Below I have tried to justify my question, "Does Proof Key for Code Exchange (PKCE) work without TLS? I believe I am missing understanding part of the spec and was hoping for some direction. I also have a second question, Does PKCE only relate to using Cookies to store the auth token (not mentioned in spec).Please help me identify the misinformation or lack of information in my comments below.
rfc7636's introduction section describes an attack authorization code interception attack on public clients. It states,
the attacker intercepts the authorization code returned from the
authorization endpoint within a communication path not protected by
Transport Layer Security (TLS) ...
The Introductions PreCondition section item 4 indicates that TLS not protecting the response .
The Introductions "To mitigate this attack" paragraph the states
This works as the mitigation since the attacker would not know this
one-time key, since it is sent over TLS and cannot be intercepted.
and
this extension utilizes a dynamically created cryptographically random
key called "code verifier".
RFC6949 mentions attacks around the use of cookies; however, rfc7636 does not specify pertaining only to cookies or local storage of the Auth token. Therefore is seems it would resolve an attack on the request if the auth token was also stored dynamically. Is this the case?
PKCE is used as a proof that the party which initiated authentication (via a browser redirect) is the same party completing it (via an HTTP POST).
It works without TLS, as in steps 4 and 8 of my blog post, where the code verifier in step 8 must match the code challenge in step 4.
Cookies are not directly related to PKCE. However, in a browser based app without PKCE or a client secret, malicious browser code only needs to send the authorization code to get tokens. If tokens are stored in cookies then the malicious code can only perform session hijacking.
PKCE was originally introduced for public clients that cannot use a client secret. These days, it is recommended for all clients that use the code flow, including those with a client secret. And of course TLS should also be used.
I am trying to do a request my Netsuite RESTlet using Alamofire (SWIFT) but I meet several difficulties:
In the documentation it's specify the different parameters needed (see below).
DOCUMENTATION:
An OAuth 1.0 RESTlet authorization header requires the data described in the following table. Some of these values can be obtained from the NetSuite UI. Other values must be calculated. Typically, your integration should include logic to identify these values and generate the finished header. Follow the OAuth 1.0 protocol to create the authorization header.
However in postman I am using extra parameters (consumer Secret and the Token Secret) and it's works if I remove them it doesn't works
To finish when i check the Authorization header generated by postman, I see only the specify parameters in the documentation :
OAuth realm="my realm",oauth_consumer_key="myConsumerKey",oauth_token="myAccessToken",
oauth_signature_method="HMAC-SHA1",oauth_timestamp="1543488570",
oauth_nonce="ERxdLbUfkeh",oauth_version="1.0",oauth_signature="UeqmxAyeUqtPoICLo%2FARsQE8B1E%3D"
If someone can explain me this, I could implement TBA authentification in my Application but for now I need to understand better this authentification.
I also spend a few hours trying to make it work. In my case I wasn't adding the account ID to the realm param. Here a picture of what I ended with:
Here where you can get the account ID:
I hope it helps
The explanation of why the consumer secret and the token secret are needed by Postman to generate the token is shown in SuiteAnswer 42019 - as referenced in the Notes section beside oauth_signature in your screenshot above. From that page:
Sign the result string from step 5 using the consumer secret and token secret concatenated using '&' (For this case, HMAC-SHA1 or HMAC-256).
In other words, Postman uses the secrets to generate the output which authenticates your credentials - you cannot generate the oauth_signature correctly without them.
I ran into a lot of issues with NetSuite broken RESTlet/TBA connections as well. I did build this out in our software to help out customers. You can see the methods I used in the article below.
Using NetSuite TBA by Calling a RESTlet from an HTTP Source or Target
I am not sure which approach I should be taking in our implementation and need some guidance.
I have a REST API (api.mysite.com) built in the Yii2 Framework (PHP) that accesses data from mysite.com (database). On mysite.com our users will be able to create Connected Apps that will provision a client id + secret - granting access to their account (full scope?).
Based on my research, the next step seems to be setting up something to actually provide the bearer tokens to be passed to the api - I have been leaning towards oAuth2, but then I read that oAuth2 does not provide authentication. Based on this I think I need OpenID Connect in order to also provide user tokens because my API needs to restrict data based on the user context.
In this approach, it is my understanding that I need to have an Authentication Server - so a few questions:
Is there software I can install to act as an OpenID Connect/oAuth2 authentication server?
