`loginRequest.requested_access_token_audience` should not be `null`

[UkonnRa]

Describe the bug

In openapi schema, field requested_access_token_audience is required, which means it cannot be null.

But what I received is:

{
   "challenge":"eaf5b69b16a441b5a861b8a71c818c0a",
   "requested_scope":[
      "openid",
      "offline",
      "profile:read",
      "email"
   ],
   "requested_access_token_audience":null, // <--- `null` here
   "skip":false,
   "subject":"",
   "oidc_context":{
      
   },
   "client":{
      "client_id":"absolem-ui",
      "client_name":"Absolem Frontend Client",
      "redirect_uris":[
         "http://127.0.0.1:4455/callback"
      ],
      "grant_types":[
         "authorization_code",
         "refresh_token"
      ],
      "response_types":[
         "code",
         "token",
         "id_token"
      ],
      "scope":"openid offline profile:read email",
      "audience":null,
      "owner":"",
      "policy_uri":"",
      "allowed_cors_origins":null,
      "tos_uri":"",
      "client_uri":"",
      "logo_uri":"",
      "contacts":null,
      "client_secret_expires_at":0,
      "subject_type":"public",
      "token_endpoint_auth_method":"none",
      "userinfo_signed_response_alg":"none",
      "created_at":"2020-09-04T15:54:55Z",
      "updated_at":"2020-09-04T15:54:55Z"
   },
   "request_url":"http://127.0.0.1:4455/.ory/hydra/public/oauth2/auth?client_id=absolem-ui\u0026redirect_uri=http%3A%2F%2F127.0.0.1%3A4455%2Fcallback\u0026response_type=code\u0026scope=openid%20offline%20profile%3Aread%20email\u0026state=89c3a3a0cfac4ed183fc05ee60e3b652\u0026code_challenge=vqvX01wjsrnwC5YQM3I80ep_XbS_nd-CHE-VxJry5dc\u0026code_challenge_method=S256\u0026response_mode=query",
   "session_id":"ec73cd37-8aac-4d40-998c-e5e5164fde23"
}

Reproducing the bug

Steps to reproduce the behavior:

1. GET http://<hydra>:4455/oauth2/auth/requests/login?login_challenge=xxx
2. You will see it

Expected behavior

EVERY required fields should not be null

Environment

• Version: v1.7.4
• Env: Docker

Additional context

[UkonnRa]

BTW, I am trying to use the generated Rust clients (by openapi-generator). Because Rust is a strict language (for example, null safety), some bugs will be exposed easier than Java or Go generated client

[aeneasr]

Right, this happens when the go array is initialized as a nil value as opposed to an empty string slice! Tracking as a bug - contribs welcomed!

[UkonnRa]

I just read the code. As you said go array is initialized as a nil value. So obviously we cannot use:

type MemoryManager struct {
...
	authRequests           map[string]LoginRequest
...
}

but should use:

type MemoryManager struct {
...
	authRequests           map[string]*LoginRequest // <-- Pointer here
...
}

Then we should use something like:

func NewLoginRequest(...) LoginRequest {
    return LoginRequest{ authRequests: []string{} }
}

[UkonnRa]

BTW, I found that this error only happened in memory manager, because SQL manager uses another initialization methods

[aeneasr]

Ah, that is quite possible. The plan is to deprecate the Memory Manager and replace it with a SQLite in memory database, in which case this error would disappear. Given that, and that the in-memory manager is only used for dev / quickstarts, I think we can keep this as a nofix with a known workaround!

[UkonnRa]

Yes, I do use memory just for dev, and 👍 for SQLite

[aeneasr]

SQLite is now merged.