Signing: enable signed package verification on Linux by default in .NET 6 SDK

src/NuGet.Core/NuGet.Build.Tasks/BuildTasksUtility.cs

@@ -15,6 +15,7 @@
 using NuGet.Common;
 using NuGet.Configuration;
 using NuGet.Credentials;
+using NuGet.Packaging.Signing;
 using NuGet.ProjectModel;
 using NuGet.Protocol;
 using NuGet.Protocol.Core.Types;
@@ -25,7 +26,6 @@
 using System.Xml.Linq;
 using NuGet.Packaging;
 using NuGet.Packaging.PackageExtraction;
-using NuGet.Packaging.Signing;
 using NuGet.PackageManagement;
 using NuGet.ProjectManagement;
 using NuGet.Shared;
@@ -191,6 +191,8 @@ public static async Task<bool> RestoreAsync(
                 UserAgent.SetUserAgentString(new UserAgentStringBuilder("NuGet Desktop MSBuild Task"));
 #endif
 
+                X509TrustStore.InitializeForDotNetSdk(log);
+
                 var restoreSummaries = new List<RestoreSummary>();
                 var providerCache = new RestoreCommandProvidersCache();
 

src/NuGet.Core/NuGet.CommandLine.XPlat/Commands/Signing/SignCommand.cs

@@ -129,6 +129,8 @@ internal static void Register(CommandLineApplication app,
 
                     setLogLevel(XPlatUtility.MSBuildVerbosityToNuGetLogLevel(verbosity.Value()));
 
+                    X509TrustStore.InitializeForDotNetSdk(args.Logger);
+
                     ISignCommandRunner runner = getCommandRunner();
                     int result = await runner.ExecuteCommandAsync(args);
                     return result;

src/NuGet.Core/NuGet.CommandLine.XPlat/Commands/Signing/TrustedSignersCommand.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.Globalization;
-using System.IO;
 using System.Threading.Tasks;
 using Microsoft.Extensions.CommandLineUtils;
 using NuGet.Commands;
@@ -267,6 +266,12 @@ private static async Task<int> ExecuteCommand(TrustCommand action,
 
                 setLogLevel(XPlatUtility.MSBuildVerbosityToNuGetLogLevel(verbosity.Value()));
 
+                // Add is the only action which does certificate chain building.
+                if (trustedSignersArgs.Action == TrustedSignersAction.Add)
+                {
+                    X509TrustStore.InitializeForDotNetSdk(logger);
+                }
+
 #pragma warning disable CS0618 // Type or member is obsolete
                 var sourceProvider = new PackageSourceProvider(settings, enablePackageSourcesChangedEvent: false);
 #pragma warning restore CS0618 // Type or member is obsolete

src/NuGet.Core/NuGet.CommandLine.XPlat/Commands/Signing/VerifyCommand.cs

@@ -9,6 +9,7 @@
 using NuGet.Commands;
 using NuGet.Common;
 using NuGet.Configuration;
+using NuGet.Packaging.Signing;
 using static NuGet.Commands.VerifyArgs;
 
 namespace NuGet.CommandLine.XPlat
@@ -64,6 +65,8 @@ internal static void Register(CommandLineApplication app,
                     args.Settings = XPlatUtility.ProcessConfigFile(configFile.Value());
                     setLogLevel(XPlatUtility.MSBuildVerbosityToNuGetLogLevel(verbosity.Value()));
 
+                    X509TrustStore.InitializeForDotNetSdk(args.Logger);
+
                     var runner = getCommandRunner();
                     var verifyTask = runner.ExecuteCommandAsync(args);
                     await verifyTask;

src/NuGet.Core/NuGet.Packaging/PackageArchiveReader.cs

@@ -524,19 +524,21 @@ public override bool CanVerifySignedPackages(SignedPackageVerifierSettings verif
                 // Please note: Linux/MAC case sensitive for env var name.
                 string signVerifyEnvVariable = _environmentVariableReader.GetEnvironmentVariable("DOTNET_NUGET_SIGNATURE_VERIFICATION");
 