Are there specific Amazon Web Services that will act as an OpenID Connect/oAuth2 Authentication Server?
I am assuming the flow will be: App makes a request to the auth server with client id + secret and receives an access token. Access token can be used to make API calls. Where are these tokens stored (I am assuming a database specific to the service/software I am using?)
When making API calls would I pass a bearer token AND a user token?
Any insight is greatly appreciated.
your understanding is not very far from reality.
Imagine you have two servers one for Authentication, this one is responsible for generating the tokens based on a Authorization Basic and base64 encoded CLientID / ClientSecret combo. This is application authentication basically. If you want to add user data as well, simply pass username / password in the post body, authenticate on the server side and then add some more data to the tokens, like the usernames, claims, roles, etc
You can control what you put in these tokens, if you use something like JWT ( Json Web Tokens ) then they are simply json bits of data.
then you have a Resource server, you hit it with a Authorization Bearer and the token you obtained from the Authorization one.
Initially the tokens are not stored anywhere, they are issued for a period of time you control. You can however do something else and store them in a db if you really want to. The expiration is much safer though, even if someone gets their hands on them they won't be available for long! In my case I used 30 minutes for token validity.
Now, you haven't specified what languages/frameworks you are looking into. If you use something like dot net then look into IdentityServer, version 4 is for Dot net core, 3 for anything below.
I also have a pretty long article on this subject if you are interested:
https://eidand.com/2015/03/28/authorization-system-with-owin-web-api-json-web-tokens/
Hopefully all this clarifies some of the questions you have.
-- Added to answer a question in comments.
The tokens contain all the information they need to be authenticated by the resource server correctly, you don't need to store them in a database for that. As I already said, you can store them but in my mind this makes them less secure. Don't forget you control what goes into a token so you can add usernames if that's what you need.
Imagine this scenario, you want to authenticate the application and the user in the same call to the Authorization Server. Do the OAuth2 in the standard way, which means authenticate the application first based on the client id / client secret. If that passes then next do the user authentication. Add the username or userid to the token you generate and any other bits of information you need. What this means that the resource server can safely assume that the username passed to it in the token has already been validated by the authentication server otherwise no token would have been generated in the the first place.
I prefer to keep these two separate myself, meaning let the AS ( Authorization Server) to deal with the application level security. Then on the RS (Resource Server) side you have an endpoint point like ValidateUser for example, which takes care of the user validation, after which you can do whatever you need. Pick whichever feels more appropriate for your project I'd say.
One final point, ALWAYS make sure all your api calls ( both AS and RS are just apis really ) are made over HTTPS and never ever have any important information transmitted via a GET call which means the URL can be intercepted. Both Headers and POST body are encrypted and secure over HTTPS.
This should address both your questions, I believe.
Question
If you would use a similar setup as the following examples:
Simple WebAPI
Javascript OIDCClient and usermanager
Would it be possible to protect other clientside files from being accessed? Say for example i have a directory with certain files which you need a certain role to be able to access them.
Would it be possible to protect my SPA from being accessed before logging in?
Or is there a better solution which would have you end up with a protected api, folders/files on a server, SPA and a silent renew mechanism like there is in the OIDCClient?
#dmccaffery helped me out by answering my question, here is his answer for those of you who are interested.
To summarize using the OIDCClient for an SPA is certainly the way to go. Exposing stuff which needs authorization should be done by using an API. Protecting parts of your Angular App can be done using a Route guard.
The way it works is as follows:
The access token is either a JWT or a bearer token (usually) and is
added by the oidc client to every HTTP request in an authorization
header — when a web API receives a reques, the bearer token
authorization middleware will parse this HTTP header and will call the
token introspection endpoint (and potentially the user info endpoint)
to have the token validated and the users claims retrieved… if the
token was manipulated by the client, it will not be valid, and an HTTP
error will be returned (usually a 403). If the token was valid, a
claims identity is created and assigned to the http request context.
The API will now have a thread with an identity already assigned to it
that represents that user.
Also he pointed out 2 pluralsight courses which would probably be useful:
https://www.pluralsight.com/courses/building-securing-restful-api-aspdotnet
https://www.pluralsight.com/courses/oauth2-openid-connect-angular-aspdotnet
I'm responsible for the API side of our product. We have several different clients, from browsers to iPads to Chromebooks. Right now, all our authentication is done directly from the client to our API, with username & password.
