Authentication Flow

1. Client sends an init request. This can be either:
   1. AuthStep::Init which just includes the username, or
   2. AuthStep::Init2 which can request a "privileged" session
2. The server responds with a list of authentication methods. (AuthState::Choose(Vec<AuthAllowed>))
3. Client requests auth with a method (AuthStep::Begin(AuthMech))
4. Server responds with an acknowledgement (AuthState::Continue(Vec<AuthAllowed>)). This is so the challenge can be included in the response, for Passkeys or other challenge-response methods.
   • If required, this challenge/response continues in a loop until the requirements are satisfied - for example, TOTP + Password.
5. The result is returned, either:
   • Success, with the User Auth Token as a String.
   • Denied, with a reason as a String.

sequenceDiagram;
    autonumber
    participant Client
    participant Kanidm
    
    Note over Client: "I'm Ferris and I want to start auth!"
    Client ->> Kanidm: AuthStep::Init(username)
    Note over Kanidm: "You can use the following methods"
    Kanidm ->> Client: AuthState::Choose(Vec<AuthAllowed>)

    loop Authentication Checks
        Note over Client: I want to use this mechanism
        Client->>Kanidm: AuthStep::Begin(AuthMech)
        Note over Kanidm: Ok, you can do that.
        Kanidm->>Client: AuthState::Continue(Vec<AuthAllowed>)
        Note over Client: Here is my credential
        Client->>Kanidm: AuthStep::Cred(AuthCredential)
        Note over Kanidm: Kanidm validates the Credential,<br /> and if more methods are required,<br /> return them.
        Kanidm->>Client: AuthState::Continue(Vec<AuthAllowed>)
        Note over Client, Kanidm: If there's no more credentials required, break the loop.

    end

    Note over Client,Kanidm: If Successful, return the auth token
    Kanidm->>Client: AuthState::Success(String Token)

    Note over Client,Kanidm: If Failed, return that and a message why.
    Kanidm-xClient: AuthState::Denied(String Token)