Make dev-certs import consistent with kestrel (dotnet#57014)

* Make dev-certs import consistent with kestrel

Kestrel checks the subject name and our magic extension - import was only checking the extension.  They can't easily share a method because import has a test hook.

src/Servers/Kestrel/Core/src/TlsConfigurationLoader.cs

@@ -176,20 +176,8 @@ public ListenOptions UseHttpsWithSni(
 
     private static bool IsDevelopmentCertificate(X509Certificate2 certificate)
     {
-        if (!string.Equals(certificate.Subject, "CN=localhost", StringComparison.Ordinal))
-        {
-            return false;
-        }
-
-        foreach (var ext in certificate.Extensions)
-        {
-            if (string.Equals(ext.Oid?.Value, CertificateManager.AspNetHttpsOid, StringComparison.Ordinal))
-            {
-                return true;
-            }
-        }
-
-        return false;
+        return string.Equals(certificate.Subject, CertificateManager.LocalhostHttpsDistinguishedName, StringComparison.Ordinal) &&
+            CertificateManager.IsHttpsDevelopmentCertificate(certificate);
     }
 
     private static bool TryGetCertificatePath(string applicationName, [NotNullWhen(true)] out string? path)

src/Shared/CertificateGeneration/CertificateManager.cs

@@ -26,7 +26,7 @@ internal abstract class CertificateManager
     private const string ServerAuthenticationEnhancedKeyUsageOidFriendlyName = "Server Authentication";
 
     private const string LocalhostHttpsDnsName = "localhost";
-    private const string LocalhostHttpsDistinguishedName = "CN=" + LocalhostHttpsDnsName;
+    internal const string LocalhostHttpsDistinguishedName = "CN=" + LocalhostHttpsDnsName;
 
     public const int RSAMinimumKeySizeInBits = 2048;
 
@@ -62,9 +62,21 @@ internal CertificateManager(string subject, int version)
         AspNetHttpsCertificateVersion = version;
     }
 
-    public static bool IsHttpsDevelopmentCertificate(X509Certificate2 certificate) =>
-        certificate.Extensions.OfType<X509Extension>()
-        .Any(e => string.Equals(AspNetHttpsOid, e.Oid?.Value, StringComparison.Ordinal));
+    /// <remarks>
+    /// This only checks if the certificate has the OID for ASP.NET Core HTTPS development certificates -
+    /// it doesn't check the subject, validity, key usages, etc.
+    /// </remarks>
+    public static bool IsHttpsDevelopmentCertificate(X509Certificate2 certificate)
+    {
+        foreach (var extension in certificate.Extensions.OfType<X509Extension>())
+        {
+            if (string.Equals(AspNetHttpsOid, extension.Oid?.Value, StringComparison.Ordinal))
+            {
+                return true;
+            }
+        }
+        return false;
+    }
 
     public IList<X509Certificate2> ListCertificates(
         StoreName storeName,
@@ -398,7 +410,10 @@ internal ImportCertificateResult ImportCertificate(string certificatePath, strin
             return ImportCertificateResult.InvalidCertificate;
         }
 
-        if (!IsHttpsDevelopmentCertificate(certificate))
+        // Note that we're checking Subject, rather than LocalhostHttpsDistinguishedName,
+        // because the tests use a different subject.
+        if (!string.Equals(certificate.Subject, Subject, StringComparison.Ordinal) || // Kestrel requires this
+            !IsHttpsDevelopmentCertificate(certificate))
         {
             if (Log.IsEnabled())
             {

src/Tools/FirstRunCertGenerator/test/CertificateManagerTests.cs

@@ -116,7 +116,7 @@ private void ListCertificates()
             var certificates = store.Certificates;
             foreach (var certificate in certificates)
             {
-                Output.WriteLine($"Certificate: '{Convert.ToBase64String(certificate.Export(X509ContentType.Cert))}'.");
+                Output.WriteLine($"Certificate: {certificate.Subject} '{Convert.ToBase64String(certificate.Export(X509ContentType.Cert))}'.");
                 certificate.Dispose();
             }
 
