Question

I have an access to an old managemnt system for my client and he wants to add more to it. I was able to contact the guy who originally wrote the main DLLs and then I got control and started building around them. But now, I need to extend the original too and I have no option but to reverse engineer.

I tried Reflector Pro and JustDecompile but the obtained source was full of errors. ILSpy works well but still, here is a sample code that I get from ILSpy:

    private static object ParseIntoValue(string stringValue, string targetType)
    {
        if (targetType != null)
        {
            if (<PrivateImplementationDetails>{C6507306-5ECF-4D05-8EE4-BD4D7781AC4E}.$$method0x600080f-1 == null)
            {
                <PrivateImplementationDetails>{C6507306-5ECF-4D05-8EE4-BD4D7781AC4E}.$$method0x600080f-1 = new Dictionary<string, int>(12)
                {
                    ...
                };
            }
            int num;
            if (<PrivateImplementationDetails>{C6507306-5ECF-4D05-8EE4-BD4D7781AC4E}.$$method0x600080f-1.TryGetValue(targetType, out num))
            {
                object result;
                switch (num)
                {

                cases are here...

                default:
                    goto IL_2A6;
                }
                return result;
            }
        }
        IL_2A6:
        return null;
    }

Its pretty clear there is some form of obfuscation applied here. Reversed code from JustDecompile and Reflector Pro was completely useless. With ILSpy, I’m able to compile a few of the projects without any modifications at all.

I need help to identify this obfuscation (if that’s the case). The original developer says he didn’t obfuscate. I’m not so sure.

Thanks.

Answer 1

The PrivateImplementationDetails in the decompiled code could be an auto-implemented property.

If you replace <PrivateImplementationDetails>{C6507306-5ECF-4D05-8EE4-BD4D7781AC4E}.$$method0x600080f-1 with a property the code seems to make sense.

Dictionary<string, int> MyProp { get; set;}

private static object ParseIntoValue(string stringValue, string targetType)
{
    if (targetType != null)
    {
        if (MyProp == null)
        {
           MyProp = new Dictionary<string, int>(12)
            {
                ...
            };
        }
        int num;
        if (MyProp.TryGetValue(targetType, out num))
        {
          ....