I am trying to implement Oauth2 spring security with Spring 4.1
I am sending password, username , client_id and client_secret but still i get bad credentials.
the request i send is as follows:
http://localhost:8080/asset-manager/oauth/token?grant_type=password&client_id=restapp&client_secret=restapp&username=ankita&password=ankita
I have the following files
spring-security.xml
<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oauth="http://www.springframework.org/schema/security/oauth2"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:sec="http://www.springframework.org/schema/security" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/security/oauth2 http://www.springframework.org/schema/security/spring-security-oauth2.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-4.1.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd ">
<!-- This is default url to get a token from OAuth -->
<http pattern="/oauth/token" create-session="stateless"
authentication-manager-ref="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<intercept-url pattern="/oauth/token" access="isFullyAuthenticated()" />
<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" />
<csrf disabled="true" />
</http>
<!-- This is where we tells spring security what URL should be protected
and what roles have access to them -->
<http pattern="/api/**" create-session="never"
entry-point-ref="oauthAuthenticationEntryPoint"
access-decision-manager-ref="accessDecisionManager"
xmlns="http://www.springframework.org/schema/security">
<anonymous enabled="false" />
<intercept-url pattern="/api/**" access="hasRole('ROLE_USER')" />
<custom-filter ref="resourceServerFilter" before="PRE_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
<csrf disabled="true" />
</http>
<bean id="oauthAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="test" />
</bean>
<bean id="requestFactory"
class="org.springframework.security.oauth2.provider.request.DefaultOAuth2RequestFactory">
<constructor-arg name="clientDetailsService" ref="clientDetails" />
</bean>
<bean id="clientAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="test/client" />
<property name="typeName" value="Basic" />
</bean>
<bean id="oauthAccessDeniedHandler"
class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler" />
<bean id="clientCredentialsTokenEndpointFilter"
class="org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter">
<property name="authenticationManager" ref="authenticationManager" />
</bean>
<bean id="accessDecisionManager"
class="org.springframework.security.access.vote.AffirmativeBased"
xmlns="http://www.springframework.org/schema/beans">
<constructor-arg>
<list>
<bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter" />
<bean class="org.springframework.security.access.vote.RoleVoter" />
<bean class="org.springframework.security.access.vote.AuthenticatedVoter" />
<bean
class="org.springframework.security.web.access.expression.WebExpressionVoter"></bean>
</list>
</constructor-arg>
</bean>
<authentication-manager id="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<authentication-provider user-service-ref="clientDetailsUserService" />
</authentication-manager>
<bean id="authenticationProcessingFilter"
class="org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter">
<property name="authenticationManager" ref="authenticationManager" />
</bean>
<!-- This is simple authentication manager, with a hardcoded user/password
combination. We can replace this with a user defined service to get few users
credentials from DB -->
<authentication-manager alias="authenticationManager"
xmlns="http://www.springframework.org/schema/security">
<authentication-provider>
<user-service>
<user name="ankita" password="ankita" authorities="ROLE_USER" />
</user-service>
</authentication-provider>
<authentication-provider user-service-ref="clientDetailsUserService" />
</authentication-manager>
<bean id="clientDetailsUserService"
class="org.springframework.security.oauth2.provider.client.ClientDetailsUserDetailsService">
<constructor-arg ref="clientDetails" />
</bean>
<!-- This defined token store, we have used inmemory tokenstore for now
but this can be changed to a user defined one -->
<bean id="tokenStore"
class="org.springframework.security.oauth2.provider.token.store.InMemoryTokenStore" />
<!-- This is where we defined token based configurations, token validity
and other things -->
<bean id="tokenServices"
class="org.springframework.security.oauth2.provider.token.DefaultTokenServices">
<property name="tokenStore" ref="tokenStore" />
<property name="supportRefreshToken" value="true" />
<property name="accessTokenValiditySeconds" value="120" />
<property name="clientDetailsService" ref="clientDetails" />
</bean>
<bean id="userApprovalHandler"
class="org.springframework.security.oauth2.provider.approval.TokenStoreUserApprovalHandler">
<property name="tokenStore" ref="tokenStore" />
<property name="clientDetailsService" ref="clientDetails" />
<property name="requestFactory" ref="requestFactory" />
</bean>
<oauth:authorization-server
client-details-service-ref="clientDetails" token-services-ref="tokenServices"
user-approval-handler-ref="userApprovalHandler">
<oauth:authorization-code />
<oauth:implicit />
<oauth:refresh-token />
<oauth:client-credentials />
<oauth:password />
</oauth:authorization-server>
<oauth:resource-server id="resourceServerFilter"
resource-id="test" token-services-ref="tokenServices" />
<oauth:client-details-service id="clientDetails">
<!-- client -->
<oauth:client client-id="restapp"
