web/flows: fix helper form not being removed from identification stage (improve password manager compatibility)

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

web/src/flows/FlowExecutor.ts

@@ -131,7 +131,7 @@ export class FlowExecutor extends LitElement implements StageHost {
             });
     }
 
-    submit(payload?: FlowChallengeResponseRequest): Promise<void> {
+    submit(payload?: FlowChallengeResponseRequest): Promise<boolean> {
         if (!payload) return Promise.reject();
         if (!this.challenge) return Promise.reject();
         // @ts-ignore
@@ -153,12 +153,18 @@ export class FlowExecutor extends LitElement implements StageHost {
                     );
                 }
                 this.challenge = data;
+                if (this.challenge.responseErrors) {
+                    return false;
+                }
+                return true;
             })
             .catch((e: Error | Response) => {
                 this.errorMessage(e);
+                return false;
             })
             .finally(() => {
                 this.loading = false;
+                return false;
             });
     }
 

web/src/flows/stages/base.ts

@@ -7,7 +7,7 @@ export interface StageHost {
     challenge?: unknown;
     flowSlug: string;
     loading: boolean;
-    submit(payload: unknown): Promise<void>;
+    submit(payload: unknown): Promise<boolean>;
 }
 
 export class BaseStage<Tin, Tout> extends LitElement {
@@ -16,14 +16,19 @@ export class BaseStage<Tin, Tout> extends LitElement {
     @property({ attribute: false })
     challenge!: Tin;
 
-    submitForm(e: Event): void {
+    async submitForm(e: Event): Promise<boolean> {
         e.preventDefault();
         const object: {
             [key: string]: unknown;
         } = {};
         const form = new FormData(this.shadowRoot?.querySelector("form") || undefined);
         form.forEach((value, key) => (object[key] = value));
-        this.host?.submit(object as unknown as Tout);
+        return this.host?.submit(object as unknown as Tout).then((successful) => {
+            if (successful) {
+                this.cleanup();
+            }
+            return successful;
+        });
     }
 
     renderNonFieldErrors(errors: ErrorDetail[]): TemplateResult {
@@ -41,4 +46,9 @@ export class BaseStage<Tin, Tout> extends LitElement {
             })}
         </div>`;
     }
+
+    cleanup(): void {
+        // Method that can be overridden by stages
+        return;
+    }
 }

web/src/flows/stages/identification/IdentificationStage.ts

@@ -41,6 +41,8 @@ export class IdentificationStage extends BaseStage<
     IdentificationChallenge,
     IdentificationChallengeResponseRequest
 > {
+    form?: HTMLFormElement;
+
     static get styles(): CSSResult[] {
         return [
             PFBase,
@@ -72,8 +74,8 @@ export class IdentificationStage extends BaseStage<
     }
 
     firstUpdated(): void {
-        const wrapperForm = document.createElement("form");
-        document.documentElement.appendChild(wrapperForm);
+        this.form = document.createElement("form");
+        document.documentElement.appendChild(this.form);
         // This is a workaround for the fact that we're in a shadow dom
         // adapted from https://github.com/home-assistant/frontend/issues/3133
         const username = document.createElement("input");
@@ -91,7 +93,7 @@ export class IdentificationStage extends BaseStage<
                     input.focus();
                 });
         };
-        wrapperForm.appendChild(username);
+        this.form.appendChild(username);
         const password = document.createElement("input");
         password.setAttribute("type", "password");
         password.setAttribute("name", "password");
@@ -115,7 +117,7 @@ export class IdentificationStage extends BaseStage<
                     input.focus();
                 });
         };
-        wrapperForm.appendChild(password);
+        this.form.appendChild(password);
         const totp = document.createElement("input");
         totp.setAttribute("type", "text");
         totp.setAttribute("name", "code");
@@ -139,7 +141,13 @@ export class IdentificationStage extends BaseStage<
                     input.focus();
                 });
         };
-        wrapperForm.appendChild(totp);
+        this.form.appendChild(totp);
+    }
+
+    cleanup(): void {
+        if (this.form) {
+            document.documentElement.removeChild(this.form);
+        }
     }
 
     renderSource(source: LoginSource): TemplateResult {