DataProtection isn't linker friendly

[davidfowl]

Here are the warnings:

C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\RegistryPolicyResolver.cs(40,47): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.RegistryPolicyResolver.PopulateOptions(Object,RegistryKey): The return value of method 'System.Object.GetType()' with dynamically accessed member kinds 'None' is passed into the implicit 'this' parameter of method 'System.Type.GetProperties()' which requires dynamically accessed member kinds 'PublicProperties'. To fix this add DynamicallyAccessedMembersAttribute to it and specify at least these member kinds 'PublicProperties'. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\RegistryPolicyResolver.cs(57,29): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.RegistryPolicyResolver.PopulateOptions(Object,RegistryKey): Reflection call 'System.Type.GetType(String,Boolean)' inside 'Microsoft.AspNetCore.DataProtection.RegistryPolicyResolver.PopulateOptions(Object,RegistryKey)' was detected with unknown value for the type name. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\RegistryPolicyResolver.cs(82,25): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.RegistryPolicyResolver.ReadKeyEscrowSinks(RegistryKey): Reflection call 'System.Type.GetType(String,Boolean)' inside 'Microsoft.AspNetCore.DataProtection.RegistryPolicyResolver.ReadKeyEscrowSinks(RegistryKey)' was detected with unknown value for the type name. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\SimpleActivator.cs(31,13): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.SimpleActivator.CreateInstance(Type,String): Reflection call 'System.Type.GetType(String,Boolean)' inside 'Microsoft.AspNetCore.DataProtection.SimpleActivator.CreateInstance(Type,String)' was detected with unknown value for the type name. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\SimpleActivator.cs(37,17): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.SimpleActivator.CreateInstance(Type,String): The return value of method 'System.Type.GetType(String,Boolean)' with dynamically accessed member kinds 'None' is passed into the implicit 'this' parameter of method 'System.Type.GetConstructor(Type[])' which requires dynamically accessed member kinds 'PublicParameterlessConstructor'. To fix this add DynamicallyAccessedMembersAttribute to it and specify at least these member kinds 'PublicParameterlessConstructor'. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\SimpleActivator.cs(40,21): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.SimpleActivator.CreateInstance(Type,String): The return value of method 'System.Type.GetType(String,Boolean)' with dynamically accessed member kinds 'None' is passed into the parameter #0 of method 'System.Object System.Activator::CreateInstance(System.Type)' which requires dynamically accessed member kinds 'PublicParameterlessConstructor'. To fix this add DynamicallyAccessedMembersAttribute to it and specify at least these member kinds 'PublicParameterlessConstructor'. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\SimpleActivator.cs(45,13): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.SimpleActivator.CreateInstance(Type,String): The return value of method 'System.Type.GetType(String,Boolean)' with dynamically accessed member kinds 'None' is passed into the implicit 'this' parameter of method 'System.Type.GetConstructor(Type[])' which requires dynamically accessed member kinds 'PublicConstructors'. To fix this add DynamicallyAccessedMembersAttribute to it and specify at least these member kinds 'PublicConstructors'. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\SimpleActivator.cs(53,13): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.SimpleActivator.CreateInstance(Type,String): The return value of method 'System.Type.GetType(String,Boolean)' with dynamically accessed member kinds 'None' is passed into the parameter #0 of method 'System.Object System.Activator::CreateInstance(System.Type)' which requires dynamically accessed member kinds 'PublicParameterlessConstructor'. To fix this add DynamicallyAccessedMembersAttribute to it and specify at least these member kinds 'PublicParameterlessConstructor'. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\TypeForwardingActivator.cs(54,17): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.TypeForwardingActivator.CreateInstance(Type,String,Boolean&): Reflection call 'System.Type.GetType(String,Boolean)' inside 'Microsoft.AspNetCore.DataProtection.TypeForwardingActivator.CreateInstance(Type,String,Boolean&)' was detected with unknown value for the type name. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\TypeForwardingActivator.cs(54,17): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.TypeForwardingActivator.CreateInstance(Type,String,Boolean&): Reflection call 'System.Type.GetType(String,Boolean)' inside 'Microsoft.AspNetCore.DataProtection.TypeForwardingActivator.CreateInstance(Type,String,Boolean&)' was detected with unknown value for the type name. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\AuthenticatedEncryption\ManagedAuthenticatedEncryptorFactory.cs(128,51): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.AuthenticatedEncryption.ManagedAuthenticatedEncryptorFactory.AlgorithmActivator.AlgorithmActivatorCore<T>.AlgorithmActivatorCore`1(): The generic parameter 'T' from 'Microsoft.AspNetCore.DataProtection.AuthenticatedEncryption.ManagedAuthenticatedEncryptorFactory.AlgorithmActivator.AlgorithmActivatorCore<T>' with dynamically accessed member kinds 'None' is passed into the generic parameter 'T' from 'System.Activator.CreateInstance<T>()' which requires dynamically accessed member kinds 'PublicParameterlessConstructor'. To fix this add DynamicallyAccessedMembersAttribute to it and specify at least these member kinds 'PublicParameterlessConstructor'. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]
C:\dev\git\aspnetcore\src\DataProtection\DataProtection\src\AuthenticatedEncryption\ConfigurationModel\ManagedAuthenticatedEncryptorDescriptorDeserializer.cs(73,17): Trim analysis warning IL2006: Microsoft.AspNetCore.DataProtection.AuthenticatedEncryption.ConfigurationModel.ManagedAuthenticatedEncryptorDescriptorDeserializer.FriendlyNameToType(String): Reflection call 'System.Type.GetType(String,Boolean)' inside 'Microsoft.AspNetCore.DataProtection.AuthenticatedEncryption.ConfigurationModel.ManagedAuthenticatedEncryptorDescriptorDeserializer.FriendlyNameToType(String)' was detected with unknown value for the type name. [C:\Users\davifowl\source\repos\WebApplication60\WebApplication60\WebApplication60.csproj]

