Add support for attestation format preferences

CHANGELOG.md

@@ -13,6 +13,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Use enums instead of string constants
   - Introduce `Version`, `Extension` and `Transport` enums and use them in `ctap2::get_info`
   - Fix serialization of the `AttestationStatementFormat` enum and use it in `ctap2::make_credential`
+- Remove `Deserialize` implementation for `ctap2::get_assertion::Response`
+- Remove `Serialize` implementation for `ctap2::{get_assertion, make_credential}::Request`
+- Move `AttestationStatement`, `AttestationStatementFormat`, `NoneAttestationStatement`, `PackedAttestationStatement` from `ctap2::make_credential` into the `ctap2` module
 
 ### Added
 
@@ -23,6 +26,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Add new fields to `get_info`
   - Add unsigned extension outputs to `make_credential` and `get_assertion`
   - Add enterprise attestation support to `get_assertion`
+  - Add support for attestation statements in `get_assertion`
+  - Add support for attestation format preferences
+- Derive `Copy` for `ctap2::AttestationStatementFormat`
 
 ## [0.2.0] - 2024-06-21
 

src/arbitrary.rs

@@ -33,6 +33,18 @@ impl<'a> Arbitrary<'a> for ctap1::register::Request<'a> {
     }
 }
 
+// cannot be derived because of missing impl for Vec<_>
+impl<'a> Arbitrary<'a> for ctap2::AttestationFormatsPreference {
+    fn arbitrary(u: &mut Unstructured<'a>) -> Result<Self> {
+        let known_formats = arbitrary_vec(u)?;
+        let unknown = u.arbitrary()?;
+        Ok(Self {
+            known_formats,
+            unknown,
+        })
+    }
+}
+
 // cannot be derived because of missing impl for serde_bytes::Bytes, EcdhEsHkdf256PublicKey
 impl<'a> Arbitrary<'a> for ctap2::client_pin::Request<'a> {
     fn arbitrary(u: &mut Unstructured<'a>) -> Result<Self> {
@@ -138,6 +150,7 @@ impl<'a> Arbitrary<'a> for ctap2::get_assertion::Request<'a> {
         };
         let pin_protocol = u.arbitrary()?;
         let enterprise_attestation = u.arbitrary()?;
+        let attestation_formats_preference = u.arbitrary()?;
         Ok(Self {
             rp_id,
             client_data_hash,
@@ -147,6 +160,7 @@ impl<'a> Arbitrary<'a> for ctap2::get_assertion::Request<'a> {
             pin_auth,
             pin_protocol,
             enterprise_attestation,
+            attestation_formats_preference,
         })
     }
 }
@@ -196,6 +210,7 @@ impl<'a> Arbitrary<'a> for ctap2::make_credential::Request<'a> {
         };
         let pin_protocol = u.arbitrary()?;
         let enterprise_attestation = u.arbitrary()?;
+        let attestation_formats_preference = u.arbitrary()?;
         Ok(Self {
             client_data_hash,
             rp,
@@ -207,6 +222,7 @@ impl<'a> Arbitrary<'a> for ctap2::make_credential::Request<'a> {
             pin_auth,
             pin_protocol,
             enterprise_attestation,
+            attestation_formats_preference,
         })
     }
 }

src/ctap2.rs

@@ -6,7 +6,7 @@ use bitflags::bitflags;
 use cbor_smol::cbor_deserialize;
 use serde::{Deserialize, Serialize};
 
-use crate::{sizes::*, Bytes, Vec};
+use crate::{sizes::*, Bytes, TryFromStrError, Vec};
 
 pub use crate::operation::{Operation, VendorOperation};
 
@@ -250,6 +250,111 @@ impl<'a, A: SerializeAttestedCredentialData, E: serde::Serialize> AuthenticatorD
     }
 }
 
