Keycloak server authentication - keycloak

I'm creating Java appliation, where I will need users to log in. Currently I'm verifying if I can configure Keycloak safe enough. I'd like to make sure my application is really authenticating users against my Keycloak server - eg I know there is something like DNS Poisining or other attacks, where my application could get to attackers server with duplicated/attackers Keycloak instance. What surprised me, I have currently configuration with follwing keys:
keycloak.auth-server-url=...
keycloak.realm=...
keycloak.resource=...
keycloak.public-client=true
keycloak.security-constraints[0].authRoles[0]=..
keycloak.security-constraints[0].securityCollections[0].patterns[0]=...
keycloak.principal-attribute=preferred_username
and no public key is needed. Even worse here: https://stackoverflow.com/a/40516696/520521 I see upvoted comment telling, my application may download key from (malicious) server.
Are there any extra steps I need to follow, to authenticate Keycloak server before starting to authenticate users against it?

Based on your configuration, it seems that you've defined your client in Keycloak as public. This allows your client to be able to call Keycloak without any authentication. This type of client is used for example when you're going to authenticate via js in webpage in which nothing can be hidden from attacker as they have access to the source of the page.
If you set the "Access Type" of your client to "confidential" (in Client Settings on Keycloak Admin UI) and save the settings, there will appear another tab (next to "Setting" tab of the client) titled "Credentials". There you can see the default secret that is created for your client. You should then put this secret as below in your keycloak.json file inside your application:
"credentials": {
"secret": "paste-the-secret-value-here"
}
You can also re-generate the value by selecting the "Regenerate Secret" button.
You can also change the "Client Authenticator" there and set it to "X509 Certificate". Then you would be asked to define a regular expression to validate the "Subject DN" of the certificate that client will be using for authentication. Any certificate matching that regex would be considered as valid and authenticated. Then you have to setup your client to use such certificate instead of defining the "secret" value in the keycloak.json file.
There is of course another option which uses "Signed JWT" which is also secure and you can find the details about how to set it up in Keycloak documentation at Client Authentication section.

I can't see a word that this is the aim, but seeing where public and private key is placed I understand that answer is, that in realm settings -> keys -> active there is list of keys. You may download public key or certificate with button on right side. In my case of Spring boot, enter application.properties file a public key under keycloak.realm-key.

Related

Keycloack - get accessToken via Password grantType - requires client_secret

As a newbie of Keycloak, I try to configure a client with a "Password" grant type. I know that this is not the preferred solution in most cases.
I created a realm 'realm2' with a client 'myclient2' and a user.
When trying to get the token with Postman, I get this error:
{
"error": "unauthorized_client",
"error_description": "Client secret not provided in request"
}
When I add the client_secret, I get the token. I tried to provide a username and password and no secret.
Via the Keycloak user interface I can also login as 'johan' in the 'realm2'.
This is my request in Postman:
In Keycloak I configured the 'realm2' with no special properties set:
The client 'myclient2' is:
I can see on the Credentials tab of the client:
I configured 1 user in the realm2 with just 'password' as a password:
How can I configure my Keycloack settings so I don't need the 'secret' but the username and password?
You could disable authentication for the client, making it public. You can do this by turning off "Client authentication" under the settings tab of your client.
EDIT: I just realized your keycloak version seems different to mine. This configuration is likely under the Access Type selector in your settings tab, by changing it from confidential to public
#Haf answer is right to the point; TL;DR: In the client Access Type dropdown menu select public instead of confidential.
Nonetheless, I want to add a bit more information behind the scenes since you stated that:
As a newbie for Keycloack I try to configure a client with a
"Password" grant type.
First, you should know that Keycloak implements OpenID Connect, which
is a simple identity layer on top of the OAuth 2.0 protocol.
According to the OAuth 2.0 protocol clients can be either confidential or public.
The main difference relates to whether or not the application is able
to hold credentials (such as a client ID and secret) securely.
Regarding the confidential clients:
Because they use a trusted backend server, confidential applications
can use grant types that require them to authenticate by specifying
their client ID and client secret when calling the Token endpoint.
Armed with this knowledge you can easily figure it out how to create a client that will not have a client secret.

