cmd/example-app: check if a provider supports a refresh token scope

Some OpenID Connect providers, notably Google, don't follow the spec
and allow refresh tokens to be requested with the "offline_access"
scope. Try to determine which we're talking to by checking the
supported_scopes listed by the provider discovery.
This commit is contained in:
Eric Chiang 2016-10-09 19:06:24 -07:00
parent 8518c30123
commit fdc529ee0d

View file

@ -30,6 +30,10 @@ type app struct {
verifier *oidc.IDTokenVerifier
provider *oidc.Provider
// Does the provider use "offline_access" scope to request a refresh token
// or does it use "access_type=offline" (e.g. Google)?
offlineAsScope bool
ctx context.Context
cancel context.CancelFunc
}
@ -102,6 +106,34 @@ func cmd() *cobra.Command {
if err != nil {
return fmt.Errorf("Failed to query provider %q: %v", issuerURL, err)
}
var s struct {
// What scopes does a provider support?
//
// See: https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
ScopesSupported []string `json:"scopes_supported"`
}
if err := provider.Claims(&s); err != nil {
return fmt.Errorf("Failed to parse provider scopes_supported: %v", err)
}
if len(s.ScopesSupported) == 0 {
// scopes_supported is a "RECOMMENDED" discovery claim, not a required
// one. If missing, assume that the provider follows the spec and has
// an "offline_access" scope.
a.offlineAsScope = true
} else {
// See if scopes_supported has the "offline_access" scope.
a.offlineAsScope = func() bool {
for _, scope := range s.ScopesSupported {
if scope == oidc.ScopeOfflineAccess {
return true
}
}
return false
}()
}
a.provider = provider
a.verifier = provider.NewVerifier(a.ctx, oidc.VerifyAudience(a.clientID))
@ -166,10 +198,15 @@ func (a *app) handleLogin(w http.ResponseWriter, r *http.Request) {
scopes = append(scopes, "audience:server:client_id:"+client)
}
// TODO(ericchiang): Determine if provider does not support "offline_access" or has
// some other mechanism for requesting refresh tokens.
scopes = append(scopes, "openid", "profile", "email", "offline_access")
http.Redirect(w, r, a.oauth2Config(scopes).AuthCodeURL(""), http.StatusSeeOther)
authCodeURL := ""
scopes = append(scopes, "openid", "profile", "email")
if a.offlineAsScope {
scopes = append(scopes, "offline_access")
authCodeURL = a.oauth2Config(scopes).AuthCodeURL("")
} else {
authCodeURL = a.oauth2Config(scopes).AuthCodeURL("", oauth2.AccessTypeOffline)
}
http.Redirect(w, r, authCodeURL, http.StatusSeeOther)
}
func (a *app) handleCallback(w http.ResponseWriter, r *http.Request) {
@ -195,7 +232,7 @@ func (a *app) handleCallback(w http.ResponseWriter, r *http.Request) {
}
token, err = oauth2Config.TokenSource(a.ctx, t).Token()
default:
http.Error(w, "no code in request", http.StatusBadRequest)
http.Error(w, fmt.Sprintf("no code in request: %q", r.Form), http.StatusBadRequest)
return
}