[Core] WAM integration

[rayluo]

Related command

• az login
• And any subsequent command that would obtain a token via MSAL's acquire_token_silent().

Description

Close #21201
Require AzureAD/microsoft-authentication-library-for-python#415

This PR is currently a draft to demonstrate how Azure CLI could enable the broker behavior from an MSAL feature branch.

Testing Guide

1. Run the following commands on a Windows 10+ machine
2. Somehow install Azure CLI from this feature branch, conceptually similar to this (however this command does not currently work)
   pip install git+https://github.com/azure/azure-cli@broker-integration
3. Then run az login, and notice how a pop-up window (rather than a browser) would pop up.
4. Try run some more (all?) different az foo bar command to make sure the token returned by broker would work

History Notes

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[yonzhan]

WAM

[jiasli]

msal[broker] can also be manually installed with

pip install .\microsoft-authentication-library-for-python\[broker]

[rayluo]

Suggested change

	"allow_broker": True
	"allow_broker": True,

:-p

[jiasli]

Why? Isn't last comma supposed to be omitted?

[rayluo]

It is less-defined, so there is no official preference that you are "supposed" to follow. However, since Python does allow the extra trailing comma, I prefer to take advantage of it.

[jiasli]

@rayluo, is WAM still considered auth code flow? If not, are we fully deprecating auth code flow for WAM-supported device?

[rayluo]

@rayluo, is WAM still considered auth code flow? If not, are we fully deprecating auth code flow for WAM-supported device?

The broker (wam) behavior is indeed implemented in MSAL's acquire_token_interactive(), therefore replacing the traditional auth-code-based behavior.

This is meant to be a transparent change to Azure CLI, so Azure CLI does not need to deprecate anything. MSAL itself will still keep the auth code flow APIs because they will still be useful for web applications.

[jiasli]

Some merge conflicts happen after supporting CAE (#23635). Also rework this PR in #23828.