Keycloak authentication: how can a external user get an token without exposing client secret

I have a query about how keycloak is supposed to be working with client without GUI access.
Basically I have:
A keycloak server configured with a realm, clients(Access type confidential) and Users
A server application with a GUI that also provide API, secure with keycloak (client, user, blablabla)
This is kind of working already as I am able to log on the GUI, have the redirect, etc..
Even accessing the APIs works well, when I have access to a GUI: I log on my UI, follow the redirect and get my UI to display the token. The the human (to differentiate the user from an application), can use the token in any API client.
In this context the user never sees the client secret, which is instinctively the right way. (note that I am very opened to people telling me my instinct is wrong!)
What I am NOT able to do so far is to find the way a server application (without GUI) can get a valid token?
The authorization_endpoint, as far as I understand it, requires both the client id and the client secret) to get a token, which I would rather avoid: I don't think giving my client secret to all my "customers" is the proper way to do it.
Alternatively I could create an API on my client that woudl ask for user credential and ask for the token in its behalf, but that would expose the clients credentials to my application, which is against the whole concept!
I tried setting my client Access type as public, but when I use the API call below I also get a error:
POST /auth/realms/realmname/protocol/openid-connect/tokenAPI
'grant_type=client_credentials'
'client_id=client_id'
'username=username'
'password=password'
{
"error": "unauthorized_client",
"error_description": "Public client not allowed to retrieve service account"
}
Would anyone know how this is supposed to be done ?
Thanks in advance.
Max
(...) A server application (without GUI) can get a valid token... typically using the Client Credentials flow.
But we would define in this case a dedicated Client for your server (client?) application to authenticate against. The returned token (not bound to a specific user) will serve for authorizations on allowed applications (i.e. your classic GUI or API clients).
So, basically you should (in very short):
define a specific confidential Client in your Keycloak
add the desired applications (or other Clients) to the Client Scope(s). Those you want to authorize transitively from this Client.
authenticate against this Client with Client Credentials flow (given the token endpoint, client id, credentials, scope)
ensure that you are authenticating through TLS and that parameters are included in request body (and not in headers - for enhanced privacy)
further harden security of your Client(s)
When you do not want anymore this particular server (client?) application to access your applications, you can change the corresponding "authentication" Client's secret/credentials or simply delete it.
"I don't think giving my client secret to all my "customers" is the proper way to do it."
You are right and the proposed method above strictly avoids that. Each customer would have its own credentials.
EDIT
(adding more details)
By performing as above, you would end up with the following scheme:
Flow Keycloak Server
C/S app. or Customer X <--- Client Creds ---> Auth. Client X
--- Access Token ---> Appl. Client <--> Appl. Server
C/S app. or Customer Y <--- Client Creds ---> Auth. Client Y
--- Access Token ---> Appl. Client <--> Appl. Server
Browser users <--- Standard ------> Appl. Client <--> Appl. Server
Note: this is not a detailed flow chart. Arrows mostly show relationships here.
Finally, please note that the terminology may differ a little here, but the proposed method is basically the same that Google uses. So you may aswell take some inpiration from there:
https://developers.google.com/identity/protocols/oauth2
I just had the same problem some weeks ago
In my case, I have a backend API and a frontend application that the users can use.
Eventually, I can't share the client_secret to the frontend application.
So here is my solution:
On keycloak, create a client (ex front_end_client) with grant type public
This client is going to be used by the frontend application to authenticate users using implicit flow (with PKCE will be more secure)
On keycloak, create a second client (On the same REALM as the first client) with grant type confidential, this client is going to be used by the backend API
Now, this is how it works:
Frontend app authenticate users and get the access token (Using the font_end_client)
The frontend app sends this token for every request to the backend
Backend app verify this token, and can retrieve permissions from it

"Unexpected error when authenticating with identity provider" error when Keycloak broker is configured as a client to another Keycloak instance