authorized-grant-types="authorization_code,client_credentials"
authorities="ROLE_USER" scope="read,write,trust" secret="secret" />
<oauth:client client-id="restapp"
authorized-grant-types="password,authorization_code,refresh_token,implicit"
secret="restapp" scope="read,write,trust" authorities="ROLE_USER" />
</oauth:client-details-service>
<bean id="httpSessionSecurityContextRepository"
class='org.springframework.security.web.context.HttpSessionSecurityContextRepository'>
<property name='allowSessionCreation' value='false' />
</bean>
<bean id="securityContextPersistenceFilter"
class="org.springframework.security.web.context.SecurityContextPersistenceFilter">
<constructor-arg ref="httpSessionSecurityContextRepository" />
</bean>
<bean id="filterChainProxy" class="org.springframework.security.web.FilterChainProxy">
<constructor-arg>
<list>
<sec:filter-chain pattern="/**"
filters="securityContextPersistenceFilter" />
</list>
</constructor-arg>
</bean>
<sec:global-method-security
pre-post-annotations="enabled" proxy-target-class="true"
authentication-manager-ref="authenticationManager"
secured-annotations="enabled">
<!--you could also wire in the expression handler up at the layer of the
http filters. See https://jira.springsource.org/browse/SEC-1452 -->
<sec:expression-handler ref="oauthExpressionHandler" />
</sec:global-method-security>
<oauth:expression-handler id="oauthExpressionHandler" />
<oauth:web-expression-handler id="oauthWebExpressionHandler" />
And this is my pom.xml
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">
<servlet>
<servlet-name>mvc-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>mvc-dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
/WEB-INF/mvc-dispatcher-servlet.xml,
/WEB-INF/spring-security.xml
</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- Spring Security -->
<filter>
<filter-name>springSecurityFilterChain</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
<filter-name>springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>
<listener>
<listener-class>org.springframework.security.web.session.HttpSessionEventPublisher</listener-class>
</listener>
Unfortunately whenever i send a request it throws this:
{
"error": "invalid_grant",
"error_description": "Bad credentials"
}
Need Help !
You only need to pass the username, password (both of these are for the user, not the client), grant_type and client_id request params.
You must send an Authorization header, containing BASIC auth using the client ID as the username and the client secret as the password.
This is how you would do it in cURL for example:
$ curl -u restapp:restapp http://localhost:8080/asset-manager/oauth/token -d grant_type=password -d client_id=restapp
I had a similar issue when upgrading from Spring Security 4.0.4 to 4.1.1.
Try changing "alias" in your authentication-manager bean definition to "id":
<authentication-manager id="authenticationManager"
xmlns="http://www.springframework.org/schema/security">
<authentication-provider>
<user-service>
<user name="ankita" password="ankita" authorities="ROLE_USER" />
</user-service>
</authentication-provider>
<authentication-provider user-service-ref="clientDetailsUserService" />
I found that for some reason the "alias" definition in the custom "authenticationManager" does not get recognized. When I changed "alias" to "id", my custom AuthenticationManager worked again.
I saw this issue when testing Spring Security 4.1.0, so I'm not sure what changed between Spring Security 4.0.4 and 4.1.0 that caused this to break.
I tried to search the release notes and issues in the Spring Security github, but couldn't find anything related to this. All I know is that this small fix worked for me.
Hope this helps.
I had to change some of the properties in spring-security.xml file with updated functionalities and also i override some of classes such as AuthenticationProvider and ClientDetailsService according to my use case, also i have used redis as my token store , you can replace it in memory token store
My updated spring-security.xml is:
<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oauth="http://www.springframework.org/schema/security/oauth2"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:sec="http://www.springframework.org/schema/security" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/security/oauth2 http://www.springframework.org/schema/security/spring-security-oauth2.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-4.1.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd ">
<!-- This is default url to get a token from OAuth -->
<http pattern="/oauth/token" create-session="stateless"
authentication-manager-ref="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<intercept-url pattern="/oauth/token" access="isFullyAuthenticated()" method="POST"/>
<intercept-url pattern="/v1/access_token" access="isFullyAuthenticated()" method="POST"/>
<anonymous enabled="false" />
<http-basic entry-point-ref="oauthAuthenticationEntryPoint" />
<!-- include this only if you need to authenticate clients via request
userService parameters -->
<custom-filter ref="clientCredentialsTokenEndpointFilter"
after="BASIC_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
<csrf disabled="true" />
</http>
<!-- This is where we tells spring security what URL should be protected
and what roles have access to them -->
<http pattern="/v1/**" create-session="stateless"
entry-point-ref="oauthAuthenticationEntryPoint"
access-decision-manager-ref="accessDecisionManager"
xmlns="http://www.springframework.org/schema/security">
