document standard deviation when using globs

add example on how to toggle the underlying
client implementation based on DevMode.

example/server/storage/client.go

@@ -32,6 +32,8 @@ type Client struct {
 	devMode                        bool
 	idTokenUserinfoClaimsAssertion bool
 	clockSkew                      time.Duration
+	postLogoutRedirectURIGlobs     []string
+	redirectURIGlobs               []string
 }
 
 // GetID must return the client_id
@@ -44,21 +46,11 @@ func (c *Client) RedirectURIs() []string {
 	return c.redirectURIs
 }
 
-// RedirectURIGlobs provide wildcarding for additional valid redirects
-func (c *Client) RedirectURIGlobs() []string {
-	return nil
-}
-
 // PostLogoutRedirectURIs must return the registered post_logout_redirect_uris for sign-outs
 func (c *Client) PostLogoutRedirectURIs() []string {
 	return []string{}
 }
 
-// PostLogoutRedirectURIGlobs provide extra wildcarding for additional valid redirects
-func (c *Client) PostLogoutRedirectURIGlobs() []string {
-	return nil
-}
-
 // ApplicationType must return the type of the client (app, native, user agent)
 func (c *Client) ApplicationType() op.ApplicationType {
 	return c.applicationType
@@ -200,3 +192,26 @@ func WebClient(id, secret string, redirectURIs ...string) *Client {
 		clockSkew:                      0,
 	}
 }
+
+type hasRedirectGlobs struct {
+	*Client
+}
+
+// RedirectURIGlobs provide wildcarding for additional valid redirects
+func (c hasRedirectGlobs) RedirectURIGlobs() []string {
+	return c.redirectURIGlobs
+}
+
+// PostLogoutRedirectURIGlobs provide extra wildcarding for additional valid redirects
+func (c hasRedirectGlobs) PostLogoutRedirectURIGlobs() []string {
+	return c.postLogoutRedirectURIGlobs
+}
+
+// RedirectGlobsClient wraps the client in a op.HasRedirectGlobs
+// only if DevMode is enabled.
+func RedirectGlobsClient(client *Client) op.Client {
+	if client.devMode {
+		return hasRedirectGlobs{client}
+	}
+	return client
+}

example/server/storage/storage.go

@@ -407,7 +407,7 @@ func (s *Storage) GetClientByClientID(ctx context.Context, clientID string) (op.
 	if !ok {
 		return nil, fmt.Errorf("client not found")
 	}
-	return client, nil
+	return RedirectGlobsClient(client), nil
 }
 
 // AuthorizeClientIDSecret implements the op.Storage interface

pkg/op/client.go

@@ -56,6 +56,12 @@ type Client interface {
 // interpretation. Redirect URIs that match either the non-glob version or the
 // glob version will be accepted. Glob URIs are only partially supported for native
 // clients: "http://" is not allowed except for loopback or in dev mode.
+//
+// Note that globbing / wildcards are not permitted by the oidc
+// standard and implementing this interface can have security implications.
+// It is advised to only return a client of this type in rare cases,
+// such as DevMode for the client being enabled.
+// https://openid.net/specs/openid-connect-core-1_0.html#AuthRequest
 type HasRedirectGlobs interface {
 	RedirectURIGlobs() []string
 	PostLogoutRedirectURIGlobs() []string