Spring Security - Access Token without client_secret in parameters - spring

I have a spring security oauth2 based application, configured with a JDBC Client Store. As per the OAuth2 specs, client secret must only be used when client-server connections are trustworthy, and certainly not from a web application - where the client secret could be extracted from.
So the question is - how do we configure to let the /oauth/token requests with a grant type as "password" produce an access token, without the client_secret key in the POST parameters?
This is my authorization server configuration. Pretty basic I would say.
<sec:http pattern="/token" create-session="stateless" use-expressions="true" authentication-manager-ref="authenticationManager">
<sec:headers>
<sec:frame-options policy="DENY" />
<sec:hsts />
</sec:headers>
<sec:csrf disabled="true" />
<sec:anonymous enabled="false" />
<sec:http-basic entry-point-ref="clientAuthenticationEntryPoint" />
<sec:custom-filter ref="clientCredentialsTokenEndpointFilter" before="BASIC_AUTH_FILTER" />
<sec:access-denied-handler ref="oauthAccessDeniedHandler" />
</sec:http>

According to RFC6749, the OAuth2 Specs, a password grant type must have the client secret passed in either as a request body parameter or as a BASE64 encoded string. The password grant type is not suited for applications that has lesser security or high risk of secrets being exposed to the outer world.
For applications which has a user-agent (web browsers), Implicit Grant Type is the best sought out method.
Refer the OAuth2 Specs here

Related

Spring OAuth2 token without ClientId and ClientSecret for External Clients

We have OAuth token generation using Spring which accepts Username/Password/ClientId/Secret, which works perfect. For External Client we just need input as username and password and generate OAuth Token.
<security:http pattern="/oauth/token" create-session="stateless"
authentication-manager-ref="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<security:intercept-url pattern="/oauth/token" access="IS_AUTHENTICATED_FULLY" />
<security:anonymous enabled="false" />
<security:http-basic entry-point-ref="clientAuthenticationEntryPoint" />
<!-- include this only if you need to authenticate clients via request parameters -->
<security:custom-filter ref="clientCredentialsTokenEndpointFilter" after="BASIC_AUTH_FILTER" />
<security:access-denied-handler ref="oauthAccessDeniedHandler" />
</security:http>
Below is the new code that we need to add, but it is asking for username and password in browser.
<security:http pattern="/**external**/oauth/token" create-session="stateless"
authentication-manager-ref="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<security:intercept-url pattern="/external/oauth/token" access="IS_AUTHENTICATED_FULLY" />
<security:anonymous enabled="false" />
<security:http-basic entry-point-ref="clientAuthenticationEntryPoint" />
<security:custom-filter ref="clientCredentialsTokenEndpointFilter" after="BASIC_AUTH_FILTER" />
<security:access-denied-handler ref="oauthAccessDeniedHandler" />
</security:http>
Please guide if we can generate OAuth without clientId and internally pass clientId to generate OAuth.
You can never generate an OAuth token without a clientId! Oauth2 has 3 ways of creating a token, Implicit, Code, and user/pass. The last should be avoided, since it means that the Oauth client will get access to the user's credentials, and OAuth was built to prevent exactly that. Implicit token are granted using only the user's credentials (typically involving only the browser). In Code-mode the OAuth client received a code (should not be in a browser), which is then exchanged to a Token. The code to Token exchange require that the Oauth client authenticates, using it's clientId and a secret, this is typically done using Basic Authentication.
I think what you need is Resource Owner Password grant type which is explained in https://www.rfc-editor.org/rfc/rfc6749#section-1.3.3
Resource Owner Password grant type should only be used with the trusted clients. So if the external client you are talking about is a trusted client (Like a native mobile app developed by the same company. ex. Facebook Mobile App), this can be used.
Flow is explained in https://www.rfc-editor.org/rfc/rfc6749#section-4.3.1
The most important aspect of Resource Owner grant type is client should not store user name and password.

