Adding list leaf for SSH public keys

[syaghi-c]

Change Scope

• Adding a leaf list for user ssh keys to add the ability to add more than one SSH key per user.
• This change is backwards compatible. We are proposing a new list leaf rather than changing the existing single leaf for ssh-key as to not break backwards compatibility.

Platform Implementations

• Implementation A: gNSI model requires support for multiple ssh keys per user:
  https://github.com/openconfig/gnsi/tree/main/credentialz#update-the-clients-authorized-key
• Implementation B: Ciena 6500
  The platform supports adding more than one public key per user

Tree View

 module: openconfig-aaa
           +--rw aaa
        |  +--rw config
        |  +--ro state
        |  +--rw authentication
        |  |  +--rw glome
        |  |  |  +--ro state
        |  |  +--rw config
        |  |  |  +--rw authentication-method*   union
        |  |  +--ro state
        |  |  |  +--ro authentication-method*   union
        |  |  +--rw admin-user
        |  |  |  +--rw config
        |  |  |  |  +--rw admin-password?          string
        |  |  |  |  +--rw admin-password-hashed?   oc-aaa-types:crypt-password-type
        |  |  |  +--ro state
        |  |  |     +--ro admin-password?          string
        |  |  |     +--ro admin-password-hashed?   oc-aaa-types:crypt-password-type
        |  |  |     +--ro admin-username?          string
        |  |  +--rw users
        |  |     +--rw user* [username]
        |  |        +--rw username    -> ../config/username
        |  |        +--rw config
        |  |        |  +--rw username?          string
        |  |        |  +--rw password?          string
        |  |        |  +--rw password-hashed?   oc-aaa-types:crypt-password-type
        |  |        |  +--rw ssh-key?           string
        |  |        |  +--rw role               union
        |  |        +--ro state
        |  |           +--ro username?          string
        |  |           +--ro password?          string
        |  |           +--ro password-hashed?   oc-aaa-types:crypt-password-type
        |  |           +--ro ssh-key?           string
        |  |           +--ro role               union
+       |  |        +---- authorized-ssh-keys
+       |  |           +---- authorized-ssh-key* [key-name]
+       |  |              +---- key-name?   -> ../config/key-name
+       |  |              +---- config
+       |  |              |  +---- key-name?             string
+       |  |              |  +---- authorized-ssh-key?   string
+       |  |              +--ro state
+       |  |                 +--ro key-name?             string
+       |  |                 +--ro authorized-ssh-key?   string

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[gemini-code-assist]

Code Review

This pull request introduces an authorized-ssh-keys list to the OpenConfig AAA model to allow users to have multiple SSH public keys. Feedback indicates that the current placement of the list within a grouping violates OpenConfig structural standards, where lists should be siblings to config and state containers rather than nested within them. Additionally, the max-elements 10 constraint is viewed as overly restrictive, and the description for the authorized-ssh-key leaf should be updated to specify supported key formats like RSA or DSA.

[earies]

Overall in support of this change as it aligns w/ most implementations tmk - Just a few comments surrounding how the key/data should be decomposed and indexed.