fix: MacProxy crash in CFNumberGetValue on iOS

src/libraries/Common/src/Interop/OSX/Interop.CoreFoundation.CFNumber.cs

@@ -7,6 +7,9 @@
 using System.Text;
 using Microsoft.Win32.SafeHandles;
 
+// Declared as signed long, which has sizeof(void*) on OSX.
+using CFIndex = System.IntPtr;
+
 internal static partial class Interop
 {
     internal static partial class CoreFoundation
@@ -16,7 +19,14 @@ internal enum CFNumberType
             kCFNumberIntType = 9,
         }
 
-        [LibraryImport(Libraries.CoreFoundationLibrary)]
-        private static unsafe partial int CFNumberGetValue(IntPtr handle, CFNumberType type, int* value);
+        // CFNumberType is declared as CF_ENUM(CFIndex, CFNumberType), so it has to be passed as a CFIndex.
+        // Passing the int-sized managed enum leaves the upper bits of the argument register unspecified.
+        [LibraryImport(Libraries.CoreFoundationLibrary, EntryPoint = "CFNumberGetValue")]
+        private static unsafe partial int _CFNumberGetValue(IntPtr handle, CFIndex type, int* value);
+
+        private static unsafe int CFNumberGetValue(IntPtr handle, CFNumberType type, int* value)
+        {
+            return _CFNumberGetValue(handle, (CFIndex)type, value);
+        }
     }
 }

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/MacProxy.cs

@@ -82,8 +82,16 @@ private static Uri GetProxyUri(string scheme, CFProxy proxy)
         public Uri? GetProxy(Uri targetUri)
         {
             using (SafeCFDictionaryHandle systemProxySettings = CFNetworkCopySystemProxySettings())
+            {
+                return GetProxy(targetUri, systemProxySettings);
+            }
+        }
+
+        // Resolves the proxy for targetUri from proxy settings in the format returned by CFNetworkCopySystemProxySettings.
+        internal static Uri? GetProxy(Uri targetUri, SafeCFDictionaryHandle proxySettings)
+        {
             using (SafeCreateHandle cfurl = CFURLCreateWithString(targetUri.AbsoluteUri))
-            using (SafeCFArrayHandle proxies = CFNetworkCopyProxiesForURL(cfurl, systemProxySettings))
+            using (SafeCFArrayHandle proxies = CFNetworkCopyProxiesForURL(cfurl, proxySettings))
             {
                 long proxyCount = CFArrayGetCount(proxies);
                 for (int i = 0; i < proxyCount; i++)

