API Authorization

All requests to the API server must have an API token. API tokens can be issued by going though the login flow, or created via the API. At this time, only browser based applications can perform login from email/password. Command line applications and services must use an API token provided via the ARVADOS_API_TOKEN environment variable or configuration file.

Browser login

Browser based applications can perform log in via the following highlevel flow:

  1. The web application presents a “login” link to /login on the API server with a return_to parameter provided in the query portion of the URL. For example https://qr1hi.arvadosapi.com/login?return_to=XXX , where return_to=XXX is the URL of the login page for the web application.
  2. The “login” link takes the browser to the login page (this may involve several redirects)
  3. The user logs in. API server authenticates the user and issues a new API token.
  4. The browser is redirected to the login page URL provided in return_to=XXX with the addition of ?api_token=xxxxapitokenxxxx.
  5. The web application gets the login request with the included authorization token.

The browser authentication process is documented in detail on the Arvados wiki.

Creating tokens via the API

The browser login method above issues a new token. Using that token, it is possible to make API calls to create additional tokens. To do so, use the create method of the API client authorizations resource.

Trusted API clients

The api_clients resource determines if web applications that have gone through the browser login flow may create or list API tokens.

After the user has authenticated, but before an authorization token is issued and browser redirect sent (sending the browser back to the return_to login page bearing api_token), the server strips the path and query portion from return_to to get url_prefix. The url_prefix is used to find or create an ApiClient object. The newly issued API client authorization (API token) is associated with this ApiClient object.

API clients may be marked as “trusted” by making an API call to create or update an api_clients resource and set the is_trusted flag to true. An authorization token associated with a “trusted” client is permitted to list authorization tokens on API client authorizations .

A authorization token which is not associated with a trusted client may only use the current method to query its own api_client_authorization object. The “untrusted” token is forbidden performing any other operations on API client authorizations, such as listing other authorizations or creating new authorizations.

Authorization tokens which are not issued via the browser login flow (created directly via the API) will not have an associated api client. This means authorization tokens created via the API are always “untrusted”.

Scopes

Scopes can restrict a token so it may only access certain resources. This is in addition to normal permission checks for the user associated with the token.

Each entry in scopes consists of a request_method and request_path, where the request_method is a HTTP method (one of GET, POST, PUT or DELETE) and request_path is the request URI. A given request is permitted if it matches a scopes exactly, or the scope ends with / and the request string is a prefix of the scope.

As a special case, a scope of [“all”] allows all resources.

Scope examples

A scope of GET /arvados/v1/collections permits listing collections.

  • Requests with different methods, such as creating a new collection using POST /arvados/v1/collections, will be rejected.
  • Requests to access other resources, such as GET /arvados/v1/groups, will be rejected.
  • Be aware that requests for specific records, such as GET /arvados/v1/collections/962eh-4zz18-xi32mpz2621o8km will also be rejected. This is because the scope GET /arvados/v1/collections does not end in /

A scope of GET /arvados/v1/collections/ (with / suffix) will permit access to individual collections.

  • The request GET /arvados/v1/collections/962eh-4zz18-xi32mpz2621o8km will succeed
  • Be aware that requests for listing GET /arvados/v1/collections (no / suffix) will be rejected, because it is not a match with the rule GET /arvados/v1/collections/
  • A listing request GET /arvados/v1/collections/ will have the trailing / suffix trimmed before the scope check, as a result it will not match the rule GET /arvados/v1/collections/.

To allow both listing objects and requesting individual objects, include both in the scope: ["GET /arvados/v1/collections", "GET /arvados/v1/collections/"]

A narrow scope such as GET /arvados/v1/collections/962eh-4zz18-xi32mpz2621o8km will disallow listing objects as well as disallow requesting any object other than those listed in the scope.


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Code samples in this documentation are licensed under the Apache License, Version 2.0.