@@ -121,17 +121,9 @@ jobs:
         run: |
           cargo build --manifest-path rust/Cargo.toml -p pinget-cli --release
           if ($LASTEXITCODE -ne 0) { throw 'Rust publisher CLI build failed.' }
-          $sdkRoot = Join-Path ${env:ProgramFiles(x86)} 'Windows Kits\10\bin'
-          $makeAppx = Get-ChildItem -LiteralPath $sdkRoot -Directory |
-            Sort-Object Name -Descending |
-            ForEach-Object { Join-Path $_.FullName 'x64\makeappx.exe' } |
-            Where-Object { Test-Path -LiteralPath $_ } |
-            Select-Object -First 1
-          if (-not $makeAppx) { throw 'Windows SDK MakeAppx was not found.' }
           & .\tests\publisher\run-production-conformance.ps1 `
             -RustCli .\rust\target\release\pinget.exe `
-            -DotnetAssembly .\dotnet\src\Devolutions.Pinget.Cli\bin\Release\net10.0\pinget.dll `
-            -MakeAppxPath $makeAppx
+            -DotnetAssembly .\dotnet\src\Devolutions.Pinget.Cli\bin\Release\net10.0\pinget.dll
           if ($LASTEXITCODE -ne 0) { throw 'Publisher interoperability checks failed.' }
 
       - name: Build native COM DLLs
@@ -193,30 +185,22 @@ jobs:
             -OutputRoot artifacts/ci-stock-winget-packages
           if ($LASTEXITCODE -ne 0) { throw 'Building the disposable x64 publisher CLIs failed.' }
 
-      - name: Run signed stock WinGet acceptance with runner-local credentials
+      - name: Install psign-tool
         shell: pwsh
         run: |
-          $sdkRoot = Join-Path ${env:ProgramFiles(x86)} 'Windows Kits\10\bin'
-          $sdkTools = Get-ChildItem -LiteralPath $sdkRoot -Directory |
-            Sort-Object Name -Descending |
-            ForEach-Object {
-              [pscustomobject]@{
-                MakeAppx = Join-Path $_.FullName 'x64\makeappx.exe'
-                SignTool = Join-Path $_.FullName 'x64\signtool.exe'
-              }
-            } |
-            Where-Object {
-              (Test-Path -LiteralPath $_.MakeAppx) -and
-              (Test-Path -LiteralPath $_.SignTool)
-            } |
-            Select-Object -First 1
-          if (-not $sdkTools) { throw 'Windows SDK MakeAppx and SignTool were not found.' }
+          # 0.8.2 is the first release whose portable MSIX signatures verify on Windows.
+          dotnet tool install Devolutions.Psign.Tool --version $env:PSIGN_VERSION --tool-path artifacts/psign
+          if ($LASTEXITCODE -ne 0) { throw 'psign-tool installation failed.' }
+        env:
+          PSIGN_VERSION: 0.8.2
 
+      - name: Run signed stock WinGet acceptance with runner-local credentials
+        shell: pwsh
+        run: |
           pwsh -NoLogo -NoProfile -File (Resolve-Path 'tests/publisher/run-ephemeral-host-publisher-gate.ps1') `
             -RustCliPath (Resolve-Path 'artifacts/ci-stock-winget/rust/win-x64/pinget.exe') `
             -DotnetCliPath (Resolve-Path 'artifacts/ci-stock-winget/dotnet-nativeaot/win-x64/pinget.exe') `
-            -MakeAppxPath $sdkTools.MakeAppx `
-            -SignToolPath $sdkTools.SignTool
+            -PsignToolPath (Resolve-Path 'artifacts/psign/psign-tool.cmd')
           if ($LASTEXITCODE -ne 0) { throw 'Signed stock WinGet acceptance failed.' }
 
       - name: Remove disposable build outputs
@@ -225,3 +209,4 @@ jobs:
         run: |
           Remove-Item -LiteralPath 'artifacts/ci-stock-winget' -Recurse -Force -ErrorAction SilentlyContinue
           Remove-Item -LiteralPath 'artifacts/ci-stock-winget-packages' -Recurse -Force -ErrorAction SilentlyContinue
+          Remove-Item -LiteralPath 'artifacts/psign' -Recurse -Force -ErrorAction SilentlyContinue
@@ -19,17 +19,22 @@ URLs; the build does not download or execute them.
   sets (version, installer, default locale and optional additional locales).
 - Separate directories for inputs, publisher state and published files.
   Do not put one inside another or use symlinks/reparse points in them.
-- For publication on Windows, the Windows SDK's `makeappx.exe` and
-  `signtool.exe`. `repository doctor` reports tool availability; explicit tool
-  paths can be supplied when they are not discoverable.
+- For signed publication, [`psign-tool`](https://github.com/Devolutions/psign)
+  **0.8.2 or later**, a cross-platform Authenticode signer: `dotnet tool
+  install -g Devolutions.Psign.Tool`. Earlier versions produce MSIX signatures
+  that Windows rejects. `repository doctor` reports whether it was found on
+  `PATH` or in the .NET global tool directory; `--psign-tool` supplies an
+  explicit path. The Windows SDK (`makeappx.exe`, `signtool.exe`) is not used:
+  the publisher writes the MSIX container itself.
 - A code-signing certificate with its private key in a PFX, and a publisher
-  distinguished name matching that certificate.
+  distinguished name matching that certificate's subject.
 