I've inherited some code that does authentication using OAuth, with the usual username/password setup. So inside my OwinAuthConfig class, I have:
var oAuthAuthorizationOptions = new OAuthAuthorizationServerOptions
{
TokenEndpointPath = new PathString("/Authenticate"),
Provider = new MyAuthorizationProvider(),
AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
AllowInsecureHttp = true
};
app.UseOAuthAuthorizationServer(oAuthAuthorizationOptions);
Then, through some dark magic, this connects up with my MyAuthorizationProvider class (which inherits OAuthAuthorizationServerProvider), and on login, this invokes the method:
public override Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
{ ... }
where context contains the important stuff (Username and Password) which I can then use to authenticate the user, build his claims, create an AuthenticationTicket and this information then magically gets returned to the client with the access token etc.
All well and good.
Now I have a new requirement - to allow 3rd party authentication from Google. In this case, the client app (iOS/Android/whatever) does the authentication with Google, and they should just pass the token (and any other required info) to me on the API side. On my side I then need to re-authenticate the Google token, and get all the user info from Google (email, name, etc.), from which I should then again link that to our User table, build up the claims etc. and return a new token to the client, which will be used in all subsequent calls.
Being kinda new to the whole OWIN pipeline thing, I'm not sure exactly how to go about this. I could write a new GoogleAuthController, that just acts like any other controller, and have an API that accepts the Google token, and returns the new token and other info in the same format that the username/password authentication API does it. But 2 things are nagging at me:
I have this awkward feeling like this is the noobie way of doing things, reinventing the wheel, and really there's a super-cool magical way of hooking things together that I should rather be using; and
In MyAuthorizationProvider.GrantResourceOwnerCredentials(), I've got access to an OAuthGrantResourceOwnerCredentialsContext object, which allows me to validate my new AuthenticationTicket. If I'm doing this inside a plain vanilla controller, I have no idea how I would mark that ticket as validated.
Any clues, please?
EDIT I've seen the Google auth flow as described here. I'm still confused by how best to manage the process from the API side. The client will be obtaining the authorization code, and then calling the API with that auth code. I get that then I've got to take that auth code and convert it to a token by calling the Google API. (Or maybe that should be the client's responsibility?) Either way, I then need to use that token to go back to the Google API and get the user's name, email and avatar image, then I need to match up that email with my own database to identify the user and build up their claims. Then I need to return a new token that the client can use to connect to me going forward.
Let me be more specific about my questions, before my question is closed as "too broad":
When the client has completed authentication with the Google API, it gets back a "code". That code still needs to be converted into a token. Whose responsibility should that be - the client or the API? (I'm leaning towards making it the client's responsibility, if just for the reason of distributing the workload better.)
Whether the client is passing through a code or a token, I need to be able to receive it in the API. Should I just use a plain vanilla Controller to receive it, with an endpoint returning an object of type AuthenticationProperties, or is there some special OWIN way of doing this?
If I'm using a plain vanilla Controller, how do I validate my token? In other words, how do I get access to the OWIN context so that I can mark the AuthenticationTicket as validated?
How do I write an automated test that simulates the client side of the process? AFAICT, the authentication wants to have a user physically click on the "Allow" button to grant my app access to their identity stuff, before it will generate the auth code. In an automated test, I would want to pass username/password etc. all from code. How do you do that?
So I found a solution of my own. It's only slightly kludgy, doesn't require referencing any Google OWIN libraries, and best of all, reuses the code from my username/password authentication.
Firstly, I get the app to call the same Authenticate endpoint as I do for username/password, only with dummy credentials, and add in a "GoogleToken" header, containing the token.
In my authentication code, I check for the GoogleToken header, and if it exists, follow that code path to validate on the Google servers, get an email address, and link to my own User table. Then the rest of the process for building claims and returning a new API token follows the original path.
start here : https://developers.google.com/identity/protocols/OAuth2#basicsteps
This explains how oAuth2 works. So you receive a Google token, now you call Google and request the user's details. you will receive their email which is enough to authenticate them. You could store the token as they are valid for a while and you can keep reusing it for whatever you need until it expires or it is invalidated.
Check this discussion on the same subject :
How can I verify a Google authentication API access token?
if you need more info on how OAuth2 works I can point you to one of my own articles : https://eidand.com/2015/03/28/authorization-system-with-owin-web-api-json-web-tokens/
There's a lot to take in, but it sounds like you need to understand how these things work together. Hope this helps.
