Use token based auth to reset passwords (#269)

Send a mail containing a password reset
token link instead of sending a clear text
password.

Ref #232

15 files changed, 156 insertions, 16 deletions

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 260e6ff..2f3a037 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -18,6 +18,7 @@ Changed
 
 - Logged admin can see any project (#262)
 - Simpler and safer authentication logic (#270)
+- Use token based auth to reset passwords (#269)
 - Better install doc (#275)
 
 Added
diff --git a/ihatemoney/forms.py b/ihatemoney/forms.py
index ead5586..c5e0b54 100644
--- a/ihatemoney/forms.py
+++ b/ihatemoney/forms.py
@@ -2,7 +2,7 @@ from flask_wtf.form import FlaskForm
 from wtforms.fields.core import SelectField, SelectMultipleField
 from wtforms.fields.html5 import DateField, DecimalField
 from wtforms.fields.simple import PasswordField, SubmitField, TextAreaField, StringField
-from wtforms.validators import Email, Required, ValidationError
+from wtforms.validators import Email, Required, ValidationError, EqualTo
 from flask_babel import lazy_gettext as _
 from flask import request
 
@@ -102,6 +102,14 @@ class PasswordReminder(FlaskForm):
             raise ValidationError(_("This project does not exists"))
 
 
+class ResetPasswordForm(FlaskForm):
+    password_validators = [Required(),
+                           EqualTo('password_confirmation', message=_("Password mismatch"))]
+    password = PasswordField(_("Password"), validators=password_validators)
+    password_confirmation = PasswordField(_("Password confirmation"), validators=[Required()])
+    submit = SubmitField(_("Reset password"))
+
+
 class BillForm(FlaskForm):
     date = DateField(_("Date"), validators=[Required()], default=datetime.now)
     what = StringField(_("What?"), validators=[Required()])
diff --git a/ihatemoney/models.py b/ihatemoney/models.py
index cd896f3..c801b74 100644
--- a/ihatemoney/models.py
+++ b/ihatemoney/models.py
@@ -2,9 +2,11 @@ from collections import defaultdict
 
 from datetime import datetime
 from flask_sqlalchemy import SQLAlchemy, BaseQuery
-from flask import g
+from flask import g, current_app
 
 from sqlalchemy import orm
+from itsdangerous import (TimedJSONWebSignatureSerializer
+                          as Serializer, BadSignature, SignatureExpired)
 
 db = SQLAlchemy()
 
@@ -199,6 +201,30 @@ class Project(db.Model):
         db.session.delete(self)
         db.session.commit()
 
+    def generate_token(self, expiration):
+        """Generate a timed and serialized JsonWebToken
+
+        :param expiration: Token expiration time (in seconds)
+        """
+        serializer = Serializer(current_app.config['SECRET_KEY'], expiration)
+        return serializer.dumps({'project_id': self.id}).decode('utf-8')
+
+    @staticmethod
+    def verify_token(token):
+        """Return the project id associated to the provided token,
+        None if the provided token is expired or not valid.
+
+        :param token: Serialized TimedJsonWebToken
+        """
+        serializer = Serializer(current_app.config['SECRET_KEY'])
+        try:
+            data = serializer.loads(token)
+        except SignatureExpired:
+            return None
+        except BadSignature:
+            return None
+        return data['project_id']
+
     def __repr__(self):
         return "<Project %s>" % self.name
 
diff --git a/ihatemoney/templates/forms.html b/ihatemoney/templates/forms.html
index ffdd165..63d1c3c 100644
--- a/ihatemoney/templates/forms.html
+++ b/ihatemoney/templates/forms.html
@@ -159,10 +159,18 @@
 {% endmacro %}
 
 {% macro remind_password(form) %}
-
     {% include "display_errors.html" %}
     {{ form.hidden_tag() }}
     {{ input(form.id) }}
     {{ submit(form.submit) }}
 
