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How to Request Tokens¶

As part of the GridFTP and GSI migration, the OSG will be transitioning authentication away from X.509 certificates to the use of bearer tokens such as SciTokens or WLCG JWT. This document is intended as a guide for OSG developers for requesting tokens necessary for software development.

Before Starting¶

Before you can request the appropriate tokens, you must have the following:

A WLCG INDIGO IAM account belonging to the wlcg, wlcg/pilots, and wlcg/xfers groups.
An installation of oidc-agent available as an RPM from the OSG repositories

Requesting Tokens¶

oidc-agent is similar to SSH agent except that it works with OpenID Connect token providers.

Start the agent and add the appropriate variables to your environment:
```
eval `oidc-agent`
```
Generate a local client profile and follow the prompts:
```
oidc-gen -w device <CLIENT NAME>
```
1. Specify the WLCG INDIGO IAM instance as the client issuer:
```
Issuer [https://iam-test.indigo-datacloud.eu/]: https://wlcg.cloud.cnaf.infn.it/
```
2. Request wlcg, offline_access, and other scopes for the capabilities that you need:
  
  Capability Scope
  
  HTCondor READ condor:/READ condor:/ALLOW
  
  HTCondor WRITE condor:/WRITE condor:/ALLOW
  
  XRootD read read:/
  
  XRootD write write:/
  
  For example, to request HTCondor READ and WRITE access, specify the following scopes:
```
This issuer supports the following scopes: openid profile email address phone offline_access wlcg iam wlcg.groups
Space delimited list of scopes or 'max' [openid profile offline_access]: wlcg offline_access condor:/READ condor:/WRITE condor:/ALLOW
```
3. When prompted, open https://wlcg.cloud.cnaf.infn.it/device in a browser, enter the code provided by oidc-gen, and click "Submit".
4. On the next page, verify the scopes and client profile name, and click "Authorize".
5. Enter a password to encrypt your local client profile. You'll need to remember this if you want to re-use this profile in subsequent sessions.
Request a token using the client name that you used above with oidc-gen:
```
oidc-token <CLIENT NAME>
```
Copy the output of oidc-token into a file on the host where you need SciToken authentication, e.g. an HTCondor or XRootD client.

Troubleshooting Tokens¶

You can inspect the payload by copy-pasting the token into the "Encoded" text box here: http://jwt.io/. Mouse over the fields and values for details.

Capability	Scope
HTCondor `READ`	`condor:/READ condor:/ALLOW`
HTCondor `WRITE`	`condor:/WRITE condor:/ALLOW`
XRootD read	`read:/`
XRootD write	`write:/`