chore(api): mark growable public response and spec types non_exhaustive (#293)

Marks the public types that model device responses and protocol data as non-exhaustive, so adding fields or variants after 1.0 does not break downstream code. Types that callers construct directly are left exhaustive to keep them ergonomic to build. This is groundwork for committing to a stable API.

Author: AlfioEmanueleFresta

libwebauthn/src/ops/webauthn/make_credential.rs

@@ -652,7 +652,8 @@ pub struct MakeCredentialsRequestExtensions {
 pub type MakeCredentialsResponseExtensions = Ctap2MakeCredentialsResponseExtensions;
 
 impl MakeCredentialRequest {
-    pub fn dummy() -> Self {
+    #[cfg(test)]
+    pub(crate) fn dummy() -> Self {
         Self {
             challenge: Vec::new(),
             origin: "example.org".to_owned(),

libwebauthn/src/proto/ctap1/model.rs

@@ -86,7 +86,7 @@ impl Ctap1RegisterRequest {
         }
     }
 
-    pub fn dummy(timeout: Duration) -> Self {
+    pub(crate) fn dummy(timeout: Duration) -> Self {
         Ctap1RegisterRequest {
             version: Ctap1Version::U2fV2,
             app_id_hash: vec![0; 32],

libwebauthn/src/proto/ctap2/model.rs

@@ -50,8 +50,29 @@ pub use credential_management::{
 mod large_blobs;
 pub use large_blobs::{Ctap2LargeBlobsRequest, Ctap2LargeBlobsResponse};
 
+/// CTAP2 command codes; `#[non_exhaustive]` so consumers handle unknown variants.
+///
+/// ```compile_fail
+/// use libwebauthn::proto::ctap2::Ctap2CommandCode;
+/// let code = Ctap2CommandCode::AuthenticatorGetInfo;
+/// let _value: u8 = match code {
+///     Ctap2CommandCode::AuthenticatorMakeCredential => 0x01,
+///     Ctap2CommandCode::AuthenticatorGetAssertion => 0x02,
+///     Ctap2CommandCode::AuthenticatorGetInfo => 0x04,
+///     Ctap2CommandCode::AuthenticatorClientPin => 0x06,
+///     Ctap2CommandCode::AuthenticatorGetNextAssertion => 0x08,
+///     Ctap2CommandCode::AuthenticatorBioEnrollment => 0x09,
+///     Ctap2CommandCode::AuthenticatorBioEnrollmentPreview => 0x40,
+///     Ctap2CommandCode::AuthenticatorCredentialManagement => 0x0A,
+///     Ctap2CommandCode::AuthenticatorCredentialManagementPreview => 0x41,
+///     Ctap2CommandCode::AuthenticatorSelection => 0x0B,
+///     Ctap2CommandCode::AuthenticatorLargeBlobs => 0x0C,
+///     Ctap2CommandCode::AuthenticatorConfig => 0x0D,
+/// };
+/// ```
 #[derive(Debug, IntoPrimitive, TryFromPrimitive, Copy, Clone, PartialEq, Serialize_repr)]
 #[repr(u8)]
+#[non_exhaustive]
 pub enum Ctap2CommandCode {
     AuthenticatorMakeCredential = 0x01,
     AuthenticatorGetAssertion = 0x02,
@@ -78,7 +99,7 @@ pub struct Ctap2PublicKeyCredentialRpEntity {
 }
 
 impl Ctap2PublicKeyCredentialRpEntity {
-    pub fn dummy() -> Self {
+    pub(crate) fn dummy() -> Self {
         Self {
             id: String::from(".dummy"),
             name: Some(String::from(".dummy")),
@@ -109,7 +130,7 @@ pub struct Ctap2PublicKeyCredentialUserEntity {
 }
 
 impl Ctap2PublicKeyCredentialUserEntity {
-    pub fn dummy() -> Self {
+    pub(crate) fn dummy() -> Self {
         Self {
             id: ByteBuf::from([1]),
             name: Some(String::from("dummy")),
@@ -150,6 +171,7 @@ pub enum Ctap2PublicKeyCredentialType {
 /// AuthenticatorTransport from a credential descriptor. Unknown values are kept in `Other` so they pass through unchanged.
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
 #[serde(from = "String", into = "String")]
+#[non_exhaustive]
 pub enum Ctap2Transport {
     Ble,
     Nfc,

libwebauthn/src/proto/ctap2/model/bio_enrollment.rs

@@ -68,6 +68,7 @@ pub struct Ctap2BioEnrollmentParams {
 }
 
 #[derive(Debug, Default, Clone, DeserializeIndexed)]
+#[non_exhaustive]
 pub struct Ctap2BioEnrollmentResponse {
     // modality (0x01) 	Unsigned Integer 	Optional 	The user verification modality.
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -145,12 +146,14 @@ pub enum Ctap2LastEnrollmentSampleStatus {
 