 {% endmacro %}
+
+{% macro reset_password(form) %}
+    {% include "display_errors.html" %}
+    {{ form.hidden_tag() }}
+    {{ input(form.password) }}
+    {{ input(form.password_confirmation) }}
+    {{ submit(form.submit) }}
+
+{% endmacro %}
diff --git a/ihatemoney/templates/password_reminder.en b/ihatemoney/templates/password_reminder.en
index 31210aa..bc7e609 100644
--- a/ihatemoney/templates/password_reminder.en
+++ b/ihatemoney/templates/password_reminder.en
@@ -1,8 +1,8 @@
 Hi,
 
-You requested to be reminded about your password for "{{ project.name }}".
-
-You can access it here: {{ config['SITE_URL'] }}{{ url_for(".list_bills", project_id=project.id) }}, the private code is "{{ project.password }}".
+You requested to reset the password of the following project: "{{ project.name }}". 
+You can reset it here: {{ url_for(".reset_password", _external=True, token=project.generate_token(expiration=3600)) }}.
+This link is only valid for 1 hour.
 
 Hope this helps,
 Some weird guys (with beards)
diff --git a/ihatemoney/templates/password_reminder.fr b/ihatemoney/templates/password_reminder.fr
index 58f04e3..d4fbc2d 100644
--- a/ihatemoney/templates/password_reminder.fr
+++ b/ihatemoney/templates/password_reminder.fr
@@ -1,7 +1,7 @@
 Salut,
 
-Vous avez demandez des informations sur votre mot de passe pour "{{ project.name }}".
-
-Vous pouvez y accéder ici {{ config['SITE_URL'] }}{{ url_for(".list_bills", project_id=project.id) }}, le code d'accès est "{{ project.password }}".
+Vous avez demandé à réinitialiser le mot de passe du projet suivant : "{{ project.name }}".
+Vous pouvez le réinitialiser ici : {{ url_for(".reset_password", _external=True, token=project.generate_token(expiration=3600)) }}.
+Ce lien est seulement valide pendant 1 heure.
 
 Faites en bon usage !
diff --git a/ihatemoney/templates/reminder_mail.en b/ihatemoney/templates/reminder_mail.en
index fe57be2..f13da5d 100644
--- a/ihatemoney/templates/reminder_mail.en
+++ b/ihatemoney/templates/reminder_mail.en
@@ -2,7 +2,7 @@ Hi,
 
 You have just (or someone else using your email address) created the project "{{ g.project.name }}" to share your expenses.
 
-You can access it here: {{ config['SITE_URL'] }}{{ url_for(".list_bills") }} (the identifier is {{ g.project.id }}),
+You can access it here: {{ url_for(".list_bills", _external=True) }} (the identifier is {{ g.project.id }}),
 and the private code is "{{ g.project.password }}".
 
 Enjoy,
diff --git a/ihatemoney/templates/reminder_mail.fr b/ihatemoney/templates/reminder_mail.fr
index 8130218..86c00ff 100644
--- a/ihatemoney/templates/reminder_mail.fr
+++ b/ihatemoney/templates/reminder_mail.fr
@@ -2,7 +2,7 @@ Hey,
 
 Vous venez de créer le projet "{{ g.project.name }}" pour partager vos dépenses.
 
-Vous pouvez y accéder ici: {{ config['SITE_URL'] }}{{ url_for(".list_bills") }} (l'identifieur est {{ g.project.id }}),
+Vous pouvez y accéder ici: {{ url_for(".list_bills", _external=True) }} (l'identifieur est {{ g.project.id }}),
 et le code d'accès "{{ g.project.password }}".
 