+#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
+#[non_exhaustive]
+#[serde(untagged)]
+#[allow(clippy::large_enum_variant)]
+pub enum AttestationStatement {
+    None(NoneAttestationStatement),
+    Packed(PackedAttestationStatement),
+}
+
+#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+#[non_exhaustive]
+#[serde(into = "&str", try_from = "&str")]
+pub enum AttestationStatementFormat {
+    None,
+    Packed,
+}
+
+impl AttestationStatementFormat {
+    const NONE: &'static str = "none";
+    const PACKED: &'static str = "packed";
+}
+
+impl From<AttestationStatementFormat> for &str {
+    fn from(format: AttestationStatementFormat) -> Self {
+        match format {
+            AttestationStatementFormat::None => AttestationStatementFormat::NONE,
+            AttestationStatementFormat::Packed => AttestationStatementFormat::PACKED,
+        }
+    }
+}
+
+impl TryFrom<&str> for AttestationStatementFormat {
+    type Error = TryFromStrError;
+
+    fn try_from(s: &str) -> core::result::Result<Self, Self::Error> {
+        match s {
+            Self::NONE => Ok(Self::None),
+            Self::PACKED => Ok(Self::Packed),
+            _ => Err(TryFromStrError),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
+pub struct NoneAttestationStatement {}
+
+#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
+pub struct PackedAttestationStatement {
+    pub alg: i32,
+    pub sig: Bytes<ASN1_SIGNATURE_LENGTH>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub x5c: Option<Vec<Bytes<1024>, 1>>,
+}
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct AttestationFormatsPreference {
+    pub(crate) known_formats: Vec<AttestationStatementFormat, 2>,
+    pub(crate) unknown: bool,
+}
+
+impl AttestationFormatsPreference {
+    pub fn known_formats(&self) -> &[AttestationStatementFormat] {
+        &self.known_formats
+    }
+
+    pub fn includes_unknown_formats(&self) -> bool {
+        self.unknown
+    }
+}
+
+impl<'de> Deserialize<'de> for AttestationFormatsPreference {
+    fn deserialize<D>(deserializer: D) -> core::result::Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        struct ValueVisitor;
+
+        impl<'de> serde::de::Visitor<'de> for ValueVisitor {
+            type Value = AttestationFormatsPreference;
+
+            fn expecting(&self, formatter: &mut core::fmt::Formatter) -> core::fmt::Result {
+                formatter.write_str("a sequence")
+            }
+
+            fn visit_seq<A>(self, mut seq: A) -> core::result::Result<Self::Value, A::Error>
+            where
+                A: serde::de::SeqAccess<'de>,
+            {
+                let mut preference = AttestationFormatsPreference::default();
+                while let Some(value) = seq.next_element::<&str>()? {
+                    if let Ok(format) = AttestationStatementFormat::try_from(value) {
+                        preference.known_formats.push(format).ok();
+                    } else {
+                        preference.unknown = true;
+                    }
+                }
+                Ok(preference)
+            }
+        }
+
+        deserializer.deserialize_seq(ValueVisitor)
+    }
+}
+
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 #[non_exhaustive]
 pub enum Error {

src/ctap2/get_assertion.rs

@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 use serde_bytes::ByteArray;
 use serde_indexed::{DeserializeIndexed, SerializeIndexed};
 
-use super::{AuthenticatorOptions, Result};
+use super::{AttestationFormatsPreference, AttestationStatement, AuthenticatorOptions, Result};
 use crate::sizes::*;
 use crate::webauthn::*;
 
@@ -85,7 +85,7 @@ pub type AuthenticatorData<'a> =
 
 pub type AllowList<'a> = Vec<PublicKeyCredentialDescriptorRef<'a>, MAX_CREDENTIAL_COUNT_IN_LIST>;
 
-#[derive(Clone, Debug, Eq, PartialEq, SerializeIndexed, DeserializeIndexed)]
+#[derive(Clone, Debug, Eq, PartialEq, DeserializeIndexed)]
 #[non_exhaustive]
 #[serde_indexed(offset = 1)]
 pub struct Request<'a> {
@@ -103,12 +103,14 @@ pub struct Request<'a> {
     pub pin_protocol: Option<u32>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub enterprise_attestation: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub attestation_formats_preference: Option<AttestationFormatsPreference>,
 }
 
 // NB: attn object definition / order at end of
 // https://fidoalliance.org/specs/fido-v2.0-ps-20190130/fido-client-to-authenticator-protocol-v2.0-ps-20190130.html#authenticatorMakeCredential
 // does not coincide with what python-fido2 expects in AttestationObject.__init__ *at all* :'-)
-#[derive(Clone, Debug, Eq, PartialEq, SerializeIndexed, DeserializeIndexed)]
+#[derive(Clone, Debug, Eq, PartialEq, SerializeIndexed)]
 #[non_exhaustive]
 #[serde_indexed(offset = 1)]
 pub struct Response {
@@ -129,6 +131,8 @@ pub struct Response {
     pub unsigned_extension_outputs: Option<UnsignedExtensionOutputs>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ep_att: Option<bool>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub att_stmt: Option<AttestationStatement>,
 }
 