-Building, verification and publication currently require Windows because
-sidecars use the native Windows Compression API. `status` and `diff` can
-inspect state on other platforms; `doctor` reports the missing capability.
-Do not infer publishing support from the availability of the CLI on a platform.
-Unsupported toolchains fail rather than silently produce unsigned output.
+Building requires Windows because sidecars are compressed with the native
+Windows Compression API. `publish`, `verify`, `status` and `diff` also run on
+Linux and macOS, so a snapshot built on Windows can be signed and published
+elsewhere. Do not infer publishing support from the availability of the CLI on
+a platform. A missing signing tool fails rather than silently producing
+unsigned output.
 
 ## Build, inspect and publish
 
@@ -92,12 +97,19 @@ For local format development only, replace the signing options with
 publisher does not install certificates, configure WinGet source trust or
 change the caller's sources.
 
-The PFX password is not stored in publisher state or normal diagnostics.
-`signtool`'s PFX interface requires passing it to the signing child process;
-privileged local process inspection can therefore observe it. Use a protected
-build agent and restrict access to both that agent and the PFX. The password
-environment-variable indirection is not a guarantee of process-level secret
-isolation.
+The PFX password is not stored in publisher state or normal diagnostics. The
+publisher hands it to `psign-tool` through a response file in a private
+temporary directory, deleted after signing, rather than on the command line.
+It is still present briefly on disk and in the signing process, so use a
+protected build agent and restrict access to both that agent and the PFX.
+
+After signing, the publisher checks the package digests, that the signer
+certificate subject matches `--publisher` and carries the Code Signing usage,
+and that the signature chains to a trusted root. On Windows the root must be
+trusted by the machine, like `signtool verify /pa`; on Linux and macOS psign's
+Microsoft AuthRoot anchors are used. For a private or self-signed root, pass
+its certificate with `--trusted-ca` (repeatable) to `publish` and
+`verify --destination`.
 
 ## Host the result
 
 
@@ -67,12 +67,14 @@ public static Command Create(Option<string?> outputOption)
         var stateVerify = new Option<string?>("--state", "Publisher working directory");
         var buildVerify = new Option<string?>("--build", "Build snapshot ID");
         var destinationVerify = new Option<string?>("--destination", "Published static source directory");
-        var signToolVerify = new Option<string?>("--signtool", "Path to signtool.exe");
+        var psignToolVerify = PsignToolOption();
+        var trustedCaVerify = TrustedCaOption();
         var verify = new Command("verify", "Verify a build snapshot or published directory");
         verify.AddOption(stateVerify);
         verify.AddOption(buildVerify);
         verify.AddOption(destinationVerify);
-        verify.AddOption(signToolVerify);
+        verify.AddOption(psignToolVerify);
+        verify.AddOption(trustedCaVerify);
         verify.SetHandler(context => Run(context, outputOption, () =>
         {
             var state = context.ParseResult.GetValueForOption(stateVerify);
@@ -81,8 +83,12 @@ public static Command Create(Option<string?> outputOption)
                 throw new PublisherException("Provide exactly one of --state or --destination.");
             if (destination is not null && context.ParseResult.GetValueForOption(buildVerify) is not null)
                 throw new PublisherException("--build cannot be combined with --destination.");
+            var psignTool = context.ParseResult.GetValueForOption(psignToolVerify);
+            var trustedCa = context.ParseResult.GetValueForOption(trustedCaVerify) ?? [];
+            if (destination is null && (psignTool is not null || trustedCa.Length > 0))
+                throw new PublisherException("--psign-tool and --trusted-ca require --destination.");
             var result = destination is not null
-                ? PublisherPackaging.VerifyDestination(destination, context.ParseResult.GetValueForOption(signToolVerify))
+                ? PublisherPackaging.VerifyDestination(destination, psignTool, trustedCa)
                 : new PublisherWorkspace(state!).Verify(context.ParseResult.GetValueForOption(buildVerify));
             return (Object(
                 ("valid", JsonValue.Create(result.Valid)),
@@ -92,22 +98,17 @@ public static Command Create(Option<string?> outputOption)
                 $"Verified {result.Subject}; artifacts: {result.ArtifactCount}.");
         }));
 
