Add sturctured get assertion and client pin fuzzers (#482)

fuzz/fuzz_targets/fuzz_target_process_ctap2_client_pin_structured.rs

@@ -0,0 +1,10 @@
+#![no_main]
+
+use fuzz_helper::{process_ctap_structured, InputType};
+use libfuzzer_sys::fuzz_target;
+
+// Fuzz inputs as CTAP2 client pin command parameters.
+// The inputs will used to construct arbitrary client pin parameters.
+fuzz_target!(|data: &[u8]| {
+    process_ctap_structured(data, InputType::CborClientPinParameter).ok();
+});

fuzz/fuzz_targets/fuzz_target_process_ctap2_get_assertion_structured.rs

@@ -0,0 +1,10 @@
+#![no_main]
+
+use fuzz_helper::{process_ctap_structured, InputType};
+use libfuzzer_sys::fuzz_target;
+
+// Fuzz inputs as CTAP2 get assertion command parameters.
+// The inputs will used to construct arbitrary get assertion parameters.
+fuzz_target!(|data: &[u8]| {
+    process_ctap_structured(data, InputType::CborGetAssertionParameter).ok();
+});