Add C#9 test for S4426

sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/Rules/CryptographicKeyShouldNotBeTooShortTest.cs

@@ -40,6 +40,15 @@ public void CryptographicKeyShouldNotBeTooShort() =>
                 ParseOptionsHelper.FromCSharp8,
                 additionalReferences: GetAdditionalReferences());
 
+        [TestMethod]
+        [TestCategory("Rule")]
+        public void CryptographicKeyShouldNotBeTooShort_CSharp9() =>
+            Verifier.VerifyAnalyzer(@"TestCases\CryptographicKeyShouldNotBeTooShort.CSharp9.cs",
+                new CryptographicKeyShouldNotBeTooShort(),
+                ParseOptionsHelper.FromCSharp9,
+                outputKind: OutputKind.ConsoleApplication,
+                additionalReferences: GetAdditionalReferences());
+
         private static IEnumerable<MetadataReference> GetAdditionalReferences() =>
             MetadataReferenceFacade.GetSystemSecurityCryptography()
                 .Concat(NuGetMetadataReference.SystemSecurityCryptographyOpenSsl())

sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/TestCases/CryptographicKeyShouldNotBeTooShort.CSharp9.cs

@@ -0,0 +1,69 @@
+using Org.BouncyCastle.Asn1.Nist;
+using Org.BouncyCastle.Asn1.Sec;
+using Org.BouncyCastle.Asn1.TeleTrust;
+using Org.BouncyCastle.Asn1.X9;
+using Org.BouncyCastle.Crypto.Generators;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Math;
+using Org.BouncyCastle.Security;
+using System;
+using System.Security.Cryptography;
+
+var x = new RSACryptoServiceProvider(); // Noncompliant {{Use a key length of at least 2048 bits for RSA cipher algorithm.}}
+RSACryptoServiceProvider y = new(); // FN
+
+record Program
+{
+    private const int validKeySizeConst = 2048;
+    private const int invalidKeySizeConst = 1024;
+
+    private static readonly int validKeySize = 2048;
+    private static readonly int invalidKeySize = 1024;
+
+    public void ConstArgumentResolution()
+    {
+        const int localValidSize = 2048;
+        new RSACryptoServiceProvider(); // Noncompliant {{Use a key length of at least 2048 bits for RSA cipher algorithm.}}
+        new RSACryptoServiceProvider(new CspParameters()); // Noncompliant - has default key size of 1024
+        new RSACryptoServiceProvider(2048);
+        new RSACryptoServiceProvider(localValidSize);
+        new RSACryptoServiceProvider(validKeySizeConst);
+        new RSACryptoServiceProvider(validKeySize);
+        new RSACryptoServiceProvider(invalidKeySize); // Compliant - FN - cannot detect static readonly from GetConstantValue
+
+        const int localInvalidSize = 1024;
+        new RSACryptoServiceProvider(1024); // Noncompliant {{Use a key length of at least 2048 bits for RSA cipher algorithm.}}
+//      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+        new RSACryptoServiceProvider(1024, new()); // Noncompliant
+        new RSACryptoServiceProvider(invalidKeySizeConst); // Noncompliant
+        new RSACryptoServiceProvider(localInvalidSize); // Noncompliant
+    }
+
+    public void KeySize()
+    {
+        ECDiffieHellmanCng ec1 = new();
+        ec1.KeySize = 512;
+        ec1.KeySize = 128; // OK - because this is not a valid key size for this object
+
+        DSACng dsa1 = new();
+        dsa1.KeySize = 512; // Noncompliant {{Use a key length of at least 2048 bits for DSA cipher algorithm.}}
+    }
+
+    public void GenerateKey()
+    {
+        ECDiffieHellmanCng ec1 = new();
+        ec1.GenerateKey(ECCurve.NamedCurves.brainpoolP160r1); // Noncompliant {{Use a key length of at least 224 bits for EC cipher algorithm.}}
+
+        ECDsaCng ec2 = new();
+        ec2.GenerateKey(ECCurve.NamedCurves.brainpoolP160t1); // Noncompliant {{Use a key length of at least 224 bits for EC cipher algorithm.}}
+
+        ECDsaOpenSsl ec3 = new();
+        ec3.GenerateKey(ECCurve.NamedCurves.brainpoolP192t1); // Noncompliant {{Use a key length of at least 224 bits for EC cipher algorithm.}}
+    }
+}
+
+// See https://github.com/dotnet/roslyn/issues/45510
+namespace System.Runtime.CompilerServices
+{
+    public class IsExternalInit { }
+}