-                // Not opt-out option, only opt-in feature.
+                bool canVerify = RuntimeEnvironmentHelper.IsLinux;
+
                 if (!string.IsNullOrEmpty(signVerifyEnvVariable))
                 {
-                    if (signVerifyEnvVariable.Equals(bool.TrueString, StringComparison.OrdinalIgnoreCase))
+                    if (string.Equals(bool.TrueString, signVerifyEnvVariable, StringComparison.OrdinalIgnoreCase))
                     {
-                        return true;
+                        canVerify = true;
+                    }
+                    else if (string.Equals(bool.FalseString, signVerifyEnvVariable, StringComparison.OrdinalIgnoreCase))
+                    {
+                        canVerify = false;
                     }
-
-                    // other values are unsupported
-                    return false;
                 }
 
-                return false;
+                return canVerify;
             }
             else
             {

src/NuGet.Core/NuGet.Packaging/Properties/AssemblyInfo.cs

@@ -6,6 +6,7 @@
 
 [assembly: CLSCompliant(true)]
 
+[assembly: InternalsVisibleTo("Dotnet.Integration.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100b5fc90e7027f67871e773a8fde8938c81dd402ba65b9201d60593e96c492651e889cc13f1415ebb53fac1131ae0bd333c5ee6021672d9718ea31a8aebd0da0072f25d87dba6fc90ffd598ed4da35e44c398c454307e8e33b8426143daec9f596836f97c8f74750e5975c64e2189f45def46b2a2b1247adc3652bf5c308055da9")]
 [assembly: InternalsVisibleTo("NuGet.Packaging.FuncTest, PublicKey=0024000004800000940000000602000000240000525341310004000001000100b5fc90e7027f67871e773a8fde8938c81dd402ba65b9201d60593e96c492651e889cc13f1415ebb53fac1131ae0bd333c5ee6021672d9718ea31a8aebd0da0072f25d87dba6fc90ffd598ed4da35e44c398c454307e8e33b8426143daec9f596836f97c8f74750e5975c64e2189f45def46b2a2b1247adc3652bf5c308055da9")]
 [assembly: InternalsVisibleTo("NuGet.Packaging.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100b5fc90e7027f67871e773a8fde8938c81dd402ba65b9201d60593e96c492651e889cc13f1415ebb53fac1131ae0bd333c5ee6021672d9718ea31a8aebd0da0072f25d87dba6fc90ffd598ed4da35e44c398c454307e8e33b8426143daec9f596836f97c8f74750e5975c64e2189f45def46b2a2b1247adc3652bf5c308055da9")]
 [assembly: InternalsVisibleTo("NuGet.Commands.Test, PublicKey=0024000004800000940000000602000000240000525341310004000001000100b5fc90e7027f67871e773a8fde8938c81dd402ba65b9201d60593e96c492651e889cc13f1415ebb53fac1131ae0bd333c5ee6021672d9718ea31a8aebd0da0072f25d87dba6fc90ffd598ed4da35e44c398c454307e8e33b8426143daec9f596836f97c8f74750e5975c64e2189f45def46b2a2b1247adc3652bf5c308055da9")]

src/NuGet.Core/NuGet.Packaging/PublicAPI/net472/PublicAPI.Unshipped.txt

@@ -1 +1,3 @@
-NuGet.Packaging.Licenses.NuGetLicenseExpressionParsingException.NuGetLicenseExpressionParsingException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) -> void
+NuGet.Packaging.Licenses.NuGetLicenseExpressionParsingException.NuGetLicenseExpressionParsingException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) -> void
+NuGet.Packaging.Signing.X509TrustStore
+static NuGet.Packaging.Signing.X509TrustStore.InitializeForDotNetSdk(NuGet.Common.ILogger logger) -> void

