For service principal authentication, replace `--username` with `--client-id`, replace `--password` with `--client-secret`, `--certificate`

[jiasli]

Related command
az login --identity

Is your feature request related to a problem? Please describe.
Azure CLI uses below arguments for service principal authentication:

• --username: client ID
• --password: client secret or certificate

such as

az login --service-principal --username xxx --password xxx --tenant xxx

These arguments are also used in user authentication:

az login --username xxx --password xxx --tenant xxx

Reusing --username and --password for both user and service principal authentication can be confusing.

Describe the solution you'd like
To be consistent with OAuth 2.0 client credentials flow parameters,

• Replace --username with --client-id
• Replace --password with --client-secret, --certificate

When supporting OIDC authentication, --federated-token is introduced, instead of reusing --password.

Describe alternatives you've considered

Additional context
--identity may require similar changes: #29480

[yonzhan]

Thank you for opening this issue, we will look into it.

[jiasli]

--certificate has been added by #30091.