Refresh Tokens

Refresh tokens are specific to the OAuth 2 specification and are only available in that version of OA4MP. Generally a user needs an access token in order to retrieve a protected asset (such as a certificate chain).

How's it work?

After a user authenticates, the client can request an access token. It is the access token that allows a client to get a certificate. Access tokens are normally fairly short-lived, on the order of 15 - 20 minutes since if one is stolen, a rogue user could (possibly) use it. The problem with this is that every time a user wants a certificate, s/he must authenticate. If the client is allowed to retrieve certificates on behalf of the user, that is awfully inconvenient.

Fortunately, there are refresh tokens. A refresh token is given to the client and allows it to get an access token. The refresh token includes a lifetime, typically 15 days, though the user can request more or less.

So how do I use it?

Generally if you are a user, you don't need to know anything else past this point.

If you are writing to the API though, you need to know the particulars of managing refresh tokens. Both tokens (access and refresh) are stored locally as part of the Asset. To get another access token, you need to submit a refresh token request along with the current refresh token. You will receive a new access token back along with a new refresh token, valid for as long as the first. All of this is managed in the single getRefreshToken call of the API, so you don't need to sweat over the details. Just make this call whenever you need a new access token and one will be retrieved.

An example.

Remember that the initial request from the client requires an system-supplied identifier that will be used henceforth. The next example creates one and then uses it to retrieve a refresh token.
    OA2ClientEnvironment ce = OA2ClientEnvironmentUtil.load("/path/to/config.xml", "name-of-config");
    OA2MPService service = new OA2MPService(ce);
    String id = "my:new:id/42";
    // Use the webapp to do the authentication. When that is done, you will have
    // an asset that contains the private key, cert request, access token, refresh token and identifier
    // So now the scenario is that the client needs to get another certificate. The refresh token
    // allows this to be done without having the user re-authenticate.

    Asset2 asset = service.refresh(id);
    service.getCert(asset);
    // Now you have the new certs. Access them as per usual, e.g.
    X509Certificate[] cert = asset.getCertificates();

User Information

User information is just information about the user that the server can return. The only basic information that is guaranteed is the name the user supplied to log on to MyProxy. Many other bits of information may be supplied by a server but this is up to the organization and its policies. The user must logon first via browser and then the call can be made.

User Info Example

This example is very similar to the one above in set up:
    OA2ClientEnvironment ce = OA2ClientEnvironmentUtil.load("/path/to/config.xml", "name-of-config");
    OA2MPService service = new OA2MPService(ce);
    String id = "my:new:id/42";
    // assuming that the user has authenticated by this point
    UserInfo userInfo = service.getUserInfo(id);
    userInfo.getName();

Last modified 09/22/16.
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