C#: Simplify dotnet-install.ps1 invocation

Using the pattern from https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-install-script.

Author: hvitved

csharp/autobuilder/Semmle.Autobuild.CSharp.Tests/BuildScripts.cs

@@ -981,8 +981,7 @@ public void TestDotnetVersionWindows()
         {
             actions.RunProcess["cmd.exe /C dotnet --list-sdks"] = 0;
             actions.RunProcessOut["cmd.exe /C dotnet --list-sdks"] = "2.1.3 [C:\\Program Files\\dotnet\\sdks]\n2.1.4 [C:\\Program Files\\dotnet\\sdks]";
-            actions.RunProcess[@"cmd.exe /C pwsh -NoProfile -ExecutionPolicy unrestricted -file C:\Project\install-dotnet.ps1 -Version 2.1.3 -InstallDir C:\Project\.dotnet"] = 0;
-            actions.RunProcess[@"cmd.exe /C del C:\Project\install-dotnet.ps1"] = 0;
+            actions.RunProcess[@"cmd.exe /C pwsh -NoProfile -ExecutionPolicy unrestricted -Command ""[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; &([scriptblock]::Create((Invoke-WebRequest -UseBasicParsing 'https://dot.net/v1/dotnet-install.ps1'))) -Version 2.1.3 -InstallDir C:\Project\.dotnet"""] = 0;
             actions.RunProcess[@"cmd.exe /C C:\Project\.dotnet\dotnet --info"] = 0;
             actions.RunProcess[@"cmd.exe /C C:\Project\.dotnet\dotnet clean C:\Project\test.csproj"] = 0;
             actions.RunProcess[@"cmd.exe /C C:\Project\.dotnet\dotnet restore C:\Project\test.csproj"] = 0;
@@ -1005,17 +1004,16 @@ public void TestDotnetVersionWindows()
             actions.LoadXml[@"C:\Project\test.csproj"] = xml;
 
             var autobuilder = CreateAutoBuilder(true, dotnetVersion: "2.1.3");
-            TestAutobuilderScript(autobuilder, 0, 7);
+            TestAutobuilderScript(autobuilder, 0, 6);
         }
 
         [Fact]
         public void TestDotnetVersionWindowsNoPwsh()
         {
             actions.RunProcess["cmd.exe /C dotnet --list-sdks"] = 0;
             actions.RunProcessOut["cmd.exe /C dotnet --list-sdks"] = "2.1.3 [C:\\Program Files\\dotnet\\sdks]\n2.1.4 [C:\\Program Files\\dotnet\\sdks]";
-            actions.RunProcess[@"cmd.exe /C pwsh -NoProfile -ExecutionPolicy unrestricted -file C:\Project\install-dotnet.ps1 -Version 2.1.3 -InstallDir C:\Project\.dotnet"] = 1;
-            actions.RunProcess[@"cmd.exe /C powershell -NoProfile -ExecutionPolicy unrestricted -file C:\Project\install-dotnet.ps1 -Version 2.1.3 -InstallDir C:\Project\.dotnet"] = 0;
-            actions.RunProcess[@"cmd.exe /C del C:\Project\install-dotnet.ps1"] = 0;
+            actions.RunProcess[@"cmd.exe /C pwsh -NoProfile -ExecutionPolicy unrestricted -Command ""[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; &([scriptblock]::Create((Invoke-WebRequest -UseBasicParsing 'https://dot.net/v1/dotnet-install.ps1'))) -Version 2.1.3 -InstallDir C:\Project\.dotnet"""] = 1;
+            actions.RunProcess[@"cmd.exe /C powershell -NoProfile -ExecutionPolicy unrestricted -Command ""[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; &([scriptblock]::Create((Invoke-WebRequest -UseBasicParsing 'https://dot.net/v1/dotnet-install.ps1'))) -Version 2.1.3 -InstallDir C:\Project\.dotnet"""] = 0;
             actions.RunProcess[@"cmd.exe /C C:\Project\.dotnet\dotnet --info"] = 0;
             actions.RunProcess[@"cmd.exe /C C:\Project\.dotnet\dotnet clean C:\Project\test.csproj"] = 0;
             actions.RunProcess[@"cmd.exe /C C:\Project\.dotnet\dotnet restore C:\Project\test.csproj"] = 0;
@@ -1038,7 +1036,7 @@ public void TestDotnetVersionWindowsNoPwsh()
             actions.LoadXml[@"C:\Project\test.csproj"] = xml;
 
             var autobuilder = CreateAutoBuilder(true, dotnetVersion: "2.1.3");
-            TestAutobuilderScript(autobuilder, 0, 8);
+            TestAutobuilderScript(autobuilder, 0, 7);
         }
 
         [Fact]

csharp/autobuilder/Semmle.Autobuild.CSharp/DotNetRule.cs

@@ -179,55 +179,20 @@ private static BuildScript DownloadDotNetVersion(Autobuilder builder, string pat
 
                     if (builder.Actions.IsWindows())
                     {
-                        var psScript = @"param([string]$Version, [string]$InstallDir)
 
-add-type @""
-using System.Net;
-using System.Security.Cryptography.X509Certificates;
-public class TrustAllCertsPolicy : ICertificatePolicy
-{
-    public bool CheckValidationResult(ServicePoint srvPoint, X509Certificate certificate, WebRequest request, int certificateProblem)
-    {
-        return true;
-    }
-}
-""@
-$AllProtocols = [System.Net.SecurityProtocolType]'Ssl3,Tls,Tls11,Tls12'
-[System.Net.ServicePointManager]::SecurityProtocol = $AllProtocols
-[System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy
-$Script = Invoke-WebRequest -useb 'https://dot.net/v1/dotnet-install.ps1'
-
-$arguments = @{
-  Channel = 'release'
-  Version = $Version
-  InstallDir = $InstallDir
-}
-
-$ScriptBlock = [scriptblock]::create("".{$($Script)} $(&{$args} @arguments)"")
-
-Invoke-Command -ScriptBlock $ScriptBlock";
-                        var psScriptFile = builder.Actions.PathCombine(builder.Options.RootDirectory, "install-dotnet.ps1");
-                        builder.Actions.WriteAllText(psScriptFile, psScript);
+                        var psCommand = $"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; &([scriptblock]::Create((Invoke-WebRequest -UseBasicParsing 'https://dot.net/v1/dotnet-install.ps1'))) -Version {version} -InstallDir {path}";
 
                         BuildScript GetInstall(string pwsh) =>
                             new CommandBuilder(builder.Actions).
                             RunCommand(pwsh).
                             Argument("-NoProfile").
                             Argument("-ExecutionPolicy").
                             Argument("unrestricted").
-                            Argument("-file").
-                            Argument(psScriptFile).
-                            Argument("-Version").
-                            Argument(version).
-                            Argument("-InstallDir").
-                            Argument(path).
+                            Argument("-Command").
+                            Argument("\"" + psCommand + "\"").
                             Script;
 
-                        var removeScript = new CommandBuilder(builder.Actions).
-                            RunCommand("del").
-                            Argument(psScriptFile);
-
-                        return (GetInstall("pwsh") | GetInstall("powershell")) & BuildScript.Try(removeScript.Script);
+                        return GetInstall("pwsh") | GetInstall("powershell");
                     }
                     else
                     {