OAuth2 client credentials
Use OAuth2 client credentials middleware to secure HTTP endpoints
The OAuth2 client credentials HTTP middleware enables the OAuth2 Client Credentials flow on a Web API without modifying the application. This design separates authentication/authorization concerns from the application, so that application operators can adopt and configure authentication/authorization providers without impacting the application code.
Component format
apiVersion: dapr.io/v1alpha1 kind: Component metadata: name: oauth2clientcredentials spec: type: middleware.http.oauth2clientcredentials version: v1 metadata: - name: clientId value: "<your client ID>" - name: clientSecret value: "<your client secret>" - name: scopes value: "https://www.googleapis.com/auth/userinfo.email" - name: tokenURL value: "https://accounts.google.com/o/oauth2/token" - name: headerName value: "authorization" - name: pathFilter value: ".*/users/.*" Warning
The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described here.Spec metadata fields
| Field | Details | Example |
|---|---|---|
| clientId | The client ID of your application that is created as part of a credential hosted by a OAuth-enabled platform | |
| clientSecret | The client secret of your application that is created as part of a credential hosted by a OAuth-enabled platform | |
| scopes | A list of space-delimited, case-sensitive strings of scopes which are typically used for authorization in the application | "https://www.googleapis.com/auth/userinfo.email" |
| tokenURL | The endpoint is used by the client to obtain an access token by presenting its authorization grant or refresh token | "https://accounts.google.com/o/oauth2/token" |
| headerName | The authorization header name to forward to your application | "authorization" |
| endpointParamsQuery | Specifies additional parameters for requests to the token endpoint | true |
| authStyle | Optionally specifies how the endpoint wants the client ID & client secret sent. See the table of possible values below | 0 |
| pathFilter | Applies the middleware only to requests matching the given path pattern | ".*/users/.*" |
Possible values for authStyle
| Value | Meaning |
|---|---|
1 | Sends the “client_id” and “client_secret” in the POST body as application/x-www-form-urlencoded parameters. |
2 | Sends the “client_id” and “client_secret” using HTTP Basic Authorization. This is an optional style described in the OAuth2 RFC 6749 section 2.3.1. |
0 | Means to auto-detect which authentication style the provider wants by trying both ways and caching the successful way for the future. |
Dapr configuration
To be applied, the middleware must be referenced in a configuration. See middleware pipelines.
apiVersion: dapr.io/v1alpha1 kind: Configuration metadata: name: appconfig spec: httpPipeline: handlers: - name: oauth2clientcredentials type: middleware.http.oauth2clientcredentials Request path filtering
The pathFilter field allows you to selectively apply OAuth2 authentication based on the HTTP request path using a regex pattern. This enables scenarios such as configuring multiple OAuth2 middlewares with different scopes for different API endpoints, implementing the least privilege principle by ensuring users only receive the minimum permissions necessary for their intended operation.
Example: Separate read-only and admin user access
In the following configuration:
- Requests to
/api/users/*endpoints receive tokens with a read-only user scopes - Requests to
/api/admin/*endpoints receive tokens with full admin scopes This reduces security risk by preventing unnecessary privilege access and limiting the blast radius of compromised tokens.
# User with read-only access scope apiVersion: dapr.io/v1alpha1 kind: Component metadata: name: oauth2clientcredentials-users spec: type: middleware.http.oauth2clientcredentials version: v1 metadata: - name: clientId value: "<your client ID>" - name: clientSecret value: "<your client secret>" - name: scopes value: "user:read profile:read" - name: tokenURL value: "https://accounts.google.com/o/oauth2/token" - name: headerName value: "authorization" - name: pathFilter value: "^/api/users/.*" --- # User with full admin access scope apiVersion: dapr.io/v1alpha1 kind: Component metadata: name: oauth2clientcredentials-admin spec: type: middleware.http.oauth2clientcredentials version: v1 metadata: - name: clientId value: "<your client ID>" - name: clientSecret value: "<your client secret>" - name: scopes value: "admin:read admin:write user:read user:write" - name: tokenURL value: "https://accounts.google.com/o/oauth2/token" - name: headerName value: "authorization" - name: pathFilter value: "^/api/admin/.*"