# ungleich-otp

ungleich-otp is a full blown authentication and authorisation service
made for micro services.

The basic idea is that every micro service has a (long term) seed and
creates time based tokens (See python pyotp, RFC4226, RFC6238).

## Setup instructions ##

This is a standard django project and thus can be easily setup using

```
pip install -r requirements.txt
```

To bootstrap the application, you need your very first trusted seed to
access the application. You can generate it using

```
to be filled in
```

After that, you can run the application using

```
python manage.py runserver
```

The usual instructions on how to setup an https proxy should be followed.

## Realms ##

Access is granting/denied based on realms. There are two reserved
realms, all other realms can be used by the users:

### Reserved realms

Conceptually the realms "ungleich-admin" and "ungleich-auth" are
reserved for higher priviliged applications.

Usually there is only 1 entry in ungleich-admin that is used to
bootstrap and manage ungleich-otp.

All micro services that are trusted to authenticate another micro
service should have an entry in the ungleich-auth realm, which allows
them to verify a token of somebody else.


| Name             | Capabilities                               |
|------------------+--------------------------------------------|
| ungleich-admin   | authenticate, create, delete, list, update |
| ungleich-auth    | authenticate                               |
| all other realms | NO ACCESS                                  |


## Usage: REST ##

- Use an existing token to connect to the service
- All REST based messages: JSON


### POST: /ungleichotp/verify

Request JSON object:

```
{
    version: "1",
    name: "your-name",
    realm: "your-realm",
    token: "current time based token",
    verifyname: "name that wants to be authenticated",
    verifyrealm: "realm that wants to be authenticated",
    verifytoken: "token that wants to be authenticated",
}
```

Response JSON object:

Either HTTP 200 with
```
{
    status: "OK",
}
```

OR return code 403:

* If token for authenticating is wrong, you get

```
{"detail":"Incorrect authentication credentials."}
```

* If token that is being verified is wrong, you get

```
{"detail":"You do not have permission to perform this action."}
```

### GET, POST, ...  /ungleichotp/

Standard django rest framework behaviour for updating / listing
objects.


## Usage: OTP

The seeds that you receive can be used for TOTP to authenticate your
apps.


## Database

The database saves a list of appuuids with their seeds and the user
assignments as well as whether the appuuid might use the BUS interface.

Fields:

- appuuid (a random UUID)
- appname (name chosen by the user)
- username (who this appuuid belongs to)
- seed  (a random base32 string)
- trusted (boolean, whether app is allowed to use the BUS and the
  verify method)


## Environment / Configuration

- POSTGRES_USERNAME
- SECRET_KEY -- random

## Random notes / stuff

django.db.backends.postgresql
django.contrib.admin

```
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'mydatabase',
        'USER': 'mydatabaseuser',
        'PASSWORD': 'mypassword',
        'HOST': '127.0.0.1',
        'PORT': '5432',
    }
}
```

Custom auth

```
from django.contrib.auth.models import User
from rest_framework import authentication
from rest_framework import exceptions

class ExampleAuthentication(authentication.BaseAuthentication):
    def authenticate(self, request):
        username = request.META.get('X_USERNAME')
        if not username:
            return None

        try:
            user = User.objects.get(username=username)
        except User.DoesNotExist:
            raise exceptions.AuthenticationFailed('No such user')

        return (user, None)

```

Custom user

Don’t forget to point AUTH_USER_MODEL to it. Do this before creating any migrations or running manage.py migrate for the first time.



## TODOs

- [x] serialize / input request
- [x] Make seed read only
- [x] Implement registering of new entries
- [x] OTPSerializer: allow to read seed for admin
- [x] Implement deleting entry
- [x] Include verify in ModelSerializer
- [x] Maybe we map name+realm == User (?)
  - name == name@realm
  - password is used for admin login (?)
  - seed
  - custom auth method
- [n] try to fake username for django based on name+realm (?)
- [n] maybe overwrite get_username() (?)
- [x] Use Custom authentication  - needs to have a user!
- [x] Implement creating new "User"
  - by POST / Model based
- [x]
- [ ] Add tests for verify
- [ ] Add tests for authentication
- [ ] Add proper documentation
- [ ] move totp constants into settings
- [ ] move field lengths into settings
- [ ] make settings adjustable by environment (?)
- [ ] Remove hard coded JSON (?)


### To document

* Login via username password interactively
* Login via name/realm/token rest

## Changelog

### 0.6, 2018-11-18

* Reuse TokenSerializer for VerifySerializer logic

### 0.5, 2018-11-18

* Require authentication on all rest endpoints by token