Standard -server to server- and -browser to server- authentication method - web-services

I have server with some resources; until now all these resources were requested through a browser by a human user, and the authentication was made with an username/password method, that generates a cookie with a token (to have the session open for some time).
Right now the system requires that other servers make GET requests to this resource server but they have to authenticate to get them. We have been using a list of authorized IPs but having two authentication methods makes the code more complex.
My questions are:
Is there any standard method or pattern to authenticate human users and servers using the same code?
If there is not, are the methods I'm using now the right ones or is there a better / more standard way to accomplish what I need?
Thanks in advance for any suggestion.

I have used a combination of basic authentication and cookies in my web services before. In basic authentication you pass the user name/password encoded in the HTTP header where it looks something like this.
Authorization: Basic QWxhZGluOnNlc2FtIG9wZW4=
The string after the word "Basic" is the encoded user name and password that is separated by a colon. The REST API can grab this information from the HTTP header and perform authentication and authorization. If authentication fails I return an HTTP Unauthorized error and if they are authenticated but are not authorized I return an HTTP Forbidden error to distinguish between failure to authentication versus authorization. If it is a web client and the person is authenticated then I pass the following in the HTTP header with a request.
Authorization: Cookie
This tells the web service to get the cookie from the HTTP request and use it for authorization instead of doing the authentication process over again.
This will allow clients that are not web browsers to use the same techniques. The client can always use basic authentication for every request, or they can use basic authentication on the initial request and maintain cookies thereafter. This technique also works well for Single Page Applications (SPAs) where you do not have a separate login page.
Note: Encoding the user name and password is not good enough security; you still want to use HTTPS/SSL to secure the communications channel.

Related

Is djangorestframework-jwt not good for http, https?

I am trying to build an API server for http and started off with djangorestframework and someone suggested using djangorestframework-jwt. However, I saw this from their homepage.
Unlike some more typical uses of JWTs, this module only generates authentication tokens that will verify the user who is requesting one of your DRF protected API resources. The actual request parameters themselves are not included in the JWT claims which means they are not signed and may be tampered with. You should only expose your API endpoints over SSL/TLS to protect against content tampering and certain kinds of replay attacks.
Does djangorestframework-jwt work for http and https? Is it safe? If not, what is the alternative? Is this the approach for authentication in a REST API?
Its http that isn't safe, nothing to do with the authentication method.
Initially, the user has to POST their login credentials. If those are sent via a http connection, anybody in between can read their username and password.
What's more, if you send the JWT token over http, somebody in between may just grab it and re-use it to authenticate their own queries against your API, until the token expires.
Good rule: if any kind of authentication is involved, use https.

How to secure web services when authentication is done at client side (frontend)

I have web application which structure is as-
webapi : django web services [NOT REST] no security implemented
frontend : Angular2. authentication implemented via SAML
Database : Mongodb
Can you please suggest best way to secure webapi, as currently anyone can access web services who has server[api] url
It will be big help if you suggest the authentication and authorization flow because I am totally stuck.
Thanks in advance.
Implement an /authentication on your API which accepts Basic authentication. Make sure you do that over HTTPS. Username and password will be collected by your Angular app and sent back to /authentication. If the user authenticates, return a session token, for example JWT (check pyjwt).
All the following communications between the front and back should contain the token, which is issued only if the user authenticated. The token is inclued in the request headers and specifically in Authororization header using the Bearer schema:
Authorization: Bearer <token>
A JWT contains the username so you can use that on each future request. Furthermore, you are not required to keep record of the issued JWT since each one is self-contained and can have predetermined expiration data.

