adds credential ordering

src/ctap/data_formats.rs

@@ -500,6 +500,7 @@ pub struct PublicKeyCredentialSource {
     pub other_ui: Option<String>,
     pub cred_random: Option<Vec<u8>>,
     pub cred_protect_policy: Option<CredentialProtectionPolicy>,
+    pub creation_order: u64,
 }
 
 // We serialize credentials for the persistent storage using CBOR maps. Each field of a credential
@@ -512,6 +513,7 @@ enum PublicKeyCredentialSourceField {
     OtherUi = 4,
     CredRandom = 5,
     CredProtectPolicy = 6,
+    CreationOrder = 7,
     // When a field is removed, its tag should be reserved and not used for new fields. We document
     // those reserved tags below.
     // Reserved tags: none.
@@ -535,6 +537,7 @@ impl From<PublicKeyCredentialSource> for cbor::Value {
             PublicKeyCredentialSourceField::OtherUi => credential.other_ui,
             PublicKeyCredentialSourceField::CredRandom => credential.cred_random,
             PublicKeyCredentialSourceField::CredProtectPolicy => credential.cred_protect_policy,
+            PublicKeyCredentialSourceField::CreationOrder => credential.creation_order,
         }
     }
 }
@@ -552,6 +555,7 @@ impl TryFrom<cbor::Value> for PublicKeyCredentialSource {
                 PublicKeyCredentialSourceField::OtherUi => other_ui,
                 PublicKeyCredentialSourceField::CredRandom => cred_random,
                 PublicKeyCredentialSourceField::CredProtectPolicy => cred_protect_policy,
+                PublicKeyCredentialSourceField::CreationOrder => creation_order,
             } = extract_map(cbor_value)?;
         }
 
@@ -569,6 +573,7 @@ impl TryFrom<cbor::Value> for PublicKeyCredentialSource {
         let cred_protect_policy = cred_protect_policy
             .map(CredentialProtectionPolicy::try_from)
             .transpose()?;
+        let creation_order = creation_order.map(extract_unsigned).unwrap_or(Ok(0))?;
         // We don't return whether there were unknown fields in the CBOR value. This means that
         // deserialization is not injective. In particular deserialization is only an inverse of
         // serialization at a given version of OpenSK. This is not a problem because:
@@ -588,6 +593,7 @@ impl TryFrom<cbor::Value> for PublicKeyCredentialSource {
             other_ui,
             cred_random,
             cred_protect_policy,
+            creation_order,
         })
     }
 }
@@ -1357,6 +1363,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: None,
+            creation_order: 0,
         };
 
         assert_eq!(

src/ctap/mod.rs

@@ -155,6 +155,7 @@ pub struct CtapState<'a, R: Rng256, CheckUserPresence: Fn(ChannelID) -> Result<(
     accepts_reset: bool,
     #[cfg(feature = "with_ctap1")]
     pub u2f_up_state: U2fUserPresenceState,
+    // Sorted by ascending order of creation, so the last element is the most recent one.
     next_credentials: Vec<PublicKeyCredentialSource>,
     next_assertion_input: Option<AssertionInput>,
 }
@@ -302,6 +303,7 @@ where
             other_ui: None,
             cred_random,
             cred_protect_policy: None,
+            creation_order: 0,
         }))
     }
 
@@ -424,7 +426,6 @@ where
         } else {
             None
         };
-        // TODO(kaczmarczyck) unsolicited output for default credProtect level
         let has_extension_output = use_hmac_extension || cred_protect_policy.is_some();
 
         let rp_id = rp.rp_id;
@@ -501,6 +502,7 @@ where
                     .map(|s| truncate_to_char_boundary(&s, 64).to_string()),
                 cred_random: cred_random.map(|c| c.to_vec()),
                 cred_protect_policy,
+                creation_order: self.persistent_store.new_creation_order()?,
             };
             self.persistent_store.store_credential(credential_source)?;
             random_id
@@ -717,8 +719,9 @@ where
 
         let credential =
             if let Some((credential, remaining_credentials)) = credentials.split_first() {
-                // TODO(kaczmarczyck) correct credential order
                 self.next_credentials = remaining_credentials.to_vec();
+                self.next_credentials
+                    .sort_unstable_by_key(|c| c.creation_order);
                 credential
             } else {
                 decrypted_credential
@@ -1091,6 +1094,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: None,
+            creation_order: 0,
         };
         assert!(ctap_state
             .persistent_store
@@ -1457,6 +1461,7 @@ mod test {
             cred_protect_policy: Some(
                 CredentialProtectionPolicy::UserVerificationOptionalWithCredentialIdList,
             ),
+            creation_order: 0,
         };
         assert!(ctap_state
             .persistent_store
@@ -1507,6 +1512,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: Some(CredentialProtectionPolicy::UserVerificationRequired),
+            creation_order: 0,
         };
         assert!(ctap_state
             .persistent_store
@@ -1550,6 +1556,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: None,
+            creation_order: 0,
         };
         assert!(ctap_state
             .persistent_store

src/ctap/storage.rs

@@ -337,6 +337,26 @@ impl PersistentStore {
             .count())
     }
 
+    pub fn new_creation_order(&self) -> Result<u64, Ctap2StatusCode> {
+        Ok(self
+            .store
+            .find_all(&Key::Credential {
+                rp_id: None,
+                credential_id: None,
+                user_handle: None,
+            })
+            .filter_map(|(_, entry)| {
+                debug_assert_eq!(entry.tag, TAG_CREDENTIAL);
+                let credential = deserialize_credential(entry.data);
+                debug_assert!(credential.is_some());
+                credential
+            })
+            .map(|c| c.creation_order)
+            .max()
+            .unwrap_or(0)
+            + 1)
+    }
+
     pub fn global_signature_counter(&self) -> Result<u32, Ctap2StatusCode> {
         Ok(self
             .store
@@ -690,6 +710,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: None,
+            creation_order: 0,
         }
     }
 
@@ -853,6 +874,7 @@ mod test {
             cred_protect_policy: Some(
                 CredentialProtectionPolicy::UserVerificationOptionalWithCredentialIdList,
             ),
+            creation_order: 0,
         };
         assert!(persistent_store.store_credential(credential).is_ok());
 
@@ -894,6 +916,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: None,
+            creation_order: 0,
         };
         assert_eq!(found_credential, Some(expected_credential));
     }
@@ -913,6 +936,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: Some(CredentialProtectionPolicy::UserVerificationRequired),
+            creation_order: 0,
         };
         assert!(persistent_store.store_credential(credential).is_ok());
 
@@ -1090,6 +1114,7 @@ mod test {
             other_ui: None,
             cred_random: None,
             cred_protect_policy: None,
+            creation_order: 0,
         };
         let serialized = serialize_credential(credential.clone()).unwrap();
         let reconstructed = deserialize_credential(&serialized).unwrap();