Azure B2C OAuth 2.0 retrieval of claims

Chris S 21 Reputation points
2020-03-30T18:33:03.927+00:00

I have Azure B2C setup and have a requirement to use OAuth 2.0 to authenticate my application and retrieve user info.
I can authenticate but have no idea how to get the claims. I can not find any endpoint listed for doing so.

Thanks,

Please see Ian's post below regarding this issue.

Thanks,

Microsoft Entra External ID
Microsoft Entra External ID
A modern identity solution for securing access to customer, citizen and partner-facing apps and services. It is the converged platform of Azure AD External Identities B2B and B2C. Replaces Azure Active Directory External Identities.
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  1. AmanpreetSingh-MSFT 56,306 Reputation points
    2020-03-30T19:08:17.287+00:00

    @Chris S you need to use https://graph.microsoft.com/v1.0/me, which returns below information about authenticated user:

    6832-capture.jpg

    If the required claims are not listed here, you can use https://graph.microsoft.com/beta/me, which will return a lot more user attributes. However, if you would like to get specific set of claims, you can append the above urls with ?$select=attribute_name. For example, https://graph.microsoft.com/v1.0/me?$select=givenName,surname will only return firstname and surname of the user.

    In order to test it go to https://developer.microsoft.com/en-us/graph/graph-explorer# and sign in by clicking on Sign in with Microsoft button on the left side and make the above calls.

    -----------------------------------------------------------------------------------------------------------

    Please "Accept as answer" wherever the information provided helps you to help others in the community.

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  1. ianskilljar 1 Reputation point
    2020-04-02T22:48:49.217+00:00

    Hi @AmanpreetSingh-MSFT !

    My name is Ian and I'm working with Chris on implementing the OIDC/OAuth2 SSO connection between Skilljar (relying party) and Universal Avionics (Azure B2C / IdP) via the OAuth2 authorization code flow.

    We've gotten to a point where we've been able to successfully receive an access token, but we're currently blocked when trying to retrieve user details. We tried several different UserInfo endpoints, with the latest attempt being: https://graph.microsoft.com/beta/me.

    This is the response we get back:

    {u'error': {u'code': u'InvalidAuthenticationToken', u'message': u'Access token validation failure.', u'innerError': {u'date': u'2020-04-02T22:19:27', u'request-id': u'ddc15e61-2944-4d4f-819c-61573f465620'}}}

    We (Skilljar) do not yet have full support for OIDC, so we can't leverage the id_token for user claims, which is why we need to interface with a UserInfo endpoint.

    We've also been unsuccessful in finding helpful documentation around this.. For reference, here's all the configuration details:

    client_id = b2e65cba-4eb2-4520-8808-d1ef4627469d

    client_secret = [omitted]

    Auth URL = https://[omitted].b2clogin.com/[omitted].onmicrosoft.com/oauth2/v2.0/authorize?p=B2C_1_SkillJarSignin

    Token URL = https://[omitted].b2clogin.com/[omitted].onmicrosoft.com/oauth2/v2.0/token?p=B2C_1_SkillJarSignin

    UserInfo URL = https://graph.microsoft.com/beta/me

    scope = b2e65cba-4eb2-4520-8808-d1ef4627469d profile email openid

    (tenant id's have been omitted with [omitted])

    Can you help us determine if there's something we're missing? Does Azure B2C's OIDC/OAuth2 support a native UserInfo endpoint?
    We've been trying out the graph endpoints, but no luck..

    Thank you!
    Ian

  2. ianskilljar 1 Reputation point
    2020-04-06T22:48:41.78+00:00

    Hi @AmanpreetSingh-MSFT !

    Thank you for the response, just to clarify, this is the scope values we're using: scope = b2e65cba-4eb2-4520-8808-d1ef4627469d profile email openid.

    Since my last comment, we've been able to add support for validating and parsing the id_token (since Azure AD B2C doesn't support a native UserInfo, so we can skip that now!).

    What we're running into is validating the id_token signature. We're a client specific set up, where we securely store the client_secret in our backend, and are using it to validate the id_token signature. We also expect it to be signed with HS256.

    We've already asked Chris to check, but can you confirm if Azure B2C has support for signing the id_token with the HS256 algo, and if so, where in the B2C dashboard can he find that setting?

    Thank you!

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  3. AmanpreetSingh-MSFT 56,306 Reputation points
    2020-04-07T08:06:13.697+00:00

    @ianskilljar Azure AD B2C currently supports only RS256 for signing the Id_token. To confirm the same, you can go to the OIDC metadata endpoint of your User Flow by using below link and look for "id_token_signing_alg_values_supported" parameter.

    Metadata URL: https://[omitted].b2clogin.com/[omitted].onmicrosoft.com/v2.0/.well-known/openid-configuration?p=B2C_1_SkillJarSignin