 #[repr(u64)]
 #[derive(Debug, Clone, FromPrimitive, PartialEq, Serialize_repr, Deserialize_repr)]
+#[non_exhaustive]
 pub enum Ctap2BioEnrollmentModality {
     Fingerprint = 0x01, // Fingerprint was too high.
 }
 
 #[repr(u64)]
 #[derive(Debug, Clone, FromPrimitive, PartialEq, Serialize_repr, Deserialize_repr)]
+#[non_exhaustive]
 pub enum Ctap2BioEnrollmentFingerprintKind {
     Touch = 0x01,
     Swipe = 0x02,

libwebauthn/src/proto/ctap2/model/client_pin.rs

@@ -224,6 +224,7 @@ pub enum Ctap2PinUvAuthProtocolCommand {
 
 #[cfg_attr(test, derive(SerializeIndexed))]
 #[derive(Debug, Clone, Default, DeserializeIndexed)]
+#[non_exhaustive]
 pub struct Ctap2ClientPinResponse {
     /// keyAgreement (0x01)
     #[serde(skip_serializing_if = "Option::is_none")]

libwebauthn/src/proto/ctap2/model/credential_management.rs

@@ -89,6 +89,7 @@ pub struct Ctap2CredentialManagementParams {
 }
 
 #[derive(Debug, Default, Clone, DeserializeIndexed)]
+#[non_exhaustive]
 pub struct Ctap2CredentialManagementResponse {
     // existingResidentCredentialsCount (0x01) 	Unsigned Integer 	Number of existing discoverable credentials present on the authenticator.
     #[serde(skip_serializing_if = "Option::is_none")]

libwebauthn/src/proto/ctap2/model/get_assertion.rs

@@ -92,6 +92,7 @@ pub struct AppleAnonymousAttestationStmt {
 
 #[derive(Debug, Clone, Deserialize, Serialize)]
 #[serde(untagged)]
+#[non_exhaustive]
 pub enum Ctap2AttestationStatement {
     PackedOrAndroid(PackedAttestationStmt),
     Tpm(TpmAttestationStmt),
@@ -512,6 +513,7 @@ pub struct CalculatedHMACGetSecretInput {
 }
 
 #[derive(Debug, Clone, DeserializeIndexed)]
+#[non_exhaustive]
 pub struct Ctap2GetAssertionResponse {
     #[serde(skip_serializing_if = "Option::is_none")]
     #[serde(index = 0x01)]
@@ -687,6 +689,7 @@ impl Ctap2GetAssertionResponse {
 
 #[derive(Debug, Default, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
+#[non_exhaustive]
 pub struct Ctap2GetAssertionResponseExtensions {
     // Stored credBlob
     #[serde(default, skip_serializing_if = "Option::is_none", with = "serde_bytes")]

libwebauthn/src/proto/ctap2/model/get_info.rs

@@ -10,6 +10,7 @@ use super::{Ctap2CredentialType, Ctap2UserVerificationOperation};
 
 #[cfg_attr(test, derive(SerializeIndexed))]
 #[derive(Debug, Clone, DeserializeIndexed, Default)]
+#[non_exhaustive]
 pub struct Ctap2GetInfoResponse {
     /// versions (0x01)
     #[serde(index = 0x01)]

libwebauthn/src/proto/ctap2/model/large_blobs.rs

@@ -88,6 +88,7 @@ impl Ctap2LargeBlobsRequest {
 
 #[cfg_attr(test, derive(SerializeIndexed))]
 #[derive(Debug, Default, Clone, DeserializeIndexed)]
+#[non_exhaustive]
 pub struct Ctap2LargeBlobsResponse {
     #[serde(skip_serializing_if = "Option::is_none")]
     #[serde(index = 0x01)]

libwebauthn/src/proto/ctap2/model/make_credential.rs

@@ -357,6 +357,7 @@ impl Ctap2MakeCredentialsRequestExtensions {
 }
 
 #[derive(Debug, Clone, DeserializeIndexed)]
+#[non_exhaustive]
 pub struct Ctap2MakeCredentialResponse {
     #[serde(index = 0x01)]
     pub format: String,
@@ -469,6 +470,7 @@ impl Ctap2UserVerifiableRequest for Ctap2MakeCredentialRequest {
 
 #[derive(Debug, Default, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
+#[non_exhaustive]
 pub struct Ctap2MakeCredentialsResponseExtensions {
     // If storing credBlob was successful
     #[serde(default, skip_serializing_if = "Option::is_none")]