I am getting an error when I try to login to Keycloak by using it as a broker.1 I am using credentials from another keycloak instance to login. So far, I am redirected to the correct login page but after entering my credentials I receive an error.
I have set up Keycloack Identity Brokering on computer 1 by following the basic steps.2 I have used the generated redirection URI of the broker to register a new client on computer 2 in another Keycloak instance.3 The client configuration present on computer 2 4 is then used to fill in Authorization URL, Token URL, Client ID and Client Secret on the Identity Broker on Computer 1. 5
I may be leaving important fields missing. Pictures are attached for reference.
I have changed some settings to get the broker to work with the other Keycloak instance. I am now sending client secret as basic auth with signed verification off. I have also enabled back-channel logout. Hope this helps someone else.
I fixed this problem by regenerating the client secret on the identity provider side and using it on keycloak. The keycloak realm data import was not working very well for me apparently.
In my case I needed to empty the hosted domain field in the "Identity providers" configuration of my Google identity provider in Keycloak.
See also:
Keycloak Google identity provider error: "Identity token does not contain hosted domain parameter"

Keycloak Applications vs Client authentication

Hi i am a bit confused as to how to secure applications through keycloak, the website shows how to secure clients. The application which i need to secure in my setup is a desktop application which uses keycloak + keycloak-gatekeeper protected endpoints.
i managed to get it working using the following library in python
https://bitbucket.org/agriness/python-keycloak/src/master/
however, it requires me to enter the client-secret and i am wondering if this is safe?
also, when i use the browser login instead, the browser doesnt need the client secret, but goes though gatekeeper, this tells me that i am doing something wrong here.
thanks
Use public access type client (Clients doc):
Public access type is for client-side clients that need to perform a browser login. With a client-side application there is no way to keep a secret safe. Instead it is very important to restrict access by configuring correct redirect URIs for the client.
You can change access type on clients - choose client - settings tab admin interface.
in your case, I would use Access type as confidential
and Authorization Enabled > on
and you should use the secrecy key to authorize your call to keylock when you want to interact with keycloak API
Keycloak keycloak = KeycloakBuilder.builder()
.serverUrl("localhost")
.realm("myRealm")
.grantType(OAuth2Constants.PASSWORD)
.clientId("myclient")
.clientSecret("xxxx-xxxxx-xxxx-xxx")
.username("foo")//the admin user
.password("password")
.build();
keycloak.realm("myRealm").users().list();

Nexus OSS Remote User Token (RUT) for SSO

Hello I am using Nexus OSS, and wanted to simulate SSO, using Remote User Token. Currently the Nexus is configured to LDAP authentication, and is working fine.
As per the instructions found here https://books.sonatype.com/nexus-book/reference/rutauth.html
Basically enabled Remote User Token and added header field Name "REMOTE_USER". This user is ldap and has access.
This instance is behind apache, so from apache, To test this RUT, I can set the header value REMOTE_USER, whoever, I don't see passed in user getting logged nor I see cookie being generated. I even tried firefox rest api client and set header, but with the same results. I can see that HTTP header is being set right.
Am I missing something?
Is there a way to debug that? Appreciate any help.
Thanks
S
RUT handles authentication, but the authenticated user still needs to be authorized to access the web UI. What this means is that you need an LDAP user or group mapping in Nexus which assigns the necessary roles and privileges to the user.
I had a similar issue with Nginx, the header was not set using the correct value.
This can be quite confusing, as the reverse proxy does not complain and simply sends a blank request header to Nexus.
Using Keycloak and Nginx (Lua), instead of a preferred_username field in the IdP response:
-- set headers with user info: this will overwrite any existing headers
-- but also scrub(!) them in case no value is provided in the token
ngx.req.set_header("X-Proxy-REMOTE-USER", res.preferred_username)
I had to use the preferred_username field returned in the response's id_token element:
-- set headers with user info: this will overwrite any existing headers
-- but also scrub(!) them in case no value is provided in the token
ngx.req.set_header("X-Proxy-REMOTE-USER", res.id_token.preferred_username)