Spring security: Why use http-basic and form-login together?

When using Spring Security how does this code work - specifically why is the basic authentication used together with form login, aren't they mutually exclusive ? In what situation does it make sense to use both of them like in the sample code below:
<http>
<intercept-url pattern='/login.jsp' access='permitAll' />
<intercept-url pattern='/**' access='ROLE_USER' />
<http-basic />
<form-login login-page='/login.jsp' always-use-default-target='true' />
</http>
I suppose that you can use them separately.
But using them together allows us to secure Rest services using Basic Auth and
Web Pages using form login.

Support SAML SSO and normal login

I have an application which is accessed by two types of users, internal and external.
I need to authenticate external users using SAML.
I need to authenticate internal users with the normal form-based login. My application need to support both types of users. I use spring security frame work.
Is it possible to support both types of users? if so can you suggest the approach at high level? Thanks.
You can easily enable support for both form and SAML authentication with configuration similar to this:
<http entry-point-ref="authenticationEntryPoint" authentication-manager-ref="authenticationManager">
<intercept-url pattern="/**" access="IS_AUTHENTICATED_FULLY"/>
<form-login login-page="/login" />
<custom-filter before="FIRST" ref="metadataGeneratorFilter"/>
<custom-filter after="BASIC_AUTH_FILTER" ref="samlFilter"/>
</http>
Make sure that your AuthenticationManager contains the samlAuthenticationProvider. And of course include other configuration parts from the Spring SAML sample application.
You can then create your custom login page which presents user with username+password fields for form-based authentication and a link/picture (or multiple of them) which initialize authentication with the IDP (by redirecting user to scheme://host:port/saml/login?idp=selectedIdpEntityId).
Your users then decide which one to use - depending on whether they's internal or external.
The part of Spring SAML documentation touching on this subject is in chapter Spring Security integration.

Basic Authentication Filter and authentication entry point not actually used from spring oauth2 token request