Update:
I don't have full access to your setup, but I hope that the following code might help you with using Google as ID provider. Please add the following code to your startup.auth.cs file.
var googleAuthOptions = new GoogleOAuth2AuthenticationOptions
{
ClientId = "ef4ob24ttbgmt2o8eikgg.apps.googleusercontent.com",
ClientSecret = "DAK0qzDasdfasasdfsadwerhNjb-",
Scope = { "openid", "profile", "email" },
Provider = new GoogleOAuth2AuthenticationProvider
{
OnAuthenticated = async ctx =>
{
//You can get the claims like this and add them to authentication
var tokenClaim = new Claim("GoogleAccessToken", ctx.AccessToken);
var emailClaim = new Claim("email", ctx.Email);
var claimsIdentity = new ClaimsIdentity();
claimsIdentity.AddClaim(tokenClaim);
claimsIdentity.AddClaim(emailClaim);
HttpContext.Current
.GetOwinContext()
.Authentication
.SignIn(claimsIdentity);
await Task.CompletedTask;
}
},
AuthenticationType = "Google"
};
app.UseGoogleAuthentication(googleAuthOptions);
This allows the Google to act as ID Provider and the OnAuthenticated gets called when the authentication is successful. You can get the claims out of it and use them to signin. Please let me know if this worked, if not give me more details about your setup (what kind of framework, client setup and may be more details about your setup in startup file).
Thank you.
Please see this link for details on how we can use Google as ID Provider. I am sure you might have looked at this link, but in case you missed it. If none of these links work for you please include specific details on where you are deviating from what is mentioned in the links.
I assume you have a different requirement than what is specified in those links. Hence, I will try to answer your questions individually. Please let me know if you have any further questions.
When the client has completed authentication with the Google API, it gets back a "code". That code still needs to be converted into a token. Whose responsibility should that be - the client or the API? (I'm leaning towards making it the client's responsibility, if just for the reason of distributing the workload better.)
Exchanging the code for access token is definitely the responsibility of the API as the token exchange involves sending the ClientId and Client Secret along with the code. Client secret is supposed to be saved on the server side (API) but not on the client
Whether the client is passing through a code or a token, I need to be able to receive it in the API. Should I just use a plain vanilla Controller to receive it, with an endpoint returning an object of type AuthenticationProperties, or is there some special OWIN way of doing this?
This should work seamlessly if you are using the Google provider as mentioned in the above links. If not, the endpoint should be an anonymous endpoint accepting the code and making a request to Google (may be by using HttpClient) to get the access token along with the profile object for user related information.
If I'm using a plain vanilla Controller, how do I validate my token? In other words, how do I get access to the OWIN context so that I can mark the AuthenticationTicket as validated?
You have to implement OnGrantAuthorizationCode as part of your MyAuthorizationProvider class. This gives access to the context to set validated to true.
How do I write an automated test that simulates the client side of the process? AFAICT, the authentication wants to have a user physically click on the "Allow" button to grant my app access to their identity stuff, before it will generate the auth code. In an automated test, I would want to pass username/password etc. all from code. How do you do that?
This can be achieved partially, but, with that partial test you can be sure of good test coverage against your code. So, you have to mock the call to the Google API and assume that you have retrieved a valid response (hard code the response you received from a valid manual test). Now test your code on how it behaves with the valid response. Mock the Google API cal for an invalid response and do the same. This is how we are testing our API now. This assumes that Google API is working fine and tests my code for both valid/ in-valid responses.
Thank you,
Soma.
Having gone through something like this recently, I'll try to answer at least some of your questions:
The client should be getting a token from Google, which you can pass unaltered through to the API:
function onSignIn(googleUser) {
var profile = googleUser.getBasicProfile();
var idToken = googleUser.getAuthResponse().id_token;
}
A plain vanilla Controller should do it. The client can subsequently post an object in there, containing at least that token plus the client id (might be useful to know where the request comes from) and even the providerUserId;
Unfortunately I'm not that familiar with the Owin stack
Fully end-to-end integration testing might be tricky, although you might achieve something through tools like Selenium, or some mocking tool. The API however should be testable just by posting some fake data to that vanilla controller, although you might have to rely on some sort of mock implementation when you get to validating that token through Google (although you could also validate it manually on the server, provided you get the Google public api key).