UserDisplayName of SessionData is unused

[leejuyuu]

Version

0.8.2

Description

The UserDisplayName field in the SessionData struct is never referenced in the package.
I suppose it is designed to store the user information in the methods like BeginRegistration()?
Maybe consider copying from User.WebAuthnDisplayName() or remove this field to avoid confusion.

Reproduction

Run the following code

code

package main

import (
	"log"

	"github.com/go-webauthn/webauthn/webauthn"
)

func main() {
	wconfig := &webauthn.Config{
		RPDisplayName: "Go Webauthn",                               // Display Name for your site
		RPID:          "go-webauthn.local",                         // Generally the FQDN for your site
		RPOrigins:     []string{"https://login.go-webauthn.local"}, // The origin URLs allowed for WebAuthn requests
	}

	w, err := webauthn.New(wconfig)
	if err != nil {
		log.Fatal(err)
	}

	u := user{id: []byte{1, 2, 3}, displayName: "Go Webauthn", name: "webauthn"}
	_, session, err := w.BeginRegistration(u)
	if err != nil {
		log.Fatal(err)
	}

	log.Println("display name: ", session.UserDisplayName)
}

type user struct {
	id                []byte
	displayName, name string
	credentials       []webauthn.Credential
}

func (u user) WebAuthnID() []byte {
	return u.id
}

func (u user) WebAuthnName() string {
	return u.name
}

func (u user) WebAuthnDisplayName() string {
	return u.displayName
}

func (u user) WebAuthnCredentials() []webauthn.Credential {
	return u.credentials
}

func (u user) WebAuthnIcon() string {
	return ""
}

The terminal prints

2023/05/29 11:48:07 display name:  

Expectations

I would expect

2023/05/29 11:48:07 display name:  Go Webauthn

Documentation

No response

[james-d-elliott]

Could you explain what the use case would be? Seems I added this to the session data by mistake and forgot to remove it.

[leejuyuu]

In my use case, I store the user name, display name, and the SessionData in a session cookie and only add them to our database until the whole webauthn process is completed. However, I can easily move that field into my own struct (actually that's what I'm currently doing).

I totally agree that field can be removed given its existence is not intended.