Generally, DataProtection tries to load types from configuration, but these types are part of data protection itself so we can preserve these types so that loading works. Funnily enough, if we used the DI system, this wouldn't be a problem 😄

Components with dependencies on DataProtection:

• Microsoft.AspNetCore.Authentication.Cookies
• Microsoft.AspNetCore.Session
• Microsoft.AspNetCore.Authentication
• Microsoft.AspNetCore.Components.Web.Extensions
• Microsoft.AspNetCore.Antiforgery
• Microsoft.AspNetCore.Mvc.ViewFeatures
• Microsoft.AspNetCore.Components.Server

[blowdart]

Well that's what you get for needing back compat to systems where DI doesn't exist :)

[davidfowl]

Well that's what you get for needing back compat to systems where DI doesn't exist :)

Hah, I was looking at the code and its unfortunately some of the most reflection heavy code in the System. That never occurred to me before...

[blowdart]

It was also written when, well DI was crap, and if you look at some the issues, the response was roll your own reflection.

However setting that side it's also policy based, where an admin outside of an application can place restrictions on the algorithms used and other key decisions that affect control flow. This is needed for some regulated environments. This type of external control does not lend itself to trimming, or indeed interop with other systems. Say for example, you trimmed app 1 to only support SHA256 because that's all trimming detected, but it also talks to app2 which sends SHA512. You'd going to have unknown and probably very hard to trace errors from that. Given it's data protection it has to fail closed/safe.

Data Protection is probably not a target for trimming, not without a real concerted effort and careful design.

[davidfowl]

I don't know what you mean by when the DI system was crap, but maybe you meant that it can't create things based on name which it still can't do. I think what you said is reasonable but the way it's designed today it sounds like an easy thing to do would be to keep all the implementations, which sounds fine as a first step.

If data protection is untrimmable a designed today then we'll need to look at the cost of the assembly an determine if it worth it and if so maybe decouple other components from the implementation here

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