Service to service calls using delegated user identity in the On-Behalf-Of flow

The OAuth 2.0 On-Behalf-Of (OBO) flow serves the use case where an application invokes a service/web API, which in turn needs to call another service/web API. The idea is to propagate the delegated user identity and permissions through the request chain. For the middle-tier service to make authenticated requests to the downstream service, it needs to secure an access token from Azure Active Directory (Azure AD), on behalf of the user.

Important

Public clients that use the OAuth 2.0 implicit grant cannot use the OBO flow. These clients must pass their access token to a middle-tier confidential client to perform OBO flows. For more info about which clients can perform OBO calls, see Client limitations.

On-Behalf-Of flow diagram

Assume that the user has been authenticated on an application using the OAuth 2.0 authorization code grant flow. At this point, the application has an access token (token A) with the user’s claims and consent to access the middle-tier web API (API A). Now, API A needs to make an authenticated request to the downstream web API (API B).

The steps that follow constitute the On-Behalf-Of flow and are explained with the help of the following diagram.

OAuth2.0 On-Behalf-Of Flow

  1. The client application makes a request to API A with the token A.
  2. API A authenticates to the Azure AD token issuance endpoint and requests a token to access API B.
  3. The Azure AD token issuance endpoint validates API A's credentials with token A and issues the access token for API B (token B).
  4. The token B is set in the authorization header of the request to API B.
  5. Data from the secured resource is returned by API B.

Register the application and service in Azure AD

Register both the client application and the middle-tier service in Azure AD.

Register the middle-tier service

  1. Sign in to the Azure portal.
  2. On the top bar, click on your account and under the Directory list, choose the Active Directory tenant where you wish to register your application.
  3. Click on More Services in the left hand nav, and choose Azure Active Directory.
  4. Click on App registrations and choose New application registration.
  5. Enter a friendly name for the application, and select the application type. Based on the application type set the sign-on URL or redirect URL to the base URL. Click on Create to create the application.
  6. While still in the Azure portal, choose your application and click on Settings. From the Settings menu, choose Keys and add a key - select a key duration of either 1 year or 2 years. When you save this page, the key value will be displayed, copy and save the value in a safe location - you will need this key later to configure the application settings in your implementation - this key value will not be displayed again, nor retrievable by any other means, so please record it as soon as it is visible from the Azure Portal.

Register the client application

  1. Sign in to the Azure portal.
  2. On the top bar, click on your account and under the Directory list, choose the Active Directory tenant where you wish to register your application.
  3. Click on More Services in the left hand nav, and choose Azure Active Directory.
  4. Click on App registrations and choose New application registration.
  5. Enter a friendly name for the application, and select the application type. Based on the application type set the sign-on URL or redirect URL to the base URL. Click on Create to create the application.
  6. Configure Permissions for your application - in the Settings menu, choose the Required permissions section, click on Add, then Select an API, and type the name of the middle-tier service in the textbox. Then, click on Select Permissions and select 'Access service name'.

Configure known client applications

In this scenario, the middle-tier service has no user interaction to obtain the user's consent to access the downstream API. Therefore, the option to grant access to the downstream API must be presented upfront as a part of the consent step during authentication. To achieve this, follow the steps below to explicitly bind the client app's registration in Azure AD with the registration of the middle-tier service, which merges the consent required by both the client and middle-tier into a single dialog.

  1. Navigate to the middle-tier service registration, and click on Manifest to open the manifest editor.
  2. In the manifest, locate the knownClientApplications array property, and add the Client ID of the client application as an element.
  3. Save the manifest by clicking the save button.

Service to service access token request

To request an access token, make an HTTP POST to the tenant-specific Azure AD endpoint with the following parameters.

https://login.microsoftonline.com/<tenant>/oauth2/token

There are two cases depending on whether the client application chooses to be secured by a shared secret, or a certificate.

First case: Access token request with a shared secret

When using a shared secret, a service-to-service access token request contains the following parameters:

Parameter Description
grant_type required The type of the token request. For a request using a JWT, the value must be urn:ietf:params:oauth:grant-type:jwt-bearer.
assertion required The value of the token used in the request.
client_id required The App ID assigned to the calling service during registration with Azure AD. To find the App ID in the Azure Management Portal, click Active Directory, click the directory, and then click the application name.
client_secret required The key registered for the calling service in Azure AD. This value should have been noted at the time of registration.
resource required The App ID URI of the receiving service (secured resource). To find the App ID URI, in the Azure Management Portal, click Active Directory, click the directory, click the application name, click All settings and then click Properties.
requested_token_use required Specifies how the request should be processed. In the On-Behalf-Of flow, the value must be on_behalf_of.
scope required A space separated list of scopes for the token request. For OpenID Connect, the scope openid must be specified.

