Obo exchange

[Eiermitsucuk]

Description

Adds an On-Behalf-Of (OBO) token exchange command to imscli. The "obo" command (alias "ob") exchanges a user access token for a new token using IMS token v4 and the RFC 8693 token-exchange grant type

Usage: "imscli obo -c -p -t -s "
Security: OBO tokens are for backend use only; they must not be sent to frontend clients.

Motivation and Context

To be able to test obo-exchange.

How Has This Been Tested?

Manual: run "obo" with valid client ID, secret, and user token plus "-s openid" (or other allowed scopes) and confirm a token is returned. Run without "-s" and confirm ims returns an error.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.