Django Oauth Toolkit Application Settings

Django Oauth Toolkit docs don't describe the redirect uris, authorization grant type, or client type fields when registering your application.
The tutorial says to set client type to confidential, grant type to password, and leave uris blank.
What do the other options do?
e.g. What is client type public vs confidential? What do the grant type password, credentials, authorization, implicit do? And what are the redirect uris for?
I have found sparse information about them but no actual explanations as they pertain to django rest framework and django oauth toolkit.
You'll get answer to all your questions once you read about Oauth2 Protocol from here
But I'll try to answer your questions in brief:
I'll be using the words client and Resource Server frequently. In Oauth2 protocol, client means the system which accesses resources, data or service. (It could be your mobile app or javascript app consuming REST API's of your API Backend (or Resource Server) . If you have implemented Facebook login in your mobile/JS apps, chances are, your API backend requests Facebook for user's information. In that case your API backend is being a client and Facebook is Resource Server)
Client Types:
Client type is either confidential or public depending on whether that client can keep it's client_secret a secret. (For example, an AngularJS app cannot keep it's client_secret hidden, since anyone can do "Inspect Element" in a browser and search for it, so such a client has to be registered as public.)
Authorization Grant Types:
There are four kinds of Authorization Grant Types in Oauth2 protocol.
Authorization Code:
In this grant type, the client requests for an authorization code first, then exchanges that authorization code for an access token. It's a two step procedure. Use this if the client is an outsider (more on it in Resource-owner password based).
Implicit:
Usually used along with public client_type. Instead of a two-step procedure above, the client gets access token in one go.
Resource-owner password based:
This is used when there is a high degree of trust between client and Resource Server. This is the case between your API backend and your Mobile app. (There is high degree of trust between your API backend and Javascript app too, but since it cannot keep it's client_secret a secret, you have to use Implicit Grant type with it). Facebook or Google etc. will never give you this kind of Authorization Grant because, for them, your API backend is an outsider.
Client Credentials:
It is least commonly used. Please read about it in above mentioned document.
Redirect URI's:
Now, as far as Redirect URI's are concerned, they are needed only in Authorization Code or Implicit grant types (Not sure about Client Credentials one, somebody please enlighten me on this in comments).
Redirect URI is given so that the Resource Server knows where to send the access token. Imagine if you are implementing Facebook login. In that case you will go to developers.facebook.com and register your application (like you did with django-oauth-toolkit), while registering your application, you will specify a Redirect URI.
Specifying a Redirect URI is a way of saying. "Hey Facebook, send the access token on this URI". So if you set Redirect URI something like https://your_domain_name.com/token/facebook/, Facebook will redirect to your specified Redirect URI at the end of Oauth2 process and give Access Token in the form of GET parameter, like https://your_domain_name.com/token/facebook/?token=some_long_string&some=other_parameters.

Two Authentications For RESTful Services

We have a central RESTful webservices application that exposes data to many different clients (parsers, web applications, touch applications, etc). The clients have different means for authenticating users, some LDAP, others not. Regardless, the RESTful application leaves the authentication of the end-user to the client, and simply authenticates the client making the request. The client will have a username and password in LDAP, along with a list of acceptable IP addresses from which the client can access the RESTful application.
Here is the tricky part: the RESTful application must audit every request with the end-user's username. Furthermore, in certain circumstances (depending on the client) the RESTful application will need the end-user's username and password for accessing a third-party application. So, every request from the client will have authentication credentials for the client itself and the end-user accessing the client.
Here comes the question. Would it be best to put the client's credentials in Basic Auth, and pass the end-user's credentials via an encrypted SALT request parameter? Or, should the client put both sets of credentials in the Basic Auth (i.e. system~username:systempwd~userpwd) and parse them out into two sets of tokens that are then authenticated. Or, another solution that is better than either of these two?
This sounds pretty much like OAuth2's "Resource Owner Password Credentials Grant" - see https://www.rfc-editor.org/rfc/rfc6749#section-4.3. You pass application/client credentials in the Authorization header and client information in the body encoded using x-www-url-encoded. Do that once at the beginning of the session and then depend on a bearer token in the authorization header after that. All of that is described in the RFC. Remember to use SSL/TLS to encrypt the credentials.

API when to use http headers for params

I've been doing this Java backend for an iPhone app (Jersey REST mainly) and implemented some web services like sign up and log in. Obviously I've needed params like username and pin. Since this services change state in the DB I've made them as POST and I've used #FormParams Jersey annotation for the params. The guy who worked on client kept sending the username and pin in the headers and it took a little while to discover where's the problem.
is this the standard, to put authentication-like data in headers? How do you do it?
if you use the standard http authentication mechanisms like Basic Authentication
then the credentials are sent in the http header
Something like this
POST /private/index.html HTTP/1.1
Host: localhost
Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==
if you planning to expose this backend through an unsecure network, i would advise you to use https - as it encrpts your header
But if you are implementing your own authentication mechanism - then you can pass the credentials anywhere you like (header or body), that way- your backend would know where to look for the username and password.
check these links for reference
Basic authentication
http authentication