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In "Build a Social Network with Flask", you hashed user passwords with bcrypt. Bcrypt is still very strong but, thanks to advances in GPUs, its days are numbered. A new way of securing user passwords is needed and I just happen to have one.
argon2's documentation- Storing Passwords in a Highly Parallelized World
classmethoddocsstaticmethoddocs
You can leave the **kwargs off of create_user if you want. I find this to be handy way to add in flags like is_admin or can_delete, you just need to add them as fields on the model or in some sort of permissions system. It's a good idea to be forward-thinking in your designs!
[MUSIC]
0:00
If you did build a social
network with Flask,
0:04
you probably remember how we hashed
our users passwords with bcrypt.
0:06
bcrypt is still an amazing
hashing Library.
0:11
But its main protection,
0:13
the fact that it can be configured to
use progressively more processor time,
0:14
has kind of been surpassed by
the creation of faster and better GPU's.
0:18
This advance in hardware means that our
software has been given a best by date.
0:22
Thankfully some for development doesn't
just sit on its laurels and new
0:26
hashing libraries and techniques have been
created that stress processors and memory.
0:29
No matter how much
processor power you have,
0:35
eventually you will run out of memory.
0:36
Let's go see about building users
with argon2 hashed passwords.
0:39
Before I can use the argon2
library to hash passwords.
0:43
I have to install it.
0:47
So for python,
I'm just gonna pip install aargon2-cffi.
0:49
There are argon2 packages for
lots of other languages.
0:53
And whenever you're installing this, you
might find that you are missing ffi, so
0:57
you'll just need to lookup
how to install that for
1:02
whatever your operating system is.
1:05
I've put a link to the argon2
docs in the teacher's notes, so
1:06
be sure to check there if there's
something you wanna know more about.
1:09
I've also included a blog post from
a friend of mine named Hinnick,
1:12
about why to use something like argon2,
instead of bcrypt or whatever.
1:15
Okay, so I've got argon2 installed.
1:21
I think it's time to make a user model.
1:23
Let's make a new model up here.
1:26
And I'm gonna make it above these others,
so that I can do foreign keys to them.
1:30
You know what, actually before, let's do
a couple of other things here real quick.
1:35
So we need to do from argon2
import PasswordHasher.
1:42
And then I have these config things here,
1:50
I think I wanna move
those into a new file.
1:52
So let's make a new file.
1:54
And we're gonna call this config.py.
1:56
And we'll take these things and cut them.
2:01
And then we will paste them into here.
2:07
And then let's get rid of that line,
and let's just say import config.
2:14
And then down here,
2:21
I'll add this as config., config.
2:24
and config.
2:29
Cool.
2:31
So, I can save that.
2:32
And I wanna add one more item in here.
2:35
I want to add a secret_key.
2:37
And then you're just going to add a bunch
of random characters to your secret key.
2:40
Just make it all fancy.
2:50
And then from here of course
I want to do import config.
2:53
Now you might consider moving the database
out to there as well just for kind of
2:56
putting everything together, but I'm not
gonna worry about that for right now.
3:03
Okay, so let's add a HASHER in here
which will be the PasswordHasher.
3:07
Okay, so let's make this user model.
3:13
All right, so
users should have a username.
3:15
And that'll be a char field and I want
that to be unique because I don't wanna
3:18
have more than one user with
the same username, of course.
3:23
And then I'm gonna do a char field for
the email address.
3:26
And I'm also gonna make
that unique because again
3:29
I don't want more than one
user to have the same stuff.
3:32
And then let's do password
is equal to a CharField.
3:36
And I'm not gonna set any
requirements on that.
3:39
So class meta database = database.
3:42
All right and
then I want to provide a method for
3:47
creating a user and this should be
3:50
a class method because I need to work
on the class and not on an instance.
3:55
So we're gonna accept the class.
4:01
And we're gonna take the username.
4:03
And we're gonna take the email.
4:05
And we're gonna take the password.
4:06
And we're gonna take any other
cards that happen to come in.
4:07
Right now we don't care about them but
who knows,
4:10
maybe in the future we want
to allow their arguments.
4:13
All right.
So first of all,
4:16
let's lowercase this email.
4:17
And then let's do cls.select
4:20
.where, we need two things here.
4:24
So, csl.email is equal to
e-mail that was passed in.
4:29
Or cls.username is like,
4:34
case insensitive, is like username.
4:37
And then do a .get on that.
4:43
And then,
if we get a cls.DoesNotExist error.
4:45
Then, that's good.
4:52
That means that the user doesn't exist.
4:54
So, we'll do An email=email.
4:58
And then I’m gonna do
user.password = user.set password.
5:05
And provide the password.
5:11
User.save and return user.
5:13
Else, let's raise an exception.
5:17
And let's say user with that email or
username already exists.
5:19
All right, cool.
5:29
So now, I need to produce
this set password method.
5:30
So this is gonna be a static method.
5:37
Because again I don't want it
to operate on an instance.
5:38
But I don't even want it
to operate on the class.
5:41
I want it to just be this method that
happens to belong to the user class.
5:43
But it doesn't care anything
at all about the class,
5:46
which is why I say static method.
5:48
So we're gonna set the password, and
we're gonna put in the password.
5:50
And we're gonna return
HASHER.hash(password).
5:55
Cool, and
then let's make a verify_password.
6:02
And this is actually going
to take an instance.
6:09
This is just a normal
everyday method nothing.
6:11
Nothing special about this one.
6:14
And we're gonna return HASHER.verify,
6:15
that self.password matches password.
6:20
And so argon2 is kind of cool because
it actually throws an exception if
6:24
the passwords don't match.
6:28
So if this step was to fail
it would throw an exception.
6:30
Because argon2 doesn't have any concept
of not matching or an invalid password.
6:33
It just know these two things don't match.
6:39
Ideally you get the idea
of how that works.
6:42
There's nothing really
different about this.
6:46
One thing I will point out is
that we don't actually need this.
6:49
In workspaces because we're using SQLite.
6:52
SQLite is really horrible with
case sensitive searching.
6:54
So SQLite will work fine without that.
6:58
You do wanna have this for
all the other databases, MySQL, Postres,
7:01
things like that.
7:05
I think we're good there and I'm going to
go and make a user resource off camera.
7:06
I want you to try and
make one on your own.
7:13
All it needs to have is a user list
with a post that will create a new user.
7:15
That's all you have to make.
7:19
Go ahead and
register it with the app and everything.
7:20
We'll check that out in the next video.
7:22
One thing that's really smart to do and
Django does it Is if you want an example
7:25
is to create a way to
upgrade password hashing.
7:28
You don't want to store
the actual passwords but
7:31
when you use a new hasher
to create an upgrade path,
7:34
that will change your users old hash to
the new one the next time they will login.
7:36
You'll have a more secure application and
7:40
they'll appreciate not getting
any we've been hacked e-mails.
7:42
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