src/NuGet.Core/NuGet.Packaging/PublicAPI/netcoreapp5.0/PublicAPI.Unshipped.txt

@@ -1 +1,3 @@
-NuGet.Packaging.Licenses.NuGetLicenseExpressionParsingException.NuGetLicenseExpressionParsingException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) -> void
+NuGet.Packaging.Licenses.NuGetLicenseExpressionParsingException.NuGetLicenseExpressionParsingException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) -> void
+NuGet.Packaging.Signing.X509TrustStore
+static NuGet.Packaging.Signing.X509TrustStore.InitializeForDotNetSdk(NuGet.Common.ILogger logger) -> void

src/NuGet.Core/NuGet.Packaging/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt

@@ -1 +1,3 @@
-NuGet.Packaging.Licenses.NuGetLicenseExpressionParsingException.NuGetLicenseExpressionParsingException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) -> void
+NuGet.Packaging.Licenses.NuGetLicenseExpressionParsingException.NuGetLicenseExpressionParsingException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) -> void
+NuGet.Packaging.Signing.X509TrustStore
+static NuGet.Packaging.Signing.X509TrustStore.InitializeForDotNetSdk(NuGet.Common.ILogger logger) -> void

src/NuGet.Core/NuGet.Packaging/Signing/TrustStore/CertificateBundleX509ChainFactory.cs

@@ -0,0 +1,63 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+#if NET5_0_OR_GREATER
+
+using System;
+using System.IO;
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+
+namespace NuGet.Packaging.Signing
+{
+    internal abstract class CertificateBundleX509ChainFactory : IX509ChainFactory
+    {
+        public X509Certificate2Collection Certificates { get; }
+        public string FilePath { get; }
+
+        protected CertificateBundleX509ChainFactory(X509Certificate2Collection certificates, string filePath = null)
+        {
+            Certificates = certificates;
+            FilePath = filePath;
+        }
+
+        public X509Chain Create()
+        {
+            X509Chain x509Chain = new();
+
+            x509Chain.ChainPolicy.TrustMode = X509ChainTrustMode.CustomRootTrust;
+
+            if (Certificates is not null && Certificates.Count > 0)
+            {
+                x509Chain.ChainPolicy.CustomTrustStore.AddRange(Certificates);
+            }
+
+            return x509Chain;
+        }
+
+        protected static bool TryImportFromPemFile(string filePath, out X509Certificate2Collection certificates)
+        {
+            certificates = new X509Certificate2Collection();
+
+            try
+            {
+                certificates.ImportFromPemFile(filePath);
+
+                return true;
+            }
+            catch (Exception ex) when
+            (
+                ex is CryptographicException ||
+                ex is FileNotFoundException ||
+                ex is DirectoryNotFoundException
+            )
+            {
+                certificates.Clear();
+            }
+
+            return false;
+        }
+    }
+}
+
+#endif

src/NuGet.Core/NuGet.Packaging/Signing/TrustStore/DotNetDefaultTrustStoreX509ChainFactory.cs

@@ -0,0 +1,15 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Security.Cryptography.X509Certificates;
+
+namespace NuGet.Packaging.Signing
+{
+    internal sealed class DotNetDefaultTrustStoreX509ChainFactory : IX509ChainFactory
+    {
+        public X509Chain Create()
+        {
+            return new X509Chain();
+        }
+    }
+}

src/NuGet.Core/NuGet.Packaging/Signing/TrustStore/FallbackCertificateBundleX509ChainFactory.cs