Example

The following HTTP POST requests an access token for the https://graph.windows.net web API. The client_id identifies the service that requests the access token.

// line breaks for legibility only

POST /oauth2/token HTTP/1.1
Host: login.microsoftonline.com
Content-Type: application/x-www-form-urlencoded

grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Ajwt-bearer
&client_id=625391af-c675-43e5-8e44-edd3e30ceb15
&client_secret=0Y1W%2BY3yYb3d9N8vSjvm8WrGzVZaAaHbHHcGbcgG%2BoI%3D
&resource=https%3A%2F%2Fgraph.windows.net
&assertion=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1dCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCIsImtpZCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCJ9.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.R-Ke-XO7lK0r5uLwxB8g5CrcPAwRln5SccJCfEjU6IUqpqcjWcDzeDdNOySiVPDU_ZU5knJmzRCF8fcjFtPsaA4R7vdIEbDuOur15FXSvE8FvVSjP_49OH6hBYqoSUAslN3FMfbO6Z8YfCIY4tSOB2I6ahQ_x4ZWFWglC3w5mK-_4iX81bqi95eV4RUKefUuHhQDXtWhrSgIEC0YiluMvA4TnaJdLq_tWXIc4_Tq_KfpkvI004ONKgU7EAMEr1wZ4aDcJV2yf22gQ1sCSig6EGSTmmzDuEPsYiyd4NhidRZJP4HiiQh-hePBQsgcSgYGvz9wC6n57ufYKh2wm_Ti3Q
&requested_token_use=on_behalf_of
&scope=openid

Second case: Access token request with a certificate

A service-to-service access token request with a certificate contains the following parameters:

Parameter Description
grant_type required The type of the token request. For a request using a JWT, the value must be urn:ietf:params:oauth:grant-type:jwt-bearer.
assertion required The value of the token used in the request.
client_id required The App ID assigned to the calling service during registration with Azure AD. To find the App ID in the Azure Management Portal, click Active Directory, click the directory, and then click the application name.
client_assertion_type required The value must be urn:ietf:params:oauth:client-assertion-type:jwt-bearer
client_assertion required An assertion (a JSON Web Token) that you need to create and sign with the certificate you registered as credentials for your application. Read about certificate credentials to learn how to register your certificate and the format of the assertion.
resource required The App ID URI of the receiving service (secured resource). To find the App ID URI, in the Azure Management Portal, click Active Directory, click the directory, click the application name, click All settings and then click Properties.
requested_token_use required Specifies how the request should be processed. In the On-Behalf-Of flow, the value must be on_behalf_of.
scope required A space separated list of scopes for the token request. For OpenID Connect, the scope openid must be specified.

Notice that the parameters are almost the same as in the case of the request by shared secret except that the client_secret parameter is replaced by two parameters: a client_assertion_type and client_assertion.

Example

The following HTTP POST requests an access token for the https://graph.windows.net web API with a certificate. The client_id identifies the service that requests the access token.

// line breaks for legibility only

POST /oauth2/token HTTP/1.1
Host: login.microsoftonline.com
Content-Type: application/x-www-form-urlencoded

grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Ajwt-bearer
&client_id=625391af-c675-43e5-8e44-edd3e30ceb15
&client_assertion_type=urn%3Aietf%3Aparams%3Aoauth%3Aclient-assertion-type%3Ajwt-bearer
&client_assertion=eyJhbGciOiJSUzI1NiIsIng1dCI6Imd4OHRHeXN5amNScUtqRlBuZDdSRnd2d1pJMCJ9.eyJ{a lot of characters here}M8U3bSUKKJDEg
&resource=https%3A%2F%2Fgraph.windows.net
&assertion=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1dCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCIsImtpZCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCJ9.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.R-Ke-XO7lK0r5uLwxB8g5CrcPAwRln5SccJCfEjU6IUqpqcjWcDzeDdNOySiVPDU_ZU5knJmzRCF8fcjFtPsaA4R7vdIEbDuOur15FXSvE8FvVSjP_49OH6hBYqoSUAslN3FMfbO6Z8YfCIY4tSOB2I6ahQ_x4ZWFWglC3w5mK-_4iX81bqi95eV4RUKefUuHhQDXtWhrSgIEC0YiluMvA4TnaJdLq_tWXIc4_Tq_KfpkvI004ONKgU7EAMEr1wZ4aDcJV2yf22gQ1sCSig6EGSTmmzDuEPsYiyd4NhidRZJP4HiiQh-hePBQsgcSgYGvz9wC6n57ufYKh2wm_Ti3Q
&requested_token_use=on_behalf_of
&scope=openid

Service to service access token response

A success response is a JSON OAuth 2.0 response with the following parameters.

