Spring Security OAuth - Provider Manager is Not Configured for Null Resource

Question

Am trying to use Spring Secruity's OAuth API to obtain an access token from an externally published API.

This curl command works (and its contents are all that I need to obtain an access token):

curl -X POST \
https://api.app.com/v1/oauth/token \
  -H 'content-type: application/x-www-form-urlencoded' \
  -d'grant_type=client_credentials&client_id=bcfrtew123&client_secret=Y67493012'

Am able to obtain an access token from the external service after running this curl command.

When using Spring Security OAuth API:

<dependency>
   <groupId>org.springframework.security.oauth</groupId>
     <artifactId>spring-security-oauth2</artifactId>
     <version>2.1.1.RELEASE</version>
</dependency>

Setup my SpringMVC Controller's method like this:

@RequestMapping(value = "/getAccessToken", method = RequestMethod.POST, consumes="application/x-www-form-urlencoded")
public OAuth2AccessToken getAccessToken(@RequestParam(value="client_id", required=true) String clientId, @RequestParam(value="client_secret", required=true) String clientSecret) throws Exception {
    String tokenUri = "https://api.app.com/v1/oauth/token";

    ResourceOwnerPasswordResourceDetails resourceDetails = new ResourceOwnerPasswordResourceDetails();

    resourceDetails.setAccessTokenUri(tokenUri);
    resourceDetails.setClientId(clientId);
    resourceDetails.setClientSecret(clientSecret);
    resourceDetails.setGrantType("client_credentials");
    resourceDetails.setScope(Arrays.asList("read", "write"));

    DefaultOAuth2ClientContext clientContext = new DefaultOAuth2ClientContext();

    oauth2RestTemplate = new OAuth2RestTemplate(resourceDetails, clientContext);

    OAuth2AccessToken token = oauth2RestTemplate.getAccessToken();
    return token;
}

When I invoke the getAccessToken call from my local tomcat instance:

access_denied 
error_description=Unable to obtain a new access token for resource 'null'. 
The provider manager is not configured to support it.

Question(s):

1. What am I missing here? Is there some annotation required for this? Is there a property that is not set or is needed?

(Please notice that the content-type needs to be "application/x-www-form-urlencoded"...)

2. How can I mimic the working curl command using Spring Security OAuth API?

3. Could it be the default values that I have set in the RequestParameters?

4. If successful, how can I set it up so that access token is always preloaded before any request made?

Answer 1

The real reason is, you are using ResourceOwnerPasswordResourceDetails for a "client_credentials" access token request. We cannot interchange ResourceOwnerPasswordResourceDetails and ClientCredentialsResourceDetails.

In ClientCredentialsResourceDetails you need to set AccessTokenUri, ClientId, ClientSecret and grantType. In ResourceOwnerPasswordResourceDetails, you need to provide Username and Password along with AccessTokenUri, ClientId, ClientSecret and GrantType.

(Some authserver do accept password token request without username and password.. But I would say it is wrong)

Refer : Securing an existing API with our own solution