fix: apply suggestions from code review (#22)

Co-authored-by: Falko Galperin <10247603+falko17@users.noreply.github.com>

build.rs

@@ -1,8 +1,8 @@
-#![recursion_limit = "512"]
 
 use cfg_aliases::cfg_aliases;
 
 fn main() {
+    // Set up some aliases for conditional compilation (in order to avoid repetition).
     cfg_aliases! {
         rustcrypto_encrypt_base: {
             any(

src/token/cose/crypto_impl/rustcrypto/mac/hmac.rs

@@ -9,7 +9,7 @@ use crate::token::cose::crypto_impl::rustcrypto::RustCryptoContext;
 use crate::token::cose::{CoseSymmetricKey, CryptoBackend};
 
 impl<RNG: RngCore + CryptoRng> RustCryptoContext<RNG> {
-    /// Compute the HMAC of `payload` using the given `key` and `payload` with the HMAC function
+    /// Compute the HMAC of `payload` using the given `key` with the HMAC function
     /// `MAC`.
     fn compute_hmac_using_mac<MAC: hmac::digest::KeyInit + Update + FixedOutput + MacMarker>(
         key: &CoseSymmetricKey<'_, <Self as CryptoBackend>::Error>,
@@ -23,8 +23,7 @@ impl<RNG: RngCore + CryptoRng> RustCryptoContext<RNG> {
         hmac.finalize().into_bytes().to_vec()
     }
 
-    /// Verify the HMAC of `payload` using the given `key` and `payload` with the HMAC function
-    /// `MAC`.
+    /// Verify the HMAC of `payload` using the given `key` with the HMAC function `MAC`.
     fn verify_hmac_using_mac<MAC: hmac::digest::KeyInit + Update + FixedOutput + MacMarker>(
         key: &CoseSymmetricKey<'_, <Self as CryptoBackend>::Error>,
         payload: &[u8],
@@ -38,7 +37,7 @@ impl<RNG: RngCore + CryptoRng> RustCryptoContext<RNG> {
         hmac.verify_slice(tag).map_err(CoseCipherError::from)
     }
 
-    /// Compute the HMAC of `payload` using the given `key` and `payload` with the HMAC function
+    /// Compute the HMAC of `payload` using the given `key` with the HMAC function
     /// specified in the `algorithm`.
     pub(super) fn compute_hmac(
         algorithm: iana::Algorithm,
@@ -61,7 +60,7 @@ impl<RNG: RngCore + CryptoRng> RustCryptoContext<RNG> {
         }
     }
 
-    /// Verify the HMAC `tag` of `payload` using the given `key` and `payload` with the HMAC
+    /// Verify the HMAC `tag` of `payload` using the given `key` with the HMAC
     /// function specified in the `algorithm`.
     pub(super) fn verify_hmac(
         algorithm: iana::Algorithm,

src/token/cose/crypto_impl/rustcrypto/mod.rs

@@ -25,7 +25,7 @@ pub enum CoseRustCryptoCipherError {
     /// Error regarding elliptic curve operations.
     #[cfg(feature = "rustcrypto-ecdsa")]
     EcError(elliptic_curve::Error),
-    /// Error in ECDSA operation
+    /// Error in ECDSA operation.
     #[cfg(feature = "rustcrypto-ecdsa")]
     EcdsaError(ecdsa::Error),
     /// Invalid elliptic curve point.

src/token/cose/crypto_impl/rustcrypto/sign/ecdsa.rs

@@ -163,10 +163,10 @@ impl<RNG: RngCore + CryptoRng> RustCryptoContext<RNG> {
             .map_err(CoseCipherError::from)
         } else {
             // x must be Some here due to the previous condition.
-            let pubkey_coord = if key.y.is_some() {
+            let pubkey_coord = if let Some(y) = key.y {
                 EncodedPoint::<CRV>::from_affine_coordinates(
                     key.x.unwrap().into(),
-                    key.y.unwrap().into(),
+                    y.into(),
                     false,
                 )
             } else {