@@ -0,0 +1,55 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+#if NET5_0_OR_GREATER
+
+using System;
+using System.IO;
+using System.Security.Cryptography.X509Certificates;
+using System.Threading;
+
+namespace NuGet.Packaging.Signing
+{
+    internal sealed class FallbackCertificateBundleX509ChainFactory : CertificateBundleX509ChainFactory
+    {
+        // These constants are dictated by the .NET SDK.
+        internal const string SubdirectoryName = "trustedroots";
+        internal const string FileName = "codesignctl.pem";
+
+        private static readonly Lazy<string> ThisAssemblyDirectoryPath = new(GetThisAssemblyDirectoryPath, LazyThreadSafetyMode.ExecutionAndPublication);
+
+        private FallbackCertificateBundleX509ChainFactory(X509Certificate2Collection certificates, string filePath)
+            : base(certificates, filePath)
+        {
+        }
+
+        internal static bool TryCreate(out FallbackCertificateBundleX509ChainFactory factory, string fileName = FileName)
+        {
+            factory = null;
+
+            string fullFilePath = Path.Combine(
+                ThisAssemblyDirectoryPath.Value,
+                SubdirectoryName,
+                fileName ?? FileName);
+
+            if (TryImportFromPemFile(fullFilePath, out X509Certificate2Collection certificates))
+            {
+                factory = new FallbackCertificateBundleX509ChainFactory(certificates, fullFilePath);
+
+                return true;
+            }
+
+            return false;
+        }
+
+        private static string GetThisAssemblyDirectoryPath()
+        {
+            string location = typeof(FallbackCertificateBundleX509ChainFactory).Assembly.Location;
+            FileInfo thisAssembly = new(location);
+
+            return thisAssembly.DirectoryName;
+        }
+    }
+}
+
+#endif

src/NuGet.Core/NuGet.Packaging/Signing/TrustStore/IX509ChainFactory.cs

@@ -0,0 +1,12 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Security.Cryptography.X509Certificates;
+
+namespace NuGet.Packaging.Signing
+{
+    internal interface IX509ChainFactory
+    {
+        X509Chain Create();
+    }
+}

src/NuGet.Core/NuGet.Packaging/Signing/TrustStore/NoCertificateBundleX509ChainFactory.cs

@@ -0,0 +1,19 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+#if NET5_0_OR_GREATER
+
+using System.Security.Cryptography.X509Certificates;
+
+namespace NuGet.Packaging.Signing
+{
+    internal sealed class NoCertificateBundleX509ChainFactory : CertificateBundleX509ChainFactory
+    {
+        internal NoCertificateBundleX509ChainFactory()
+            : base(new X509Certificate2Collection())
+        {
+        }
+    }
+}
+
+#endif

src/NuGet.Core/NuGet.Packaging/Signing/TrustStore/SystemCertificateBundleX509ChainFactory.cs

@@ -0,0 +1,49 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+#if NET5_0_OR_GREATER
+
+using System.Collections.Generic;
+using System.Security.Cryptography.X509Certificates;
+
+namespace NuGet.Packaging.Signing
+{
+    internal sealed class SystemCertificateBundleX509ChainFactory : CertificateBundleX509ChainFactory
+    {
+        internal static readonly IReadOnlyList<string> ProbePaths = new[]
+        {
+            "/etc/pki/ca-trust/extracted/pem/objsign-ca-bundle.pem"
+        };
+
+        private SystemCertificateBundleX509ChainFactory(X509Certificate2Collection certificates, string filePath)
+            : base(certificates, filePath)
+        {
+        }
+
+        internal static bool TryCreate(out SystemCertificateBundleX509ChainFactory factory)
+        {
+            return TryCreate(ProbePaths, out factory);
+        }
+
+        // For testing purposes only.
+        internal static bool TryCreate(IReadOnlyList<string> probePaths, out SystemCertificateBundleX509ChainFactory factory)
+        {
+            factory = null;
+
+            foreach (string probePath in probePaths)
+            {
+                if (TryImportFromPemFile(probePath, out X509Certificate2Collection certificates)
+                    && certificates.Count > 0)
+                {
+                    factory = new SystemCertificateBundleX509ChainFactory(certificates, probePath);
+
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+}
+
+#endif