Spring Boot Oauth2 token request - Bad client credentials from BasicAuthenticationFilter - spring-boot

Question

Requesting help on a Spring Boot OAuth2 app's BadCredentialsException when , after user authentication and approval, my Oauth2 client app requests a token from the token endpoint of the OAuth2 AuthServer.
The Spring Boot OAuth2 applications are based off the now famous Dave Syer Spring Boot/ Oauth2 UI Client/Oauth2 AuthServer/JWT example https://github.com/spring-guides/tut-spring-security-and-angular-js/tree/master/oauth2
This is in the Client Apps' debug:
DEBUG org.springframework.web.client.RestTemplate - Created POST request for "authserver/uaa/oauth/token"
DEBUG org.springframework.security.oauth2.client.token.grant.code.AuthorizationCodeAccessTokenProvider - Encoding and sending form: {grant_type=[authorization_code], code=[xxxxx], redirect_uri=[oauthclientapp/login]}
DEBUG org.springframework.web.client.RestTemplate - POST request for "authserver/uaa/oauth/token" resulted in 200 (null)
DEBUG org.springframework.security.oauth2.client.filter.OAuth2ClientAuthenticationProcessingFilter - Authentication request failed: org.springframework.security.authentication.BadCredentialsException: Could not obtain access token
This is the AuthServer's debug:
DEBUG org.springframework.security.web.FilterChainProxy - /oauth/token at position 9 of 15 in additional filter chain; firing Filter: 'BasicAuthenticationFilter'
DEBUG org.springframework.security.web.authentication.www.BasicAuthenticationFilter - Basic Authentication Authorization header found for user 'clientID'
DEBUG org.springframework.security.authentication.ProviderManager - Authentication attempt using org.springframework.security.authentication.dao.DaoAuthenticationProvider
DEBUG org.springframework.security.authentication.dao.DaoAuthenticationProvider - User 'clientID' not found
DEBUG org.springframework.security.web.authentication.www.BasicAuthenticationFilter - Authentication request for failed: org.springframework.security.authentication.BadCredentialsException: Bad credentials
The Oauth2 client app is just like the one in the example, no customization in the token request process, just whatever #EnableOAuth2Sso gives us. The ClientDetails config on the AuthServer is also just like the example, sample below, so nothing special.
Any suggestions to better troubleshoot this are much appreciated. Thanks.
#Override
public void configure(ClientDetailsServiceConfigurer clients) throws Exception {
clients.inMemory()
.withClient("clientID")
.secret("acmesecret")
.authorizedGrantTypes("authorization_code", "refresh_token",
"password").scopes("openid");
}

Answer 1

I had the same error with your config when sending POST request to /oauth/token endpoint like this:
curl localhost:8080/oauth/token -d grant_type=authorization_code -d client_id=acme -d redirect_uri=http://localhost:4200/redirectUrl -d code=5chf5f
My intention was to use authorization code flow and I didn't want to provide the client_secret parameter which caused the error
-d client_sercret=acmesecret
If your situation is the same you may want to add another client with no secret for authorization code flow:
#Override
public void configure(ClientDetailsServiceConfigurer clients) throws Exception {
clients.inMemory()
.withClient("clientWithSecret")
.secret("acmesecret")
.authorizedGrantTypes("password")
.scopes("openid")
.and()
.withClient("clientNoSecret")
.authorizedGrantTypes("authorization_code", "refresh_token")
.scopes("openid");
}