Parameter Description
token_type Indicates the token type value. The only type that Azure AD supports is Bearer. For more information about bearer tokens, see the OAuth 2.0 Authorization Framework: Bearer Token Usage (RFC 6750).
scope The scope of access granted in the token.
expires_in The length of time the access token is valid (in seconds).
expires_on The time when the access token expires. The date is represented as the number of seconds from 1970-01-01T0:0:0Z UTC until the expiration time. This value is used to determine the lifetime of cached tokens.
resource The App ID URI of the receiving service (secured resource).
access_token The requested access token. The calling service can use this token to authenticate to the receiving service.
id_token The requested id token. The calling service can use this to verify the user's identity and begin a session with the user.
refresh_token The refresh token for the requested access token. The calling service can use this token to request another access token after the current access token expires.

Success response example

The following example shows a success response to a request for an access token for the https://graph.windows.net web API.

{
    "token_type":"Bearer",
    "scope":"User.Read",
    "expires_in":"43482",
    "ext_expires_in":"302683",
    "expires_on":"1493466951",
    "not_before":"1493423168",
    "resource":"https://graph.windows.net",
    "access_token":"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1dCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCIsImtpZCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCJ9.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.cqmUVjfVbqWsxJLUI1Z4FRx1mNQAHP-L0F4EMN09r8FY9bIKeO-0q1eTdP11Nkj_k4BmtaZsTcK_mUygdMqEp9AfyVyA1HYvokcgGCW_Z6DMlVGqlIU4ssEkL9abgl1REHElPhpwBFFBBenOk9iHddD1GddTn6vJbKC3qAaNM5VarjSPu50bVvCrqKNvFixTb5bbdnSz-Qr6n6ACiEimiI1aNOPR2DeKUyWBPaQcU5EAK0ef5IsVJC1yaYDlAcUYIILMDLCD9ebjsy0t9pj_7lvjzUSrbMdSCCdzCqez_MSNxrk1Nu9AecugkBYp3UVUZOIyythVrj6-sVvLZKUutQ",
    "refresh_token":"AQABAAAAAABnfiG-mA6NTae7CdWW7QfdjKGu9-t1scy_TDEmLi4eLQMjJGt_nAoVu6A4oSu1KsRiz8XyQIPKQxSGfbf2FoSK-hm2K8TYzbJuswYusQpJaHUQnSqEvdaCeFuqXHBv84wjFhuanzF9dQZB_Ng5za9xKlUENrNtlq9XuLNVKzxEyeUM7JyxzdY7JiEphWImwgOYf6II316d0Z6-H3oYsFezf4Xsjz-MOBYEov0P64UaB5nJMvDyApV-NWpgklLASfNoSPGb67Bc02aFRZrm4kLk-xTl6eKE6hSo0XU2z2t70stFJDxvNQobnvNHrAmBaHWPAcC3FGwFnBOojpZB2tzG1gLEbmdROVDp8kHEYAwnRK947Py12fJNKExUdN0njmXrKxNZ_fEM33LHW1Tf4kMX_GvNmbWHtBnIyG0w5emb-b54ef5AwV5_tGUeivTCCysgucEc-S7G8Cz0xNJ_BOiM_4bAv9iFmrm9STkltpz0-Tftg8WKmaJiC0xXj6uTf4ZkX79mJJIuuM7XP4ARIcLpkktyg2Iym9jcZqymRkGH2Rm9sxBwC4eeZXM7M5a7TJ-5CqOdfuE3sBPq40RdEWMFLcrAzFvP0VDR8NKHIrPR1AcUruat9DETmTNJukdlJN3O41nWdZOVoJM-uKN3uz2wQ2Ld1z0Mb9_6YfMox9KTJNzRzcL52r4V_y3kB6ekaOZ9wQ3HxGBQ4zFt-2U0mSszIAA",
    "id_token":"eyJ0eXAiOiJKV1QiLCJhbGciOiJub25lIn0.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."
}

Error response example

An error response is returned by Azure AD token endpoint when trying to acquire an access token for the downstream API, if the downstream API has a conditional access policy such as multi-factor authentication set on it. The middle-tier service should surface this error to the client application so that the client application can provide the user interaction to satisfy the conditional access policy.