src/libraries/System.Net.Http/tests/UnitTests/MacProxyTest.cs

@@ -0,0 +1,117 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Runtime.InteropServices;
+using Microsoft.Win32.SafeHandles;
+using Xunit;
+
+namespace System.Net.Http.Tests
+{
+    // Runs MacProxy against proxy settings created in-process, in the format returned by
+    // CFNetworkCopySystemProxySettings, so the tests don't depend on the machine's proxy configuration.
+    // The tests that return a proxy read its port with CFNumberGetValue, whose CFNumberType parameter is
+    // CFIndex-sized. Passing it as a 32-bit value crashed on the CoreCLR interpreter (iOS, tvOS, Mac Catalyst).
+    public partial class MacProxyTest
+    {
+        private static readonly Uri s_targetUri = new Uri("http://www.example.com/");
+        private static readonly Uri s_proxyUri = new Uri("http://127.0.0.1:8888/");
+
+        [Fact]
+        public void GetProxy_HttpProxy_ReturnsProxyUri()
+        {
+            using SafeCFDictionaryHandle settings = CreateProxySettings(
+                ("kCFNetworkProxiesHTTPEnable", CreateNumber(1)),
+                ("kCFNetworkProxiesHTTPProxy", Interop.CoreFoundation.CFStringCreateWithCString("127.0.0.1")),
+                ("kCFNetworkProxiesHTTPPort", CreateNumber(8888)));
+
+            Assert.Equal(s_proxyUri, MacProxy.GetProxy(s_targetUri, settings));
+        }
+
+        [Fact]
+        public void GetProxy_ProxyAutoConfigurationScript_ReturnsProxyUri()
+        {
+            using SafeCFDictionaryHandle settings = CreateProxySettings(
+                ("kCFNetworkProxiesProxyAutoConfigEnable", CreateNumber(1)),
+                ("kCFNetworkProxiesProxyAutoConfigJavaScript", Interop.CoreFoundation.CFStringCreateWithCString(
+                    "function FindProxyForURL(url, host) { return \"PROXY 127.0.0.1:8888\"; }")));
+
+            Assert.Equal(s_proxyUri, MacProxy.GetProxy(s_targetUri, settings));
+        }
+
+        [Fact]
+        public void GetProxy_ProxyAutoConfigurationScriptReturnsDirect_ReturnsNull()
+        {
+            using SafeCFDictionaryHandle settings = CreateProxySettings(
+                ("kCFNetworkProxiesProxyAutoConfigEnable", CreateNumber(1)),
+                ("kCFNetworkProxiesProxyAutoConfigJavaScript", Interop.CoreFoundation.CFStringCreateWithCString(
+                    "function FindProxyForURL(url, host) { return \"DIRECT\"; }")));
+
+            Assert.Null(MacProxy.GetProxy(s_targetUri, settings));
+        }
+
+        [Fact]
+        public void GetProxy_NoProxy_ReturnsNull()
+        {
+            using SafeCFDictionaryHandle settings = CreateProxySettings();
+
+            Assert.Null(MacProxy.GetProxy(s_targetUri, settings));
+        }
+
+        private static unsafe SafeCreateHandle CreateNumber(int value) =>
+            CFNumberCreate(IntPtr.Zero, kCFNumberIntType, &value);
+
+        // Keys are the names of CFStringRef constants exported by CFNetwork. The values are released once the dictionary has retained them.
+        private static unsafe SafeCFDictionaryHandle CreateProxySettings(params (string Key, SafeCreateHandle Value)[] settings)
+        {
+            try
+            {
+                IntPtr cfNetwork = NativeLibrary.Load(Interop.Libraries.CFNetworkLibrary);
+                IntPtr coreFoundation = NativeLibrary.Load(Interop.Libraries.CoreFoundationLibrary);
+
+                IntPtr[] keys = new IntPtr[settings.Length];
+                IntPtr[] values = new IntPtr[settings.Length];
+                for (int i = 0; i < settings.Length; i++)
+                {
+                    keys[i] = Marshal.ReadIntPtr(NativeLibrary.GetExport(cfNetwork, settings[i].Key));
+                    values[i] = settings[i].Value.DangerousGetHandle();
+                }
+
+                fixed (IntPtr* pKeys = keys)
+                fixed (IntPtr* pValues = values)
+                {
+                    return CFDictionaryCreate(IntPtr.Zero, pKeys, pValues, settings.Length,
+                        NativeLibrary.GetExport(coreFoundation, "kCFTypeDictionaryKeyCallBacks"),
+                        NativeLibrary.GetExport(coreFoundation, "kCFTypeDictionaryValueCallBacks"));
+                }
+            }
+            finally
+            {
+                foreach ((_, SafeCreateHandle value) in settings)
+                {
+                    value.Dispose();
+                }
+            }
+        }
+
+        // CFNumberType is declared as CF_ENUM(CFIndex, CFNumberType).
+        private const nint kCFNumberIntType = 9;
+
+        [LibraryImport(Interop.Libraries.CoreFoundationLibrary)]
+        private static unsafe partial SafeCreateHandle CFNumberCreate(IntPtr allocator, nint theType, int* valuePtr);
+
+        [LibraryImport(Interop.Libraries.CoreFoundationLibrary)]
+        private static unsafe partial SafeCFDictionaryHandle CFDictionaryCreate(
+            IntPtr allocator, IntPtr* keys, IntPtr* values, nint numValues, IntPtr keyCallBacks, IntPtr valueCallBacks);
+    }
+}
+
+internal static partial class Interop
+{
+    // Interop\OSX\Interop.Libraries.cs can't be compiled next to Interop\Windows\Interop.Libraries.cs
+    // (both define MsQuic), so define the libraries that the MacProxy interop uses.
+    internal static partial class Libraries
+    {
+        internal const string CoreFoundationLibrary = "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation";
+        internal const string CFNetworkLibrary = "/System/Library/Frameworks/CFNetwork.framework/CFNetwork";
+    }
+}

src/libraries/System.Net.Http/tests/UnitTests/System.Net.Http.Unit.Tests.csproj

@@ -259,7 +259,6 @@
     <Compile Include="DigestAuthenticationTests.cs" />
     <Compile Include="Fakes\HttpClientHandler.cs" />
     <Compile Include="Fakes\HttpTelemetry.cs" />
-    <Compile Include="Fakes\MacProxy.cs" Condition="'$(TargetPlatformIdentifier)' == 'osx' or '$(TargetPlatformIdentifier)' == 'ios' or '$(TargetPlatformIdentifier)' == 'tvos'" />
     <Compile Include="Headers\AltSvcHeaderParserTest.cs" />
     <Compile Include="Headers\AuthenticationHeaderParserTest.cs" />
     <Compile Include="Headers\AuthenticationHeaderValueTest.cs" />
@@ -430,4 +429,29 @@
     <Compile Include="..\..\..\System.Net.Http.WinHttpHandler\tests\UnitTests\TestServer.cs"
              Link="WinHttpHandler\UnitTests\TestServer.cs" />
   </ItemGroup>
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'osx' or '$(TargetPlatformIdentifier)' == 'ios' or '$(TargetPlatformIdentifier)' == 'tvos' or '$(TargetPlatformIdentifier)' == 'maccatalyst'">
+    <Compile Include="MacProxyTest.cs" />
+    <Compile Include="..\..\src\System\Net\Http\SocketsHttpHandler\MacProxy.cs"
+             Link="ProductionCode\System\Net\Http\SocketsHttpHandler\MacProxy.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.CFArray.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.CFArray.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.CFData.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.CFData.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.CFDictionary.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.CFDictionary.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.CFNumber.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.CFNumber.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.CFProxy.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.CFProxy.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.CFString.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.CFString.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.CoreFoundation.CFUrl.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.CoreFoundation.CFUrl.cs" />
+    <Compile Include="$(CommonPath)Interop\OSX\Interop.RunLoop.cs"
+             Link="ProductionCode\Common\Interop\OSX\Interop.RunLoop.cs" />
+    <Compile Include="$(CommonPath)Microsoft\Win32\SafeHandles\SafeCreateHandle.OSX.cs"
+             Link="ProductionCode\Common\Microsoft\Win32\SafeHandles\SafeCreateHandle.OSX.cs" />
+  </ItemGroup>
 </Project>