--- id: ms_entra_id title: Microsoft Entra ID --- Provider for Microsoft Entra ID. Fully compliant with OIDC, with support for group overage and multi-tenant apps. ## Config Options The provider is OIDC-compliant, so all the OIDC parameters are honored. Additional provider-specific configuration parameters are: | Flag | Toml Field | Type | Description | Default | | --------------------------- | -------------------------- | -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- | | `--entra-id-allowed-tenant` | `entra_id_allowed_tenants` | string \| list | List of allowed tenants. In case of multi-tenant apps, incoming tokens are issued by different issuers and OIDC issuer verification needs to be disabled. When not specified, all tenants are allowed. Redundant for single-tenant apps (regular ID token validation matches the issuer). | | | `--entra-id-federated-token-auth` | `entra_id_federated_token_auth` | boolean | Enable oAuth2 client authentication with federated token projected by Entra Workload Identity plugin, instead of client secret. | false | ## Configure App registration To begin, create an App registration, set a redirect URI, and generate a secret. All account types are supported, including single-tenant, multi-tenant, multi-tenant with Microsoft accounts, and Microsoft accounts only.
See Azure Portal example
See Terraform example ``` resource "azuread_application" "auth" { display_name = "oauth2-proxy" sign_in_audience = "AzureADMyOrg" # Others are also supported web { redirect_uris = [ "https://podinfo.lakis.tech/oauth2/callback", ] } // We don't specify any required API permissions - we allow user consent only } resource "azuread_service_principal" "sp" { client_id = azuread_application.auth.client_id app_role_assignment_required = false } resource "azuread_service_principal_password" "pass" { service_principal_id = azuread_service_principal.sp.id } ```
### Configure groups If you want to make use of groups, you can configure *groups claim* to be present in ID Tokens issued by the App registration.
See Azure Portal example
See Terraform example ``` resource "azuread_application" "auth" { display_name = "oauth2-proxy" sign_in_audience = "AzureADMyOrg" group_membership_claims = [ "SecurityGroup" ] web { redirect_uris = [ "https://podinfo.lakis.tech/oauth2/callback", ] } } resource "azuread_service_principal" "sp" { client_id = azuread_application.auth.client_id app_role_assignment_required = false } resource "azuread_service_principal_password" "pass" { service_principal_id = azuread_service_principal.sp.id } ```
### Scopes and claims For single-tenant and multi-tenant apps without groups, the only required scope is `openid` (See: [Scopes and permissions](https://learn.microsoft.com/en-us/entra/identity-platform/scopes-oidc#the-openid-scope)). To make use of groups - for example use `allowed_groups` setting or authorize based on groups inside your service - you need to enable *groups claims* in the App Registration. When enabled, list of groups is present in the issued ID token. No additional scopes are required besides `openid`. This works up to 200 groups. When user has more than 200 group memberships, OAuth2-Proxy attempts to retrieve the complete list from Microsoft Graph API's [`transitiveMemberOf`](https://learn.microsoft.com/en-us/graph/api/user-list-transitivememberof). Endpoint requires `User.Read` scope (delegated permission). This permission can be by default consented by user during first login. Set scope to `openid User.Read` to request user consent. Without proper scope, user with 200+ groups will authenticate with 0 groups. See: [group overages](https://learn.microsoft.com/en-us/security/zero-trust/develop/configure-tokens-group-claims-app-roles#group-overages). Alternatively to user consent, both `openid` and `User.Read` permissions can be consented by admistrator. Then, user is not asked for consent on the first login, and group overage works with `openid` scope only. Admin consent can also be required for some tenants. It can be granted with [azuread_service_principal_delegated_permission_grant](https://registry.terraform.io/providers/hashicorp/azuread/latest/docs/resources/service_principal_delegated_permission_grant) terraform resource. For personal microsoft accounts, required scope is `openid profile email`. See: [Overview of permissions and consent in the Microsoft identity platform](https://learn.microsoft.com/en-us/entra/identity-platform/permissions-consent-overview). ### Multi-tenant