<anonymous enabled="false" />
<intercept-url pattern="/v1/application/register" access="hasRole('ROLE_ADMIN')" />
<intercept-url pattern="/v1/application/{clientId}" access="hasAnyRole('ROLE_USER','ROLE_ADMIN')" />
<custom-filter ref="resourceServerFilter" before="PRE_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
<csrf disabled="true" />
</http>
<bean id="oauthAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="test" />
</bean>
<bean id="clientAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="test/client" />
<property name="typeName" value="Basic" />
</bean>
<bean id="oauthAccessDeniedHandler"
class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler" />
<bean id="clientCredentialsTokenEndpointFilter"
class="org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter">
<property name="authenticationManager" ref="authenticationManager" />
</bean>
<bean id="accessDecisionManager" class="org.springframework.security.access.vote.UnanimousBased"
xmlns="http://www.springframework.org/schema/beans">
<constructor-arg>
<list>
<bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter" />
<bean class="org.springframework.security.access.vote.RoleVoter" />
<bean class="org.springframework.security.access.vote.AuthenticatedVoter" />
<bean
class="org.springframework.security.web.access.expression.WebExpressionVoter" />
</list>
</constructor-arg>
</bean>
<authentication-manager id="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<!-- <authentication-provider user-service-ref="clientDetailsUserService"
/> -->
<authentication-provider ref="AuthenticationProvider" />
</authentication-manager>
<bean id="clientDetailsUserService"
class="org.springframework.security.oauth2.provider.client.ClientDetailsUserDetailsService">
<constructor-arg ref="clientDetailsService" />
</bean>
<authentication-manager
xmlns="http://www.springframework.org/schema/security" alias="authenticationManager">
<authentication-provider ref="AuthenticationProvider" />
</authentication-manager>
<bean id="AuthenticationProvider"
class="com.timeinc.security.biz.client.security.impl.AuthenticationProviderImpl">
<property name="userService" ref="userService"></property>
</bean>
<bean id="tokenStore"
class="org.springframework.security.oauth2.provider.token.store.redis.RedisTokenStore">
<constructor-arg name="connectionFactory" ref="redisConnectionFactory" />
</bean>
<!--create redis connection factory and set db 1 -->
<bean id="redisConnectionFactory"
class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
<property name="hostName" value="${redisHost}" />
<property name="port" value="${redisPort}" />
<property name="password" value="${redisPassword}" />
<property name="database" value="${redisDatabase}" />
</bean>
<bean id="tokenServices" class="com.timeinc.security.biz.client.security.impl.DefaultTokenServicesImpl">
<property name="tokenStore" ref="tokenStore" />
<property name="supportRefreshToken" value="true" />
<property name="accessTokenValiditySeconds" value="${accessTokenValiditySeconds}" />
<property name="refreshTokenValiditySeconds" value="${refreshTokenValiditySeconds}"></property>
<property name="clientDetailsService" ref="clientDetailsService" />
</bean>
<bean id="requestFactory"
class="org.springframework.security.oauth2.provider.request.DefaultOAuth2RequestFactory">
<constructor-arg name="clientDetailsService" ref="clientDetailsService" />
</bean>
<bean id="userApprovalHandler"
class="org.springframework.security.oauth2.provider.approval.TokenStoreUserApprovalHandler">
<property name="tokenStore" ref="tokenStore" />
<property name="clientDetailsService" ref="clientDetailsService" />
<property name="requestFactory" ref="requestFactory" />
</bean>
<oauth:authorization-server
client-details-service-ref="clientDetailsService" token-services-ref="tokenServices"
user-approval-handler-ref="userApprovalHandler">
<oauth:authorization-code />
<oauth:implicit />
<oauth:refresh-token />
<oauth:client-credentials />
<oauth:password />
</oauth:authorization-server>
<oauth:resource-server id="resourceServerFilter"
resource-id="test" token-services-ref="tokenServices" />
<bean id="clientDetailsService" class="com.timeinc.security.biz.client.security.impl.ClientDetailsServiceImpl">
<property name="appClient" ref="appClient"></property>
</bean>
<bean id="httpSessionSecurityContextRepository"
class='org.springframework.security.web.context.HttpSessionSecurityContextRepository'>
<property name='allowSessionCreation' value='false' />
</bean>
<bean id="userService" class="com.timeinc.security.biz.client.security.impl.UserDetailsServiceImpl">
<property name="appClient" ref="appClient"></property>
</bean>
<bean id="securityContextPersistenceFilter"
class="org.springframework.security.web.context.SecurityContextPersistenceFilter">
<constructor-arg ref="httpSessionSecurityContextRepository" />
</bean>
<bean id="filterChainProxy" class="org.springframework.security.web.FilterChainProxy">
<constructor-arg>
<list>
<sec:filter-chain pattern="/**"
filters="securityContextPersistenceFilter" />
</list>
</constructor-arg>
</bean>
<sec:global-method-security
pre-post-annotations="enabled" proxy-target-class="true">
<!--you could also wire in the expression handler up at the layer of the
http filters. See https://jira.springsource.org/browse/SEC-1452 -->
<sec:expression-handler ref="oauthExpressionHandler" />
</sec:global-method-security>
<oauth:expression-handler id="oauthExpressionHandler" />
<oauth:web-expression-handler id="oauthWebExpressionHandler" />
</beans>
Related
I'm not an expert in Spring Security..
