Error: "Undefined symbols for architecture arm64: _SSLClose" when building projects to iPad

[bearyung]

Description

Repo project that demonstrates the issue: https://github.com/bearyung/test_ios

Open the project and build it to the physical iOS device (e.g. iPad with iOS 17.2)

Below error shows during deploying the project:

0>Xamarin.Shared.Sdk.targets(1559,3): Error : clang++ exited with code 1: Undefined symbols for architecture arm64: "_SSLClose", referenced from: _AppleCryptoNative_SslShutdown in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o) "_SSLCopyALPNProtocols", referenced from: _AppleCryptoNative_SslGetAlpnSelected in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o) "_SSLCopyDistinguishedNames", referenced from: _AppleCryptoNative_SslCopyCADistinguishedNames in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o) "_SSLCopyPeerTrust", referenced from: _AppleCryptoNative_SslCopyCertChain in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o) _AppleCryptoNative_SslIsHostnameMatch in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o) "_SSLCreateContext", referenced from: _AppleCryptoNative_SslCreateContext in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o) "_SSLGetNegotiatedCipher", referenced from: _AppleCryptoNative_SslGetCipherSuite in libSystem.Security.Cryptography.Native.Apple.

It seems .NET runtime still uses these deprecated API
https://github.com/dotnet/runtime/blame/v8.0.4/src/native/libs/System.Security.Cryptography.Native.Apple/pal_ssl.c#L594
https://developer.apple.com/documentation/security/1397869-sslclose

Reproduction Steps

mkdir test_ios
cd test_ios

dotnet new install Microsoft.iOS.Templates
dotnet new 

1. Open the solution DemoNew with Rider created above
2. Nuget the NetCoreServer v.8.0.7
3. Create a simple TCP server (ChatServer.cs and ChatSession.cs in the sample repo)
4. Run the Project in iOS Simulator (success)
5. Run the project in iOS device (failed)

Expected behavior

The project should be able to build and run on iOS device, just like it can build and run on iOS simulators.

Actual behavior

The project should be able to compiled and run on iOS device.Target _LinkNativeExecutable:
Tool xcrun execution started with arguments: clang++ -mios-version-min=13.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS17.2.sdk -arch arm64 /Users/michaelyung/RiderProjects/test_ios/obj/Debug/net8.0-ios/ios-arm64/nativelibraries/aot-output/arm64/aot-instances.dll.o /Users/michaelyung/RiderProjects/test_ios/obj/Debug/net8.0-ios/ios-arm64/nativelibraries/aot-output/arm64/test_ios.dll.o
[ trimmed ]
0>Xamarin.Shared.Sdk.targets(1559,3): Error : clang++ exited with code 1:
Undefined symbols for architecture arm64:
"_SSLClose", referenced from:
_AppleCryptoNative_SslShutdown in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o)
"_SSLCopyALPNProtocols", referenced from:
_AppleCryptoNative_SslGetAlpnSelected in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o)
"_SSLCopyDistinguishedNames", referenced from:
_AppleCryptoNative_SslCopyCADistinguishedNames in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o)
"_SSLCopyPeerTrust", referenced from:
_AppleCryptoNative_SslCopyCertChain in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o)
_AppleCryptoNative_SslIsHostnameMatch in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o)
"_SSLCreateContext", referenced from:
_AppleCryptoNative_SslCreateContext in libSystem.Security.Cryptography.Native.Apple.a(pal_ssl.c.o)
"_SSLGetNegotiatedCipher", referenced from:
_AppleCryptoNative_SslGetCipherSuite in libSystem.Security.Cryptography.Native.Apple.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

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[vitek-karas]

@ivanpovazan could you please take a look?

[ivanpovazan]

It seems like we are not linking against Security framework.
@bearyung Could you try adding this to your project file and retry?

  <ItemGroup>
    <_LinkerFrameworks Include="Security" />
  </ItemGroup>

[bearyung]

@ivanpovazan added the _linkerFrameworks as a workaround solved the issue, below is the fragment I've added to the project file:

  <!-- Manually add Security to the frameworks we link against. -->
  <Target Name="AddSecurity" Condition="'$(TargetFramework)' == 'net8.0-ios'" AfterTargets="_LoadLinkerOutput" BeforeTargets="_ComputeLinkNativeExecutableInputs">
    <ItemGroup>
      <_LinkerFrameworks Include="Security" />
    </ItemGroup>
  </Target>

[ivanpovazan]

Glad it worked.
The fix has been merged in xamarin/xamarin-macios#20413 and will become available in the upcoming servicing releases (so the workaround will not be needed anymore).

For this reason, I will close the issue. Please feel free to reopen it if you encounter any other related problems.

[StefanLaumann]

@bearyung I had the same problem, and your code snippet solved it for me :-)
Thanks a lot !!!