 Faites en bon usage !
diff --git a/ihatemoney/templates/reset_password.html b/ihatemoney/templates/reset_password.html
new file mode 100644
index 0000000..78b5853
--- /dev/null
+++ b/ihatemoney/templates/reset_password.html
@@ -0,0 +1,12 @@
+{% extends "layout.html" %}
+
+{% block content %}
+{% if error %}
+<div class="alert alert-danger">{{ error }}</div>
+{% else %}
+<h2>{{ _("Reset your password") }}</h2>
+<form class="form-horizontal" method="post">
+{{ forms.reset_password(form) }}
+</form>
+{% endif %}
+{% endblock %}
diff --git a/ihatemoney/tests/tests.py b/ihatemoney/tests/tests.py
index 6c0ccb9..f918746 100644
--- a/ihatemoney/tests/tests.py
+++ b/ihatemoney/tests/tests.py
@@ -169,6 +169,30 @@ class BudgetTestCase(IhatemoneyTestCase):
             self.assertIn("raclette", outbox[0].body)
             self.assertIn("raclette@notmyidea.org", outbox[0].recipients)
 
+    def test_password_reset(self):
+        # test that a password can be changed using a link sent by mail
+
+        self.create_project("raclette")
+        # Get password resetting link from mail
+        with self.app.mail.record_messages() as outbox:
+            self.client.post("/password-reminder", data={"id": "raclette"})
+            self.assertEqual(len(outbox), 1)
+            url_start = outbox[0].body.find('You can reset it here: ') + 23
+            url_end = outbox[0].body.find('.\n', url_start)
+            url = outbox[0].body[url_start:url_end]
+        # Test that we got a valid token
+        resp = self.client.get(url)
+        self.assertIn("Password confirmation</label>", resp.data.decode('utf-8'))
+        # Test that password can be changed
+        self.client.post(url, data={'password': 'pass', 'password_confirmation': 'pass'})
+        resp = self.login('raclette', password='pass')
+        self.assertIn("<title>Account manager - raclette</title>", resp.data.decode('utf-8'))
+        # Test empty and null tokens
+        resp = self.client.get("/reset-password")
+        self.assertIn("No token provided", resp.data.decode('utf-8'))
+        resp = self.client.get("/reset-password?token=token")
+        self.assertIn("Invalid token", resp.data.decode('utf-8'))
+
     def test_project_creation(self):
         with self.app.test_client() as c:
 
diff --git a/ihatemoney/translations/fr/LC_MESSAGES/messages.mo b/ihatemoney/translations/fr/LC_MESSAGES/messages.mo
index 56b50d3..249c996 100644
--- a/ihatemoney/translations/fr/LC_MESSAGES/messages.mo
+++ b/ihatemoney/translations/fr/LC_MESSAGES/messages.mo
diff --git a/ihatemoney/translations/fr/LC_MESSAGES/messages.po b/ihatemoney/translations/fr/LC_MESSAGES/messages.po
index 93a80a9..5e030bf 100644
--- a/ihatemoney/translations/fr/LC_MESSAGES/messages.po
+++ b/ihatemoney/translations/fr/LC_MESSAGES/messages.po
@@ -65,6 +65,18 @@ msgstr ""
 msgid "Get in"
 msgstr "Entrer"
 
+#: forms.py:107
+msgid "Password mismatch"
+msgstr "Les mots de passe fournis ne sont pas les mêmes."
+
+#: forms.py:109
+msgid "Password confirmation"
+msgstr "Confirmation du mot de passe"
+
+#: forms.py:107
+msgid "Password"
+msgstr "Mot de passe"
+
 #: forms.py:108
 msgid "Send me the code by email"
 msgstr "Envoyez moi le code par email"
@@ -185,8 +197,8 @@ msgid "%(msg_compl)sThe project identifier is %(project)s"
 msgstr "L'identifiant de ce projet est '%(project)s'"
 
 #: web.py:185
-msgid "a mail has been sent to you with the password"
-msgstr "Un email vous a été envoyé avec le mot de passe"
+msgid "A link to reset your password has been sent to your email."
+msgstr "Un lien pour changer votre mot de passe vous a été envoyé par mail."
 