I have one single angularjs app, which has OAuth2 based authentication and authorization.
Now I need to add additional app, but users and passwords should be the same for both apps.
So.. I need to have one sso server and two resource servers.
I want to implement that with modern spring boot.
Currently I authenticate users against /oauth/token with grant_type=password
I wonder if there are some samples of SSO and Resource servers that would allow me to authenticate users against http://sso.host/oauth/token?username=someuser&password=somepass&grant_type=password
so.. I will get my acccess and refresh tokens as the result of success authentication.
And access token would be good to use against http://resource.host/rest/someresource
while refresh token would be good to get access_tokens at http://sso.host/oauth/token?grant_type=refresh
I don't want my apps to be redirected to any urls..
I don't need any login forms, just json responses.
Here is my current spting-security-oauth.xml config:
<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oauth="http://www.springframework.org/schema/security/oauth2"
xmlns:context="http://www.springframework.org/schema/context" xmlns:sec="http://www.springframework.org/schema/security" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/security/oauth2 http://www.springframework.org/schema/security/spring-security-oauth2-2.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.2.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd "><beans>
<authorization-server client-details-service-ref="clientDetails" token-services-ref="tokenServices" xmlns="http://www.springframework.org/schema/security/oauth2">
<refresh-token />
<client-credentials />
<password authentication-manager-ref="userAuthenticationManager" disabled="false"/>
</authorization-server>
<authentication-manager id="clientAuthenticationManager" xmlns="http://www.springframework.org/schema/security">
<authentication-provider user-service-ref="clientDetailsUserService" />
</authentication-manager>
<authentication-manager alias="userAuthenticationManager" xmlns="http://www.springframework.org/schema/security">
<authentication-provider>
<user-service>
<user name="username" password="password" authorities="ROLE_USER" />
</user-service>
</authentication-provider>
</authentication-manager>
<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>
<oauth:resource-server id="resourceServerFilter" resource-id="rest_server" token-services-ref="tokenServices" />
<oauth:client-details-service id="clientDetails">
<oauth:client client-id="the_client" secret="" scope="read,write" authorized-grant-types="password,refresh_token,client_credentials" authorities="ROLE_USER"/>
</oauth:client-details-service>
<http pattern="/rest/**" create-session="never" entry-point-ref="oauthAuthenticationEntryPoint" access-decision-manager-ref="accessDecisionManager" xmlns="http://www.springframework.org/schema/security">
<anonymous enabled="false" />
<intercept-url pattern="/rest/**" access="ROLE_USER" />
<custom-filter ref="resourceServerFilter" before="PRE_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
</http>
<bean id="tokenStore" class="org.springframework.security.oauth2.provider.token.store.InMemoryTokenStore" />
<bean id="tokenServices" class="org.springframework.security.oauth2.provider.token.DefaultTokenServices">
<property name="tokenStore" ref="tokenStore" />
<property name="supportRefreshToken" value="true" />
<property name="clientDetailsService" ref="clientDetails" />
<property name="accessTokenValiditySeconds" value="300" />
<property name="refreshTokenValiditySeconds" value="3600" />
</bean>
<bean id="accessDecisionManager" class="org.springframework.security.access.vote.UnanimousBased">
<constructor-arg>
<list>
<bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter" />
<bean class="org.springframework.security.access.vote.RoleVoter" />
<bean class="org.springframework.security.access.vote.AuthenticatedVoter" />
</list>
</constructor-arg>
</bean>
<bean id="oauthAuthenticationEntryPoint" class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="test" />
</bean>
<bean id="clientAuthenticationEntryPoint" class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="theRealm/client" />
<property name="typeName" value="Basic" />
</bean>
<bean id="clientCredentialsTokenEndpointFilter" class="org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter">
<property name="authenticationManager" ref="clientAuthenticationManager" />
</bean>
<bean id="clientDetailsUserService" class="org.springframework.security.oauth2.provider.client.ClientDetailsUserDetailsService">
<constructor-arg ref="clientDetails" />
</bean>
<bean id="oauthAccessDeniedHandler" class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler" />
<sec:global-method-security pre-post-annotations="enabled" proxy-target-class="true">
<sec:expression-handler ref="oauthExpressionHandler" />
</sec:global-method-security>
<oauth:expression-handler id="oauthExpressionHandler" />
<oauth:web-expression-handler id="oauthWebExpressionHandler" />
I don't think you can naturally do SSO with the password grant type. You're probably best with the authorization code flow. Oauth2 sso happens because both client apps check for the authenticated session on the authorization server and, if one has already logged in, the second app doesn't need to provide credentials again.
https://spring.io/blog/2015/02/03/sso-with-oauth2-angular-js-and-spring-security-part-v is a good example with angularjs and spring boot.