@@ -225,7 +225,7 @@ public void EnsureCreateHttpsCertificate_CanExportTheCertInPemFormat_WithoutKey(
     public void EnsureCreateHttpsCertificate_CanImport_ExportedPfx()
     {
         // Arrange
-        const string CertificateName = nameof(EnsureCreateHttpsCertificate_DoesNotCreateACertificate_WhenThereIsAnExistingHttpsCertificates) + ".pfx";
+        const string CertificateName = nameof(EnsureCreateHttpsCertificate_CanImport_ExportedPfx) + ".pfx";
         var certificatePassword = Guid.NewGuid().ToString();
 
         _fixture.CleanupCertificates();
@@ -258,7 +258,7 @@ public void EnsureCreateHttpsCertificate_CanImport_ExportedPfx()
     public void EnsureCreateHttpsCertificate_CanImport_ExportedPfx_FailsIfThereAreCertificatesPresent()
     {
         // Arrange
-        const string CertificateName = nameof(EnsureCreateHttpsCertificate_DoesNotCreateACertificate_WhenThereIsAnExistingHttpsCertificates) + ".pfx";
+        const string CertificateName = nameof(EnsureCreateHttpsCertificate_CanImport_ExportedPfx_FailsIfThereAreCertificatesPresent) + ".pfx";
         var certificatePassword = Guid.NewGuid().ToString();
 
         _fixture.CleanupCertificates();
@@ -280,6 +280,47 @@ public void EnsureCreateHttpsCertificate_CanImport_ExportedPfx_FailsIfThereAreCe
         Assert.Equal(ImportCertificateResult.ExistingCertificatesPresent, result);
     }
 
+    [ConditionalFact]
+    [SkipOnHelix("https://github.com/dotnet/aspnetcore/issues/6720", Queues = "All.OSX")]
+    public void EnsureCreateHttpsCertificate_CannotImportIfTheSubjectNameIsWrong()
+    {
+        // Arrange
+        const string CertificateName = nameof(EnsureCreateHttpsCertificate_CannotImportIfTheSubjectNameIsWrong) + ".pfx";
+        var certificatePassword = Guid.NewGuid().ToString();
+
+        _fixture.CleanupCertificates();
+
+        var now = DateTimeOffset.UtcNow;
+        now = new DateTimeOffset(now.Year, now.Month, now.Day, now.Hour, now.Minute, now.Second, 0, now.Offset);
+        var creation = _manager.EnsureAspNetCoreHttpsDevelopmentCertificate(now, now.AddYears(1), path: null, trust: false, isInteractive: false);
+        Output.WriteLine(creation.ToString());
+        ListCertificates();
+
+        var httpsCertificate = _manager.ListCertificates(StoreName.My, StoreLocation.CurrentUser, isValid: false).Single(c => c.Subject == TestCertificateSubject);
+
+        _manager.CleanupHttpsCertificates();
+
+        using var privateKey = httpsCertificate.GetRSAPrivateKey();
+        var csr = new CertificateRequest(httpsCertificate.Subject + "Not", privateKey, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+        foreach (var extension in httpsCertificate.Extensions)
+        {
+            csr.CertificateExtensions.Add(extension);
+        }
+        var wrongSubjectCertificate = csr.CreateSelfSigned(httpsCertificate.NotBefore, httpsCertificate.NotAfter);
+
+        Assert.True(CertificateManager.IsHttpsDevelopmentCertificate(wrongSubjectCertificate));
+        Assert.NotEqual(_manager.Subject, wrongSubjectCertificate.Subject);
+
+        File.WriteAllBytes(CertificateName, wrongSubjectCertificate.Export(X509ContentType.Pfx, certificatePassword));
+
+        // Act
+        var result = _manager.ImportCertificate(CertificateName, certificatePassword);
+
+        // Assert
+        Assert.Equal(ImportCertificateResult.NoDevelopmentHttpsCertificate, result);
+        Assert.Empty(_manager.ListCertificates(StoreName.My, StoreLocation.CurrentUser, isValid: false));
+    }
+
     [ConditionalFact]
     [SkipOnHelix("https://github.com/dotnet/aspnetcore/issues/6720", Queues = "All.OSX")]
     public void EnsureCreateHttpsCertificate_CanExportTheCertInPemFormat_WithoutPassword()