check nonce only if it was passed (kilork#33)

src/client.rs

@@ -266,7 +266,7 @@ impl<C: CompactJson + Claims, P: Provider + Configurable> Client<P, C> {
     /// - Jose Error if the Token isn't decoded
     /// - Validation::Mismatch::Issuer if the provider issuer and token issuer mismatch
     /// - Validation::Mismatch::Nonce if a given nonce and the token nonce mismatch
-    /// - Validation::Missing::Nonce if either the token or args has a nonce and the other does not
+    /// - Validation::Missing::Nonce if args has a nonce and the token does not
     /// - Validation::Missing::Audience if the token aud doesn't contain the client id
     /// - Validation::Missing::AuthorizedParty if there are multiple audiences and azp is missing
     /// - Validation::Mismatch::AuthorizedParty if the azp is not the client_id

src/validation.rs

@@ -16,8 +16,8 @@ pub fn validate_token_issuer<C: Claims>(claims: &C, config: &Config) -> Result<(
 }
 
 pub fn validate_token_nonce<C: Claims>(claims: &C, nonce: Option<&str>) -> Result<(), Error> {
-    match nonce {
-        Some(expected) => match claims.nonce() {
+    if let Some(expected) = nonce {
+        match claims.nonce() {
             Some(actual) => {
                 if expected != actual {
                     let expected = expected.to_string();
@@ -26,11 +26,6 @@ pub fn validate_token_nonce<C: Claims>(claims: &C, nonce: Option<&str>) -> Resul
                 }
             }
             None => return Err(Validation::Missing(Missing::Nonce).into()),
-        },
-        None => {
-            if claims.nonce().is_some() {
-                return Err(Validation::Missing(Missing::Nonce).into());
-            }
         }
     }