That is, if you want SSO, I think you'll need redirection to the authorization server for initial login.
Currently I use spring mvc oauth2 to secure my web application.
I tried to do curl -X POST "http://localhost:8080/project/oauth/token?client_id=the_client&grant_type=password&username=user&password=password&response_type=token"
I got reply.
{"error":"unauthorized","error_description":"There is no client authentication. Try adding an appropriate authentication filter."}
Then I checked the code of TokenEndpoint.java, It show the Principal is null.
The exception is Handling error: InsufficientAuthenticationException, There is no client authentication. Try adding an appropriate authentication filter.
Here is the spring-security.xml
<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oauth2="http://www.springframework.org/schema/security/oauth2"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:security="http://www.springframework.org/schema/security"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd http://www.springframework.org/schema/security/oauth2 http://www.springframework.org/schema/security/spring-security-oauth2.xsd">
<bean id="tokenStore"
class="org.springframework.security.oauth2.provider.token.store.InMemoryTokenStore" />
<bean id="tokenServices"
class="org.springframework.security.oauth2.provider.token.DefaultTokenServices">
<property name="tokenStore" ref="tokenStore" />
<property name="supportRefreshToken" value="true" />
</bean>
<bean id="clientAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint" />
<bean id="accessDeniedHandler"
class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler" />
<bean id="userApprovalHandler"
class="org.springframework.security.oauth2.provider.approval.DefaultUserApprovalHandler" />
<!--client -->
<bean id="clientDetailsService" class="oauth2.CustomJdbcClientDetailsService">
<constructor-arg index="0" ref="dataSource" />
</bean>
<bean id="clientDetailsUserDetailsService"
class="org.springframework.security.oauth2.provider.client.ClientDetailsUserDetailsService">
<constructor-arg ref="clientDetailsService" />
</bean>
<bean id="clientCredentialsTokenEndpointFilter"
class="org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter">
<property name="authenticationManager" ref="clientAuthenticationManager" />
</bean>
<security:authentication-manager id="clientAuthenticationManager">
<security:authentication-provider
user-service-ref="clientDetailsUserDetailsService" />
</security:authentication-manager>
<oauth2:authorization-server
client-details-service-ref="clientDetailsService" token-services-ref="tokenServices"
user-approval-handler-ref="userApprovalHandler">
<oauth2:authorization-code />
<oauth2:implicit />
<oauth2:refresh-token />
<oauth2:client-credentials />
<oauth2:password />
</oauth2:authorization-server>
<security:http pattern="/oauth/token" create-session="stateless">
<security:anonymous enabled="false" />
<security:http-basic entry-point-ref="clientAuthenticationEntryPoint" />
<security:custom-filter ref="clientCredentialsTokenEndpointFilter"
before="BASIC_AUTH_FILTER" />
<security:access-denied-handler ref="accessDeniedHandler" />
</security:http>
<!--client -->
<!--user -->
<bean id="userService" class="services.UserServicesImpl" />
<security:authentication-manager alias="authenticationManager">
<security:authentication-provider
user-service-ref="userService">
<!--<security:password-encoder hash="md5"/> -->
</security:authentication-provider>
</security:authentication-manager>
<!--user -->
<oauth2:resource-server id="mobileResourceServer"
resource-id="mobile-resource" token-services-ref="tokenServices" />
<bean id="accessDecisionManager" class="org.springframework.security.access.vote.UnanimousBased">
<constructor-arg>
<list>
<bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter" />
<bean class="org.springframework.security.access.vote.RoleVoter" />
<bean class="org.springframework.security.access.vote.AuthenticatedVoter" />
</list>
</constructor-arg>
</bean>
<security:http pattern="/rest/**" create-session="never"
entry-point-ref="clientAuthenticationEntryPoint"
access-decision-manager-ref="accessDecisionManager" use-expressions="false">
<security:anonymous enabled="false" />
<security:intercept-url pattern="/rest/**"
access="ROLE_DRIVER" />
<security:custom-filter ref="mobileResourceServer"
before="PRE_AUTH_FILTER" />
<security:access-denied-handler ref="accessDeniedHandler" />
</security:http>
I don't know why it is wrong, Please help me thanks.
You have to provide a query parameter named "client_secret" for the client authentication.
Below is the security.xml file, which I am using to incorporate spring-security-oauth2.
