expose algorithm used to create ecdsa keypair (#834)

* expose algorithm used to create ecdsa keypair

* must use

* Update external test to call EcdsaKeyPair::algorithm()

---------

Co-authored-by: Justin Smith <[email protected]>

Author: soundofspace

aws-lc-rs/src/ec/key_pair.rs

@@ -201,6 +201,12 @@ impl EcdsaKeyPair {
         PrivateKey(self)
     }
 
+    /// [`EcdsaSigningAlgorithm`] which was used to create this [`EcdsaKeyPair`]
+    #[must_use]
+    pub fn algorithm(&self) -> &'static EcdsaSigningAlgorithm {
+        self.algorithm
+    }
+
     /// Returns the signature of the message using a random nonce.
     ///
     /// # *ring* Compatibility
@@ -318,5 +324,6 @@ mod tests {
         assert_eq!(key_pair.evp_pkey, key_pair_5208.evp_pkey);
         assert_eq!(key_pair.evp_pkey, key_pair_5915.evp_pkey);
         assert_eq!(key_pair_5208.evp_pkey, key_pair_5915.evp_pkey);
+        assert_eq!(key_pair_5915.algorithm, &ECDSA_P256_SHA256_FIXED_SIGNING);
     }
 }

aws-lc-rs/tests/ecdsa_tests.rs

@@ -140,7 +140,8 @@ fn ecdsa_generate_pkcs8_test() {
         println!();
         println!();
 
-        EcdsaKeyPair::from_pkcs8(alg, pkcs8.as_ref()).unwrap();
+        let key_pair = EcdsaKeyPair::from_pkcs8(alg, pkcs8.as_ref()).unwrap();
+        assert_eq!(key_pair.algorithm(), *alg);
     }
 }