adds a feature flag for CTAP2.1, addresses comments

Cargo.toml

@@ -25,6 +25,7 @@ std = ["cbor/std", "crypto/std", "crypto/derive_debug"]
 ram_storage = []
 verbose = ["debug_ctap"]
 with_ctap1 = ["crypto/with_ctap1"]
+with_ctap2_1 = []
 
 [dev-dependencies]
 elf2tab = "0.4.0"

README.md

@@ -28,9 +28,11 @@ few limitations:
 Although we tested and implemented our firmware based on the published
 [CTAP2.0 specifications](https://fidoalliance.org/specs/fido-v2.0-ps-20190130/fido-client-to-authenticator-protocol-v2.0-ps-20190130.html),
 our implementation was not reviewed nor officially tested and doesn't claim to
-be FIDO Certified. With the upcoming next version of the
-[CTAP2.1 specifications](https://fidoalliance.org/specs/fido2/fido-client-to-authenticator-protocol-v2.1-rd-20191217.html),
-we started adding features, so master is currently between version 2.0 and 2.1.
+be FIDO Certified.
+We started adding features of the upcoming next version of the
+[CTAP2.1 specifications](https://fidoalliance.org/specs/fido2/fido-client-to-authenticator-protocol-v2.1-rd-20191217.html).
+The development is currently between 2.0 and 2.1, with updates hidden behind a feature flag.
+Please add the flag `shell --ctap2-1` to the deploy command to include them.
 
 ### Cryptography
 

deploy.py

@@ -741,6 +741,14 @@ def main(args):
       help=("Compiles the OpenSK application without backward compatible "
             "support for U2F/CTAP1 protocol."),
   )
+  main_parser.add_argument(
+      "--ctap2-1",
+      action=RemoveConstAction,
+      const="with_ctap2_1",
+      dest="features",
+      help=("Compiles the OpenSK application with backward compatible "
+            "support for CTAP2.1 protocol."),
+  )
   main_parser.add_argument(
       "--regen-keys",
       action="store_true",

run_desktop_tests.sh

@@ -30,6 +30,7 @@ cargo build --manifest-path third_party/tock/tools/sha256sum/Cargo.toml
 echo "Checking that CTAP2 builds properly..."
 cargo check --release --target=thumbv7em-none-eabi
 cargo check --release --target=thumbv7em-none-eabi --features with_ctap1
+cargo check --release --target=thumbv7em-none-eabi --features with_ctap2_1
 cargo check --release --target=thumbv7em-none-eabi --features debug_ctap
 cargo check --release --target=thumbv7em-none-eabi --features panic_console
 cargo check --release --target=thumbv7em-none-eabi --features debug_allocations
@@ -86,4 +87,10 @@ then
 
   echo "Running unit tests on the desktop (debug mode + CTAP1)..."
   cargo test --features std,with_ctap1
+
+  echo "Running unit tests on the desktop (release mode + CTAP2.1)..."
+  cargo test --release --features std,with_ctap2_1
+
+  echo "Running unit tests on the desktop (debug mode + CTAP2.1)..."
+  cargo test --features std,with_ctap2_1
 fi

src/ctap/command.rs

@@ -23,9 +23,10 @@ use alloc::string::String;
 use alloc::vec::Vec;
 use core::convert::TryFrom;
 
-// Depending on your memory, you can use Some(n) to limit request sizes.
+// Depending on your memory, you can use Some(n) to limit request sizes in
+// MakeCredential and GetAssertion. This affects allowList and excludeList.
 // You might also want to set the max credential size in process_get_info then.
-pub const MAX_CREDENTIAL_COUNT_IN_LIST: Option<u64> = None;
+pub const MAX_CREDENTIAL_COUNT_IN_LIST: Option<usize> = None;
 