 #[derive(Debug)]
@@ -151,6 +155,7 @@ impl ResponseBuilder {
             large_blob_key: None,
             unsigned_extension_outputs: None,
             ep_att: None,
+            att_stmt: None,
         }
     }
 }

src/ctap2/get_info.rs

@@ -120,7 +120,7 @@ pub struct Response {
     // FIDO_2_2
     #[cfg(feature = "get-info-full")]
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub attestation_formats: Option<Vec<super::make_credential::AttestationStatementFormat, 2>>,
+    pub attestation_formats: Option<Vec<super::AttestationStatementFormat, 2>>,
 
     // 0x17
     // FIDO_2_2

src/ctap2/make_credential.rs

@@ -1,12 +1,14 @@
-use crate::{Bytes, TryFromStrError, Vec};
+use crate::Vec;
 
 use serde::{Deserialize, Serialize};
 use serde_bytes::ByteArray;
 use serde_indexed::{DeserializeIndexed, SerializeIndexed};
 
-use super::{AuthenticatorOptions, Error};
+use super::{
+    AttestationFormatsPreference, AttestationStatement, AttestationStatementFormat,
+    AuthenticatorOptions, Error,
+};
 use crate::ctap2::credential_management::CredentialProtectionPolicy;
-use crate::sizes::*;
 use crate::webauthn::*;
 
 impl TryFrom<u8> for CredentialProtectionPolicy {
@@ -45,7 +47,7 @@ pub struct Extensions {
     pub third_party_payment: Option<bool>,
 }
 
-#[derive(Clone, Debug, Eq, PartialEq, SerializeIndexed, DeserializeIndexed)]
+#[derive(Clone, Debug, Eq, PartialEq, DeserializeIndexed)]
 #[non_exhaustive]
 #[serde_indexed(offset = 1)]
 pub struct Request<'a> {
@@ -65,6 +67,8 @@ pub struct Request<'a> {
     pub pin_protocol: Option<u32>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub enterprise_attestation: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub attestation_formats_preference: Option<AttestationFormatsPreference>,
 }
 
 pub type AttestationObject = Response;
@@ -143,60 +147,6 @@ impl ResponseBuilder {
     }
 }
 
-#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
-#[non_exhaustive]
-#[serde(untagged)]
-#[allow(clippy::large_enum_variant)]
-pub enum AttestationStatement {
-    None(NoneAttestationStatement),
-    Packed(PackedAttestationStatement),
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
-#[non_exhaustive]
-#[serde(into = "&str", try_from = "&str")]
-pub enum AttestationStatementFormat {
-    None,
-    Packed,
-}
-
-impl AttestationStatementFormat {
-    const NONE: &'static str = "none";
-    const PACKED: &'static str = "packed";
-}
-
-impl From<AttestationStatementFormat> for &str {
-    fn from(format: AttestationStatementFormat) -> Self {
-        match format {
-            AttestationStatementFormat::None => AttestationStatementFormat::NONE,
-            AttestationStatementFormat::Packed => AttestationStatementFormat::PACKED,
-        }
-    }
-}
-
-impl TryFrom<&str> for AttestationStatementFormat {
-    type Error = TryFromStrError;
-
-    fn try_from(s: &str) -> Result<Self, Self::Error> {
-        match s {
-            Self::NONE => Ok(Self::None),
-            Self::PACKED => Ok(Self::Packed),
-            _ => Err(TryFromStrError),
-        }
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
-pub struct NoneAttestationStatement {}
-
-#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
-pub struct PackedAttestationStatement {
-    pub alg: i32,
-    pub sig: Bytes<ASN1_SIGNATURE_LENGTH>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub x5c: Option<Vec<Bytes<1024>, 1>>,
-}
-
 #[derive(Clone, Debug, Eq, PartialEq, Serialize)]
 #[non_exhaustive]
 pub struct UnsignedExtensionOutputs {}