Bug 1831392 - add an excluded WebAuthn credential prompt. r=keeler

Depends on D177944

Differential Revision: https://phabricator.services.mozilla.com/D178113

browser/base/content/browser.js

@@ -7573,6 +7573,14 @@ var WebAuthnPromptHelper = {
       this.pin_required(mgr, data);
     } else if (data.action == "select-sign-result") {
       this.select_sign_result(mgr, data);
+    } else if (data.action == "already-registered") {
+      this.show_info(
+        mgr,
+        data.origin,
+        data.tid,
+        "alreadyRegistered",
+        "webauthn.alreadyRegisteredPrompt"
+      );
     } else if (data.action == "select-device") {
       this.show_info(
         mgr,

browser/locales/en-US/chrome/browser/browser.properties

@@ -431,6 +431,7 @@ webauthn.deviceBlockedPrompt=User verification failed on %S. There are no attemp
 webauthn.pinAuthBlockedPrompt=User verification failed on %S. There were too many failed attempts in a row and PIN authentication has been temporarily blocked. Your device needs a power cycle (unplug and re-insert).
 # LOCALIZATION NOTE (webauthn.pinNotSetPrompt): %S is hostname
 webauthn.pinNotSetPrompt=User verification failed on %S. You may need to set a PIN on your device.
+webauthn.alreadyRegisteredPrompt=This device is already registered. Try a different device.
 webauthn.cancel=Cancel
 webauthn.cancel.accesskey=c
 webauthn.proceed=Proceed

dom/webauthn/authrs_bridge/src/lib.rs

@@ -66,6 +66,7 @@ fn authrs_to_nserror(e: &AuthenticatorError) -> nsresult {
         AuthenticatorError::PinError(PinError::PinAuthBlocked) => NS_ERROR_DOM_OPERATION_ERR,
         AuthenticatorError::PinError(PinError::PinBlocked) => NS_ERROR_DOM_OPERATION_ERR,
         AuthenticatorError::PinError(PinError::PinNotSet) => NS_ERROR_DOM_OPERATION_ERR,
+        AuthenticatorError::CredentialExcluded => NS_ERROR_DOM_OPERATION_ERR,
         _ => NS_ERROR_DOM_UNKNOWN_ERR,
     }
 }
@@ -547,6 +548,7 @@ impl AuthrsTransport {
         .dispatch_background_task()?;
 
         let controller = self.controller.clone();
+        let callback_origin = origin.to_string();
         let state_callback = StateCallback::<Result<RegisterResult, AuthenticatorError>>::new(
             Box::new(move |result| {
                 let result = match result {
@@ -562,6 +564,16 @@ impl AuthrsTransport {
                         }
                         Ok(RegisterResult::CTAP2(attestation_object))
                     }
+                    Err(e @ AuthenticatorError::CredentialExcluded) => {
+                        let notification_str = make_prompt(
+                            "already-registered",
+                            tid,
+                            &callback_origin,
+                            browsing_context_id,
+                        );
+                        controller.send_prompt(tid, &notification_str);
+                        Err(e)
+                    }
                     Err(e) => Err(e),
                 };
                 let _ = controller.finish_register(tid, result);