I have implemented resource owner flow with spring oauth2 based on spring's sparklr sample application and a couple of samples I found online. I tested the token request part with curl like this in order to provide both client and user credentials:
curl -v --data "username=user1&password=user1&client_id=client1&client_secret=client1&grant_type=password" -X POST "http://localhost:8080/samplerestspringoauth2/oauth/token"
and it works correctly, however I have made the following observation:
Although according to the examples I saw, I make use of the BasicAuthentication filter, this is not really used in the security process. Since the token request does not contain an Authentication header, the BasicAuthentication filter just skips doing any checks. ClientCredentialsTokenEndpointFilter and authentication-server are the only ones performing security checks during the token request. After noticing this and verifying it via debugging, I tried to remove completely the following part:
<http-basic entry-point-ref="clientAuthenticationEntryPoint" />
from the configuration. But then I got the warning:
"No AuthenticationEntryPoint could be established. Please make sure
you have a login mechanism configured through the namespace (such as
form-login) or specify a custom AuthenticationEntryPoint with the
'entry-point-ref' attribute".
As a next step, I added the entry-point-ref="clientAuthenticationEntryPoint in the http namespace, and got rid of the warning. I tested the app and played correctly.
However, in addition to the above, I have also made the following observation during debugging:
The ClientCredentialsTokenEndpointFilter, contains its own OAuth2AuthenticationEntryPoint entry point inside a private variable, and uses that when failing due to wrong client credentials.
Therefore, it does not matter what entry point I specify either in the basic filter, or in the http namespace. At the end ClientCredentialsTokenEndpointFilter will use its own private OAuth2AuthenticationEntryPoint.
To summarize my conclusions seem to be the following:
The basic filter is not used and can be removed, if we specify the
endpoint in the http namespace instead.
Specifying either a basic
filter,or an endpoint in http namespace is needed only for the
compiler to stop the warning. They have no practical use, and the
endpoint used is hardcoded inside
ClientCredentialsTokenEndpointFilter.
Below I put the http and endpoint configuration for the token request for your reference. I skip the rest of configuration for keeping the post easy to read:
<http pattern="/oauth/token" create-session="stateless"
authentication-manager-ref="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<intercept-url pattern="/oauth/token" access="IS_AUTHENTICATED_FULLY" />
<anonymous enabled="false" />
<http-basic entry-point-ref="clientAuthenticationEntryPoint" />
<custom-filter ref="clientCredentialsTokenEndpointFilter"
before="BASIC_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
</http>
<bean id="clientAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="springsec/client" />
<property name="typeName" value="Basic" />
</bean>
I also assume that the same issue also occurs in the original sparklr application (which is spring oauth2 sample app) configuration for token request which is very similar. That can be found in https://github.com/spring-projects/spring-security-oauth/blob/master/samples/oauth2/sparklr/src/main/webapp/WEB-INF/spring-servlet.xml, and the related part is below:
<http pattern="/oauth/token" create-session="stateless"
authentication-manager-ref="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<intercept-url pattern="/**" method="GET" access="ROLE_DENY" />
<intercept-url pattern="/**" method="PUT" access="ROLE_DENY" />
<intercept-url pattern="/**" method="DELETE" access="ROLE_DENY" />
<intercept-url pattern="/**" access="IS_AUTHENTICATED_FULLY" />
<anonymous enabled="false" />
<http-basic entry-point-ref="clientAuthenticationEntryPoint" />
<!-- include this only if you need to authenticate clients via request
parameters -->
<custom-filter ref="clientCredentialsTokenEndpointFilter"
after="BASIC_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
</http>
I would expect spring oauth2 to more appropriately interact with spring security instead of having to put unnecessary and misleading configuration, and that makes me think that I may have missed something. Since security is a sensitive aspect I wanted to share that with you and ask if my conclusion correct.
The /oauth/token provides two different ways to authenticate clients which are requesting tokens:
Using HTTP-Basic authentication (when "http-basic" element is present)
The authentication is handled with org.springframework.security.web.authentication.www.BasicAuthenticationFilter and processes the "Authorization" HTTP header which contains base64 encoded credentials of the client. The filter only performs processing when the Authorization header is present. This method is always tried first. The entry point defined on http-basic will only be invoked when user has supplied an "Authorization" header with invalid content - that's why you don't see the entry point invoked in your debugger, try to set an Authorization HTTP header and your breakpoint will get a hit.
As defined in the OAuth standard using client_id and client_secret HTTP paremeters
This is handled using org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter and by default uses entry point which sends back WWW-Authenticate header to the client. The default entry point can be customized (there's a setAuthenticationEntryPoint method). The entry point is only used when you supply client_id parameter.
Both of these methods use different ways to obtain client's username+password, but verify it against the same authentication manager.
The "No AuthenticationEntryPoint could be established" error which you observe when taking out the <http-basic> element is coming from Spring Security itself, not from the OAuth Extension. The reason is that Spring Security is not able to tell that there's a default entry point already configured inside of the custom filter ClientCredentialsTokenEndpointFilter. And the HTTP configuration of Spring Security always must have at least one entry point available.
So, the complete logic goes as follows:
when you include "Authorization" header with invalid credentials and <http-basic> element is present , system will use entry point defined on the <http-basic> element. If none is specified (attribute entry-point-ref is missing), system will create a default instance of BasicAuthenticationEntryPoint automatically for you and use it.
when you include HTTP parameter "client_id" and "client_secret" with invalid credentials and custom filter clientCredentialsTokenEndpointFilter is present, system will use entry point defined in the clientCredentialsTokenEndpointFilter bean (which is by default instance of OAuth2AuthenticationEntryPoint)
in case neither "Authorization" header nor "client_id" parameter are present and the endpoint requires authentication ("IS_AUTHENTICATED_FULLY"), system will use the entry point defined on the <http entry-point-ref="">, if present, otherwise it will use the entry point defined on the http-basic (as above)
in case you don't specify neither http-basic (or other default authentication method which Spring recognizes), nor default entry point using the <http entry-point-ref="">, system will fail with "No AuthenticationEntryPoint could be established", because it requires at least one entry point and it doesn't understand that there's one available inside the clientCredentialsTokenEndpointFilter.
Regarding your observations:
>> The basic filter is not used and can be removed, if we specify the
endpoint in the http namespace instead.
> This is true in case you are authentication your clients using client_id + client_secret
>> Specifying either a basic filter,or an endpoint in http namespace is
needed only for the compiler to stop the warning. They have no
practical use, and the endpoint used is hardcoded inside
ClientCredentialsTokenEndpointFilter.
> Partly true, as the entry point will be used in case client_id is missing.
The configuration is indeed confusing (which is partly caused by the fact that OAuth isn't a native part of Spring Security, but an extension), but all of those settings make sense and are used in specific situations.
The changes you made have no security implications.