-        var makeAppxDoctor = new Option<string?>("--makeappx", "Path to makeappx.exe");
-        var signToolDoctor = new Option<string?>("--signtool", "Path to signtool.exe");
-        var doctor = new Command("doctor", "Check local publisher capabilities and packaging tools");
-        doctor.AddOption(makeAppxDoctor);
-        doctor.AddOption(signToolDoctor);
+        var psignToolDoctor = PsignToolOption();
+        var doctor = new Command("doctor", "Check local publisher capabilities and signing tools");
+        doctor.AddOption(psignToolDoctor);
         doctor.SetHandler(context => Run(context, outputOption, () =>
         {
-            var result = PublisherPackaging.Doctor(
-                context.ParseResult.GetValueForOption(makeAppxDoctor),
-                context.ParseResult.GetValueForOption(signToolDoctor));
+            var result = PublisherPackaging.Doctor(context.ParseResult.GetValueForOption(psignToolDoctor));
             return (Object(
                 ("operatingSystem", JsonValue.Create(result.OperatingSystem)),
-                ("makeAppxPath", JsonValue.Create(result.MakeAppxPath)),
-                ("signToolPath", JsonValue.Create(result.SignToolPath)),
+                ("psignToolPath", JsonValue.Create(result.PsignToolPath)),
                 ("nativeMsZipAvailable", JsonValue.Create(result.NativeMsZipAvailable))),
-                $"MSZIP: {(result.NativeMsZipAvailable ? "available" : "unavailable")}; makeappx: {result.MakeAppxPath ?? "not found"}; signtool: {result.SignToolPath ?? "not found"}.");
+                $"MSZIP: {(result.NativeMsZipAvailable ? "available" : "unavailable")}; psign-tool: {result.PsignToolPath ?? "not found"}; signed publishing available: {(result.SignedPublishAvailable ? "yes" : "no")}.");
         }));
 
         var statePublish = new Option<string>("--state", "Publisher working directory") { IsRequired = true };
@@ -118,15 +119,15 @@ public static Command Create(Option<string?> outputOption)
         var pfxPublish = new Option<string?>("--pfx", "PFX file used to sign the source MSIX");
         var passwordEnvPublish = new Option<string?>("--password-env", "Environment variable containing the PFX password");
         var unsignedPublish = new Option<bool>("--unsigned-development", "Allow explicitly unsigned development publishing");
-        var makeAppxPublish = new Option<string?>("--makeappx", "Path to makeappx.exe");
-        var signToolPublish = new Option<string?>("--signtool", "Path to signtool.exe");
+        var psignToolPublish = PsignToolOption();
+        var trustedCaPublish = TrustedCaOption();
         var timestampPublish = new Option<string?>("--timestamp-url", "HTTPS RFC 3161 timestamp service URL");
         var buildPublish = new Option<string?>("--build", "Build snapshot ID (defaults to latest)");
         var publish = new Command("publish", "Package and publish a source2.msix and immutable artifacts");
         foreach (var option in new Option[]
                  {
                      statePublish, destinationPublish, namePublish, publisherPublish, versionPublish,
-                     pfxPublish, passwordEnvPublish, unsignedPublish, makeAppxPublish, signToolPublish, buildPublish, timestampPublish,
+                     pfxPublish, passwordEnvPublish, unsignedPublish, psignToolPublish, trustedCaPublish, buildPublish, timestampPublish,
                  })
             publish.AddOption(option);
         publish.SetHandler(context => Run(context, outputOption, () =>
@@ -140,10 +141,10 @@ public static Command Create(Option<string?> outputOption)
                 context.ParseResult.GetValueForOption(pfxPublish),
                 context.ParseResult.GetValueForOption(passwordEnvPublish),
                 context.ParseResult.GetValueForOption(unsignedPublish),
-                context.ParseResult.GetValueForOption(makeAppxPublish),
-                context.ParseResult.GetValueForOption(signToolPublish),
+                context.ParseResult.GetValueForOption(psignToolPublish),
                 context.ParseResult.GetValueForOption(buildPublish),
-                context.ParseResult.GetValueForOption(timestampPublish)));
+                context.ParseResult.GetValueForOption(timestampPublish),
+                context.ParseResult.GetValueForOption(trustedCaPublish)));
             return (Object(
                 ("valid", JsonValue.Create(result.Valid)),
                 ("subject", JsonValue.Create(result.Subject)),
@@ -161,6 +162,16 @@ public static Command Create(Option<string?> outputOption)
         return root;
     }
 
+    private static Option<string?> PsignToolOption() =>
+        new("--psign-tool", "Path to psign-tool (searched on PATH and in the .NET global tool directory when omitted)");
+
+    private static Option<string[]> TrustedCaOption() =>
+        new("--trusted-ca", "Certificate trusted as a signature anchor instead of the platform default (repeatable)")
+        {
+            ArgumentHelpName = "certificate",
+            AllowMultipleArgumentsPerToken = false,
+        };
+
     private static Option<string> InputOption()
     {
         var option = new Option<string>("--input", "Root directory containing WinGet YAML manifests") { IsRequired = true };