Add log messages for requests, responses and errors

This patch adds log messages for each request and response (and
deserialization or protocol errors) in the dispatch module.  This makes
it easier to keep track of the executed commands by just looking at the
log output from fido_authenticator::dispatch.

src/dispatch.rs

@@ -174,10 +174,58 @@ where
     );
 
     // Goal of these nested scopes is to keep stack small.
-    let ctap_request = ctap2::Request::deserialize(data).map_err(|error| error as u8)?;
+    let ctap_request = ctap2::Request::deserialize(data)
+        .map(|request| {
+            info!("Received CTAP2 request {:?}", request_operation(&request));
+            trace!("CTAP2 request: {:?}", request);
+            request
+        })
+        .map_err(|error| {
+            error!("Failed to deserialize CTAP2 request: {:?}", error);
+            trace!("The problematic input data was: {}", hex_str!(data));
+            error as u8
+        })?;
     debug!("2a SP: {:X}", msp());
     use ctap2::Authenticator;
     authenticator
         .call_ctap2(&ctap_request)
-        .map_err(|error| error as u8)
+        .map(|response| {
+            info!("Sending CTAP2 response {:?}", response_operation(&response));
+            trace!("CTAP2 response: {:?}", response);
+            response
+        })
+        .map_err(|error| {
+            info!("CTAP2 error: {:?}", error);
+            error as u8
+        })
+}
+
+#[allow(unused)]
+fn request_operation(request: &ctap2::Request) -> ctap2::Operation {
+    match request {
+        ctap2::Request::MakeCredential(_) => ctap2::Operation::MakeCredential,
+        ctap2::Request::GetAssertion(_) => ctap2::Operation::GetAssertion,
+        ctap2::Request::GetNextAssertion => ctap2::Operation::GetNextAssertion,
+        ctap2::Request::GetInfo => ctap2::Operation::GetInfo,
+        ctap2::Request::ClientPin(_) => ctap2::Operation::ClientPin,
+        ctap2::Request::Reset => ctap2::Operation::Reset,
+        ctap2::Request::CredentialManagement(_) => ctap2::Operation::CredentialManagement,
+        ctap2::Request::Selection => ctap2::Operation::Selection,
+        ctap2::Request::Vendor(operation) => ctap2::Operation::Vendor(*operation),
+    }
+}
+
+#[allow(unused)]
+fn response_operation(request: &ctap2::Response) -> Option<ctap2::Operation> {
+    match request {
+        ctap2::Response::MakeCredential(_) => Some(ctap2::Operation::MakeCredential),
+        ctap2::Response::GetAssertion(_) => Some(ctap2::Operation::GetAssertion),
+        ctap2::Response::GetNextAssertion(_) => Some(ctap2::Operation::GetNextAssertion),
+        ctap2::Response::GetInfo(_) => Some(ctap2::Operation::GetInfo),
+        ctap2::Response::ClientPin(_) => Some(ctap2::Operation::ClientPin),
+        ctap2::Response::Reset => Some(ctap2::Operation::Reset),
+        ctap2::Response::CredentialManagement(_) => Some(ctap2::Operation::CredentialManagement),
+        ctap2::Response::Selection => Some(ctap2::Operation::Selection),
+        ctap2::Response::Vendor => None,
+    }
 }