<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oauth="http://www.springframework.org/schema/security/oauth2"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:sec="http://www.springframework.org/schema/security" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/security/oauth2 http://www.springframework.org/schema/security/spring-security-oauth2-2.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.2.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd ">
<!-- #author Nagesh.Chauhan(neel4soft#gmail.com) -->
<!-- This is default url to get a token from OAuth -->
<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" />
<!-- 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>
<!-- This is where we tells spring security what URL should be protected
and what roles have access to them -->
<http pattern="/api/**" create-session="never"
entry-point-ref="oauthAuthenticationEntryPoint"
access-decision-manager-ref="accessDecisionManager"
xmlns="http://www.springframework.org/schema/security">
<anonymous enabled="false" />
<intercept-url pattern="/api/**" access="ROLE_APP" />
<custom-filter ref="resourceServerFilter" before="PRE_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
</http>
<bean id="oauthAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="test" />
</bean>
<bean id="clientAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="test/client" />
<property name="typeName" value="Basic" />
</bean>
<bean id="oauthAccessDeniedHandler"
class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler" />
<bean id="clientCredentialsTokenEndpointFilter"
class="org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter">
<property name="authenticationManager" ref="clientAuthenticationManager" />
</bean>
<bean id="accessDecisionManager" class="org.springframework.security.access.vote.UnanimousBased"
xmlns="http://www.springframework.org/schema/beans">
<constructor-arg>
<list>
<bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter" />
<bean class="org.springframework.security.access.vote.RoleVoter" />
<bean class="org.springframework.security.access.vote.AuthenticatedVoter" />
</list>
</constructor-arg>
</bean>
<authentication-manager id="clientAuthenticationManager"
xmlns="http://www.springframework.org/schema/security">
<authentication-provider user-service-ref="clientDetailsUserService" />
</authentication-manager>
<!-- This is simple authentication manager, with a hardcoded user/password
combination. We can replace this with a user defined service to get few users
credentials from DB -->
<authentication-manager alias="authenticationManager"
xmlns="http://www.springframework.org/schema/security">
<authentication-provider>
<user-service>
<user name="beingjavaguys" password="spring#java" authorities="ROLE_APP" />
</user-service>
</authentication-provider>
</authentication-manager>
<bean id="clientDetailsUserService"
class="org.springframework.security.oauth2.provider.client.ClientDetailsUserDetailsService">
<constructor-arg ref="clientDetails" />
</bean>
<!-- This defined token store, we have used inmemory tokenstore for now
but this can be changed to a user defined one -->
<bean id="tokenStore"
class="org.springframework.security.oauth2.provider.token.InMemoryTokenStore" />
<!-- This is where we defined token based configurations, token validity
and other things -->
<bean id="tokenServices"
class="org.springframework.security.oauth2.provider.token.DefaultTokenServices">
<property name="tokenStore" ref="tokenStore" />
<property name="supportRefreshToken" value="true" />
<property name="accessTokenValiditySeconds" value="120" />
<property name="clientDetailsService" ref="clientDetails" />
</bean>
<bean id="userApprovalHandler"
class="org.springframework.security.oauth2.provider.approval.TokenServicesUserApprovalHandler">
<property name="tokenServices" ref="tokenServices" />
</bean>
<oauth:authorization-server
client-details-service-ref="clientDetails" token-services-ref="tokenServices"
user-approval-handler-ref="userApprovalHandler">
<oauth:authorization-code />
<oauth:implicit />
<oauth:refresh-token />
<oauth:client-credentials />
<oauth:password />
</oauth:authorization-server>
<oauth:resource-server id="resourceServerFilter"
resource-id="test" token-services-ref="tokenServices" />
<oauth:client-details-service id="clientDetails">
<!-- client -->
<oauth:client client-id="restapp"
authorized-grant-types="authorization_code,client_credentials"
authorities="ROLE_APP" scope="read,write,trust" secret="secret" />
<oauth:client client-id="restapp"
authorized-grant-types="password,authorization_code,refresh_token,implicit"
secret="restapp" authorities="ROLE_APP" />
</oauth:client-details-service>
<sec:global-method-security
pre-post-annotations="enabled" proxy-target-class="true">
<!--you could also wire in the expression handler up at the layer of the
http filters. See https://jira.springsource.org/browse/SEC-1452 -->
<sec:expression-handler ref="oauthExpressionHandler" />
</sec:global-method-security>
<oauth:expression-handler id="oauthExpressionHandler" />
<oauth:web-expression-handler id="oauthWebExpressionHandler" />
As of now for getting the token I have to make the request in below format:
[http://localhost:8080/SpringRestSecurityOauth/oauth/token?grant_type=password&client_id=restapp&client_secret=restapp&username=beingjavaguys&password=spring#java]
Now I want the query paramters to be sent in json format like
{
"grant_type":"password",
"client_id":"restapp",
"client_secret":"restapp",
"username":"beingjavaguys",
"password":"spring#java"
}
What changes I have to do in spring-security.xml file so that I send query paramters in json?
