TypeInitializationException from MessagePackSerializer.Get<IList<MessagePackObjectDictionary>>()

[benjamin-bader]

This happens on Windows Phone 8.1, in a WinRT project (not Silverlight), as a result of a security-critical method call:

{System.MethodAccessException: Attempt by security transparent method 'MsgPack.Serialization.SerializationContext..ctor(MsgPack.Serialization.SerializerRepository, MsgPack.PackerCompatibilityOptions)' to access security critical method 'System.Collections.Concurrent.ConcurrentDictionary`2<System.__Canon,System.__Canon>..ctor()' failed.
   at MsgPack.Serialization.SerializationContext..ctor(SerializerRepository serializers, PackerCompatibilityOptions packerCompatibilityOptions)
   at MsgPack.Serialization.SerializationContext..ctor(SerializerRepository allwaysNull)
   at MsgPack.Serialization.SerializationContext..cctor()}

The code that produces this exception is, in its entirety:

private byte[] Serialize(IList<MessagePackObjectDictionary> syncInfo)
{
    return MessagePackSerializer
        .Get<IList<MessagePackObjectDictionary>>()
        .PackSingleObject(syncInfo);
}

[benjamin-bader]

The strange thing about this error is that nothing on ConcurrentDictionary seems to be marked as security-critical; perhaps this is another problem manifesting incorrectly. Regardless, it happens every time. I'll investigate this.

[yfakariya]

I found that [AllowPartiallyTrustedCallers] causes Universal Apps are not worked correctly in Windows Phone, but I could not find the difference between Store Apps and Phone Apps in terms of Code Access Security.

[benjamin-bader]

Thanks for your attention; this certainly seems like a Microsoft bug.

I was able to work around it by using the non-ConcurrentDictionary typeLock code paths (along with a few other changes, like removing BigIntegerSerializer which triggered the same bad behavior).

If you have interest, I'll be happy to make a pull request.

[yfakariya]

I'm afraid that other security failures occurred, so I tried to remove APTCA from WinRT build because it is not required in reality (see https://msdn.microsoft.com/en-us/library/windows/apps/jj657973.aspx).
Would you try prerelease version (0.5.10-beta1) from NuGet?

[benjamin-bader]

Yes, that fix sounds much better. I'm surprised that such an effect would be visible, when documentation directly states that the attribute has no effect on Store apps.

I'll be able to try in about six hours, and will report back then. Thank you!

[benjamin-bader]

This seems to be working fine - thanks!