CLR4 보안 - yield 구문 내에서 SecurityCritical 메서드 사용 불가 - 2번째 이야기

예전에도 yield 관련 구문해서 보안 오류 발생하는 것을 기록했었는데요.

CLR4 보안 - yield 구문 내에서 SecurityCritical 메서드 사용 불가
; https://www.sysnet.pe.kr/2/0/1683

Exception thrown: 'System.MethodAccessException' in [...].dll

Additional information: Attempt by security transparent method 'Microsoft.Diagnostics.Runtime.Desktop.DesktopRuntimeBase+<EnumerateStackFrames>d__80.<>m__Finally1()' to access security critical method 'System.Runtime.InteropServices.Marshal.FinalReleaseComObject(System.Object)' failed.

Assembly 'TestLibrary, Version=5.1.2.1, Culture=neutral, PublicKeyToken=cc862a9be44088eb' is marked with the AllowPartiallyTrustedCallersAttribute, and uses the level 2 security transparency model.  Level 2 transparency causes all methods in AllowPartiallyTrustedCallers assemblies to become security transparent by default, which may be the cause of this exception.

using System.Security;
using System.IO;
using System.Collections.Generic;

[assembly: AllowPartiallyTrustedCallers]

public class SecurityService
{
    // ... [생략: GetFileHandle] ...

    [SecuritySafeCritical]
    public static IEnumerable GetList(FileStream fs)
    {
        yield return fs.Handle.ToInt64();
    }
}

using System.Security;
using System.IO;
using System.Collections.Generic;

[assembly: AllowPartiallyTrustedCallers]

public class SecurityService
{
    // ... [생략: GetFileHandle] ...

    public static IEnumerable GetList(FileStream fs)
    {
        long handle = GetHandleValue(fs);
        yield return handle;
    }

    [SecuritySafeCritical]
    long GetHandleValue(FileStream fs)
    {
        return fs.Handle.ToInt64();
    }
}