 // CTAP specification (version 20190130) section 6.1
 #[cfg_attr(any(test, feature = "debug_ctap"), derive(Debug, PartialEq))]
@@ -136,25 +137,19 @@ impl TryFrom<cbor::Value> for AuthenticatorMakeCredentialParameters {
         )?)?;
 
         let cred_param_vec = read_array(ok_or_missing(param_map.get(&cbor_unsigned!(4)))?)?;
-        let mut pub_key_cred_params = vec![];
-        for cred_param_map_value in cred_param_vec {
-            if let Ok(cred_param) = PublicKeyCredentialParameter::try_from(cred_param_map_value) {
-                pub_key_cred_params.push(cred_param);
-            }
-        }
+        let pub_key_cred_params = cred_param_vec
+            .iter()
+            .map(PublicKeyCredentialParameter::try_from)
+            .collect::<Result<Vec<PublicKeyCredentialParameter>, Ctap2StatusCode>>()?;
 
         let exclude_list = match param_map.get(&cbor_unsigned!(5)) {
             Some(entry) => {
                 let exclude_list_vec = read_array(entry)?;
-                let mut exclude_list = vec![];
-                for exclude_list_value in exclude_list_vec {
-                    if let Some(count) = MAX_CREDENTIAL_COUNT_IN_LIST {
-                        if exclude_list.len() as u64 >= count {
-                            break;
-                        }
-                    }
-                    exclude_list.push(PublicKeyCredentialDescriptor::try_from(exclude_list_value)?);
-                }
+                let exclude_list = exclude_list_vec
+                    .iter()
+                    .take(MAX_CREDENTIAL_COUNT_IN_LIST.unwrap_or(exclude_list_vec.len()))
+                    .map(PublicKeyCredentialDescriptor::try_from)
+                    .collect::<Result<Vec<PublicKeyCredentialDescriptor>, Ctap2StatusCode>>()?;
                 Some(exclude_list)
             }
             None => None,
@@ -222,15 +217,11 @@ impl TryFrom<cbor::Value> for AuthenticatorGetAssertionParameters {
         let allow_list = match param_map.get(&cbor_unsigned!(3)) {
             Some(entry) => {
                 let allow_list_vec = read_array(entry)?;
-                let mut allow_list = vec![];
-                for allow_list_value in allow_list_vec {
-                    if let Some(count) = MAX_CREDENTIAL_COUNT_IN_LIST {
-                        if allow_list.len() as u64 >= count {
-                            break;
-                        }
-                    }
-                    allow_list.push(PublicKeyCredentialDescriptor::try_from(allow_list_value)?);
-                }
+                let allow_list = allow_list_vec
+                    .iter()
+                    .take(MAX_CREDENTIAL_COUNT_IN_LIST.unwrap_or(allow_list_vec.len()))
+                    .map(PublicKeyCredentialDescriptor::try_from)
+                    .collect::<Result<Vec<PublicKeyCredentialDescriptor>, Ctap2StatusCode>>()?;
                 Some(allow_list)
             }
             None => None,
@@ -330,7 +321,7 @@ mod test {
         AuthenticatorTransport, PublicKeyCredentialRpEntity, PublicKeyCredentialType,
         PublicKeyCredentialUserEntity,
     };
-    use super::super::CREDENTIAL_PARAMETER;
+    use super::super::ES256_CRED_PARAM;
     use super::*;
     use alloc::collections::BTreeMap;
 
@@ -349,7 +340,7 @@ mod test {
                 "displayName" => "bar",
                 "icon" => "example.com/foo/icon.png",
             },
-            4 => cbor_array![CREDENTIAL_PARAMETER],
+            4 => cbor_array![ES256_CRED_PARAM],
             5 => cbor_array![],
             8 => vec![0x12, 0x34],
             9 => 1,
@@ -380,7 +371,7 @@ mod test {
             client_data_hash,
             rp,
             user,
-            pub_key_cred_params: vec![CREDENTIAL_PARAMETER],
+            pub_key_cred_params: vec![ES256_CRED_PARAM],
             exclude_list: Some(vec![]),
             extensions: None,
             options,