AFAIK that is not supported out of the box. To do that you would have to write your own REST service interface.
However the format you suggest also seems less 'REST-like' then the supported version (a GET request should be used for retrieving information). At least if you see it as retrieving and not creating a token.
I have project based on Spring Security OAuth 2.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:oauth="http://www.springframework.org/schema/security/oauth2"
xmlns:sec="http://www.springframework.org/schema/security"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/security
http://www.springframework.org/schema/security/spring-security-3.2.xsd
http://www.springframework.org/schema/security/oauth2
http://www.springframework.org/schema/security/spring-security-oauth2-1.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd">
<!-- Definition of the Authentication Service -->
<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" after="BASIC_AUTH_FILTER"/>
<access-denied-handler ref="oauthAccessDeniedHandler"/>
</http>
<!-- Protected resources -->
<http pattern="/employee/**"
create-session="never"
entry-point-ref="oauthAuthenticationEntryPoint"
access-decision-manager-ref="accessDecisionManager"
xmlns="http://www.springframework.org/schema/security">
<anonymous enabled="false"/>
<intercept-url pattern="/employee/**"
access="ROLE_USER"/>
<custom-filter ref="resourceServerFilter"
before="PRE_AUTH_FILTER"/>
<access-denied-handler
ref="oauthAccessDeniedHandler"/>
</http>
<bean id="oauthAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="dstest"/>
</bean>
<bean id="clientAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="dstest/client"/>
<property name="typeName" value="Basic"/>
</bean>
<bean id="oauthAccessDeniedHandler"
class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler"/>
<bean id="clientCredentialsTokenEndpointFilter"
class="org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter">
<property name="authenticationManager" ref="clientAuthenticationManager"/>
</bean>
<bean id="accessDecisionManager" class="org.springframework.security.access.vote.UnanimousBased"
xmlns="http://www.springframework.org/schema/beans">
<constructor-arg>
<list>
<bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter"/>
<bean class="org.springframework.security.access.vote.RoleVoter"/>
<bean class="org.springframework.security.access.vote.AuthenticatedVoter"/>
</list>
</constructor-arg>
</bean>
<!-- Authentication in config file -->
<authentication-manager id="clientAuthenticationManager" xmlns="http://www.springframework.org/schema/security">
<authentication-provider user-service-ref="clientDetailsUserService"/>
</authentication-manager>
<authentication-manager alias="authenticationManager" xmlns="http://www.springframework.org/schema/security">
<authentication-provider>
<user-service id="userDetailsService">
<user name="admin" password="password" authorities="ROLE_USER"/>
</user-service>
</authentication-provider>
</authentication-manager>
<bean id="clientDetailsUserService"
class="org.springframework.security.oauth2.provider.client.ClientDetailsUserDetailsService">
<constructor-arg ref="clientDetails"/>
</bean>
<!-- Token Store -->
<bean id="tokenStore" class="org.springframework.security.oauth2.provider.token.InMemoryTokenStore"/>
<bean id="tokenServices" class="org.springframework.security.oauth2.provider.token.DefaultTokenServices">
<property name="tokenStore" ref="tokenStore"/>
<property name="supportRefreshToken" value="true"/>
<property name="clientDetailsService" ref="clientDetails"/>
<property name="accessTokenValiditySeconds" value="10"/>
</bean>
<bean id="userApprovalHandler"
class="org.springframework.security.oauth2.provider.approval.TokenServicesUserApprovalHandler">
<property name="tokenServices" ref="tokenServices"/>
</bean>
<!-- Token management -->
<oauth:authorization-server client-details-service-ref="clientDetails" token-services-ref="tokenServices"
user-approval-handler-ref="userApprovalHandler">
<oauth:authorization-code/>
<oauth:implicit/>
<oauth:refresh-token/>
<oauth:client-credentials/>
<oauth:password/>
</oauth:authorization-server>
<oauth:resource-server id="resourceServerFilter"
resource-id="dstest"
token-services-ref="tokenServices"/>
<!-- Client Definition -->
<oauth:client-details-service id="clientDetails">
<oauth:client client-id="my-trusted-client"
authorized-grant-types="password,authorization_code,refresh_token,implicit,redirect"
authorities="ROLE_CLIENT, ROLE_TRUSTED_CLIENT"
redirect-uri="/web"
scope="read,write,trust"
access-token-validity="30"
refresh-token-validity="600"/>
</oauth:client-details-service>
<sec:global-method-security pre-post-annotations="enabled" proxy-target-class="true">
<sec:expression-handler ref="oauthExpressionHandler"/>
</sec:global-method-security>
<oauth:expression-handler id="oauthExpressionHandler"/>
<oauth:web-expression-handler id="oauthWebExpressionHandler"/>
</beans>
I want to add Basic Authorozation for /oauth/token.
e.q. :
curl -v --user admin:password "http//localhost:8080/oauthtest/oauth/token?grant_type=password&client_if=my-tr
usted-client&client_secret=2343k242j"
(Authorization: Basic YWRtaW46cGFzc3dvcmQ= in header instead &username=admin&password=password params in url)
How can I do it?
