[SOLVED] Python, and Flask, and Bcrypt, oh my!

Question

Attempting to verify passwords with Flask and Bcrypt. Cannot use flask.ext.bcrypt because of a lack of a Visual Studio 2010 component on my system, so I am just using bcrypt.
I am saving the password to a database and in doing so am having to encode it otherwise I get a TypeError: Unicode-objects must be encoded before hashing. Code would be similar to:
```models.py
import bcrypt
import datetime
from flask.ext.login import UserMixin
from peewee import *
from playhouse.postgres_ext import PostgresqlExtDatabase
DATABASE = PostgresqlExtDatabase(database='leaderboard', user='postgres')
ROUNDS = 5     # Number of hash rounds, set low for development, increase for production
class BaseModel(Model):
    class Meta:
         database = DATABASE
class User(UserMixin, BaseModel):
    email = CharField(unique=True)
    password = CharField(maxlength=100)
    joinedat = DateTimeField(default=datetime.datetime.now)
class Meta:
    order_by = ('joined_at',)

@classmethod
def create_user(cls, email, password):
    try:
        with DATABASE.transaction():
            cls.create(
                email=email,
                password=bcrypt.hashpw(password.encode('utf-8', bcrypt.gensalt(ROUNDS))
            )
    except IntegrityError:
        raise ValueError("Sorry, user already exists.")
def initialize():
    DATABASE.connect()
    DATABASE.create_tables([User], safe=True)
    DATABASE.close()
```
That seems to work just fine as long as I include the encode('utf-8').
```forms.py
from flask.ext.wtf import Form
from wtforms import StringField, PasswordField
from wtforms.validators import (DataRequired, Email)
class LoginForm(Form):
    """The form for logging into the site"""
    email = StringField('Email', validators=[DataRequired(), Email()])
    password = PasswordField('Password', validators=[DataRequired()])
```
With me so far?
Now, in my application when I go to check the password in the form against the database I have:
login_route.py
if bcrypt.hashpw(form.password.data, student.password) == student.password:

Wham! Back to my TypeError from before. My question then, and perhaps @Kenneth Love (https://teamtreehouse.com/kennethlove) would be so kind as to shed some light on the subject, is when and where is bcrypt expecting encoding to occur and, more importantly, how can I verify my passwords?
Any help is very much appreciated.
Ken

Ken Alger · Accepted Answer

Sorry for dropping this thread guys, I'll attempt to recall what I did, but if what I post isn't working for you, please bear with me and we can work through it together, okay?
1) I included hashpw from bcrypt: 
python
from bcrypt import hashpw

2) In my route I changed by password check to (tabs not accurate in snippet):
python
if student.password == hashpw(form.password.data.encode('UTF_8'), 
      student.password.encode('UTF_8')).decode():

If memory serves the way the hashing works with UTF-8 requires those encode() methods and then the decode() pops it back out to be able to do the equality check. Took me quite a bit of searching to figure it out and even longer playing with various orders of encoding and decoding and where to have the UTF-8. Kind of was one of those "Holly cow, that worked!" moments when it finally worked.
Post back with other questions. I'll try to be more responsive than 4 or 5 months. :cry:
Happy coding,  
Ken

Chris Freeman · Answer

I was also getting Unicode-objects must be encoded before hashing errors. I was most curious about how thing worked in the Workspace but not locally. I downloaded a workspace and it failed locally. I figured it was an environment problem. bcrypt was not working for me.
In the workspace I ran the command:
bash
$ pip freeze > requirements.txt

Looking at this file, I did not see bcrypt. Instead, there was py-bcrypt! So uninstalled bcrypt and its dependents:
```bash
No longer needed
$ pip uninstall bcripyt
$ pip uninstall cff8
$ pip uninstall pycparcer
get py-bcrypt
$ pip install py-bcrypt
```
Then everything worked as expected. No need to add .encode() to passwords, From scratch, I was able to run flask locally using my answer to How to run flask locally (https://teamtreehouse.com/community/how-to-run-flask-locally)

Ken Alger · Answer

Never mind, I was able to figure it out.

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Ken Alger

[SOLVED] Python, and Flask, and Bcrypt, oh my!

3 Answers

Ken Alger

Ken Alger

Chris Freeman

Chris Freeman

Ken Alger

Ken Alger

Andrew Hill

Andrew Hill

Chris Freeman

Chris Freeman

Chris Freeman

Chris Freeman