Merge pull request #97 from msirringhaus/add_cred_excluded_error

Add CredentialExcluded error

When attempting to register a credential that already exists on the authenticator, an error is returned.
This passes the error detail to the UI to present to the user.

Author: iinuwa

credentialsd-common/src/model.rs

@@ -274,6 +274,8 @@ pub enum Error {
     AuthenticatorError,
     /// No matching credentials were found on the device.
     NoCredentials,
+    /// Credential was already registered with this device (credential ID contained in excludeCredentials)
+    CredentialExcluded,
     /// Too many incorrect PIN attempts, and authenticator must be removed and
     /// reinserted to continue any more PIN attempts.
     ///
@@ -292,6 +294,7 @@ impl Display for Error {
         match self {
             Self::AuthenticatorError => f.write_str("AuthenticatorError"),
             Self::NoCredentials => f.write_str("NoCredentials"),
+            Self::CredentialExcluded => f.write_str("CredentialExcluded"),
             Self::PinAttemptsExhausted => f.write_str("PinAttemptsExhausted"),
             Self::Internal(s) => write!(f, "InternalError: {s}"),
         }

credentialsd-common/src/server.rs

@@ -336,6 +336,9 @@ pub enum ServiceError {
     /// No matching credentials were found on the device.
     NoCredentials,
 
+    /// Credential was already registered with this device (credential ID contained in excludeCredentials)
+    CredentialExcluded,
+
     /// Too many incorrect PIN attempts, and authenticator must be removed and
     /// reinserted to continue any more PIN attempts.
     ///
@@ -363,6 +366,7 @@ impl From<ServiceError> for crate::model::Error {
         match value {
             ServiceError::AuthenticatorError => Self::AuthenticatorError,
             ServiceError::NoCredentials => Self::NoCredentials,
+            ServiceError::CredentialExcluded => Self::CredentialExcluded,
             ServiceError::PinAttemptsExhausted => Self::PinAttemptsExhausted,
             // TODO: this is bogus, we should refactor to remove the tuple field
             // and let the client decide how to render the error.
@@ -439,6 +443,7 @@ impl TryFrom<UsbState> for crate::model::UsbState {
                     match error_code.as_ref() {
                         "AuthenticatorError" => ServiceError::AuthenticatorError,
                         "NoCredentials" => ServiceError::NoCredentials,
+                        "CredentialExcluded" => ServiceError::CredentialExcluded,
                         "PinAttemptsExhausted" => ServiceError::PinAttemptsExhausted,
                         _ => ServiceError::Internal,
                     }

credentialsd-ui/src/gui/view_model/mod.rs

@@ -230,6 +230,9 @@ impl<F: FlowController + Send> ViewModel<F> {
                                 Error::AuthenticatorError | Error::Internal(_) => {
                                     "Something went wrong while retrieving a credential. Please try again later or use a different authenticator."
                                 }
+                                Error::CredentialExcluded => {
+                                    "This credential is already registered on this authenticator."
+                                }
                             });
                             self.tx_update
                                 .send(ViewUpdate::Failed(error_msg))

credentialsd/src/credential_service/usb.rs

@@ -343,6 +343,7 @@ async fn handle_events(
             .map_err(|err| match err {
                 WebAuthnError::Ctap(CtapError::PINAuthBlocked) => Error::PinAttemptsExhausted,
                 WebAuthnError::Ctap(CtapError::NoCredentials) => Error::NoCredentials,
+                WebAuthnError::Ctap(CtapError::CredentialExcluded) => Error::CredentialExcluded,
                 _ => Error::AuthenticatorError,
             });
             if let Err(err) = signal_tx.send(response).await {