Configuration of Microsoft Graph OAuth2 authentication in Spring Security - Error AADSTS90014 - spring-security

Question

I am writing an SSO provider for MS Graph APIs Azure AD v2 endpoint leveraging Spring OAuth2.
I am progressing with the implementation and constant testing but I stumbled upon an error returned by AAD which is puzzling me. After all, this should all be plain standard OAuth 2 flow.
I successfully configured my application on MS dev portal, providing a localhost redirect URL (which, for the record, is the only supporting the http scheme. Kudos to MS). So when I invoke http://localhost/myapp/auth/office365 Spring security successfully intercepts the invocation, provides a correct redirect to my browser with client ID to https://login.microsoftonline.com/common/oauth2/v2.0/authorize with expected parameters.
Microsoft shows a consent screen to me, after which I get redirected back to my Spring Security application via HTTP GET with expected authorization code parameter.
The problem is that when the application tries to negotiate the given authorization code for a bearer token headaches start. Spring Security invokes a POST to https://login.microsoftonline.com/common/oauth2/v2.0/token but ends in 401 error.
Here is the stack trace
error="invalid_request", error_description="AADSTS90014: The request body must contain the following parameter: 'client_id'.
Trace ID: 9acd2a10-1cfb-443f-9c57-78d608c00c00
Correlation ID: bf063914-8926-4e8f-b102-7522d0e3b0af
Timestamp: 2017-10-09 15:51:44Z", correlation_id="bf063914-8926-4e8f-b102-7522d0e3b0af", error_codes="[90014]", timestamp="2017-10-09 15:51:44Z", trace_id="9acd2a10-1cfb-443f-9c57-78d608c00c00"
at org.springframework.security.oauth2.common.exceptions.OAuth2ExceptionJackson2Deserializer.deserialize(OAuth2ExceptionJackson2Deserializer.java:100)
at org.springframework.security.oauth2.common.exceptions.OAuth2ExceptionJackson2Deserializer.deserialize(OAuth2ExceptionJackson2Deserializer.java:33)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4001)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3072)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:235)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readInternal(AbstractJackson2HttpMessageConverter.java:215)
at org.springframework.http.converter.AbstractHttpMessageConverter.read(AbstractHttpMessageConverter.java:193)
at org.springframework.security.oauth2.client.token.OAuth2AccessTokenSupport$AccessTokenErrorHandler.handleError(OAuth2AccessTokenSupport.java:235)
at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:700)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:653)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:621)
at org.springframework.security.oauth2.client.token.OAuth2AccessTokenSupport.retrieveToken(OAuth2AccessTokenSupport.java:137)
at org.springframework.security.oauth2.client.token.grant.code.AuthorizationCodeAccessTokenProvider.obtainAccessToken(AuthorizationCodeAccessTokenProvider.java:209)
at org.springframework.security.oauth2.client.token.AccessTokenProviderChain.obtainNewAccessTokenInternal(AccessTokenProviderChain.java:148)
at org.springframework.security.oauth2.client.token.AccessTokenProviderChain.obtainAccessToken(AccessTokenProviderChain.java:121)
at org.springframework.security.oauth2.client.OAuth2RestTemplate.acquireAccessToken(OAuth2RestTemplate.java:221)
at org.springframework.security.oauth2.client.OAuth2RestTemplate.getAccessToken(OAuth2RestTemplate.java:173)
at org.springframework.security.oauth2.client.filter.OAuth2ClientAuthenticationProcessingFilter.attemptAuthentication(OAuth2ClientAuthenticationProcessingFilter.java:105)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:212)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
I have looked into Spring security implementation to find the cause,.
It happens that the error message error="invalid_request", error_description="AADSTS90014: The request body must contain the following parameter: 'client_id'. is self explanatory: MS Graph wants the client ID (which is still supplied by the basic authentication header) in the request body. Stop for a moment. I want to use plain old Spring Security and not third-party specific jars in order not to pollute my classpath.
Looking into Java source code of Spring OAuth 2 the problem is damn clear. Spring uses the client ID only in getParametersForAuthorizeRequest, which is used to generate the redirect URL. When it comes to getParametersForTokenRequest the client ID is not specified in the form.
Question: who is right here? How do I tell Spring that MS wants the client id in the token request after an authorization code has been obtained?

Answer 1

Just to clarify, you're not actually authenticating with or against Microsoft Graph. You're actually authenticating against Azure Active Directory. The Microsoft Graph API accepts the bearer token you'll end up with but it doesn't issue the access token itself.
It isn't clear which endpoint you're using for the Authorization Code flow, AAD has two of them: v1 and v2. The primary difference being that v2 uses a central registration and can authenticate both work/school and personal accounts.
Regardless of the endpoint, you do need to supply the clientid in the request body when you're requesting an access token. There are actually several values you need to provide in the body. Also note that these need to be provided as application/x-www-form-urlencoded.
For the v1 endpoint you provide (line breaks for readability only):
grant_type=authorization_code
&client_id={client-id}
&code={authoization-code}
&redirect_uri={redirect-uri}
&client_secret={client-secret}
&resource={resource-uri}
The v2 endpoint is almost identical but uses scope instead of resource:
grant_type=authorization_code
&client_id={client-id}
&code={authoization-code}
&redirect_uri={redirect-uri}
&client_secret={client-secret}
&scope={scopes}
OP's edit
Now, back to Spring Security. Spring by default uses an HTTP basic authentication scheme against Azure AD. In that scheme, the client ID and secret are encoded into the HTTP Authorization header, then the form only contains the authorization code and state parameter, so here is why I (the OP, ndr) was puzzled about why AAD refused the authorization.
In order to pass client ID and secret into the form, we can tell Spring Security to use a different supported authentication scheme. The form authentication scheme will push the client ID and secret into the form.
The below code works and retrieves the access token.
<oauth2:resource
id="msAdAuthenticationSource"
client-id="${oauth.appId}"
client-secret="${oauth.appSecret}"
type="authorization_code"
authentication-scheme="form"
client-authentication-scheme="form"
use-current-uri="true"
user-authorization-uri="${oauth.authorizationUri}"
access-token-uri="${oauth.accessTokenUri}"
scope="${oauth.scopes}"
pre-established-redirect-uri="${oauth.redirectUri}" />
Please note the two
authentication-scheme="form"
client-authentication-scheme="form"
Problem solved, a lot more to come!