apps To authenticate apps from multiple tenants (including personal Microsoft accounts), set the common OIDC issuer url and disable verification: ```toml oidc_issuer_url=https://login.microsoftonline.com/common/v2.0 insecure_oidc_skip_issuer_verification=true ``` `insecure_oidc_skip_issuer_verification` setting is required to disable following checks: * Startup check for matching issuer URL returned from [discovery document](https://login.microsoftonline.com/common/v2.0/.well-known/openid-configuration) with `oidc_issuer_url` setting. Required, as document's `issuer` field doesn't equal to `https://login.microsoftonline.com/common/v2.0`. See [OIDC Discovery 4.3](https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfigurationValidation). * Matching ID token's `issuer` claim with `oidc_issuer_url` setting during ID token validation. Required to support tokens issued by diffrerent tenants. See [OIDC Core 3.1.3.7](https://openid.net/specs/openid-connect-core-1_0.html#IDTokenValidation). To provide additional security, Entra ID provider performs check on the ID token's `issuer` claim to match the `https://login.microsoftonline.com/{tenant-id}/v2.0` template. ### Workload Identity Provider supports authentication with federated token, without need of using client secret. Following conditions have to be met: * Cluster has public OIDC provider URL. For major cloud providers, it can be enabled with a single flag, for example for [Azure Kubernetes Service deployed with Terraform](https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/kubernetes_cluster), it's `oidc_issuer_enabled`. * Workload Identity admission webhook is deployed on the cluster. For AKS, it can be enabled with a flag (`workload_identity_enabled` in Terraform resource), for clusters outside of Azure, it can be installed from [helm chart](https://github.com/Azure/azure-workload-identity). * Appropriate federated credential is added to application registration.
See federated credential terraform example ``` resource "azuread_application_federated_identity_credential" "fedcred" { application_id = azuread_application.application.id # ID of your application display_name = "federation-cred" description = "Workload identity for oauth2-proxy" audiences = ["api://AzureADTokenExchange"] # Fixed value issuer = "https://cluster-oidc-issuer-url..." subject = "system:serviceaccount:oauth2-proxy-namespace-name:oauth2-proxy-sa-name" # set proper NS and SA name } ```
* Kubernetes service account associated with oauth2-proxy deployment, is annotated with `azure.workload.identity/client-id: ` * oauth2-proxy pod is labeled with `azure.workload.identity/use: "true"` * oauth2-proxy is configured with `entra_id_federated_token_auth` set to `true`. `client_secret` setting can be omitted when using federated token authentication. See: [Azure Workload Identity documentation](https://azure.github.io/azure-workload-identity/docs/). ### Example configurations Single-tenant app without groups (*groups claim* not enabled). Consider using generic OIDC provider: ```toml provider="entra-id" oidc_issuer_url="https://login.microsoftonline.com//v2.0" client_id="" client_secret="" scope="openid" ``` Single-tenant app with up to 200 groups (*groups claim* enabled). Consider using generic OIDC provider: ```toml provider="entra-id" oidc_issuer_url="https://login.microsoftonline.com//v2.0" client_id="" client_secret="" scope="openid" allowed_groups=["ac51800c-2679-4ecb-8130-636380a3b491"] ``` Single-tenant app with more than 200 groups: ```toml provider="entra-id" oidc_issuer_url="https://login.microsoftonline.com//v2.0" client_id="" client_secret="" scope="openid User.Read" allowed_groups=["968b4844-d5e7-4e18-a834-59927959369f"] ``` Single-tenant app with more than 200 groups and workload identity enabled: ```toml provider="entra-id" oidc_issuer_url="https://login.microsoftonline.com//v2.0" client_id="" scope="openid User.Read" allowed_groups=["968b4844-d5e7-4e18-a834-59927959369f"] entra_id_federated_token_auth=true ``` Multi-tenant app with Microsoft personal accounts & one Entra tenant allowed, with group overage considered: ```toml provider="entra-id" oidc_issuer_url="https://login.microsoftonline.com/common/v2.0" client_id="" client_secret="" insecure_oidc_skip_issuer_verification=true scope="openid profile email User.Read" entra_id_allowed_tenants=["9188040d-6c67-4c5b-b112-36a304b66dad",""] # Allow only and Personal MS Accounts tenant email_domains="*" ```