[msbuild] Sign simulator apps by default. Fixes dotnet#18469.

Fixes dotnet#18469.

Author: rolfbjarne

msbuild/Xamarin.MacDev.Tasks/Tasks/DetectSigningIdentity.cs

@@ -591,64 +591,7 @@ public override bool Execute ()
 					return !Log.HasLoggedErrors;
 				}
 			} else {
-				// Framework is either iOS, tvOS or watchOS
-				if (SdkIsSimulator) {
-					if (AppleSdkSettings.XcodeVersion.Major >= 8 && RequireProvisioningProfile) {
-						// Note: Starting with Xcode 8.0, we need to codesign iOS Simulator builds that enable Entitlements
-						// in order for them to run. The "-" key is a special value allowed by the codesign utility that
-						// allows us to get away with not having an actual codesign key.
-						DetectedCodeSigningKey = "-";
-
-						if (!IsAutoCodeSignProfile (ProvisioningProfile)) {
-							identity.Profile = MobileProvisionIndex.GetMobileProvision (platform, ProvisioningProfile);
-
-							if (identity.Profile is null) {
-								Log.LogError (MSBStrings.E0140, PlatformName, ProvisioningProfile);
-								return false;
-							}
-
-							identity.AppId = ConstructValidAppId (identity.Profile, identity.BundleId);
-							if (identity.AppId is null) {
-								Log.LogError (MSBStrings.E0141, identity.BundleId, ProvisioningProfile);
-								return false;
-							}
-
-							provisioningProfileName = identity.Profile.Name;
-
-							DetectedProvisioningProfile = identity.Profile.Uuid;
-							DetectedDistributionType = identity.Profile.DistributionType.ToString ();
-						} else {
-							certs = new X509Certificate2 [0];
-
-							if ((profiles = GetProvisioningProfiles (platform, type, identity, certs)) is null)
-								return false;
-
-							if ((pairs = GetCodeSignIdentityPairs (profiles, certs)) is null)
-								return false;
-
-							var match = GetBestMatch (pairs, identity);
-							identity.Profile = match.Profile;
-							identity.AppId = match.AppId;
-
-							if (identity.Profile is not null) {
-								DetectedDistributionType = identity.Profile.DistributionType.ToString ();
-								DetectedProvisioningProfile = identity.Profile.Uuid;
-								provisioningProfileName = identity.Profile.Name;
-							}
-
-							DetectedAppId = identity.AppId;
-						}
-					} else {
-						// Note: Do not codesign. Codesigning seems to break the iOS Simulator in older versions of Xcode.
-						DetectedCodeSigningKey = null;
-					}
-
-					ReportDetectedCodesignInfo ();
-
-					return !Log.HasLoggedErrors;
-				}
-
-				if (!SdkIsSimulator && !RequireCodeSigning) {
+				if (SdkIsSimulator || !RequireCodeSigning) {
 					// The "-" key is a special value allowed by the codesign utility that
 					// allows us to get away with not having an actual codesign key.
 					DetectedCodeSigningKey = "-";

msbuild/Xamarin.Shared/Xamarin.Shared.props

@@ -143,14 +143,12 @@ Copyright (C) 2020 Microsoft. All rights reserved.
 	</PropertyGroup>
 
 	<!-- RequireCodeSigning -->
-	<!-- iOS/watchOS/tvOS is simple: device builds require code signing, simulator builds do not. This is a big lie, for some simulator builds need to be signed, but the _DetectCodeSigning task handles those cases. -->
+	<!-- iOS/watchOS/tvOS is simple: device builds require code signing, simulator builds technically don't even though some important features won't work unless the app is signed (launch screen won't show for instance) -->
 	<PropertyGroup Condition="'$(_PlatformName)' != 'macOS' And '$(_PlatformName)' != 'MacCatalyst'">
 		<!-- Make it possible to override the default logic by setting EnableCodeSigning -->
 		<_RequireCodeSigning Condition="'$(_RequireCodeSigning)' == ''">$(EnableCodeSigning)</_RequireCodeSigning>
-		<!-- Device builds must be signed -->
-		<_RequireCodeSigning Condition="'$(_RequireCodeSigning)' == '' And '$(ComputedPlatform)' == 'iPhone'">true</_RequireCodeSigning>
-		<!-- Otherwise code signing is disabled by default (simulator builds)-->
-		<_RequireCodeSigning Condition="'$(_RequireCodeSigning)' == ''">false</_RequireCodeSigning>
+		<!-- Device builds must be signed, and some features won't work in the simulator if the app isn't signed (launch screen for instance), so default to always sign -->
+		<_RequireCodeSigning Condition="'$(_RequireCodeSigning)' == ''">true</_RequireCodeSigning>
 	</PropertyGroup>
 	<!-- macOS is a bit more complicated:
 		* 'EnableCodeSigning' specifies whether the app is signed or not, and this defaults to false if it's not set.

msbuild/Xamarin.Shared/Xamarin.Shared.targets

@@ -1831,9 +1831,14 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 	</PropertyGroup>
 
 	<Target Name="_DetectSigningIdentity" Condition="'$(_CanOutputAppBundle)' == 'true'" DependsOnTargets="$(_DetectSigningIdentityDependsOn)">
+		<PropertyGroup>
+			<_CodesignEntitlements Condition="'$(_CodesignEntitlements)' == '' And '$(_SdkIsSimulator)' != 'true'">$(CodesignEntitlement)</_CodesignEntitlements>
+			<_CodesignProvision Condition="'$(_CodesignProvision)' == '' And '$(_SdkIsSimulator)' != 'true'">$(CodesignProvision)</_CodesignProvision>
+			<_SigningKey Condition="'$(_SigningKey)' == '' And '$(_SdkIsSimulator)' != 'true'">$(_SpecifiedCodesignKey)</_SigningKey>
+		</PropertyGroup>
 		<DetectSigningIdentity
 			SessionId="$(BuildSessionId)"
-			CodesignEntitlements="$(CodesignEntitlements)"
+			CodesignEntitlements="$(_CodesignEntitlements)"
 			CodesignRequireProvisioningProfile="$(CodesignRequireProvisioningProfile)"
 			Condition="'$(IsMacEnabled)' == 'true'"
 			AppBundleName="$(_AppBundleName)"
@@ -1843,8 +1848,8 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			RequireCodeSigning="$(_RequireCodeSigning)"
 			SdkIsSimulator="$(_SdkIsSimulator)"
 			SdkPlatform="$(_SdkPlatform)"
-			ProvisioningProfile="$(CodesignProvision)"
-			SigningKey="$(_SpecifiedCodesignKey)"
+			ProvisioningProfile="$(_CodesignProvision)"
+			SigningKey="$(_SigningKey)"
 			DetectedCodeSigningKey="$(_CodeSigningKey)"
 			TargetFrameworkMoniker="$(_ComputedTargetFrameworkMoniker)"
 			>