public static void VerifyCACert(X509Certificate2 cert, string subject, int pathLengthConstraint)
        {
            TestContext.Out.WriteLine($"{nameof(VerifyCACert)}:");

            Assert.NotNull(cert);
            TestContext.Out.WriteLine(cert);
            Assert.False(cert.HasPrivateKey);
            Assert.True(X509Utils.CompareDistinguishedName(subject, cert.Subject));
            Assert.True(X509Utils.CompareDistinguishedName(subject, cert.Issuer));

            // test basic constraints
            var constraints = X509Extensions.FindExtension <X509BasicConstraintsExtension>(cert);

            Assert.NotNull(constraints);
            TestContext.Out.WriteLine(constraints.Format(true));
            Assert.True(constraints.Critical);
            Assert.True(constraints.CertificateAuthority);
            if (pathLengthConstraint < 0)
            {
                Assert.False(constraints.HasPathLengthConstraint);
            }
            else
            {
                Assert.True(constraints.HasPathLengthConstraint);
                Assert.AreEqual(pathLengthConstraint, constraints.PathLengthConstraint);
            }

            // key usage
            var keyUsage = X509Extensions.FindExtension <X509KeyUsageExtension>(cert);

            Assert.NotNull(keyUsage);
            TestContext.Out.WriteLine(keyUsage.Format(true));
            Assert.True(keyUsage.Critical);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.CrlSign) == X509KeyUsageFlags.CrlSign);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.DataEncipherment) == 0);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.DecipherOnly) == 0);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.DigitalSignature) == X509KeyUsageFlags.DigitalSignature);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.EncipherOnly) == 0);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.KeyAgreement) == 0);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.KeyCertSign) == X509KeyUsageFlags.KeyCertSign);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.KeyEncipherment) == 0);
            Assert.True((keyUsage.KeyUsages & X509KeyUsageFlags.NonRepudiation) == 0);

            // enhanced key usage
            X509EnhancedKeyUsageExtension enhancedKeyUsage = X509Extensions.FindExtension <X509EnhancedKeyUsageExtension>(cert);

            Assert.Null(enhancedKeyUsage);

            // test for authority key
            X509AuthorityKeyIdentifierExtension authority = X509Extensions.FindExtension <X509AuthorityKeyIdentifierExtension>(cert);

            Assert.NotNull(authority);
            TestContext.Out.WriteLine(authority.Format(true));
            Assert.NotNull(authority.SerialNumber);
            Assert.NotNull(authority.GetSerialNumber());
            Assert.NotNull(authority.KeyIdentifier);
            Assert.NotNull(authority.Issuer);
            Assert.NotNull(authority.ToString());
            Assert.AreEqual(authority.SerialNumber, Utils.ToHexString(authority.GetSerialNumber(), true));

            // verify authority key in signed cert
            X509SubjectKeyIdentifierExtension subjectKeyId = X509Extensions.FindExtension <X509SubjectKeyIdentifierExtension>(cert);

            TestContext.Out.WriteLine(subjectKeyId.Format(true));
            Assert.AreEqual(subjectKeyId.SubjectKeyIdentifier, authority.KeyIdentifier);
            Assert.AreEqual(cert.SerialNumber, authority.SerialNumber);
            Assert.AreEqual(cert.GetSerialNumber(), authority.GetSerialNumber());

            X509SubjectAltNameExtension subjectAlternateName = X509Extensions.FindExtension <X509SubjectAltNameExtension>(cert);

            Assert.Null(subjectAlternateName);
        }