Spring Security 3 RestTemplate POST to j_spring_security_check

I am using Spring Security 3 with REST endpoints. I managed to get a basic Spring Security working.
Part of the security-context.xml
<security:http auto-config="true" use-expressions="true" access-denied-page="/rest/denied" >
<security:intercept-url pattern="/rest/*" access="ROLE_USER"/>
and basic config as found on the web
<security:authentication-manager>
<security:authentication-provider user-service-ref="userDetailsService">
<security:password-encoder ref="passwordEncoder"/>
</security:authentication-provider>
<!-- Use a Md5 encoder since the user's passwords are stored as Md5 in the database -->
<bean class="org.springframework.security.authentication.encoding.Md5PasswordEncoder" id="passwordEncoder"/>
<!-- An in-memory list of users. No need to access an external database layer.
See Spring Security 3.1 Reference 5.2.1 In-Memory Authentication -->
<!-- john's password is admin, while jane;s password is user -->
<security:user-service id="userDetailsService">
<security:user name="john" password="21232f297a57a5a743894a0e4a801fc3" authorities="ROLE_USER, ROLE_ADMIN" />
<security:user name="jane" password="ee11cbb19052e40b07aac0ca060c23ee" authorities="ROLE_USER" />
</security:user-service>
I want to login to j_spring_security_check using a RestTemplate POST.
HttpEntity<String> entity = new HttpEntity<String>(request, headers);
HashMap<String, String> map = new HashMap<String, String>();
map.put("j_username", "john");
map.put("j_password","21232f297a57a5a743894a0e4a801fc3");
String response = restTemplate.postForObject("http://localhost:8080/rest/j_spring_security_check", map, String.class);
but in the log, it seems the username parameter is not being read
DEBUG o.s.s.authentication.ProviderManager - Authentication attempt using org.springframework.security.authentication.dao.DaoAuthenticationProvider
DEBUG o.s.s.a.d.DaoAuthenticationProvider - User '' not found
DEBUG o.s.s.w.a.UsernamePasswordAuthenticationFilter - Authentication request failed: org.springframework.security.authentication.BadCredentialsException: Bad credentials
What is the correct way to get the REST Template to post auth credentials? Is there a better way to login in/ get authorized other than j_spring_security_check? Does the information go in the header?
Thanks in advance.
This seems like a duplicate of another SO question. You are probably approaching this the wrong way, though. Typically if you are issuing a REST request you wouldn't be authenticating at the same time - this doesn't make any sense - certainly not using form POST style logic.
For authentication of REST requests you should be using another form of authentication (assuming these requests are generated programmatically):
* HTTP Basic auth
* X.509 certificates
OR if this is happening through an XHR / Javascript origin, you should be prepared to have the request fail and redirect the user to the login mechanism. Typically handling REST style requests with Spring Security is not at all the same as handling regular secured pages. You should be prepared for some amount of complexity.
Good luck!

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