 #: web.py:211
 msgid "Project successfully deleted"
@@ -197,6 +209,26 @@ msgstr "Projet supprimé"
 msgid "You have been invited to share your expenses for %(project)s"
 msgstr "Vous avez été invité à partager vos dépenses pour %(project)s"
 
+#: web.py:259
+#, python-format
+msgid ""No token provided""
+msgstr "Aucun token n'a été fourni."
+
+#: web.py:259
+#, python-format
+msgid "Unknown project"
+msgstr "Project inconnu"
+
+#: web.py:261
+#, python-format
+msgid "Invalid token"
+msgstr "Token invalide"
+
+#: web.py:267
+#, python-format
+msgid "Password successfully reset."
+msgstr "Le mot de passe a été changé avec succès."
+
 #: web.py:261
 msgid "Your invitations have been sent"
 msgstr "Vos invitations ont bien été envoyées"
@@ -500,6 +532,10 @@ msgstr "Rappel du code d'accès"
 msgid "Your projects"
 msgstr "Vos projets"
 
+#: templates/reset_password.html:2
+msgid "Reset your password"
+msgstr "Changez votre mot de passe"
+
 #: templates/send_invites.html:6
 msgid "Invite people"
 msgstr "Invitez des gens"
diff --git a/ihatemoney/web.py b/ihatemoney/web.py
index 92b7ddc..7e4c563 100644
--- a/ihatemoney/web.py
+++ b/ihatemoney/web.py
@@ -24,7 +24,7 @@ from functools import wraps
 from ihatemoney.models import db, Project, Person, Bill
 from ihatemoney.forms import (
     AdminAuthenticationForm, AuthenticationForm, EditProjectForm,
-    InviteForm, MemberForm, PasswordReminder, ProjectForm, get_billform_for,
+    InviteForm, MemberForm, PasswordReminder, ResetPasswordForm, ProjectForm, get_billform_for,
     ExportForm
 )
 from ihatemoney.utils import Redirect303, list_of_dicts2json, list_of_dicts2csv, LoginThrottler
@@ -263,17 +263,40 @@ def remind_password():
             # get the project
             project = Project.query.get(form.id.data)
 
-            # send the password reminder
+            # send a link to reset the password
             password_reminder = "password_reminder.%s" % get_locale().language
             current_app.mail.send(Message(
                 "password recovery",
                 body=render_template(password_reminder, project=project),
                 recipients=[project.contact_email]))
-            flash(_("a mail has been sent to you with the password"))
+            flash(_("A link to reset your password has been sent to your email."))
 
     return render_template("password_reminder.html", form=form)
 
 
+@main.route('/reset-password', methods=['GET', 'POST'])
+def reset_password():
+    form = ResetPasswordForm()
+    token = request.args.get('token')
+    if not token:
+        return render_template('reset_password.html', form=form, error=_("No token provided"))
+    project_id = Project.verify_token(token)
+    if not project_id:
+        return render_template('reset_password.html', form=form, error=_("Invalid token"))
+    project = Project.query.get(project_id)
+    if not project:
+        return render_template('reset_password.html', form=form, error=_("Unknown project"))
+
+    if request.method == "POST":
+        if form.validate():
+            project.password = form.password.data
+            db.session.add(project)
+            db.session.commit()
+            flash(_("Password successfully reset."))
+            return redirect(url_for(".home"))
+    return render_template('reset_password.html', form=form)
+
+
 @main.route("/<project_id>/edit", methods=["GET", "POST"])
 def edit_project():
     edit_form = EditProjectForm()
diff --git a/requirements.txt b/requirements.txt
index be77004..4145851 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,3 +10,4 @@ jinja2>=2.6
 raven
 blinker
 six>=1.10
+itsdangerous>=0.24
diff --git a/setup.py b/setup.py
index 0ba3784..e90dea2 100644
--- a/setup.py
+++ b/setup.py
@@ -29,6 +29,7 @@ REQUIREMENTS = [
     'raven',
     'blinker',
     'six>=1.10',
+    'itsdangerous>=0.24',
 ]
 
 DEPENDENCY_LINKS = [