Add unknown variant to KeyAlgorithm

Cargo.toml

@@ -36,6 +36,7 @@ ring = { version = "0.17.4", features = ["std", "wasm32_unknown_unknown_js"] }
 
 [dev-dependencies]
 wasm-bindgen-test = "0.3.1"
+proptest = {version = "1.5.0", default-features =  false, features = ["std"]}
 
 [target.'cfg(not(all(target_arch = "wasm32", not(any(target_os = "emscripten", target_os = "wasi")))))'.dev-dependencies]
 # For the custom time example

proptest-regressions/jwk.txt

@@ -0,0 +1,7 @@
+# Seeds for failure cases proptest has generated in the past. It is
+# automatically read and these particular cases re-run before any
+# novel cases are generated.
+#
+# It is recommended to check this file in to source control so that
+# everyone who runs the test benefits from these saved cases.
+cc 9588ed7692395e4050cf8adc38499186bbdf9b288462e7fa6c19099a3c557464 # shrinks to s = ""

src/jwk.rs

@@ -188,6 +188,10 @@ pub enum KeyAlgorithm {
     /// RSAES-OAEP-256 using SHA-2
     #[serde(rename = "RSA-OAEP-256")]
     RSA_OAEP_256,
+
+    /// Catch-All for when the key algorithm can not be determined or is not supported
+    #[serde(other)]
+    UNKNOWN_ALGORITHM,
 }
 
 impl FromStr for KeyAlgorithm {
@@ -435,9 +439,10 @@ impl JwkSet {
 
 #[cfg(test)]
 mod tests {
-    use crate::jwk::{AlgorithmParameters, JwkSet, OctetKeyType};
+    use crate::jwk::{AlgorithmParameters, JwkSet, KeyAlgorithm, OctetKeyType};
     use crate::serialization::b64_encode;
     use crate::Algorithm;
+    use proptest::proptest;
     use serde_json::json;
     use wasm_bindgen_test::wasm_bindgen_test;
 
@@ -471,4 +476,22 @@ mod tests {
             _ => panic!("Unexpected key algorithm"),
         }
     }
+
+    #[test]
+    fn deserialize_unknown_key_algorithm() {
+        let key_alg_json = json!("");
+        let key_alg_result: KeyAlgorithm =
+            serde_json::from_value(key_alg_json).expect("Could not deserialize json");
+        assert_eq!(key_alg_result, KeyAlgorithm::UNKNOWN_ALGORITHM);
+    }
+
+    // Rather than testing against a particular case, test against a sampling of random strings
+    proptest! {
+        #[test]
+        fn deserialize_arbitrary_key_algorithm(s in ".*"){
+            let key_alg_json = json!(s);
+            let _key_alg_result: KeyAlgorithm = serde_json::from_value(key_alg_json).expect("Could not deserialize json");
+            // We don't need to assert a specific variant - we only care that the above line does not panic
+        }
+    }
 }