template import RequestContext
-from django.utils.http import urlquote
+from django.utils.http import urlquote, base36_to_int
 from django.utils.html import escape
 from django.utils.translation import ugettext as _
 from django.contrib.auth.models import User
@@ -65,19 +66,29 @@ def redirect_to_login(next, login_url=None, redirect_field_name=REDIRECT_FIELD_N
         login_url = settings.LOGIN_URL
     return HttpResponseRedirect('%s?%s=%s' % (login_url, urlquote(redirect_field_name), urlquote(next)))
 
+# 4 views for password reset:
+# - password_reset sends the mail
+# - password_reset_done shows a success message for the above
+# - password_reset_confirm checks the link the user clicked and 
+#   prompts for a new password
+# - password_reset_complete shows a success message for the above
+
 def password_reset(request, is_admin_site=False, template_name='registration/password_reset_form.html',
         email_template_name='registration/password_reset_email.html',
-        password_reset_form=PasswordResetForm):
+        password_reset_form=PasswordResetForm, token_generator=default_token_generator):
     if request.method == "POST":
         form = password_reset_form(request.POST)
         if form.is_valid():
+            opts = {}
+            opts['use_https'] = request.is_secure()
+            opts['token_generator'] = token_generator
             if is_admin_site:
-                form.save(domain_override=request.META['HTTP_HOST'])
+                opts['domain_override'] = request.META['HTTP_HOST']
             else:
-                if Site._meta.installed:
+                opts['email_template_name'] = email_template_name
-                    form.save(email_template_name=email_template_name)
+                if not Site._meta.installed:
-                else:
+                    opts['domain_override'] = RequestSite(request).domain
-                    form.save(domain_override=RequestSite(request).domain, email_template_name=email_template_name)
+            form.save(**opts)
             return HttpResponseRedirect('%sdone/' % request.path)
     else:
         form = password_reset_form()
@@ -88,6 +99,39 @@ def password_reset(request, is_admin_site=False, template_name='registration/pas
 def password_reset_done(request, template_name='registration/password_reset_done.html'):
     return render_to_response(template_name, context_instance=RequestContext(request))
 
+def password_reset_confirm(request, uidb36=None, token=None, template_name='registration/password_reset_confirm.html',
+                           token_generator=default_token_generator, set_password_form=SetPasswordForm):
+    """
+    View that checks the hash in a password reset link and presents a
+    form for entering a new password.
+    """
+    assert uidb36 is not None and token is not None # checked by URLconf
+    try:
+        uid_int = base36_to_int(uidb36)
+    except ValueError:
+        raise Http404
+
+    user = get_object_or_404(User, id=uid_int)
+    context_instance = RequestContext(request)
+
+    if token_generator.check_token(user, token):
+        context_instance['validlink'] = True
+        if request.method == 'POST':
+            form = set_password_form(user, request.POST)
+            if form.is_valid():
+                form.save()
+                return HttpResponseRedirect("../done/")
+        else:
+            form = set_password_form(None)
+    else:
+        context_instance['validlink'] = False
+        form = None
+    context_instance['form'] = form    
+    return render_to_response(template_name, context_instance=context_instance)
+
+def password_reset_complete(request, template_name='registration/password_reset_complete.html'):
+    return render_to_response(template_name, context_instance=RequestContext(request))
+
 def password_change(request, template_name='registration/password_change_form.html'):
     if request.method == "POST":
         form = PasswordChangeForm(request.user, request.POST)

django/utils/http.py

@@ -65,3 +65,32 @@ def http_date(epoch_seconds=None):
     """
     rfcdate = formatdate(epoch_seconds)
     return '%s GMT' % rfcdate[:25]
+
+# Base 36 functions: useful for generating compact URLs
+
+def base36_to_int(s):
+    """
+    Convertd a base 36 string to an integer
+    """
+    return int(s, 36)
+
+def int_to_base36(i):
+    """
+    Converts an integer to a base36 string
+    """
+    digits = "0123456789abcdefghijklmnopqrstuvwxyz"
+    factor = 0
+    # Find starting factor
+    while True:
+        factor += 1
+        if i < 36 ** factor:
+            factor -= 1
+            break
+    base36 = []
+    # Construct base36 representation
+    while factor >= 0:
+        j = 36 ** factor
+        base36.append(digits[i / j])
+        i = i % j
+        factor -= 1
+    return ''.join(base36)