tests: add Microsoft.Bcl.Cryptography package reference and update certificate loading method

Author: DennisDyallo

Yubico.YubiKey/tests/utilities/Yubico.YubiKey.TestUtilities.csproj

@@ -31,6 +31,7 @@ limitations under the License. -->
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Bcl.Cryptography" Version="9.0.2" />
     <PackageReference Include="Moq" Version="4.16.1" />
     <PackageReference Include="Xunit.SkippableFact" Version="1.4.13" />
   </ItemGroup>

Yubico.YubiKey/tests/utilities/Yubico/YubiKey/TestUtilities/TestKeys.cs

@@ -14,6 +14,9 @@ namespace Yubico.YubiKey.TestUtilities
     /// </summary>
     public abstract class TestCrypto
     {
+        /// <summary>
+        /// The raw byte representation of the cryptographic data in DER format.
+        /// </summary>
         protected readonly byte[] _bytes;
         protected readonly string _pemStringFull;
 
@@ -164,7 +167,7 @@ private TestCertificate(string filePath, bool isAttestation) : base(filePath)
         /// <returns>X509Certificate2 instance initialized with the certificate data</returns>
         public X509Certificate2 AsX509Certificate2()
         {
-            return new X509Certificate2(_bytes);
+            return X509CertificateLoader.LoadCertificate(_bytes);
         }
 
         /// <summary>