I practice spring security oauth2 with client credentials grant type
Here is my xml files for spring security oauth
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oauth="http://www.springframework.org/schema/security/oauth2"
xmlns:sec="http://www.springframework.org/schema/security" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-4.0.xsd
http://www.springframework.org/schema/security/oauth2 http://www.springframework.org/schema/security/spring-security-oauth2-1.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd">
<sec:debug />
<oauth:authorization-server
client-details-service-ref="clientDetails" token-services-ref="tokenServices">
<oauth:client-credentials />
</oauth:authorization-server>
<sec:authentication-manager alias="clientAuthenticationManager">
<sec:authentication-provider
user-service-ref="clientDetailsUserService">
</sec:authentication-provider>
</sec:authentication-manager>
<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" />
<!-- include this only if you need to authenticate clients via request
parameters -->
<custom-filter ref="clientCredentialsTokenEndpointFilter"
before="BASIC_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
</http>
<oauth:resource-server id="resourceServerFilter"
resource-id="rest_server" token-services-ref="tokenServices" />
<oauth:client-details-service id="clientDetails">
<oauth:client client-id="abc" authorized-grant-types="client_credentials"
authorities="ROLE_RESTREAD" secret="123" />
</oauth:client-details-service>
<http pattern="/**" create-session="never" entry-point-ref="oauthAuthenticationEntryPoint"
access-decision-manager-ref="accessDecisionManager"
xmlns="http://www.springframework.org/schema/security">
<anonymous enabled="false" />
<intercept-url pattern="/prot**" access="ROLE_RESTREAD"
method="GET" />
<custom-filter ref="resourceServerFilter" before="PRE_AUTH_FILTER" />
<access-denied-handler ref="oauthAccessDeniedHandler" />
</http>
<bean id="tokenStore"
class="org.springframework.security.oauth2.provider.token.store.InMemoryTokenStore" />
<bean id="tokenServices"
class="org.springframework.security.oauth2.provider.token.DefaultTokenServices">
<property name="tokenStore" ref="tokenStore" />
<property name="supportRefreshToken" value="false" />
<property name="clientDetailsService" ref="clientDetails" />
<property name="accessTokenValiditySeconds" value="400000" />
<property name="refreshTokenValiditySeconds" value="0" />
</bean>
<bean id="accessDecisionManager" class="org.springframework.security.access.vote.UnanimousBased"
xmlns="http://www.springframework.org/schema/beans">
<constructor-arg>
<list>
<bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter" />
<bean class="org.springframework.security.access.vote.AuthenticatedVoter" />
<bean
class="org.springframework.security.web.access.expression.WebExpressionVoter" />
</list>
</constructor-arg>
</bean>
<bean id="oauthAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="theRealm" />
</bean>
<bean id="clientAuthenticationEntryPoint"
class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
<property name="realmName" value="theRealm/client" />
<property name="typeName" value="Basic" />
</bean>
<bean id="clientCredentialsTokenEndpointFilter"
class="org.springframework.security.oauth2.provider.client.ClientCredentialsTokenEndpointFilter">
<property name="authenticationManager" ref="clientAuthenticationManager" />
</bean>
<bean id="clientDetailsUserService"
class="org.springframework.security.oauth2.provider.client.ClientDetailsUserDetailsService">
<constructor-arg ref="clientDetails" />
</bean>
<bean id="oauthAccessDeniedHandler"
class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler" />
<sec:global-method-security
pre-post-annotations="enabled" proxy-target-class="true">
<sec:expression-handler ref="oauthExpressionHandler" />
</sec:global-method-security>
<oauth:expression-handler id="oauthExpressionHandler" />
<oauth:web-expression-handler id="oauthWebExpressionHandler" />
</beans>
And I test on mac terminal :
curl -X -v -d 'client_id=abc&client_secret=123&grant_type=client_credentials' -X POST "http://localhost:8080/WiBDA_User/oauth/token"
But got error :
{"error":"access_denied","error_description":"Expected CSRF token not found. Has your session expired?"}
Please tell me what's wrong??
Thank you.
As of Spring Security 4.0, CSRF protection is enabled by default with XML configuration. If you would like to disable CSRF protection, the corresponding XML configuration can be seen below.
<http>
<csrf disabled="true"/>
</http>
Source : http://docs.spring.io/spring-security/site/docs/current/reference/html/csrf.html#csrf-configure
UPDATE : Please update your code to the new java-config, it is easy to understand and configure.