{
    "error":"interaction_required",
    "error_description":"AADSTS50079: Due to a configuration change made by your administrator, or because you moved to a new location, you must enroll in multi-factor authentication to access 'bf8d80f9-9098-4972-b203-500f535113b1'.\r\nTrace ID: b72a68c3-0926-4b8e-bc35-3150069c2800\r\nCorrelation ID: 73d656cf-54b1-4eb2-b429-26d8165a52d7\r\nTimestamp: 2017-05-01 22:43:20Z",
    "error_codes":[50079],
    "timestamp":"2017-05-01 22:43:20Z",
    "trace_id":"b72a68c3-0926-4b8e-bc35-3150069c2800",
    "correlation_id":"73d656cf-54b1-4eb2-b429-26d8165a52d7",
    "claims":"{\"access_token\":{\"polids\":{\"essential\":true,\"values\":[\"9ab03e19-ed42-4168-b6b7-7001fb3e933a\"]}}}"
}

Use the access token to access the secured resource

Now the middle-tier service can use the token acquired above to make authenticated requests to the downstream web API, by setting the token in the Authorization header.

Example

GET /me?api-version=2013-11-08 HTTP/1.1
Host: graph.windows.net
Authorization: Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1dCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCIsImtpZCI6InowMzl6ZHNGdWl6cEJmQlZLMVRuMjVRSFlPMCJ9.eyJhdWQiOiJodHRwczovL2dyYXBoLndpbmRvd3MubmV0IiwiaXNzIjoiaHR0cHM6Ly9zdHMud2luZG93cy5uZXQvMjYwMzljY2UtNDg5ZC00MDAyLTgyOTMtNWIwYzUxMzRlYWNiLyIsImlhdCI6MTQ5MzQyMzE2OCwibmJmIjoxNDkzNDIzMTY4LCJleHAiOjE0OTM0NjY5NTEsImFjciI6IjEiLCJhaW8iOiJBU1FBMi84REFBQUE1NnZGVmp0WlNjNWdBVWwrY1Z0VFpyM0VvV2NvZEoveWV1S2ZqcTZRdC9NPSIsImFtciI6WyJwd2QiXSwiYXBwaWQiOiI2MjUzOTFhZi1jNjc1LTQzZTUtOGU0NC1lZGQzZTMwY2ViMTUiLCJhcHBpZGFjciI6IjEiLCJlX2V4cCI6MzAyNjgzLCJmYW1pbHlfbmFtZSI6IlRlc3QiLCJnaXZlbl9uYW1lIjoiTmF2eWEiLCJpcGFkZHIiOiIxNjcuMjIwLjEuMTc3IiwibmFtZSI6Ik5hdnlhIFRlc3QiLCJvaWQiOiIxY2Q0YmNhYy1iODA4LTQyM2EtOWUyZi04MjdmYmIxYmI3MzkiLCJwbGF0ZiI6IjMiLCJwdWlkIjoiMTAwMzNGRkZBMTJFRDdGRSIsInNjcCI6IlVzZXIuUmVhZCIsInN1YiI6IjNKTUlaSWJlYTc1R2hfWHdDN2ZzX0JDc3kxa1l1ekZKLTUyVm1Zd0JuM3ciLCJ0aWQiOiIyNjAzOWNjZS00ODlkLTQwMDItODI5My01YjBjNTEzNGVhY2IiLCJ1bmlxdWVfbmFtZSI6Im5hdnlhQGRkb2JhbGlhbm91dGxvb2sub25taWNyb3NvZnQuY29tIiwidXBuIjoibmF2eWFAZGRvYmFsaWFub3V0bG9vay5vbm1pY3Jvc29mdC5jb20iLCJ1dGkiOiJ4Q3dmemhhLVAwV0pRT0x4Q0dnS0FBIiwidmVyIjoiMS4wIn0.cqmUVjfVbqWsxJLUI1Z4FRx1mNQAHP-L0F4EMN09r8FY9bIKeO-0q1eTdP11Nkj_k4BmtaZsTcK_mUygdMqEp9AfyVyA1HYvokcgGCW_Z6DMlVGqlIU4ssEkL9abgl1REHElPhpwBFFBBenOk9iHddD1GddTn6vJbKC3qAaNM5VarjSPu50bVvCrqKNvFixTb5bbdnSz-Qr6n6ACiEimiI1aNOPR2DeKUyWBPaQcU5EAK0ef5IsVJC1yaYDlAcUYIILMDLCD9ebjsy0t9pj_7lvjzUSrbMdSCCdzCqez_MSNxrk1Nu9AecugkBYp3UVUZOIyythVrj6-sVvLZKUutQ

Client limitations

Public clients with wildcard reply URLs cannot use an id_token for OBO flows. However, a confidential client can still redeem access tokens acquired through the implicit grant flow even if the public client has a wildcard redirect URI registered.

Next steps

Learn more about the OAuth 2.0 protocol and another way to perform service to service auth using client credentials.